基于环境基尼系数的控制单元水污染负荷分配优化研究

将基尼系数这一福利经济学概念引入松花江流域水污染物负荷分配过程,综合考虑水循环的社会-经济-资源-环境因素,从社会经济发展、科技进步水平、水污染治理水平和资源禀赋差异角度出发,遴选出人均GDP、重污染行业总产值比重、人均水污染物产生强度、工业水污染物去除率、生活水污染物去除率、单位国土面积水资源量、国控劣Ⅴ类断面占比7项指标,以COD及NH_3-N负荷为控制因子,辅以贡献系数这一表征外部不公平性参数,构建了以基尼系数为度量标准的流域水污染负荷优化分配模型,并据此制订了松花江流域33个控制单元基于公平性的水污染负荷分配方案。研究表明,2012年松花江流域基于7项指标的基尼系数值均大于0.4,超过了基尼系数合理警戒线,说明流域控制单元间COD及NH_3-N排放在社会经济和资源环境方面存在不公平现象,其中松花江干流和第二松花江流域是不公平性特征最为突出的两个流域。在Lingo模型优化分配得到的2020年流域各单元COD削减方案中,单元21的年削减量最大,为1.82万t/a,单元10的年均削减率最高,达8%;在相应NH_3-N削减方案中,单元21的年削减量及削减率均为最大,分别达到0.08万t/a及8%。

Application of total water pollutant load distribution in control-unit based on the environmental Gini coefficient

Gini coefficient,the concept of welfare economics,was introduced into the process of water pollutants load distribution in the Songhua River Basin.Synthetically considering the socio-economic-resource-environmental factors of water cycle,and from the perspective of difference in social and economic development,scientific and technological progress level,water pollution control level and resource endowment,this paper took COD and NH3-N load as control factor,and then selected index system consisting of per capita GDP,industrial output value of key industries,the per capita water pollutants strength,industrial wastewater pollutant removal efficiency,urban wastewater removal rate,the water resource quantity in unit area and the percentage of monitoring section which was worse than V grade and used contribution coefficient as a parameter that characterized external unfairness in building up a water waste load distribution model based on Gini coefficient and further made a water waste load distribution scheme in the 33 control-units of Songhua River basin based on the equity principle.The optimized model aiming at minimal sum value of each Gini coefficient was built by setting reasonable constraint conditions and computing optimized value of Gini coefficient and the amount of pollutant reduction in the 33 control-units was calculated finally.According to the research,the Gini coefficients based on the 7-index in the year of 2012 exceeded 0.4,which was the level of international red warning line.This result showed that the distributions of COD and NH3-N emissions were extremely uneven especially in the Songhua River mainstream and the Second Songhua River basin.In the optimized allocation of COD reduction program by the Lingo model in every river basin unit in 2020,the control-unit 21 had the largest reducing quantity of COD with the number of 18.2 thousand tons per year.And the largest decrease rate was control-unit 10 with the number of 8％,while the corresponding two values in the reduction plan of NH3-N were 800 tons per year and 8％ in the contr 21.