Value composition and quantitative calculation of economic value produced by river ecological base flow

The definition of the economic value (EV) produced by river ecological base flow (REBF) is the role of REBF in avoiding river shrink or dry up and maintaining ecosystem health and natural process of river. Scientific and accurate establishment of quantitative method for calculating the EV produced by REBF is helpful for human to understand the benefits of REBF protection directly and optimize the allocation of water resources by means of economics. Based on the characteristics of non-consumable and multi-values of REBF, we first identified its value composition by referring to the EV classification of river. Next, we established calculation methods for each sub-value using evaluation techniques of resources and environment economics. Finally, on the basis of calculation results of sub-values and the relationship of sub-values, we determined the maximum EV supported by each kind of water requirements of REBF, and summed up all independent parts to obtain the total EV. This method can remove repeated calculation in the process of assessing the EV produced by REBF. Our results indicated that the minimum total EV produced by REBF in the Shaanxi section of the Wei River was 4.54 billion yuan in 2017, which is close to previous studies. The new method developed here should provide a better theoretical support for quantitative research of the EV produced by REBF and scientific management of limited water resources coming from river.