Agricultural non-point source pollution in Ningxia irrigation district and preliminary study of load estimation methods.

摘要: 【Objective】 This study was to establish the load estimation method of nitrogen and phosphorus loss from agriculture which suitable for irrigation district,in order simply effectively calculate agricultural non-point source pollution in district.【Method】The Ningxia district were assessed by Johnes export coefficient method.The traditional had been improved accordance with characteristics area,in factor on impact output added.【Result】 The results showed that TN(total N) 0.9556 TP(total P) 0.8776 2006;according model,TN rate 20 296.29 t TP 1 092.02 2006,while according 19 395.33 958.30 2006.Compared model,the relative error TN model reduced 5%,and 13%.【Conclusion】 It is concluded predicted result more approximately actual area than model,that say applicable district.