Analysia On Relations Of Railfall Runoff And NonPoint Pollution Concentration And Loss Amount Of Chai River Basin

Rainfall runoff pollution is a kind of pollution phenomenon occurs with the happening of rainfall runoff, also known as non-point source pollution. experts and scholars in China have discussed the influence of rainfall - runoff pollution characteristics, influence factors and controlling approach from different angles and scales of different areas Runoff process causes N, P nutrient losses from the loss of farmland ecosystems, which directly leads to the degradation of soil quality. On the other hand, this will pollute containing water, which is the main manifestation of agricultural non-point pollution The surrounding of Chaihe reservoir is occupied by crop farming and agriculture assisted by breeding and industry. These activities increase environment problem. Farming USES such as pesticide and fertilizer and animal feces, the living garbage produced by human activities, flow into the reservoir with rainfall runoff and influence the water quality Non-point pollution load depends on rainfall condition, watershed methods of land use and the underlying features and its changes process are closely related to rainfall duration, sampling time and land use type. The above characteristics and conditions vary when the runoff and non-point load loss are different. Therefore, even in the same area runoff process line and concentration change process line is also different in different rainfall time. There is no common change ruleIn this thesis, catchment area of upstream of Chaihe reservoir was selected as the research object. The mechanism of non-point pollution was discussed and studied. National and international research development was analyzed. Detailed investigation was made from geographical position, meteorology condition, topography, geology, soil, plants, hydrology, rainfall over the years and social economy etc aspects. Comprehensive analysis was made on Chaihe reservoir water quality. Data of storm runoff, sediment, concentration of pollutant from Chaihepu hydrological station and surrounding rainfall runoff pollution characters were analyzed. Research on the relation between storm runoff quantity, main pollutant concentration and pollutant instant loss quantity was highlighted to expose the pattern of non-point pollution, from which the measurement was put forward. The purpose is to provide reference to the control of non-point source pollution of Chaihe basinThe results show: although agricultural non-point pollutant output involves many influencing factors, its relation to rainfall runoff has the obvious rule 1 In rainfall period, non-point pollutants concentration changes are the slightly different, but pollutants concentration change and rainfall runoff change are basically similar. In each sampling time, the change of the concentration peak and the rainfall runoff peak are almost the same. This means that there is close relationship between the two 2The rainfall conditions has the great influence on nitrogen and phosphorus loss in heavy rainfall runoff. The overall performance of nitrogen and phosphorus concentration showed that concentration of pollutant is higher in early period than in the late period, which has obvious scour effect. This is the basic features of storm runoff pollution emission process 3 In rainfall period, non-point pollutant's instantaneous change is quite same as the rainfall runoff change. Smaller in the earlier period with less rainfall, pollutants loss grew sharply to peak along with the increase of rainfall, runoff, reduced gradually after the peak After adopting a certain non-point pollution control and supervision and management measures, nonpoint source influence on water quality of the reservoir can be reduced...