基于分配指数的渤海TN总量分配研究

Load Allocation of Total Nitrogen around Bohai Sea Based on Allocation Index

以控制渤海富营养化、减少TN排放量为目的,对渤海TN总量分配进行了研究.综合考虑污染物总量分配的公平性和效率,采用环境容量、水资源量、人口、耕地面积、GDP和现状排放量6个因子建立了渤海污染物总量分配指数,构建了基于线性响应场的污染物总量分配模型.考虑到权重系数的影响,分别按全指标、强调水资源利用和强调非点源3类,构建了7种权重系数方案（F11、F12、F13、F14、F21、F31、F32）.结果表明,渤海2010年TN入海量（16.4×10^4t/a）是其环境容量（4.7×10^4t/a）的3.5倍,同时受污染源位置和分配公平性的影响,接近或超过一半以上的环境容量实际上并不能被充分利用.采用总体削减率和削减率≥95%的污染源所占比例2个指标,对7种权重方案下的总量分配结果进行了比较.方案中凡是过分强调单项因子（如环境容量、水资源量、耕地面积等）的TN分配结果均具有明显的不足,只有F13方案兼顾了公平和效率.综合考虑TN总体削减率和削减率≥95%的污染源所占比例2个指标,建议方案F13为推荐方案,其TN总体削减率为85%,其中前10位的污染源削减量之和可占总削减量的79%.

To control eutrophication in the Bohai Sea with consideration of equity and efficiency,a total pollutant load allocation model was built based on the linear response field with a total load allocation index（ TLAI） constructed with six factors： environmental capacity,water resources,population,agriculture area,GDP and present discharge load. To evaluate the effects of the factors in the TLAI on the allocation results,seven weight coefficient scenarios（ F11,F12,F13,F14,F21,F31,F32） were put forward in three categories： complete factors,emphasis on the water resources and emphasis on the non-point sources. The result showed that the amount of TN effluent discharge load（ 16. 4 × 10^4t/a） was 3. 5 times higher than the environmental capacity（ 4. 7 × 10^4t/a） of the Bohai Sea. However,more than 50% of the environmental capacity could not be allocated due to the locations of the pollution sources and the principle of equity. The allocation results were compared by two indices： the total reduction rate and ratio of the pollution sources with reduction rates equal or greater than 95%. The allocation results of the scenarios,which only emphasized certain factors such as environmental capacity,water resources and farmland,were obviously infeasible. Both fairness and efficiency were considered in the scenario F13. Considering the total reduction rate and the ratio of pollution sources with more than 95% cut rates,the scenario F13 was more preferred than others. Based on the scenario,the reduction rate of total nitrogen was 85%,and the 10 biggest reduction pollution sources contributed about 79% of the total reduction amount.