The Sitemap XML protocol is also extended to provide a way of listing multiple Sitemaps in a 'Sitemap index' file. The maximum Sitemap size of 50 MiB or 50,000 URLs means this is necessary for large sites. An example of Sitemap index referencing one separate sitemap follows.
Cultural or artificial eutrophication occurs when human activity introduces increased amounts of these nutrients, which speed up plant growth and eventually choke the lake of all of its animal life.n nature, eutrophication is a common phenomenon in freshwater ecosystems and is really a part of the normal aging process of many lakes and ponds. Some never experience it because of a lack of warmth and light, but many do.
Eutrophication is a natural process that typically occurs as lakes age. However, human-caused, accelerated eutrophication (called cultural eutrophication) occurs more rapidly, and causes problems in the affected water bodies, as described below.. EUTROPHICATION. Fertilizers cause problems with water quality when they runoff into rivers or percolate into groundwater. In fact, agriculture (including livestock agriculture) is the largest source of nonpoint water pollution in the US.