Effect of the social distancing measures on the spread of COVID-19 in 10 highly infected countries

From the end of 2019, an unprecedented novel coronavirus, which was named COVID-19 by the World Health Organization (WHO) emerged from Wuhan city, China. Despite rigorous global containment and quarantine efforts, the incidence of COVID-19 has continued to rise, with over 4 million confirmed-cases and over 300,000 deaths worldwide until mid-May. This study aims to present the effect of the promulgation of social distancing measures on the spread of COVID-19 in the cases of 10 highly infected countries. The authors focus on the statistics of the COVID-19 confirmed-cases and deaths in 10 highly infected countries, including The U.S., Spain, Italy, The U.K., France, Germany, Russia, Turkey, Iran and China, and the response to the pandemic of these countries in the period from January 11 to May 2, 2020. The relationships between the social distancing measures and the statistics of COVID-19 confirmed-cases and deaths were analyzed in order to elucidate the effectiveness of the social distancing measures on the spread of COVID-19 in 10 highly infected countries. The results showed it took1–4 weeks since the highest level of social distancing measures promulgation until the daily confirmed-cases and deaths showed signs of decreasing. The effectiveness of the social distancing measures on the spread of COVID-19 was different between the 10 focused countries. This variation is due to the difference in the levels of promulgated social distancing measures, as well as the difference in the COVID-19 spread situation at the time of promulgation between the countries.

Effect of the social distancing measures on the spread of COVID-19 in 10 highly infected countries Tran Phuoc Bao Thu a, ⁎, Pham Nguyen Hong Ngoc a , Nguyen Minh Hai b , Le Anh Tuan c a Graduate School of Regional Development and Creativity, Utsunomiya University, Yoto 7-1-2, Utsunomiya city, Japan b School of Regional Design, Utsunomiya University, Yoto 7-1-2, Utsunomiya city, Japan c Risk Management and Safety Science Center, The University of Da Nang, 41 Le Duan, Da Nang city, Viet Nam

H I G H L I G H T S
• The statistics of the  confirmed-cases and deaths in 10 highly infected countries was collected • The effectiveness of the social distancing measures on the spread of COVID-19 was analyzed • It takes 1-4 weeks since the promulgation of highest level of measures until the number of cases starts to decrease. • The effectiveness of the social distancing measures on the spread of COVID-19 was different between the 10 focused countries.

G R A P H I C A L A B S T R A C T
a b s t r a c t a r t i c l e i n f o emerged from Wuhan city, China (Yu et al., 2020). The daily spread of the novel coronavirus has become one of the most common public concerns all over the world. On January 30, 2020, WHO declared a global public health emergency (PHEIC) for COVID-19, warning that the epidemic was truly a serious health emergency (Middleton et al., 2020). While medical researchers are urgently getting underway to develop the treatment drugs and vaccines to prevent the coronavirus (Le et al., 2020), reasonable social measures may significantly limit the spread of COVID-19 within the community (West et al., 2020;Sen-Crowe et al., 2020).
The social distancing measures, which can be called "lockdown" have been considered and promulgated in order to limit human interaction at close distances in certain regions as well as in a national scale. To evaluate the effectiveness of the social distancing measures on the spread of Tobías or Saez et al. have analyzed the trends of confirmed-cases and deaths in Spain and Italy before and after their respective national lockdowns using the statistics on a time-series (Tobías, 2020;Saez et al., 2020). The results showed incidence trends were considerably reduced in both countries after the social distancing measures. Danny Ibarra-Vega has developed a mathematical model with the systems dynamics methodology to evaluate the effectiveness of the quarantines or lockdowns on the reduction in community contacts for a population scale of 100,000 (Ibarra-Vega, 2020). Katz et al. have sought to identify the key features of preparedness and the primary concerns of local public health officials in deciding to implement social distancing measures for the case of The U.S. (Katz et al., 2019). Jarvis et al. have evaluated the effectiveness of the physical distancing measures on the transmission of COVID-19 in The U.K. (Jarvis et al., 2020). Lin et al. have developed a conceptual model for COVID-19 outbreak in Wuhan, China with individual reaction and governmental action (Lin et al., 2020). Atangana has used a mathematical model to demonstrate the effect of social distancing measures on the spread of COVID-19 in Italy. The study also took into account the possibility of transmission from dead bodies to humans (Atangana, 2020).
Various numbers of studies have been implemented on the effectiveness of the social distancing measures in specific regions. However, the conditions regarding economic scale, political institutions or medical system etc. of each country greatly differs. Moreover, the period and the scale of COVID-19 spread in countries are also different. Therefore, the levels and the timing of the social distancing measures taken as well as the effectiveness of these measures are not the same between countries. Consequently, the effectiveness of the social distancing measures on the spread of COVID-19 should be objectively evaluated based on a data of a broader scale. The analyses focused on the relationships between the timing, the levels of the social measures and the growth or decline rate of the COVID-19 confirmed-cases in different countries are a useful reference for subsequent social measures as long as coronaviruses still exist in the community.
In this article, the daily statistics of COVID-19 confirmed-and deathcases of 10 countries including The U.S., Spain, Italy, The U.K., France, Germany, Turkey, Iran and China, for almost 4 months, were collected from the database of WHO (World Health Organization coronavirus disease (COVID-2019) Situation Reports, 2020). Moreover, the social measures to prevent the spread of COVID-19 of these countries were collected from the national or regional official websites, and news sites, which daily update information about the pandemic. The relationships between the timing, levels of the social measures and the growth or decline rate of the COVID-19 daily confirmed-cases were analyzed by combining the collected information with a time-series.

Data collection
Since the day the world confirmed the first cases by COVID-19, the confirmed-cases have escalated to millions. The outbreak initially began in China, and weeks later the disease started to break out in other parts of the world including Europe and the Americas (World Health Organization WHO Timeline-COVID-19, 2020). The infection is spreading day by day and has lasted more than 4 months since the end of December 2019. The current numbers of confirmed-cases and deaths in The U.S. and European countries have strikingly exceeded that of China. This article focused on 10 countries that had high levels of infection and still continue to persist based on WHO's statistics (WHO Coronavirus Disease (COVID-19) Dashboard, 2020). There are many reasons why these countries became the world leading countries in the number of confirmed-cases. One of them may stem from the large number of people coming into their territories, which greatly attract tourism or immigration from other countries. Moreover, many of these severely infected countries are developed countries whose economy will suffer from undoubtedly dramatic downturn when the social distancing measures are promulgated.
In previous studies, the characteristics of population or climate were confirmed to have an important effect on the spread of COVID-19 (Eslami and Jalili, 2020;Ferreira et al., 2020;Wu et al., 2020). The number of COVID-19 tests performed daily also varies from country to country (Our World in Data, Coronavirus Testing, 2020). Therefore, the analyses in this article were performed assuming that these variables within a country were a constant during the focused period. In addition, the analyses primarily focused on assessing the increase or decrease of infection instead of the absolute value of confirmed-death-cases in each country.
In this article, the daily data of COVID-19 confirmed and death-cases in the period from January 11, 2020 to May 2, 2020 was collected from the statistical reports that record the number of worldwide infections daily by the World Health Organization (World Health Organization coronavirus disease (COVID-2019) Situation Reports, 2020). The information related to the social measures of the focused countries was collected from government announcements on national or regional official websites, or on many news sites, which daily update information about the pandemic (the details of references are shown in Table 1 below).

Investigation of the social measures of 10 highly infected countries and definition of the levels of the social distancing measures
Depending on situation of each country, the prohibitions enacted are different but the national measures are generally classified into three main categories: travel restrictions, facilities shutdown and social distancing. Governments issued travel restriction measures including travel bans from other countries to limit the spread of the virus from outside of their borders, and domestic travel restrictions to limit the spread of the virus among their citizens. The facilities shutdown measures are aimed to further limit the domestic outbreak, by reducing crowds in non-essential places such as bars, restaurants, festivals and prioritizing the safety of children by closing schools. The social distancing measures can be considered the highest level, where people in regions or the whole country are required to stay at home. While the social distancing measures are evidently beneficial in limiting the spread of infection, they also greatly affect people's lives and the whole nation's economy in negative ways. Therefore, many countries took their time to consider the best response before declaring restriction measures.
Specific measures of 10 highly infected countries, their promulgated date and the references are shown in Table 1. In this table, the travel restrictions include: (1) ban entry from highly infected countries (China, Iran, etc.); (2) close national borders and suspend foreign travel; (3) domestic transportation restrictions. The facilities shutdown includes: (1) close schools; (2) close non-essential services and public events; (3) work-from-home order. The social distancing includes: (1) restriction against going outside; (2) stay at home order. There are 2 levels for each order of facilities shutdown and social distancing: (R) by region and (N) nationwide.
In many cases, COVID-19 infected people do not show any symptom in the early stage, hence they are not aware of their condition and continue to interact with other people. Among measures in Table 1, travel restrictions and facilities shutdown can prevent them to some extent from contacting others and spread the coronavirus, but not completely. Therefore, the social distancing measures were promulgated after or at the same time as the travel restrictions and facilities shutdown measures in most focused countries. The social distancing measures request everyone to stay indoors. Therefore, social distancing measures are considered the strongest measure against contagion within the community. Based on the analyses results described below, the decrease in the daily COVID-19 confirmed-cases appeared after social distancing measures were promulgated. Therefore, in this study, social distancing measures have been more focused than the other measures in Table 1. The social distancing measures are divided into 4 detailed levels as follows.
Level 1: Warnings against going out by region, which is the lightest level, only promulgated on specific areas affected by the spread of virus.
Level 2: Warnings against going out on a nationwide scale. Level 3: Stay-at-home measures by region. This measure prevents people in highly affected regions from going outside with very few exceptions, including shopping for basic necessities or seeking medical help. Level 4: Stay-at-home measures on a nationwide scale. Everyone in the country is required to stay home unless it is absolutely vital for them to go out. This measure is similar to level 3, but on a bigger scale in response to the national state of emergency.

