Heavy rains have caused disasters across China this summer, bringing the worst landslides in decades. The most deadly disaster happened on August 8 when a big landslide hit Zhouqu County in Gansu province, killing at least 1,407 people. On August 18, landslides hit Gongshan, a town in northwestern Yunnan. At least 38 people were killed and 54 are missing. Heavy rains also caused landslides in several counties in Sichuan province. People were forced to evacuate  to safe places. Landslides and devastation Landslides take place when dirt and rocks slide down a slope together. Sometimes these landslides are small, and hardly noticeable. Other times however, they can be massive, involving the entire side of a mountain. Landslides can be caused by a number of different things. Often rain, which adds weight to the side of a slope, can cause one. Other times they might be caused by erosion .When a stream slowly removes the base of a slope, it weakens the entire side of the mountain. As a slide moves down a mountain slope, it can pick up great speed and energy. Some slides travel at a speed of 300km an hour. The resulting winds can be so powerful that they are known to strip  the leaves off surrounding trees. Earthquakes and landslides Some experts think the landslides in Sichuan were related to the magnitude-8.0 Wenchuan earthquake on May 12, 2008. The quake has caused a change in the structure of the Earth's surface, making it more likely that land will slide in the rain, according to geologist Xu Qiang of the Chengdu University of Technology. Landslides pose  threats to 140 cities and towns in the country, one quarter of which are in Sichuan, said Wei Fangqiang, a researcher with the Chinese Academy of Sciences. Landslide prevention If you want to avoid being a landslide victim, the easiest thing to do is avoid living on slopes or close to mountains. If you live in a landslide-threatened area, try not to water the slopes if possible. If there are large rocks on the slopes above your house, remove them so that they don't cause damage if they fall. It might also be helpful to plant trees on the slopes. Over time, the tree roots may make the soil firmer. The landslides around China are mentioned at the beginning of the article to  _  .
warn travelers to keep away from those places show that the environment in China is getting worse introduce the topic of landslides express concern for those affected by landslides