太湖流域水质改善的政策影响因素分析

The policy determinants of the water quality improvement of Tai Lake Catchment

从江苏省太湖流域的水污染防治政策和生态补偿政策中提取水环境政策的影响因素,运用相关性分析方法分析政策、气候和水质之间的关系,并运用逐步回归分析方法分析政策、气候和水质之间的因果关系。实证分析发现:(1)政策对水质的影响差异显著。工业污染源防治政策对Ⅰ～Ⅲ类水质占比、Ⅳ类水质占比和Ⅴ类水质占比影响显著,生态补偿政策对Ⅳ类水质占比、劣Ⅴ类水质占比和水质总分影响显著,农业污染源防治政策和生活污染源防治政策对水质的影响不显著。(2)气温和降水量对水质的影响差异显著。气温对Ⅰ～Ⅲ类水质占比、Ⅳ类水质占比、Ⅴ类水质占比、劣Ⅴ类水质占比和水质总分的影响均不显著;降水量在99%的水平上显著正向影响Ⅴ类水质占比。据此,提出推进工业污染源防治、完善水污染防治的生态补偿、发展城市清洁和绿色农业等对策,以期进一步改善太湖流域水质。

The water policy variables, derived from the Tai Lake Catchment water pollution control and treatment policy and the ecological policy, were analyzed with climate and water quality variables through correlation analysis and stepwise regression analysis. The empirical study shows that the impacts of policy variables are significantly different. Industrial pollutant control and treatment policy significantly influences the percentages of Ⅰ~Ⅲ,Ⅳ and Ⅴ typed water. Ecological policy significantly influences the percentages of Ⅳ, below Ⅴ typed water and the total score of water quality. Living and agricultural pollutant control and treatment policies are insignificant to water quality. The impacts of temperature and rainfall are significantly different. Temperature has no remarkable impact on water quality variables of Ⅰ~Ⅲ,Ⅳ,Ⅴ and below Ⅴ typed water, while rainfall positively influences the percentage of Ⅴ typed water at the significance of 99%. Based on these findings, the paper suggests that the government needs to strengthen industrial pollutant control and treatment policy, improve ecological policy, guarantee city street cleanness and develop rural green agriculture in order to further improve water quality in Tai Lake Catchment.