Results and discussions
3.1. Relationship between the social distancing measures and the statistics of COVID-19 confirmed-cases Fig. 1 shows the time-series of the daily confirmed-cases from January 11 to May 2, 2020 of 10 highly infected countries. Based on information from coronaviruses such as MERS and SARS, the incubation period of Covid-19 can be up to 14 days according to the World Health The China Daily, 2020 1/24 √ 3/27 √ Organization (World Health Organization coronavirus disease (COVID-2019) Situation Report -73, 2020). Hence, people who are suspected to be infected or exposed to the virus might not show any symptom, therefore unable to be classified as a confirmed-case, until one or two weeks later. Therefore, it takes a certain period of time until the effectiveness of measures can be observed on the data of confirmed-cases.
Here, the 14 days from the promulgation of social distancing measures are shown by colored bands in Fig. 1. The beginning of each band marks the date the measures were put into effect. In addition, the data on the figure was analyzed using the trendlines, each of which represents the estimated trend of daily case transition of the month, starting from January to the beginning of May. The trendlines are quadratic polynomials, which better illustrate the fluctuating trends than linear polynomials. Moreover, it is also important to note that the value scale of the vertical axis in these figures is different from each other. Fig. 1 shows that it took approximately 1-4 weeks since the promulgation of highest level of social distancing measures in each country until the numbers of daily confirmed-cases showed positive results. Within a month since strictest social distancing measures were placed, the number of daily confirmed-cases in most countries reached their peaks and began to decrease. It took Iran and Turkey only one week since the highest level of the social distancing measures were promulgated until the number of daily confirmed-cases started to decrease. The number of weeks before observable recovery in Germany, France, Spain, China and Italy were 1.5, 2, 2.5, 2.5 and 3.5 respectively.
Meanwhile, it took The U.K. and The U.S. about 4 weeks since the highest level of the social distancing measures were promulgated until the number of daily confirmed-cases started to stop rising. However, the trends of the decline in the daily confirmed-cases in these countries were not as clear as those in other countries. In addition, Russia has showed no sign of flattening its curve. 3 weeks after the date of promulgation of the first social distancing measures, the state of infection in this country was still extreme, forcing the government to issue a higher level of social distancing measure. Still, up until the beginning of May, the number of confirmed-cases in this country continued to increase.
Results of Fig. 1 show that the effectiveness of the social distancing measures on the spread of COVID-19 is different between 10 countries. This variation may be due to the difference in the content of promulgated social distancing measures, as well as the difference in the daily confirmed-cases at the time of promulgation between the countries. Some countries including Spain, France, Iran and China only promulgated one social distancing measures throughout the focused timeseries. Comparison between these countries shows that the stronger the level of social distancing, the faster it took for the number of daily confirmed-cases to decrease. Meanwhile, other countries started with lower levels before continuing to promulgate stricter measures in order to cope with their specific situations. The time gap between promulgated measures was also different between the countries. For instance, in order to cope with its tremendous rise in the number of cases, The U.S. Government promulgated 3 different levels of social distancing measures quite close together. In Germany, 2 levels of social distancing measures were put into effect on the same day, whereas the time gap between promulgated measures in The U.K. and Italy were 1 and 2 weeks respectively. The two social distancing measures promulgated in Russia were the same level as that of Turkey, and the measures in both countries were promulgated at the same interval of 3 weeks. However, the effectiveness of the social distancing measures was evident in the data of Italy, Germany and Turkey, but not clearly in the data of The U.S. and The U.K. One of the reasons for the case of The U.S. is considered to be because the daily confirmed-cases in The U.S. were relatively high at the promulgated date of the highest level of social distancing measures, and the situation was more difficult to control than other countries at the time when the social distancing measures were promulgated. Moreover, Russia has showed no sign of flattening its curve. There have been several explanations for the situation of Russia, one of which is said to be due to "relatively low" compliance with lockdown, said Christopher Gerry, Director of Russian and East European Studies at the School of Global and Area Studies at Oxford University (https://time.com/5836890/russia-coronavirus/). Other reasons for the continued increase in confirmed-cases in Russia are attributed to poor testing early on preventing the authorities from tracking how far the virus had spread, resulting in the fact that social distancing measures were not strong enough and were imposed quite late.
Based on above results, it can be confirmed that the daily confirmed-cases in most countries declined (despite differences in scale) after social distancing measures were promulgated. Therefore, it can be said that although social distancing is not the radical measure against the pandemic, but while vaccination and medicine are under research and development, the social distancing measures have appeared to have tremendously positive effect on limiting the COVID-19 spread.

Relationship between the social distancing measures and the statistics of COVID-19 deaths
Similar to Fig. 1, Fig. 2 shows the time-series of daily death-cases of the above countries and the date of promulgation of social distancing measures. Meo et al. pointed out that the number of COVID-19 confirmed-cases had been proportional to the number of deaths (Meo et al., 2020). The analyses in this study also showed the similar trends between the confirmed-cases and death-cases in the focused countries. It took roughly the same amount of time for the daily death-cases and the daily confirmed-cases to start declining in Spain, Turkey and Iran. Meanwhile, the period of time it took for the daily death-cases to decline in Germany, France, Italy and China was 2 weeks slower than the time needed for the daily confirmed-cases in these countries to start declining.
In contrast, it took The U.S. 4 weeks since the promulgation of highest level of social distancing measures to control the increase of the daily death-cases, but the daily deaths did not seem to slow down, although after 4.5 weeks, it has stopped rising sharply like the last few weeks. Despite various measures being issued quite close together, fatality rate due to the coronavirus in The U.S. has still been severe. In The U.K., it seems social distancing measures have not made significant difference in the daily death-cases, and the daily deaths fluctuated throughout April. In Russia, although two levels of social distancing measures have been placed in March, up until the end of April, the daily confirmed-cases and deaths continued to rise significantly. The trends in the numbers of deaths in these countries are also similar to the trends of the daily confirmed-cases analyzed in Section 3.1.
Although the trends of the daily deaths and the daily confirmedcases are similar in most of the focused countries, the ratio of the daily deaths to confirmed-cases is not necessarily the same between countries. It is considered to be the result of many reasons, including difference in the daily testing numbers, the counting method of deaths and the medical systems, etc. between countries (Johns Hopkins University and Medicine, Coronavirus Resource Center, 2020). While this is a very important issue, it is difficult to evaluate based on only the collected data in this study. Therefore, the authors did not analyze this issue in depth within the scope of this study.

