Dynamic monitoring on soil and water losses in non-point source pollution based on USLE

Based on the results of Nanjing non-point source pollution of soil erosion and non-point source pollution quantitative monitoring research during 2001—2010 with USLE,the dynamic changes of non-point pollution caused by soil and water losses in Jiangning region,Nanjing Municipality were analyzed. The results showed that the pollution degree of total nitrogen and total phosphorus in non-point pollution was moderate,the pollution degree of ammonia and nitrogen was light, and the available phosphorus was slight non-point pollution in Jiangning. Comparing the average value between during the decade( 2001—2010) and during the four-year data( 1997—2000) of non-point pollution,the total area and amount of pollution which higher than the micro-pollution were significantly reduced,the area reduction of ammonia nitrogen,total nitrogen and available phosphorus was 11%- 24%,and the amount reduction of pollution was 21%- 32%. Among those four types of pollutants,lightly polluted area accounted for the highest proportion of total polluted area( higher than slightly,the same as below),and moderate pollution ranked second. The area of degrees of strength,pole-strength and intense pollution were similar to each other. Additionally,the proportion in amount of intense pollution was very serious,especially the proportion of the total nitrogen pollution reached 37. 4%.