The impacts of human activities on the Wuliangsuhai wetland environment

Abstract

Wuliangsuhai wetland is the biggest freshwater lake in the Yellow River basin, and also the biggest wetland in the same latitude on the earth. In 2002, Wuliangsuhai was listed in the international wetland inventories by International Wetland Treaty Organization and had become the biodiversity preserve deeply concerned by international society. For its important position, Wuliangsuhai is the unique carrying and drainage way to the Hetao irrigation area. The major recharge water sources of Wuliangsuhai wetland are farmland drainage water containing lots of nitrogen and phosphorus, industrial waste water from paper mill and domestic sewage. On the basis of Landsat TM or ETM data of 19 years from 1986 to 2004 and the four seasons satellite data in 2001, integrating with historical materials of Wuliangsuhai and in- situ water quality monitoring data from 2002 to 2004, the impacts of human activities on the wetland water environment were analyzed. The results showed the increase of artificial reeds area and dense water weed area, the deterioration of water environment, the rise of lake eutrophication, and the reduction or extinction of aquatic resources. In evidence, Wuliangsuhai wetland has been confronted with serious threat. Simultaneously, the deteriorations of wetland environment also influenced the normal life and production of local residents. Since 2003, Wuliangsuhai fishery raised money from various channels so as to infuse fresh water in the farmland fallow periods, so far, the wetland environment has become better in some degree. However, it is difficult to resume the wetland function to the unpolluted state. So it can be concluded that the approach of treatment after pollution is not in accord with natural law, and the wetland resources could not be developed sustainablely until that time when people is harmonious with wetland environment and use the wetland resources efficiently in the range of water environment carrying capacity.