Characteristics of Non—Point Source Pollution in the Watershed of Miyun Reservoir,Beijing,China

Characteristics of Non—Point Source Pollution in the Watershed of Miyun Reservoir,Beijing,China

王晓燕;贺伟;等

【期刊名称】《中国地球化学学报：英文版》 【年(卷),期】2002(021)001

【摘要】Nitrogen and phosphorus are the major nutrients to cause eutrophication to degrade water quality of the Miyun Reservoir,a very important drinking water source of Bijing,China,and they are mainly from non-point sources.The watershed in Miyun County was selected as the study region with a totoal area of 1400km2.Four typical monitoring catchments and two experimental units were used to monitor the precipitation,runoff,sediment yield and pollutant loading related to various land uses in the meantime.The results show that the total nutrient

loss

amounts

of

TN

and

TP

are

898.07t/a,and

40.70t/a,respectively,in which nutrients N and P carried by runoff are 91.3% and 77.3%,respectively.There is relatively heavier soil eroson in the northern mountain area whereas the main nutrient loss occurs near the northeast edge of the reservoir.Different land uses would influence the loss amounts of non-point source pollutants.The amount of nutrient loss from the agricultural land per unit is highest,that from forestry comes next that from grassland is lowest.However,due to the variability of land use areas,agricultural land contributes a lot to TP and forestry