基于能值拓展的流域生态外溢价值补偿研究——以渭河流域上游为例

Study of watershed spillover ecological value compensation based on expansion emergy:a case of Weihe Watershed Upstream

流域上、下游间环境保护成本和收益的区域错配问题严重影响我国流域整体发展的公平与效率,下游地区对上游地区给予适当的经济补偿已成为解决流域区域间经济发展失衡、实现流域水资源可持续发展的重要手段。文章首先构建基于能值拓展的流域生态外溢价值计量模型,从能量投入和能级转化的角度,以能值的形式反映流域客观存在的社会、经济和生态的功能服务价值,利用能值分析法测算流域生态系统服务能值与水足迹法确定流域自身消费的生态能值,通过比较流域生态系统服务能值和流域生态能值自身消费情况,判断流域的生态盈亏状态,并进一步利用能值-货币比率将生态外溢能值转化为生态外溢价值,得到相对客观和稳健的补偿标准。然后以渭河流域上游为例,测算得到2013年渭河流域上游的生态外溢能值为1.16×1022sej,可知流域上游在扣除自身消费的生态能值后还为流域下游提供生态服务,处于生态盈余的状态。为激励上游地区加大流域生态环境保护力度,同时也为实现区域发展的公平与效率和流域水资源的可持续发展,下游地区应对上游地区支付水资源生态环境补偿,根据能值-货币比率得到上游应获得16.31亿元的补偿金额,并根据水资源可利用量进一步分配,得到定西市和天水市应分别获得7.50亿元和8.81亿元的补偿金额。基于该研究结果,建议通过扩大对流域上游地区的转移支付、完善水资源市场构建、健全流域生态补偿立法等政策提高上游地方政府的生态保护努力水平,优化水资源配置,实现流域整体的可持续发展。

The regional mismatch of environmental protection costs and benefits between the watershed upstream and downstream seriously affected the fairness and efficiency of the watershed overall development. Giving upstream appropriate financial compensation by downstream became an important way to solve inter-basin regional economic development imbalance and to achieve watershed sustainable development. Firstly, the paper built watershed spillover ecological value model based on expansion emergy, used emergy to reflect the social, economic and ecological function service value of watershed from the perspective of energy investment and energy level conversion, estimated watershed ecosystem service emergy by using emergy analysis method, and calculated the eco-emergy of watershed＇ s own consumption by using water footprint method. It determined ecological profit and loss status by comparing watershed ecological system service emergy and emergy consumption itself, and transferred the spillover ecological emergy to spillover ecological value by further using the emergy-value ratio, thus obtaining a relatively objective and robust compensation standard. Then, taking Weihe watershed upstream as an example, it estimated that the spillover ecological emergy of Weihe watershed upstream was 1.16 ×10^22sej in 2013, and it showed that watershed upstream provided ecological services for watershed downstream after deducting the ecological emergy of its own consumption, which was in a state of ecological surplus. In order to encourage the upstream areas to make more environmental protection efforts, and to achieve the fairness and efficiency of regional development and sustainable development of watershed water resources, downstream areas should pay water ecological compensation to upstream areas, and upstream should receive compensation of 1. 631 billion yuan according to emergy-value ratio ; compensations were further distributed according to the amount of available water resources. Dingxi and Tianshui should receive compensation 750 million yuan and 881 million yuan. Based on the results, it suggested that raising ecological protection effort level of upstream governments, optimizing water resources allocation and achieving the sustainable development of the whole watershed should be realized through increasing transfer payments for upstream areas, perfecting water resource market construction and improving watershed ecological compensation legislation.