In the past, our research center only carried diffuse pollution research by Chaohu Lake in Eastern China. In recent four years, our research sites have been spread to cases in North China and Central China, and the types of land uses cover the rural areas, villages and the urban regions. We have conducted characterized diffuse pollution researches by Chaohu Lake, with multipond systems, in watershed of Yuqiao Reservoir, for drinking water source conservation, and in Hanyang District of Wuhan City, for urban drainage pollution control.

The researches obtained fruitful results. We have found the fundamental rules of pollution creation, transport and retention from diffuse sources in areas with different meteorological and hydrological characteristics. We have raised various control measures. In North China, small precipitation and high soil seepage rate makes large amount of pollutants accumulated in the ground surface and only heavy rainfall, which only very few times, can wash these pollutants to the downstream waters. It is found that the watershed retention system, composed of small stone dams, swales, vegetated water ways, dry ponds and estuary wetland can effectively retain diffuse pollution. In the research in Wuhan City, we found the characteristic curves of pollution and hydrological load from various urban areas. We developed effective technologies for the control diffuse pollution from new residential areas, tourist areas and old city areas. To control the sources, transport and sink of diffuse pollution, several demonstration engineering practices were constructed in Hanyang District of Wuhan City. Because of these progresses, Professor Chengqing YIN, the leading scientist in our center, was invited to make a keynote speech on the 7th INTECOL International Wetlands Conference at Utrecht, the Netherlands in July 26-31, 2004, after another honour of winning International Ibaraki-Kasumigaura Prize in 1999. Some of the results have been published in international journals of Ambio; Water, Air and Soil Pollution; Agriculture, Ecosystems and Environment; Journal of Environmental Science and others; many are published in domestic scientific journals. More important is these results have been used in the new city planning of 40 km2 in Wuhan City and will set a good technical example for the construction of blooming new cities in China.