区域用水环境经济综合效率及其影响因素——基于DEA和Malmquist指数模型

仅考虑经济效益而忽略环境损害的水资源利用效率指标不能全面反映区域用水的真实效果.本文基于DEA和Malmquist指数模型,提出区域用水环境经济综合效率(WEEE)概念及其评价方法,分析了2001~2012年河南省主要地市的WEEE及其影响因素.结果表明,研究时段内水资源利用保持了较高经济效率,但环境效率相对较差并由此拉低全省WEEE平均约2%;2012年WEEE未达到DEA有效的地市水资源投入平均冗余率约为18%,COD和NH₃-N平均超排率分别约为49%和49.2%,说明这些地市存在水资源利用低效和水污染物排放较高的问题.通过分析水资源利用的全要素生产率(TFP)发现,技术变化指数在研究时段内下降了2%,是抑制WEEE增长的最主要因素.为了在水资源利用过程中取得更好的环境和经济综合效益,河南省应加大对工农业节水和水污染防治的科技投入,并在严格控制用水总量的同时进一步加强水污染物的减排工作.

A study of water environment-economy integrated efficiency and its driving factors for regional water use based on a combination of DEA and Malmquist index

Because the relevant environmental damages were not incorporated into evaluating conventional water-use efficiency, this efficiency indicator was incapable of depicting the real comprehensive effects except economic outputs. The concept of environment-economy integrated efficiency for regional water use(WEEE) was raised along with its evaluation method based on a combination of DEA and Malmquist index. The WEEE of Henan province was then studied by using the data on water uses and related economic outputs and pollution discharges from 2001 to 2012. In contrast to a higher level economic efficiency, a lower level environmental efficiency had been witnessed for water uses of the province. To a large extent due to a poor environmental efficiency, the provincial WEEE was dragged down by about 2% if compared to the sole economic efficiency. Meanwhile, the cities with WEEEs of inefficient DEA in the province had exhibited the problems of low efficient water uses and excessive pollutant discharges. The averaged input redundancy rate of water resource reached 18% in 2012, and the extra emission rates of COD and NH₃-N were about 49% and 49.2% respectively. An analysis of variations of the total factor productivity(TFP) indicated that the technical change index was the most influential factor, resulting in an annually averaged decline of 2% in Henan's WEEE in the study period. Thus, it was recommended that more inputs need be made into technical innovations to realize water saving and water pollution control. The total volume control of water use should be enforced along with abatement of water pollutants.