Spatial Analysis and Pollution Evaluation about Water Environment Actuality of Rural Surface Water in Typical Regions of Jiangsu Province
|School||Nanjing Agricultural College|
|Keywords||Jiangsu Province Rural surface water environment Pollution assessment Spatial feature analysis Influence factors|
Surface water pollution of rural circumstance was a universal environmental problem in Jiangsu province. With the development of economy, the quality of water was getting worse and worse. Which directly restricted the sustainable development of society and economy. The level of economic development was unbalanced in different areas in Jiangsu province, and the feather of the pollution of regional water environment was diverse in different regions, so, the knowledge of the condition and feather of the surface water function area pollution of rural circumstance in each region was very important both in theory and realism to control surface water pollution of rural circumstance, improve the ecological environment and realizing the harmonized development of economy and environment.By sampling and analyzing the pollution of surface water function area about rural circumstance in typical regions of Jiangsu province, the article summarized the condition of the water circumstance, and analyzed the main pollution indexes of regional difference; it analyzed and evaluated the situation of the water pollution that in rural surface water function area in typical regions of Jiangsu province with single factor evaluating method and Nemerow index; it researched the spatial distribution and aggregating tendency of rural surface water environmental pollution on country scale using GIS and local space autocorrelation method; the paper also analyzed the influences of macroscopic impact factors which included society, nature, agriculture economy and so on using regression analysis. The results showed as follows:(1) Whole situation:The water environment quality of the rural surface water function area in Jiangsu province was not well and the rate of samples which did not reach III species was almost 50% in 2008.The rate of reaching standard of typical regions, the south Jiangsu province is the lowest among three regions,and the central Jiangsu province is lower than the north.(2) The results of regional difference analysis:One hand, the DO index showed significant difference between typical regions of southern Jiangsu and other areas of Jiangsu, which was both in spring and autumn. The other hand, the index of CODmn and NH3-H showed significant difference among different seasons in typical regions of southern Jiangsu, the index of DO also showed significant difference among different seasons in typical regions of center Jiangsu and northern Jiangsu.(3) Pollution evaluation:The single factor evaluating results showed that the quality of water environment in typical regions of north Jiangsu was better than typical regions of middle part and the pollution indexes in typical regions of south Jiangsu was over standard relatively serious. The index of NH3-H was the major pollution index in surface water of rural circumstance. From the comprehensive evaluation, as for the quality of water environment, the north Jiangsu and typical regions of middle part were well, and typical regions of the south Jiangsu was worse than others.(4) The changes in the spring and autumn period:Many indexes in the autumn have improvement trend than in the spring, the comprehensive evaluation of the rural surface water in autumn is better than that in spring.(5) Spatial autocorrelation:According to the spatial distribution of the main pollution indexes of surface water environment in Jiangsu province countryside, from spring to autumn, the index of CODmn showed obvious changer in the spatial distribution, in spring the pollution regions were always localize; and the space momentum of the CODmn index had little change, which formed a relatively stable and obvious space momentum area. The DO index showed obvious difference in regional spatial, in the south Jiangsu it was on the low side, while in northern Jiangsu it was relatively abundant; the change of the space momentum of the DO index was comparatively remarkable and the homoplasy was enhanced.(6) Influencing factors:In the principal component analysis of influencing factors about water environment pollution of rural surface water in Jiangsu, we can see that the discharge amount of industrial waste water, GDP, expenditure of environment protection are the main influencing factors. And the influence extent was increasing gradually.From stepwise regression analysis of influencing factors about water environment pollution of rural surface water in Jiangsu,we can see the main influencing factors of CODmn are population density、agricultural chemical fertilizer application in unit surface water resources、yield per unit area in inland aquaculture、population in unit surface water resources. Population density is the uppermost related factors. The main influencing factors of DO are GDP per unit area、inland aquacultural yield in unit surface water resources、population density、the total yield of meat by unit surface water resources which can load GDP per unit area is the uppermost related factors.(7) Control countermeasure: the author put forward the macroscopic countermeasures of the surface water environment pollution control and relevant suggestions based on every region: the south Jiangsu province can strengthen environmental protection devotion and the control of industrial pollution; the central Jiangsu province can strengthen the major area pollution treatment; the north Jiangsu province can strengthen the construction of agricultural pollution, of course, it is necessary to pay attention to the influence of industrial development.