Research On Water Environment Effects Of Soil And Water Conservation

In our country non-point source pollution has become main pollution source of many water source areas, caused serious jeopardy to the people's life and health and economic and social sustainable development. Soil and water conservation measures are an important way to control non-point source contamination, protect water source quality and ensure drinking water security.For the paper ,we studied the mechanism of the water environmental effects of soil and water conservation and the quantitative analysies ,which were associated with the special items of the Ministry of Water Resources of the People's Republic of China "Water Resources and Water Environment Effects of Soil and Water Concervation".According to the major functions of soil and water conservation measures and the characteristics of water environment and non-point source pollution ,the concept of water environment effects of soil and water conservation was put forward.That is the role of soil and water conservation measures absorbing, filtering, moving and converting of some harmful substances, controlling non-point source pollution of watershed or regional, improving surface water and groundwater quality.According to the sources and causes of pollutants ,the types of non-point source pollution were divided into agriculture, soil erosion, rural life, urban runoff, precipitation and dustfalling.By the combination of representative investigation and collecting present research documentation, the mechanism of water environment effects of soil and water conservation was systematically opened out.The common mechanism is through their basic functions, the soil and water conservation measures could control sources system, meeting system and contaminant transport channels of non-point source pollution, reduce pollutants flux of pollutant source system and meeting system. The individual mechanism is the effects of soil and water conservation on fertilizers, pesticides and heavy metals transforming in the soil.By means of weighted average,water environment effects of soil and water conservation were quantitatively analyzed in Beijing city which had Severe water shortage in rocky mountain areas.Results showed that after soil and water conservation measures were taken,,total soil and water conservation measures in Beijing City reduced the loss amount of suface runoff 2754.12×10⁴t;soil loss amount 35.20×10⁴t;the TP loss amount of suface runoff 18.10t; the TN loss amount of suface runoff 60.70t; the COD_Mn loss amount of suface runoff 223.70t.In accordance with norm method, Water environment effects of soil and water conservation were quantitatively analyzed in Yan'an city which had serious soil erosion in loess areas.Results showed thatafter soil and water conservation measures were taken,the conservation amount of runoff N and P were 28.48t. 1.53 t respectively: the conservation amount of sediment N and P were 95.09t and 158.60t respectively.