The agricultural non-point source pollution has become the most important factor of water pollution.The one-standard pollution load method of analysis in 17 towns along Erhai showed that Xizhou's rural life pollution was the head,and Yousuo's livestock manure and chemical fertilizer were the largest sources of pollution load.Cluster analysis results showed that the average of one-standard pollation load of the divided four types was 293.43,511.96,865.59 and 1104.75 m3,respectively,indicating that the relative differences of the agricultural n...