The growth rate of daily confirmed-cases at the time of promulgating the highest levels of social distancing measures
Atalan collected data from 49 countries to prove the effectiveness of the social distancing measures on the suppression of COVID-19. Analysis was made using the length of lockdown period as a main parameter (Atalan, 2020). In this study, the authors have focused on other parameters including levels, timing of promulgation of the social distancing measures as described above. The timing of social distancing measures promulgation plays an important role in the limitation of infected cases. The social distancing measures that are promulgated when the growth rate of daily confirmed-cases is out of control evidently result in severe conditions. Here, Eq. (1) is defined as follows to evaluate the growth rate of daily confirmedcases at the promulgated time of highest-level social distancing measures since 2 weeks prior (hereinafter referred to as growth rate of daily confirmed-cases).
where, G R : Growth rate of daily confirmed-cases (unit: percent (%)) C: The daily confirmed-cases at the promulgated date of the highest level of social distancing measures (unit: cases) C 0 : The daily confirmed-cases at the time of 2 weeks prior to the promulgated date of the highest level of social distancing measures (unit: cases). Note that, the daily confirmed-cases (C and C 0 ) in Eq. (1) were determined by the intersection of the trendline and the focused date in Fig. 1. In addition, for example, a growth rate of 100% means that 2 weeks before the social distancing measures was promulgated, there was almost no confirmed-cases. The growth rates of daily confirmed-cases of the 10 focused countries, that were calculated based on Eq. (1), are shown in Table 2. The growth rates of daily confirmed-cases at the date when the social distancing measures were put into effect, are fairly comparable between EU member countries (except Germany), The U.K. and The U.S. The U.S. and The U.K. promulgated their ultimate social distancing measures when the growth rates of daily confirmed-cases in both countries reached 99.9%, which was closely followed by Spain, France and Italy at 99.2%, 96.2% and 95.4% respectively. Meanwhile, the growth rates of Germany, Russia, Turkey and Iran are 85.0%, 72.2%, 70.7% and 62.8%, respectively, being lower than those of EU member countries (except Germany), The U.K. and The U.S.
China has started to promulgate their highest level of social distancing order on January 23, 2020, a short period of time after the announcement of the virus spread (BBC News, 2020). As the daily confirmed-cases at the time of 2 weeks prior (January 9, 2020) was outside the time period focused in this study, the growth rate of daily confirmed-cases of China cannot be calculated by Eq. (1). It was undoubtedly expected that China would be the first country to impose the social distancing measures as the virus first emerged in its cities, it is said that the social distancing measures in China was one of the strictest to prevent the virus spread (The Guardian, 2020).
The calculation results in Table 2 do not represent the delay or timeliness of the timing of promulgating the social distancing measures of the countries. However, these results show that the growth rates of EU member countries (except Germany), The U.K. and The U.S. at the time of promulgating the highest social distancing measures were higher than those of other countries. This means that the spread situation of COVID-19 was difficult to control at the time of promulgating the social distancing measures in these countries. This partly affects the effectiveness of the social distancing measures on the spread of COVID-19. Excluding the case of Russia, the social distancing measures were effective in a faster period of time in countries with low growth rates of daily confirmed-cases such as Iran, Turkey or Germany as described in Section 3.1. This also affects the decline rate of daily confirmed-cases after the peak as described in Section 3.4 below.
3.4. The decline rate of daily confirmed-cases after the spread reached its peak The situation of COVID-19 spread of countries at the time of promulgating the social distancing measures were different, hence the effectiveness of these measures was apparently different between countries. The effect of the social distancing measures can be evaluated by the time it took for the spread to start decreasing and the decline rate of this decrease. In this article, the following Eq. (2) is defined to evaluate the decline rate of daily confirmed-cases from the date of the cases of each country reached its peak to 2 weeks later (hereinafter referred to as decline rate of confirmed-cases).
where, D R : Decline rate of daily confirmed-cases (unit: percent (%)) D peak : The highest number of daily confirmed-cases in the focused period since January 11 to May 2 (unit: cases) D 1 : The daily confirmed-cases 2 weeks after the peak (unit: cases). Similar to Eq. (1), the daily confirmed-cases (D peack and D 1 ) in Eq.
(2) were determined by the intersection of the trendline and the focused date in Fig. 2. In addition, for example, a decline rate of 100% means that 2 weeks after the peak there was almost no daily confirmed-cases.
The decline rates of daily confirmed-cases of the 10 focused countries, that were calculated based on Eq. (2), are shown in Table 3. Since the number of daily confirmed-cases in Russia reached its peak in May 2, the number of 2 weeks later is out of the time-series in this study. Therefore, the decline rate of daily confirmed-cases of Russia cannot be calculated. The decline rates of daily confirmed-cases in Table 3 are lower than their growth rates of daily confirmed-cases in Table 2. Unlike the similarity in the growth rates, the decline rates of these countries vary noticeably. However, the reversal trend between growth and decline rates of daily confirmed-cases, can be observed by comparing Tables 2 and 3, where the higher growth rates leads to the lower decline rates. In other word, the containment of COVID-19 spread may take more time for countries that have high growth rates of daily confirmed-cases at the time of promulgating the social distancing measures. Namely, The U.S. and The U.K. are two countries with the highest growth rates of daily confirmed-cases resulting in their significantly low decline rate (14.8% and 25.9% respectively). On the other hand, the fact that China, Iran and Turkey have the highest decline rates may be partly because they are also the three countries that started to promulgate highest level of social distancing measures when growth rates were lowest.
Based on above analysis, it can be confirmed that the trends of growth and decline of daily confirmed-cases differs between countries. Consequently, nations must evaluate their specific conditions to come up with the reasonable level and timing for social distancing measures. Since the social distancing measures may bring social isolation and negative psychological consequences on human, evaluating the change in post-lockdown social distancing is also an important topic in the future (Block et al., 2020).

Conclusion
In this study, the daily statistics of COVID-19 confirmed and deathcases of 10 countries including The U.S., Spain, Italy, The U.K., France, Germany, Turkey, Iran and China, for almost 4 months, and the social measures for the prevention of the spread of COVID-19 in these countries were collected. The relationships between the timing, levels of the social measures and the growth or decline rates of daily confirmed-cases were analyzed by combining the collected information with a time-series. Findings from this research are summarized as follows.
1. In most of the 10 countries, it took 1-4 weeks since the point of highest level of social distancing measures promulgation until the numbers of daily confirmed-cases and daily deaths showed signs of decreasing. 2. The effectiveness of the social distancing measures on the spread of COVID-19 was different between the 10 focused countries. This variation is considered to be due to the difference in the level of promulgated social distancing measures, as well as the difference in the COVID-19 spread situation at the time of promulgations between the countries. 3. The transition of daily confirmed-cases and daily death-cases in each country has similar trends. 4. The growth rates of daily confirmed-cases of EU member countries (except Germany), The U.K. and The U.S. at the time of promulgating the highest social distancing measures were higher than that of other focused countries. This means that the spread situation of COVID-19 was difficult to control at the time of promulgating the social distancing measures in these countries. 5. The growth rate of daily confirmed-cases at the time of promulgating the social distancing measures partly influences the decline rates of daily confirmed-cases after the spread reached its peak. However, this study also has several limitations. The influence of public gatherings that have been happening in the US and European countries, was not considered in the evaluation of the effectiveness of social distancing measures in this study. This is because the timings, magnitudes and processes of these gatherings are too complicated for a quantitative evaluation. In addition, apart from main social distancing measures widely publicized by the governments of the 10 countries, there have also been small and regional measures in localities in each country. Since these measures were not widely publicized or difficult to collect correctly, they were not taken into account in this study. Moreover, the COVID-19 pandemic is still going on at the time of this research, some countries are still in quarantine, while others have put terminations to their social distancing measures. The termination process of different countries is also different, as many countries eased measures gradually. The evaluation of the social distancing measures on the spread of COVID-19 should continue in the future work based on a larger scale of data.

Funding
This paper received no funding.

Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.


Mechanism for collective property sharing in mixed marriage

Author’s Information: This research discusses the mechanism of sharing joint assets for mixed marriage partners. The results of the study illustrate the applicable provisions with the facts that occur in the community regarding land ownership for Indonesian husbands or wives in mixed marriages. The research method used in this research is normative research method. The statutory approach and the conceptual approach The statutory approach is an approach using legislation and regulations. And the conceptual approach is to refer to legal principles. These principles can be found in scholarly views or legal doctrines . This study aims to analyze the mechanism for sharing joint assets in marriage, is based on the prevailing laws and regulations and provides legal certainty for the husband or wife of Indonesian citizens regarding the status of land ownership in joint assets for mixed marriages. Based on the results of the research, a conclusion is obtained that land ownership for Indonesian citizens due to mixed marriages without being equated with land rights for their foreign partners, which is only limited to use rights. Legal certainty for current Indonesian citizens to be entitled to land with ownership rights.

Introduction
In Indonesia, mixed marriage is a familiar phenomenon. In the history of the nation's founders, this mixed marriage has been going on in Indonesia for a long time. Starting with a trade mission, until finally it produced offspring known as Indo Chinese, Indo Arabic , Indo Dutch, almost part of Indonesian society is now not purely indigenous but has mixed with other countries. (Ratulangi, n.d.) In Article 57 of Law No. 1 of 1974 on Marriage is stated that: "The definition of a mixed marriage is a marriage between two people who exist in Indonesia and subject to a different law, because of differences in nationality and one of the parties of Indonesian nationality, while the element -The elements contained in a mixed marriage, namely (Undang-Undang Nomor 12 Tahun 2006, n.d.): 1) Marriage that is conducted in the jurisdiction of Indonesia; 2) Each is subject to different laws because of different nationalities and one of the parties is Indonesian citizenship. Furthermore, with the occurrence of mixed marriages, several problems will arise due to the occurrence of marriage, namely related to the legal consequences of marriage, among others, the result of marriage to husband and wife, the result of marriage on assets, and the consequences of marriage to children. Especially on a result of marriage teradap property, raised their innate property and joint property. Congenital assets are assets controlled by their respective owners, namely husband or wife. And each husband and wife has the full right to take legal actions against their property. This is as regulated in article 36 paragraph 2 of Law Number 1 Year 1974 concerning marriage. While joint assets are assets controlled by husband and wife , husband or wife can act on joint assets with the consent of both parties. In Article 36 paragraph 1 of Law Number 1 Year 1974 concerning Marriage, it is regulated on this matter . Joint assets husband and wife have the same rights and obligations.
Furthermore, it is reaffirmed in Article 35 paragraph 1 and 2 of Law Number 1 of 1974 concerning Marriage which reads "Paragraph ( 1) Assets acquired during marriage become joint assets. (Paragraph 2) The inheritance of each husband and wife and the property obtained by each as a gift or inheritance is under their respective control as long as the parties do not determine otherwise.
In Article 21 paragraph (3) UUPA it is stated that: "Foreigners who after the enactment of this law obtain property rights due to inheritance without a will or a mixture of assets due to marriage, likewise Indonesian citizens who have property rights and after this Law is enacted lose their citizenship are obliged to relinquish this right within the period of time.(Undang-Undang Nomor 5 Tahun 1960 tentang Peraturan-Peraturan Dasar Pokok Agraria, n.d.) 1 (one) year after the right was obtained or the citizenship was lost. If in the past period, the ownership rights are not released, then the right is canceled because the law and land fall to the state, provided that the rights of the other party continue to impose them.
Indonesian citizens should still apply the rules contained in Article 21 paragraph (1), namely "only Indonesian citizens have the right to property rights". In Article 21 paragraph (1) of the above-mentioned Law, it is clear that every Indonesian citizen without exception is entitled to land with the status of ownership rights. However, in reality, land rights with ownership rights for Indonesian citizens in mixed marriages are strongly influenced by the existence of a marriage agreement.(Undang-Undang Nomor 5 Tahun 1960 tentang Peraturan-Peraturan Dasar Pokok Agraria, n.d.) The point of the problem in the occurrence of a divorce is joint property. The Marriage Law (Article 37) only states that if the marriage breaks up due to divorce, joint assets are regulated according to their respective laws. In the explanation of the P origin of the states that is "legal" respectively mean religious law, customary law, and the law -other laws. If we look at the legal system as mentioned earlier, the settlement for this collective property can be determined as follows: For those who are married according to Islam, it must be distributed according to Islamic law which refers to the compilation of Islamic law. So if referring to this legal basis, the legal consequences of mixed marriages are based on the chronology of the case below, so for Indonesian citizens who are married to foreign citizens, it will be difficult to own land or buildings with property rights status .
Because couples in mixed marriages feel aggrieved by a number of provisions in the UUPA and the Marriage Law. Foreign nationals who are married to Indonesians cannot have rights to land, let alone share assets after the break-up of the marriage. As a result, mixed marriage couples feel disadvantaged by Law Number 5 of 1960 concerning Basic Agrarian Regulations (UUPA) and Law Number 1 of 1974 concerning Marriage (UUP).
He considered that Article 21 paragraph (1) and Article 36 paragraph (1) of the UUPA have different meanings from what the 1945 Constitution aspires to. The problem is, the phrase "WNI" is interpreted as "Indonesian citizens who are not married or Indonesian citizens who are married to other Indonesians ". , the fact is that many Indonesian citizens marry foreigners, but still retain Indonesian citizenship and live permanently in Indonesia. Indonesian citizens who are married to foreigners do not lose their citizenship , they remain as Indonesian citizens who have the same rights as other Indonesian citizens. There is not a single law which states that there is a difference between the citizenship status of Indonesian citizens who are married to foreigners as stipulated in Article 2 of Law Number 12 of 2006 concerning Citizenship.

