The Load Research and Comprehensive Evaluation on the Agricultural Non-Point Source Pollution in Nantong
|School||Nanjing Agricultural College|
|Keywords||Agriculture Non-Point Source Pollution’s Load Equivalent Standard Discharged GIS SPSS Clustering Analysis Prevention Measures|
Agricultural non-point source pollution (ANPSP) is a universal environmental problem nowdays. It directly restricts the sustainable development of society and economy in the world. Recently, along with the large-scale development of agriculture in every area agricultural non-point source pollution problems become extremely serious. The knowledge of the condition and characteristic of the non-point source pollution indifferent area was very important both in theoretical and actual sense to control agricultural non-point source pollution and protect our ecological environment for realizing the harmonized development of resource, environment and agriculture in China.This paper studied the Nantong area, the annual load of agricultural non-point source pollution is calculated under the condition of existing data by the investigation analysis of pollutant caused by all kinds of pollution sources, equivalent standard discharged and equivalent standard pollution index were adopted to synthesize analysis and evaluate various sorts of pollution sources and pollutant simultaneous. Use Arcmap in GIS to divide district and advance the corresponding control measures to agricultural non-point source pollution.This paper studied the agricultural non-point source pollution which included the domestic living pollution, animals’ feces pollution, fish breeding pond pollution and chemical fertilizer pollution. A integrated investigation and analysis for non-point source pollution was conducted in Nantong urban district and six countries. The results indicated that:1.Loading rate of all kinds of agricultural non-point source pollution to water was animals’ feces 73.18%,domestic living pollution 17.42%, fish breeding pond3.50%, chemical fertilizer5.90%; the equivalent standard pollution loading rate was animals’feces 37.19%, domestic living pollution 23.64%, fish breeding pond 27.07%, chemical fertilizer 12.09%. 2.The losed amount of CODcr、TN and TP caused by agricultural non-point source pollution in 2009 was 284634.61、47787.50t and 13488.69t respectively, and the percent was 82.29%,13.81% and 3.90% respectively. Converted to the equivalent standard amount was 14231.73 m3、47787.50 m3 and 67443.46 m3, and the equivalent standard pollution loading rate was 10.99%、36.91% and 52.09% respectively, which indicated that the water was polluted seriously by TP, next was TN and the last was CODcr.3.From the regions, total equivalent standard discharged in Rudong was the highest, reaching to 26441.26m3, contamination rate index was23.28%; the second was Rugao, reaching to 22635.62 m3, contamination rate index was 19.93%. govern district was the lowest, only was 3187.47m3, contamination rate index was 2.81%.the other’s pollutant situation was the same basically. All kinds of areas, pollutant severely degree was closely relative to people density’s high or low, animals, raising amount, water productions, raising amount and chemical fertilizers using amount in certain degree.4.From the diffuse concentration, Haian’s pollution diffuse concentration was much higher than other areas, reaching to 251.13 mg/1, because that agriculture, fishing and animal husbandry was all very developed, and a water resource is pretty small. The second was Rugao, reaching to 229.22 mg/1; all other areas pollution diffuse concentration was about the same; the lowest was govern area, only was 11.31 mg/l. Average pollution diffuse concentration of the whole area was 135.12 mg/l.5.Synthesized evaluation’s result by using SPSS based blurred equivalent matrix to pollution indicated that we can divide the whole Nantong area into three types:the first type was domestic living pollution, mainly in govern area pollution’s equivalent standard pollution loading reached to 39.77%.It was closely relative to much people and highllinglevel. The second was fish breeding pond pollution, mainly in Haimen and Qidong, pollution’s equivalent standard pollution loading reached to 30.72% and 32.69%.It was closely relative to large area’s raising. The third was animals’ feces pollution mainly in Tongzhou, Haian, Rudong and Rugao, pollution’s equivalent standard pollution loading separately reached to 32.02%,57.74%,38.48% and 45.25%. It was closely relative to large area’s cultivated farmlands.6. In differentiated pollution type, on the basis of the whole level of pollution in Nantong divides, the results showed that: from CODcr perspective, the whole Nantong area are I level, not a threat to the environment; Judging from TN Rudong, Haimen, of the TN pollution and Qidong reach toⅡlevel, achieve a slight threat for environment, Haian, Rugao, level of Tongzhou city and Nantong of environmental pollution already TN, achieve a threat, reach toⅢlevel; Judging from the TP, Nantong area to the local environment pollution has TP pose a serious threat, reach toⅣlevel.In the knowledge of the various agricultural non-point pollution consequences, in view of the different types of pollution and the pollutants, and proposed a comprehensive management control countermeasures. Suggestions in accordance with law, at all levels of the government decision-making, focusing on the producing pollution’s object, science and technology as the support, strengthen rural sewage management, reasonable layout the scale and structure of animal husbandry, reduce fishponds pollution, strictly control the intensive use of agricultural chemicals, to ensure economic, social and ecological environment coordinated development.