河道生态基流生态经济价值及其时间变化研究

Study on eco-economic value of river ecological base flow and its temporal variation

为了解决普遍采用单方水资源价值计算河道生态基流价值的缺陷,以及探索河道生态基流价值定量化计算新方法,采用水力学方法将河道生态基流从径流量中分离出来,并确定河道生态基流对应水面面积,进而采用当量因子法计算河道生态基流价值和并探索分析了河道生态基流价值的时间变化特征。以渭河干流宝鸡段为例进行研究,结果表明:渭河干流宝鸡段的丰水年、平水年以及枯水年的年平均河道生态基流量分别为5.82 m^(3)/s、3.59 m^(3)/s和2.76 m^(3)/s。近21 a来,该段河道生态基流价值在时间上总体呈下降趋势,该价值多年平均值为5.61亿元,单方河道生态基流价值为6.27元/m^(3),单方价值与价值总量变化趋势相反。河道生态基流价值年内变化具有明显的周期性,总体呈倒"V"字型,汛期河道生态基流价值比非汛期大,单方河道生态基流价值与之相反。通过相同区域以及相近区域的河道生态基流价值研究成果以及价值变化特征的对比分析,证明研究成果较为合理。该方法可为河道生态基流合理保障提供定量化依据。

In order to solve the defect that the eco-economic value of river ecological base flow is generally calculated by means of the value of water resources per square meter and explore a new method for the quantitative calculation of the value of river ecological base flow, the river ecological base flow is separated from runoff with the relevant hydraulics method and the water surface area corresponding to river ecological base flow is determined, and then the value of river ecological base flow is calculated with equivalent factor method, while the temporal changing characteristics of the value of river ecological base flow is analyzed as well. By taking Baoji Section of the main stream of Weihe River as the study case, a relevant study is made and the result shows that the annual mean river ecological base flows of the wet year, normal flow year and dry year of Baoji Section of the main stream of Weihe River are 5.82 m^(3)/s, 3.59 m^(3)/s and 2.76 m^(3)/s respectively, while the value of the ecological base flow of the river section is generally exhibits a decreasing trend, for which the long-time mean annual value is 561 million yuan with the value of the ecological base flow per square meter of 6.27 yuan/m^(3), thus the value per square meter is just opposite to the changing trend of the value. The annual variation of the value of river ecological base flow has an obvious periodicity and generally exhibits an inverted V type, while the value of river ecological base flow is larger in flood season if compare with that in the non-flood season, but the value of river ecological base flow per square meter is just in contrast. It is demonstrated through the comparative analyses of the results from the studies made on the same regions and the adjacent regions that this study result is more reasonable, and then the method can provide the relevant quantitative basis for the reasonable guarantee of river ecological base flow.