Research Methods
In this study, researchers used this type of approach Legislation according to Peter Mahmud Marzuki "The statute approach is carried out by examining all laws and regulations related to the legal issue being handled. The statutory approach is an approach using legislation and regulations ". (Marzuki, 2010). As the type of research used is normative legal research. The technique of collecting legal materials used in this research is none other than those stated by Mukti Fajar and Yulianto Achmad that: "Data collection techniques in normative legal research are carried out by literature study of legal materials, both primary legal materials, secondary legal materials, as well as tertiary legal materials. (Achmad, n.d.) The analysis technique used is descriptiveanalysis, namely a simple description of a condition or position of legal or non -legal propositions .

The Mechanism of Mixed Marriage in Indonesia on Joint Property Ownership for Indonesians in Marriage
In BW Indonesia's civil law, namely recognizing the sharing of joint assets in the event of a divorce, this joint property is divided into two and each gets half of the assets. Whereas for those who are subject to the Civil Code , in the event of a divorce, the joint property is divided into two between the husband and ex-wife files. In a mixed marriage, again it must be seen which law they agree to use by seeing how the marriage is carried out. Because it is related to foreigners who have a different legal system, it is better if in a mixed marriage it should be carried out through proper legal procedures in accordance with the prevailing laws and regulations and as far as possible be accompanied by a marriage agreement concerning the status of assets in the marriage later. . Thus, legal certainty in an undertaken marriage can be more secure for all parties. (Manan, 2006) Seeing the above explanation, of course, these assets stand alone even in a divorce like that the husband's property belongs to the husband and the wife's property belongs to the wife when they are divorced, but when they are not divorced, Indonesian law does not allow joint assets. for the perpetrators of these mixed marriages certainly makes some people menggangap discrimination against foreigners with the law in Indonesia.

a. The Mechanism of Mixed Marriage between Indonesian Citizens and Foreigners in Indonesia
Currently, there are many Indonesians who intend to have mixed marriages (marriages with different nationalities) but are constrained or at least lack of information on this. Therefore, in the following research, the researcher provides other basic information regarding matters related to mixed marriages, especially for Indonesian citizens (WNI) who are going to marry in Indonesia to male foreign citizens (WNA) based on the current law. this (Law No. 1 of 1974 concerning Marriage).(UU Nomor 1 Tahun 1974 Tentang Perkawinan, n.d.)

Mixed Marriage
Marriage between two people who in Indonesia are subject to different laws, due to differences in nationality, is known as Mixed Marriage (Article 57 of Law No.1 of 1974 concerning Marriage). This means that the marriage that you will do is a mixed marriage. 16

In accordance with the Applicable Law
Mixed marriages that are held in Indonesia are carried out according to Marriage Law and must fulfill the conditions of marriage. Marriage requirements include: there is an agreement between the two prospective brides, permission from both parents / guardians for those who are not yet 21 years old, and as well (see article 6 of the Marriage Law).(UU Nomor 1 Tahun 1974 Tentang Perkawinan, n.d.)

Certificate of Marriage Registration Officer
If all the conditions have been met, you can ask the marriage registrar to provide a certificate from the marriage registrar of each party, -you and your future husband, -(article 60 paragraph 1 of the Marriage Law). This certificate contains information that it is true that the conditions have been met and there are no obstacles to getting married. If the marriage registrar refuses to provide a certificate, then it can ask the Court to issue a Decree, stating that the rejection is unwarranted (article 60 paragraph 3 of the Marriage Law), this Certificate or Decree in lieu of Information is valid for six months. If during that time, the marriage has not been carried out, then the Certificate or Decree will no longer have power (article 60 paragraph 5 of the Marriage Law).

The papers to prepare
There are several other letters that must also be prepared, namely:

a. For future husbands
You must ask your future husband to complete the papers from his area or country of origin. To be able to get married in Indonesia, he must also submit a "Certificate" stating that he can marry and will marry an Indonesian citizen. This decree is issued by the competent authority in the country. In addition, it must also be attached: This marriage registration is intended to obtain a marriage certificate (excerpt from a marriage book) by authorized employees. For those who are Muslim, the recording is carried out by the employee of the marriage registrar or the assistant to the registrar of divorce divorces. As for non-Muslims, the recording is carried out by Civil Registry Officers.

Legalize Marriage Certificate Quotes
The excerpt from the Marriage Certificate that you have obtained, still has to be legalized at the Ministry of Law and Human Rights and the Ministry of Foreign Affairs, and registered at the embassy in the country of origin of your husband. With this legalization, your marriage is legal and accepted internationally, both for the law in the country of origin. husband, as well as according to Indonesian law a. Legal Consequences There are several consequences that you must accept if you marry a foreigner. One of the most important is related to the status of children. Based on the latest Citizenship Law, children born from the marriage of an Indonesian woman to a foreign man, as well as children born from the marriage of a foreign woman to an Indonesian citizen, are now both recognized as Indonesian citizens . The child will have dual nationality , and after the child is 18 years old or already married, he must make his choice. The statement to vote must be submitted no later than 3 (three) years after the child turns 18 years old or after marriage. So be prepared to take care of the procedure for selecting citizenship for mixed marriages that take place outside Indonesia, it must be registered at the Civil Registry office no later than 1 (one) year after the person concerned returns to Indonesia. If not, then your marriage has not been recognized by our laws. The proof of marriage is registered at the Marriage Registration Office where you live in Indonesia (article 56 paragraph (2) Law No. 1/74).
Based on an interview with Drs. Syamsudin Ibrahim as head of the Gorontalo city population service which the researcher has made as a resource person that according to Mr. Syamsudin's observations at the civil registry office, there is nothing more specific about the distribution of joint assets for perpetrators of mixed marriages. so that the data in the civil registry office is not yet complete and the government needs to be updated again regarding the distribution of joint assets.
The law that must be used in the sharing of joint assets is Islamic law which is more precisely using the Law in the Compilation of Islamic Law and in Islamic law does not recognize the mixing of personal assets into the form of joint assets but it is recommended that there is mutual understanding between husband and wife in managing assets. personal, do not let this management cause damage to the relationship resulting in divorce.
Regarding Mixed Marriage, based on the perspective of the Koran, Islam does not recognize mixed marriage, because the position of fellow Muslims is the same and a noble person is in the sight of Allah SWT. The measure is to show devotion and obedience to Allah, not based on territorial or national boundaries. As contained in the Koran surah al-Hujuraat (49)  Regarding the property rights of Indonesian citizens which are based on Law Number 5 of 1960 concerning Agrarian Principles, which is approximately 40 years old, it is felt that it is very necessary to undergo changes, because it is no longer in accordance with developments that occur in society. According to the Advisor for the Forum for Land Study and Consultation (FKKP) Chairul Basri , land ownership rights are attached to the subject of the owner. If the subject is an Indonesian citizen, then he / she has the right to own ownership rights. Meanwhile, his foreign partner as a foreign subject is only entitled to have the right to use. (Indonesia, n.d.) Indonesian citizens who carry out mixed marriages without a marriage agreement should still be entitled to land with ownership rights, as long as they do not give up their citizenship (remain Indonesian citizens). Although there is joint ownership of land with ownership rights in a mixed marriage without a marriage agreement, the status of the land rights should be separated. Indonesian citizens are still entitled to land with ownership rights, while foreign spouses are only entitled to land with usufruct status. Indeed there are difficulties in understanding of Article 21 paragraph (3) Act -Act No. 5 of 1960. The solution, expected to be briefed in the future of our society (socialization) of the Act in force in Indonesia so as Indonesian citizens are no longer violated rightsit's rights and our society is smarter about the law.

