SCIENTIA GEOGRAPHICA SINICA ›› 2004, Vol. 24 ›› Issue (2): 227-231.doi: 10.13249/j.cnki.sgs.2004.02.227

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Loss of Non-point Source Pollutants from Shixia Small Watershed, Miyun Reservoir, Beijing

WANG Xiao-Yan1, WANG Xiao-Feng1, WANG Qing-Ping1, Wang Zhen-Gang1, CAI Xin-Guang2   

  1. 1. College of Resource, Environment and Tourism, Capital Normal University, Beijing 100037;
    2. Soil Conservation Station of Miyun County, Beijing 101500
  • Received:2003-04-20 Revised:2003-09-10 Online:2004-03-20 Published:2004-03-20

Abstract: Nitrogen and phosphorus, coming mainly from non-point sources (NPS), are major nutrients to cause eutrophication to degrade water quality of Miyun Reservoir, and the only source of surface drinking water in Beijing, China. Based on the land use and geographical condition, the research area is classified into different types of non-point source areas as follows: agricultural land, forestland, orchard, garigue and village. Several runoff units of various land use areas are selected to monitor rainfall, runoff and water quality synchronously for nutrient loss from runoff and sediment at various land use areas. On the basis of geomorphic and land use, this small watershed is divided into several plots. Using USLE equation and SCS runoff curve, soil erosion mount and runoff of each plot are calculated. Considering the actual concentration of nutrient, loading of nutrient of surface runoff and sediment are estimated. The results show that TP, TN concentrations of diffuse samples from villages and livestock units are nearly 10 times of that in other land use areas. High nutrient loads are associated with village land use, which has improper livestock breeding. These areas should be treated as critical areas of non-point source pollution. Different land use influences intensively the loss of pollutants, especially slope tilling in agricultural land. The amount of nutrient loss from per agricultural land and orchard is the highest, then is that from garigue. Nutrient is enriched in sediment. Phosphorus is migrated with sediment, while the dissoluble form in runoff is very little. Being carrier of loss nutrients, the fine particles are thought to be the controlling focus.

CLC Number: 

  • X144