洱海流域城镇化对农村生活污水排放量的影响

Impacts of Urbanization on Rural Domestic Sewage Emissions in Erhai Lake Basin

为揭示城镇化对流域内农村生活污水排放量的影响程度,以洱海流域为研究对象,采用综合指标评价法,选取城镇人口所占比例、农民年人均纯收入、农村水冲厕普及率及建成区面积4项指标,从人口、经济、社会生活方式、空间4个维度建立洱海流域城镇化综合评价体系,综合评价了流域城镇化水平,并采用相关分析法和多元回归分析法研究洱海流域城镇化4项指标对流域农村生活污水排放量的影响.结果表明:2006—2012年,洱海流域的城镇化水平不断提高,大理市城镇化综合水平领先于洱源县.大理市农村生活污水的排放量与城镇人口所占比例相关关系不明显,相关系数为0.246;与农民年人均纯收入、农村水冲厕普及率和建成区面积呈显著正相关,相关系数分别为0.951、0.980、0.969;洱源县农村生活污水的排放量与这4项指标的相关性较大理市明显,相关系数分别为0.754、0.973、0.998、0.975.4项指标对大理市农村生活污水排放量的影响权重为农村水冲厕普及率>农民年人均纯收入>建成区面积>城镇人口所占比例,对洱源县农村生活污水排放量的影响权重为农村水冲厕普及率>城镇人口所占比例>建成区面积>农民年人均纯收入.研究显示,在现有城镇化水平下,对洱海流域农村生活污水排放量最主要的影响因素为农村水冲厕的普及率,社会生活方式城镇化对洱海流域农村生活污水排量的影响最突出.

Analyzing the environmental impacts of urbanization is an important premise of environmental administration and pollution control. This research took Erhai Lake Basin as the research object,adopted a composite indicator assessment and selected four indicatorsproportion of urban population, rural per capita net income, penetration of rural flush toilets and built-up area-to establish a comprehensive assessment system for urbanization in Erhai Lake Basin in terms of four aspects： demographic urbanization,economic urbanization,social urbanization and spatial urbanization. The system comprehensively evaluated the urbanization level in the area and analyzed the relationships between the four indicators and rural domestic sewage discharge using correlation analysis and multiple regression analysis. The results indicated that the level of urbanization in Erhai Lake Basin improved in every aspect over the period of2006-2012,and also that Dali City is ahead of Eryuan County in terms of urbanization level. The rural domestic sewage discharge in Dali City was not significantly correlated with the proportion of urban population,with a correlation coefficient of 0. 246. It was highly positively correlated to rural per capita income,rural flush toilets penetration and built-up area,with correlation coefficients of 0. 951,0. 980 and0. 969,respectively. In Eryuan,correlations between rural sewage discharge and all four indicators were better than those in Dali,with correlation coefficients 0. 754,0. 973,0. 998 and 0. 975,respectively. The effective weight of the four indicators in Dali ranked as： rural penetration of flush toilets 〉rural per capita net income〉 built-up area 〉proportion of urban population. The effective weight of the four aspects of urbanization in Eryuan ranked as： rural penetration of flush toilets〉 proportion of urban population〉 built-up area 〉rural per capita net income. Studies have shown that,under the existing level of urbanization,the main factor influencing rural domestic sewage discharge in Erhai Lake Basin was penetration ofrural flush toilets,which means social life style urbanization is the main influencing aspect for rural sewage discharge.