Regulation on the distribution of joint assets in mixed marriages.
Having opened up relations with the outside world, nowadays many foreigners live in Indonesia. They generally stay because they work, do business, or live temporarily as tourists to spend their holidays or as sometimes deliberately brought in by the State which is to be used as an asset for the country, this often happens as well, as is known most in the world of sports, especially in football. a ball that people often refer to as a transfer player. Therefore, it is commonplace if there is a marriage between them and Indonesian citizens. Maybe it does not matter if their marriage can run permanently according to the purpose of a marriage as it is referred to in the Marriage Law, namely the formation of a happy and eternal family / household based on the One Godhead. However, it will be a problem for the parties if there is a divorce, especially regarding the position of the child and the distribution of marital assets. Marriages between Indonesian citizens and foreigners in Indonesian law are called mixed marriages, namely marriages between two people who in Indonesia are subject to different laws due to differences in nationality and one of them is Indonesian citizenship (Article 57 UUP). This marriage is carried out in Indonesia, so in this mixed marriage, one of the parties can obtain the citizenship of the husband / wife and can also lose his citizenship according to the methods stipulated in the applicable Indonesian Citizenship Law. (Tutik, 2006) Mixed Marriage according to Law no. 1 of 1974 is what is meant by mixed marriage in this Law, which is a marriage between two people who in Indonesia are subject to different laws, due to differences in nationality and one of the parties is a foreign citizen and one of the parties is an Indonesian citizen.(UU Nomor 1 Tahun 1974 Tentang Perkawinan, n.d.) a. Article 38 of Law No. 1 of 1974 explains that a marriage can break up because: b. Death, the death of a person is a symptom of nature as the nature of a living being because death is unavoidable and is something that causes the break of the marriage of the husband and wife concerned. (Darmabrata, 2004) c. Divorce, Article 14 of Government Regulation No. 9 of 1975 explains that the breakdown of a marriage due to divorce is the break up of a marriage because it is declared thalaq by a husband in a marriage held according to Islam. In this case , divorce is seen as the end of an unstable marriage in which the husband and wife then live separately and are officially recognized by the applicable law. c.
(2) Women as referred to in paragraph (1) or men as referred to in paragraph (2), if they wish to remain Indonesian citizens, can submit a statement letter regarding their wishes to the Officials or Representatives of the Republic of Indonesia whose territory includes the residence of the woman or man. unless the application results in dual citizenship.
d. (2) The statement letter as referred to in paragraph (3) can be submitted by the woman as referred to in paragraph (1) or by the man as referred to in paragraph (2) after 3 (three) years from the date the marriage took place.
So, if we look at the provisions of Article 26 paragraph (1) and paragraph (3) of the Citizenship Law, it can be seen that if the law of the country of origin of the husband grants citizenship to his partner due to mixed marriage, the wife who is an Indonesian citizen can lose Indonesian citizenship, unless she applies a statement to remain an Indonesian citizen and also the citizenship status of the foreign husband if the mixed marriage partner resides in Indonesia. In the provisions of the Citizenship Law, it does not specify that a foreigner who is married to an Indonesian citizen will automatically become an Indonesian citizen, including if he resides in Indonesia. The thing that the foreigner needs to pay attention to while living in Indonesia is that he must have a residence permit, if the foreigner has lived in Indonesia for 5 consecutive years or 10 consecutive years, then he or she meets the requirements to apply to become an Indonesian citizen if he wishes (see Article 9 letter b of the Citizenship Law).

a. Common Property Ownership According to Islamic Law
The study of shared assets in Islamic Law is inseparable from the discussion of the concept of syirkah in marriage. Many scholars argue that joint property is included in the concept of shirkah, considering that the concept of shared assets is not found in the reference to the text of the Al-Quran and Hadith , then we can actually do it. qiyas (comparison) with the existing concept of fiqh , namely about the syirkah itself . So , it cannot be said that since the issue of shared assets is not mentioned in the Koran, the discussion of collective assets becomes far-fetched. (Susanto, 2000) According to Yahya Harahap that the perspective of Islamic Law on the Joint Assets is in line with what was stated by Ismail Muhammad Syah in his dissertation that the search with husband and wife should be included in rub'u mu'amalah , but in fact it was not specifically discussed about this. This may be due to the fact that generally the authors of fiqh books are Arabs who do not recognize the existence of customs regarding the search with husband and wife. However, they talked about partnership which in Arabic is known as syirkah, by for search problems with a couple are included partnership, so to determine the law needs to be discussed first dahulutentang kinds of partnerships as has been discussed by the Expert Fiqh in their books. (Manan, 2006) According to Amir Syarifuddin Islamic law regulates that the marriage agreement must be made at the time the marriage contract is carried out or afterwards and must be carried out with a special contract in the form of syirkah , if these two elements are not applied, then the personal property belonging to each husband and wife cannot be categorized as joint property. and tetapmenjadi personal property each (Manan, 2006), syirkah is a contract between people who unite in terms of capital and profit. (Sabiq, 1981) In Islamic law there is no mixing of personal assets into the form of joint assets but it is recommended that there is mutual understanding between husband and wife in managing these personal assets, lest this management results in damage to the relationship which results in divorce, so in this case Islamic law allows for a marriage agreement before the marriage was carried out. The agreement can be in the form of a merger of individual personal assets into joint assets, it can also be determined that there is no merger of private property into joint assets, if the agreement is made before the marriage is carried out, then the agreement is valid and must be enforced. (Manan, 2006) Islamic law regulates a separate system between the husband's property and the wife's property as long as the person concerned does not specify otherwise (not stipulated in the marriage agreement). Islamic law also provides leeway for the two of them to make a marriage agreement according to their wishes, and the agreement finally binds them legally.
View of Islamic law that separates wealth of husband and wife actually facilitate the separation which includes treasures husband danmana which includes treasures wife, where wealth congenital the husband and where hartabawaan wife before marriage, where the treasures were acquired husband and treasure acquired wives individually during marriage, as well as which joint assets are obtained collectively during the marriage. This separation will be very useful in separating the husband's assets and the wife's assets in case of divorce in their marriage. The provisions of Islamic law remain in effect until the end of the marriage or one of the two dies.
Based on the results of interviews with a resource person who conducted a mixed marriage, namely a woman with the initials T who works as an employee at the Gorontalo State University, Faculty of sports and health, which researchers interviewed on Tuesday, January 28, 2018 at the Sports and Health Faculty at 03.00 This has been married to foreign citizens of African nationality 7 years ago in Indonesia. Marriage between Indonesian citizens and foreigners in Indonesian law is referred to as mixed marriage, which is a marriage between two people who in Indonesia are subject to different laws due to differences in nationality and one of them is an Indonesian citizen (Article 57 UUP). Because this marriage is carried out in Indonesia, in a mixed marriage, one of the parties can obtain the citizenship of the husband / wife and can also lose his citizenship according to the methods specified in the applicable Indonesian Citizenship Law.
Their marriage was blessed with 1 son. ex-husband who had the initials J works as a football player in Indonesia, before he died he had several times to strengthen the team football persigo (Football Association gorontalo ) After he died he left a fortune in money of 90 million which has not been melted by the PSSI, mobi , l and houses and land. However , in this division, of course, must follow. In such cases, the settlement / distribution is adjusted to the contents of the agreement and the propriety applies .
The point of the problem in the occurrence of a divorce is joint property. The Marriage Law (Article 37) only states that if the marriage breaks up due to divorce, joint assets are regulated according to their respective laws. In the elucidation of the article, it is stated that what is meant by "the law" is religious law, customary law, and other laws . If we look at the legal system as mentioned earlier, the settlement for joint property can be determined as follows: For those who are married according to Islam, it must be distributed based on the compilation of Islamic law, whereas Islamic law does not recognize joint property as well as positive Indonesian law. in Article Article 21 paragraph (1) LoGA only Indonesian citizen (citizen) who may have owned.
So if referring to this legal basis, the legal consequences of marriage that occur above can be said that mixed marriage will bring legal consequences to the parties who do it, as well as Mixed Marriage. As for the legal consequences of Mixed Marriages relating to the nationality of the spouse, the citizenship of the child, and the assets in marriage, especially the ownership of immovable property in the form of land, because according to Law number 5 of 1960 on Agrarian Principles it is stated that, only Indonesian citizens who can have freehold rights over land. For Indonesian citizens who are married to foreign citizens, it will be difficult to own land or buildings with Hak Milik status . This is because the Indonesian Marriage Law stipulates that property acquired during marriage becomes joint property, where both parties have the same rights over the property. Meanwhile, the Basic Agrarian Law states that foreign citizens cannot own land with freehold status. The problem that often arises is when there is a divorce, either a divorce or a divorce in a mixed marriage, and one of the parties demands that the distribution of the property is gono gini. So the wife is treated as stipulated in Article 21 of the Basic Agrarian Law, she is equalized with a foreigner, that is, she cannot have property rights, if she gets a gift or will during the marriage, then she must give up her rights or reduce the status of her land to Right to Use. To overcome this, it is better if a Marriage Agreement is made at the time or before the marriage takes place, to avoid mixing of assets between the wife's assets and the husband's assets. The Marriage Agreement must be made before a Notary Public and must not conflict with the Law.
In the distribution of joint assets, there are factors or obstacles faced by everyone who engages in a mixed marriage. There are several problems related to the sharing of assets together. Problems arise related to the distribution of joint assets in the form of movable and immovable objects. Regarding immovable objects, the problem lies with the ownership status in the event of a divorce. Another problem is related to which law will be used in the distribution of the joint assets. The sources and types of legal materials used are primary legal materials supported by secondary legal materials. Primary legal materials are obtained from statutory documents related to this research, while secondary legal materials are obtained from books, journals, relevant scientific works and other legal materials. In analyzing the data have been obtained by means of classifying materials primary law and secondary later analysis using methods of interpretation or interpretation, so as to explain the existing problems more detail .
In terms of its object, this regulation needs to be revised again because this is a discrimination against foreigners / Indonesians and needs reinterpretation and socialization of society .
a. In terms of the subject, there must be a regulation prohibiting that Indonesian citizens are not allowed to continue marriage with foreigners, so that the existing rules in Indonesia and also in the Compilation of Islamic Law continue to run.
b. In terms of the subject, there must be a regulation prohibiting that Indonesian citizens are not allowed to marry foreigners, so that the existing rules in Indonesia and also in the complications of Islamic law continue to run.

Conclusion
The mechanism of mixed marriage between Indonesian citizens and foreigners in Indonesia, namely: 1) Mixed Marriage Marriage between two people ; 2) Indonesia is subject to a different law; 3) In accordance with the Applicable Law u; 4) Certificate from Employee of Marriage Registrar; 5) The papers to be prepared . The regulation regarding the distribution of joint assets in mixed marriages according to Law Number 5 of 1960 concerning Agrarian Principles states that only Indonesian citizens can own ownership rights over land. For Indonesian citizens who are married to foreign citizens, it will be difficult to own land or buildings with Hak Milik status . This relates to the nationality of the spouse, the nationality of the child, and the assets in marriage, especially the ownership of immovable property in the form of land.


Multi-hazard dependencies can increase or decrease risk

In risk analysis, it is recognized that hazards can often combine to worsen their joint impact, but impact data for a rail network show that hazards can also tend to be mutually exclusive at seasonal timescales. Ignoring this overestimates worst-case risk, so we therefore champion a broader view of risk from compound hazards.

as examples, we illustrate that, from this perspective, some hazards tend to be mutually exclusive due to low-frequency modes of variability. Pairwise views of a multi-hazard environment that target instances where risk is exacerbated 7-9 might therefore overestimate worst-case risk. This complication is one reason for the ongoing development of multi-variate statistical frameworks to better model hazardous extremes [10][11][12][13] , but cases are under-reported. Thus, we highlight the need for a broader and more holistic view of multi-hazard risks applied at spatial scales meaningful to stakeholders, which include the climatological timescales relevant to them. From this standpoint, it becomes clear that hazards can be influenced by modes of atmospheric variability in ways that reduce the likelihood of some hazard combinations, thereby moderating tail-end (that is, worst-case) risk ( Fig. 1). How such risk moderation works is explained using an analogy of rolling dice and by relating hazards to climate modes, such as the El Niño/ Southern Oscillation (ENSO).

el Niño example
Consider weather-related hazards in Australia. During summer, El Niño tends to reduce the likelihood of tropical cyclones 2 and flooding 8 , but enhances drought 14 and wildfire 15  Britain. a, Impact-centric 1,3 conceptualization of the multi-hazard system. Two hazard modes, each associated with a dominant wind direction (blue arrows), drive six hazards (circles). Rail infrastructure (red) is exposed to all six hazards, while (re)insurance (black) is primarily concerned with only two hazards in Mode 2. b, Losses in terms of magnitude and frequency, with rare 'worst cases' on the right-hand side (grey band). A conventional view that does not consider dependencies (grey) might underestimate risk if two hazards (for example, flood and wind) compound. However, where exposed assets are subject to hazards driven by two opposing modes (red), compounding effects are suppressed, so care is needed to avoid overestimating risk. Solid arrows represent effect magnitudes seen within the Network Rail loss data ( Fig. 2

Illustration using dice
A probabilistic configuration of multi-hazards that protects against worst-case combinations can be illustrated by rolling dice. Imagine that flooding and wind damage happen if a six is rolled on a standard die. In traditional risk analysis 17 , flooding and extreme winds are treated as independent phenomena so would have a die each. A 'worst case' scenario is when both occur (two sixes), on average 1-in-36 throws. If flooding and wind always happen together, however, only one die is needed and both hazards occur if a six is thrown (1-in-6 rolls). Thus, assessing such hazards independently underestimates risk 7,9,17 . Flooding and wind damage in a tropical cyclone are strongly related 8 and thus close to this specific case. To replicate a situation where flooding and wind never happen together, a rule is introduced that rolling a six on one die dictates (somehow) that the other die must score a one; two sixes are not allowed. Hence, neglecting a relationship in which states are mutually exclusive overestimates worst-case risk.
Where there is a weaker tendency for phenomena to occur together, such as for flooding and wind in extratropical cyclones 1,7 (Box 1), two similarly loaded dice is a more apt analogy. Both would tend to score high or low such that the chance of two sixes is greater, perhaps 1-in-12. On the other hand, hazards (for example, flooding and wildfire in Australia) might tend to be mutually exclusive over a season or year. Then the loading of the dice would be such that if a six is rolled on the first die, the chance of a second six is reduced. This lowers the probability of two sixes, a worst-case impact, to perhaps 1-in-60 throws on average. Supplementary Discussion 3 describes a series of exercises using standard dice that can be used to illustrate and verify these statistical assertions. These arguments apply to ENSO-driven hazard modes in Australia and to impactful winter weather in Great Britain.

great Britain case study
Given that risk relates to potential for loss, an impact-centric approach 1,3 is essential. The holistic view advocated here requires consideration of multi-hazards and their dependencies at timescales relevant to stakeholders for their hazard-specific exposure (that is, assets at risk; Fig. 1a). For instance, wintertime weather-related impacts on the rail network in Great Britain (2006-2018) quantitatively show how such interactions can suppress tail-end risk, mitigating pairwise compound effects (detailed in Box 1). In a narrow (bivariate) multi-hazard view, based on the idea that storms might drive concurrent flooding and wind damage 7,8 , the largest losses for these hazards compound substantially, increasing by 28% above those simulated when assuming that the damage types are independent (Fig. 2d). This view is

Box 1 | a case study of compound risk in great Britain
A case study of weather-related impacts ( Fig. 2a and Supplementary Discussion 1) on the rail network in Great Britain illustrates that interactions may suppress tail-end (worst-case) risk, mitigating pairwise compound effects (Fig. 2d). Here, impact is expressed as delays to trains which, when monetized, cost Network Rail an estimated £64.6 million annually. Most (72.5%) of these costs occur in the 'winter' half-year (October-March). Thus, winter is selected as our temporal domain for a seasonal-scale analysis, which in Great Britain is hydro-meteorologically distinct from summer (see Supplementary Fig. 1).
From a narrow (bivariate) multi-hazard perspective, the largest losses (13-yr return period) for flooding and wind damage (Wi) compound substantially (+28%), as shown in Fig. 2d. Simulation modelling 1,10 is conducted to demonstrate that this observation (dark blue line) is not due to chance (P < 0.05) by breaking all hazard inter-relationships. In the simulation (see Supplementary Discussion 1), this was achieved by shuffling the years in which losses occur independently for each hazard, and 10,000 of these random realizations are used (dashed line).
However, a wider (multivariate) view yields a distinctly different outcome. When one set of hazards in Great Britain is active, the other main group is typically not. The categories of loss may be, visually or otherwise, grouped into subsets that tend to coincide (that is, are correlated; Fig. 2b). Specifically, when flooding and wind damage incidents are prevalent, impacts due to cold and snow are muted. When summed in pairs (snow + cold and flooding + wind damage), there is no overlap between the years in which each pair's top five losses occur (P = 0.024, χ 2 test), and an inverse correlation is evident (Fig. 2e). In Fig. 2d, this mutual avoidance expresses itself as the largest losses (that is, a 13-yr return period) being suppressed to the level of entirely random selection (dashed line), even as each of the pairs is demonstrated to compound (blue lines). This new observation adds to growing evidence of a seasonal scale flooding-wind damage association for Great Britain 1,7,18 .
We propose the term 'hazard modes' for subsets of partially associated hazards (Fig. 2b). For Great Britain, we hypothesize a simple westerly versus north-easterly driver of the hazard modes (wind damage + flooding: westerly, or snow + cold: northeasterly; Fig. 2c). Low pressure systems (named storms) are associated with westerly and cyclonic synoptic-scale atmospheric patterns 18 , and although individual storms are typically viewed as either causing flooding or wind damage 4,16 , some cause both (for example, Storm Desmond); particular seasons have also been identified as notably 'wet and stormy' 18 . Opposing this behaviour, episodes of extreme wintertime cold or snow in Great Britain are typified by advection of cold air from the north and east, and 'blocking' anticyclonic circulation 5,19 . The wintertime frequency of mobile westerly and cyclonic flows are known to trade off against more stable anticyclonic conditions 20 . Here, we show that the North Atlantic Oscillation is a useful metric to capture these behaviours through its correlations with the hazard modes (Fig. 2f,g).

comment
NaTure CLImaTe ChaNge | VOL 10 | JuLy 2020 | 586-598 | www.nature.com/natureclimatechange appropriate for domestic property (re) insurance where these two hazards dominate 1 . However, Network Rail is also exposed to substantial cold and snow impacts, which themselves compound by +8% during winter. Assuming now that hazards are paired, but the pairs are independent given that no published study explicitly suggests otherwise, yields a simulated increase in overall loss of +17%. However, these calculations would overestimate risk. This is demonstrated by simulating the total effect of all dependencies acting together on these four hazards, which results in little net effect

Fig. 2 | Winter multi-hazard impacts in great
Britain. a, National total winter (October-March) losses for nine hazards affecting Network Rail, of which seven are substantive, namely <0.1% of total losses. b, Correlations between the loss classifications. *P < 0.05, **P < 0.01, ***P < 0.001. c, Illustration of the proposed 'hazard modes'. d, The effect of interdependencies between hazards upon seasonal loss totals calculated as the difference between observations (solid lines), and simulation modelling in which randomization has been used to break any process-based linkages between hazards (dashed line). Larger, rarer losses have greater return periods in this exceedance probability plot. Loss values greater than zero indicate that selected hazard combinations compound, or alternatively negative values show that combined impacts are suppressed. Statistical significance of the tendency to compound is computed using the AEP method 1 and simulation. Details of data and simulation methods are provided in Supplementary Discussion 1. e-g, Scatter plots showing correlations between paired categories of losses, and between these pairs and the NAO. Pearson's r and its statstical significance are displayed, and the grey shading represents the 95% confidence interval for the trend line. comment NaTure CLImaTe ChaNge | VOL 10 | JuLy 2020 | 586-598 | www.nature.com/natureclimatechange (approximately -1%; Fig. 2d). This occurs because when flooding and wind incidents are prevalent, impacts due to cold and snow are muted. Therefore, a broad multi-hazard approach evidently leads to a very different conclusion from bivariate view(s) (Fig. 1b).
Mutual exclusivity is not self-evident. Storm Ciara (8-10 February 2020) led to disruption from snow, flooding and wind damage. However, some hazards are more likely under particular synoptic-scale conditions 16,18,19 (weather types 20 ), so if the frequency of a weather type is high over the season, the damage from its associated hazards will also be high. Mutual exclusivity arises as the frequency of different weather types trade off against one another 20 . The greater the difference in hazard likelihood between weather types and the clearer the seasonal trade-off in their frequency, the stronger this effect will be.
For Great Britain, wintertime frequencies of cyclonic (flood and wind damage 7,18 ) and anticyclonic or north-easterly (cold and snow damage 5,19 ) weather types show strong compensation 20 , explaining the emergence of 'hazard modes' (Box 1). These modes, however, may not persist in a future climate. Even if the trade-off in circulation types persists, air masses associated with cold and snow hazards may warm sufficiently to no longer yield damage, reducing annual average losses by ~30% (Fig. 2a). To resolve the effect of such dependencies and to test simplified hypotheses like this, statistical frameworks for multivariate extremes [10][11][12][13] and/or climate models are needed.

a broader view of compound risk
In summary, dependencies between causative hazards can both compound and suppress risk (for examples, see refs. 1,3,9 ; Figs. 1b and 2d). Both over and under-estimation of risk is problematic for the systems and people affected. To neither waste resources nor to be underprepared, scientists, society and decision-makers need to be alert to both. To date, however, the focus of the modelling community (especially within climate science) has been on those aspects of dependency that make outcomes worse. Our contribution highlights that the opposite can also be true (Fig. 1b). We therefore advocate a broad view of compound risk -a refinement of the established 'compound event' viewpoint that might better serve hazard and risk management communities.
The term 'compound' , as applied to risks, developed from its meaning 'make (something bad) worse; intensify the negative aspects of ' 3,6,17 (see Supplementary Discussion 2). Recently, the definition has been expanded 3,6 , but only rarely is a beneficial side effect 3 or reduction of risk noted as a caveat 21 , and the importance of these tends to be downplayed. We believe that this wider description, including such positive connotations, is viable, as the word compound also means to 'mix or combine constituents' (in this case, a mix of hazards). An 'event' , however, is an occurrence rooted in a specific time and place. Thus, perhaps the phrase 'compound event risk' could be explicitly kept narrow. Conversely, we advocate that 'compound risk' be applied more holistically and used to accommodate compound events 3,6 that increase impact severity, but also used to include those impacts that combine within extended timeframes and those that combine in ways that are mutually exclusive.
Based on the examples above, situations are likely to be common globally where multi-hazard risk is systematically suppressed with respect to selected narrow (for example, bivariate or pairwise) configurations. We suspect that these are under-diagnosed due to (1) lack of systematic collection and analysis of impact data; (2) difficulties in comparing hazards (for example, time lags between extreme events, different hazard metrics 1,17 and time lags between end-member conditions, like El Niño/La Niña); and lastly (3) a need for greater awareness that such situations should be identified. The subtle balance between hazards is also non-stationary as climate changes 2,3 , so diagnosis is needed for future climates. Moreover, dependencies are not only between causative hazards but are also embedded in vulnerability and how impacts cascade 3 . Broad, holistic, stakeholder-relevant assessments of compound risk for multi-hazard environments are therefore needed to improve assessments of current and future risk. ❐


Research on the Service Mode of Creative Products Design of Bengbu University under the Powerful Industrial City Strategy

Under the perspective of powerful industrial city strategy and based on the creative product design in Bengbu University, this paper constructs a service mode that is compatible with the creative product design in Bengbu University by combing the product design service theory according to Bengbu University’s positioning in application-oriented university.By strengthening the supply of design service and adopting the combination of multiple innovative measures of regional culture, university-enterprise cooperation, studio and craftsmanship spirit, etc., it strives to enhance student’s professional practice ability comprehensively, to promote enterprise’s research and innovation level. It is aimed to cultivate high-quality practical talents that are suitable for supporting the development of powerful industrial. It also provides referential theoretical basis and reference for the related researches on product design service.

Powerful Industrial City
Emphasizing on the powerful industrial city strategy is a comprehensive representation of Bengbu's following of the demands on high-quality development. At the same time,the instructive ideology of "science and technology are the primary productive force"should be popularized all around, which can facilitate the implementation of the Scientific Outlook on Development. The significant service capacity of innovation should be extinguished, indicating its support to the economy growth and the development of society. The allocation of technology resources should be improved continuously, thriving in enhancing the technology level, highlighting the important role of the powerful industrial city strategy and the service provided by technology outcomes to the society.In summary, the goal of powerful industrial city strategy is to achieve accelerated development and to take new cultural creativity and services as the focus of reform [1]. The key is to promote industrial transformation and upgrading,strengthen innovative services,enhance industrial value and the ability in providing professional services,forming the development model of "manufacturing + service". At the same time, it is also necessary to explore technological innovation actively, promote local industries and local universities to conduct joint research and cooperation in innovation,and to construct R & D service platforms jointly. It is devoted to build Bengbu into a core base for the development of important high-tech industries under the "Industrial Strong City", and to enhance the level of urban development, thereby enhancing regional competitiveness.
Based on the exposition above, it is not hard to find that if we want to realize the construction of powerful industrial city, not only shall we emphasize the development of high-tech industries and relevant services, but also have to cultivate comprehensive talents that are capable of conduct research and design. Those talents are the most direct and power human resources for promoting the construction of powerful industrial city. Therefore, regional universities should make their contribution by responding to the urgent demand of delivering relevant talents for the construction of local economy and development of society. At the same time, local universities have to adjust their own direction and scientific research plan on talents' cultivation according to the principle of targeted development, the local economic development dynamics and structural characteristics of the new industry.So,the development of professionals and talents' training can better serve the industrial transformation and upgrading,as well as the development of powerful industrial city. Therefore, Bengbu University has to fully utilize their design studio with advanced equipment and their featured major of creative products design to construct the service platform. On one hand, this service model can enhance the capability of independent innovation of Bengbu university,fasten the conversion of research results and realize the merging of manufacturing and teaching;on the other hand, it could utilize the school's advantages in talent and equipment in the cooperation with enterprises, to provide support in research and development for the enterprises and to deliver talents to them. It can create a correlative dependence between enterprises and universities,increase the technology level of enterprise's development, thus promote the development of local economy.

Product Design Service
From the perspective of design science, products are displayed in the practical physical form, while service is an intangible value that derived from physical form. It can be seen that product and service have fundamentally different attributes [2]. However, with the advancing of Made in China 2025 strategy and Industrial 4.0 strategy, the design philosophy that oriented by creating service value has become the research hotspot of product design.Only by integrating"featured service"into the research and manufacture of products can the enterprise's new product gain their position on the market and acquire the recognition in the industry. And that has become the breakthrough direction for current product design and innovation [3]. As a brand-new research and development mode, it conducts systematic planning and studying on the new product from the aspects of concepts and services [4]. For product design, the intangible service has taken the leading role in developing, and products have been converted to a platform that displays service. How to provide a more valuable service is the core of the transformation from"practical economy"to"intangible economy"For enterprises, this new model of comprehensive optimization is the most effective way.Eventually,it will give enterprises more features of their own, and distinguish them in the market.Their practical products will be attached with invisible added value, realizing a benign development,as well as achieving the goals of social benefit and economic benefit.
Therefore, as a regional university,Bengbu University should fully utilize their major of creative product design,combine it with the enterprises that manufacture creative products and provide supporting service. A comprehensive service platform for product design should be launched, as to provide professional talents and technical supports for the design innovation of enterprises. Cooperating in designing and building creative products that embedded with local cultural features can push the research and development innovation of product design. Culture resources should be applied to improve enterprise's resource allocation, and the transformation of creativity economy can realize enterprise's sustainable development. It meets the demands of industrial transformation and upgrading under the powerful industrial city strategy, and further realize the inheritance of culture and creates income for the economy.

Creative Product Design
In recent year, creative product has been enrolled in many scholar's research scope. It is a byproduct of the growing creativity industry. Creative product design is practical product presented by a creative process that uses methods in design science. Among which the creativity connotation is the core, making the product has both invisible creative value and practical value [5]. Creative products have extreme high innovativeness and originality. Creative talents and technologies are the core. And by the cooperation between professionals with different skills and the design ideology that converts mined innovative idea to creative products,the industrial cluster effect will be realized, which could further be used to present the high added value in the service of creative products [6].Creative products value analysis figure 1.

Figure 1. Creative Products Value Analysis
The rising of industry drives demand of talents that have professional creative products. As a university that possesses creative product major, its role should be played, as to display the university's visible value and invisible value in cultivating professional talents. This new operation pattern is based on the practice of university' creative product design, and to build a featured brand for creative products. Such pattern can not only present the university's featured education philosophy, expand its social impact, realize the integration of humanistic quality and artistic practice,but also guaranteed the same direction of the school's cultivation of talents and the development of industry, that further improve the image of regional brand and the promotion of related industry.
As for now,some well-known universities in China has formed a complete research, develop and service system for creative products. Comparing with other universities,Bengbu University has not formed a complete industrial service system, no matter from the design to production,or to the cooperated promotion and the construction of service platform.
There is a great significance in researching the development path of the creative products in Bengbu University by combining with the rising service mode under the powerful industrial city strategy. The powerful industrial city strategy put forward new demands for the development of creativity industry, as well as the philosophy of industry transformation and upgrading.From the aspect of creative products design, Bengbu University has featured product design major.If its duty of service has to be distinguished, the links of talents cultivation, university-enterprise cooperation and investment in creativity industry should be emphasized.The creative mind of the major of product design should be strengthened and the creative spirit should be expanded, to form an atmosphere that facilitates creative product design.Combining with the university's professional talents and hardware equipment, the cooperated research with corresponding enterprises should be conducted in various phases like creative design phase,production phase and cooperation phase, realizing a merging of production, learning and researching. The resource advantages that owned by the region should be fully utilized in actively designing the creative products that have its own features and in correspondence with the consumption demand of the market. Such creativity resource could be converted to a new industry, and thus promote the transformation and upgrading of the traditional industries, realizing a sustainable development. The service platform for creative products design in Bengbu university with distinguished characteristics should be advanced,making it an effective method in serving the powerful industrial city strategy.

Construction method of the Service Mode for Creative Product Design in Bengbu University
The construction framework of Bengbu university creative product design service model is shown in Figure  2 4.1 Integrated with regional culture Utilizing regional culture resource, converting it to creative products and making it in correspondence with mass demand are the trend of creativity industry in the future. Regional features culture is an important inspiration source for creativity product design in Bengbu University, it can not only distinguish the creative products from the similar products in the markets, but also present the regional characteristics of talents cultivation.Therefore, Bengbu University's advantages of having special cultural resources should be fully utilized. Typical featured cultures like Huai River Culture, Dayu Culture have very significant research value.It should be integrated into the design philosophy of creative products.During the practice process, the value connotations and cultural elements of regional cultural resources should be deeply mined.And those cultural elements should be extracted and integrated by adopting creative design methods. The philosophy of creative design can not only realize the innovation and inheritance of regional culture, but also provide new ideas and schemes for the design of creative products, thus increase the value and market competitiveness of creative product's design. In the same time, taking the creative product design in Bengbu University as the service platform, the model effect of art education in Bengbu University can be distinguished. It can further promote the construction of economy and culture by creative products and provide concrete power for promoting the creative product's brand and the employment of local talents in the industry.

University-Enterprise Cooperation
The strategy of a powerful industrial city requires that industries continue to be upgraded. Therefore, Bengbu University needs to build a talent cultivating mechanism that combines with industrial development to cultivate talents who can undertake the strategy of building an industrially strong city. University-Enterprise cooperation can help schools cultivate applied talents who meet enterprise development's needs through various forms of cooperation,in or out of school. It is also an important method of talent cultivating. Therefore, it should explore a new model of Bengbu University creative product design University-Enterprise cooperation that conforms to the strategy of the powerful industrial city and make it serve the strategy of the powerful industrial city.Bengbu University has established a product design practice center at present. Therefore, it can integrate the respective superior resources and conduct cooperation in creative product development and design, professional talent cultivating plans, discipline construction, make and practice teaching plans depending on its schools-enterprises cooperation of creative product design.
This mode of cooperation organically combines enterprise design needs and professional practice links, cooperates with relevant companies to develop actual creative products, further close the distance between students and actual products,drive students' enthusiasm for professional learning, and strengthening the training of actual creative products design ability for students to achieve the purpose of university talents cultivating. It deeply reflects the integration of practical teaching, creative product development, technology research and development, creative product incubation, trainingpracticing Figure 2. The Construction Framework of Bengbu University Creative Product Design Service Model combination, brings the most satisfactory design concepts to enterprises with the lowest resource consumption and cost input, promotes enterprise product upgrades, renews and diversification of product types, to improve the success rate of enterprise product development and market share, to achieve a win-win result between school and enterprises and reach a good cooperative relationship. Taking this opportunity, it will further create a creative product design service platform with a perfect system to promote the transformation of design achievements and provide service support to enterprises research and development innovation and industrial development.
Bengbu university creative product design school enterprise cooperation service model is shown in Figure  3.
The specific methods of University-Enterprise cooperation can start from the following two aspects:

Actual Projects
Bengbu University product design form good and deeper cooperation and interact through the actual projects.
Enterprise research and development project, the scientific research project applied by teachers, the scientific research project which has students participate in and others can make up actual projects. By

Discipline Competition
Professional discipline competition is an important and nonnegligible teaching method which can stimulate students' enthusiasm to participate in professional learning. It can not only enrich the courses teaching methods but also can promote the construction of professional courses, promote the enterprises'technology innovation, promote the transformation of competitions' achievements,further improve the integration of production, learning and research to achieve win-win result between schools and enterprises.

Studio
"Studio" is a new type of practical teaching model based on University-Enterprise cooperation and actual projects,which is recognized and adopted by more and more educational circles. The cultivating model which bring comprehensive and actual projects practice in the studio for students to complete and let teachers and professional personnel enter the school to guide and comment, can further promote the improvement of professional practical skills, improve innovative thinking, and enhance the teamwork capabilities based on satisfying students to become highly skilled talents who meet the needs of enterprises and markets. Therefore, Bengbu University should set up the studios for creative product design, make responsibilities and management plans of studios and relevant talent cultivating programs to achieve the small-sized class and distinctive talent cultivating. In order to increase the employment rate of students after graduation and convey competitive talents, it is necessary to carry out diversified cooperation with enterprises through studios. At the same time, in order to promote the teaching achievements innovation, the studio can combine practical courses and projects to form the integration of teaching, research and development and social services. In the studio, students' creative product design achievements can be promoted and displayed through design exhibitions or professional discipline competitions, and design culture weeks, so that it can build a good service platform through the studio and provide services for the disciplines' development and the construction of a powerful industrial city.

Craftsmanship Spirit
In 2016, Premier Li Keqiang proposed the craftsmanship spirit in the government report which reflects the importance attached to the manufacturing industry. This is consistent with the strategic objective of a powerful industrial city that they both focus on the development of the manufacturing industry. The core of the manufacturing industry is product design while the industrial development of the manufacturing industry depends on product design and universities are training bases that convey professional talents for product design. Therefore, it is necessary for universities to strengthen the education of craftsmanship spirit for students when cultivating product design professional talents.
"Keep improving, be brave to explore, practice and innovate" is the ideology core of craftsmanship spirit [7]. The cultivating requirements of product design major for students advocate the pursuit of perfection and the spirit of service which pull out all the stops. Hence, the core of these two concepts is consistent. Incorporating craftsmanship spirit into Bengbu University creative product design practice teaching, combining University-Enterprise cooperation and studio model can help students better establish professional ideals and learning goals, enhance students' enthusiasm for major learning, develop them a positive and focused learning attitude, enable students to be creative, willing to innovate, enhance students' innovative ability, so as to create more excellent creative product design works, thus contributing to the development of a powerful industrial city.

Conclusion
In conclusion, this paper systematically analyzes, summarizes, integrates, and proposes a service model suitable for Bengbu University's creative product design under the guidance of a powerful industrial city strategy, based on the product design service concept. This model not only meets the need for applied talents for new industries under the construction of a powerful industrial city, but also meets the positioning of Bengbu University to construct an applied school.Because the most important thing about it is to enable students to carry out professional practical learning in the industrial chain, enrich the practical teaching system. At the same time, it can focus on cultivating students' practical ability and cultivate compound-type talents with innovative ability for the industry. Meanwhile, it can highlight the value of Bengbu University's creative product design services and then form a unique brand connected effect. It develops product innovation for enterprises in many ways which makes products competitive.It provides new ideas for new type industries development, promotes industry development with a service platform,which can promote economic transformation and growth, consequently promoting the construction of a strong industrial city.