Cumulative Environmental Effects of Hydropower Stations Based on the Water Footprint Method—Yalong River Basin, China

Yu Yu,Jia Jia,Xu Xu,Wang Wang,Ma Ma,Dai Dai,Wu Wu

doi:10.3390/su11215958

Abstract

The construction of hydropower stations is not without controversy as they have a certain degree of impact on the ecological environment. Moreover, the water footprint and its cumulative effects on the environment (The relationship between the degree of hydropower development and utilization in the basin and the environment) of the development and utilization of cascade hydropower stations are incompletely understood. In this paper, we calculate the evaporated water footprint (EWF, water evaporated from reservoirs) and the product water footprint of hydropower stations (PWF, water consumption per unit of electricity production), and the blue water scarcity (BWS, the ratio of the total blue water footprint to blue water availability) based on data from 19 selected hydropower stations in the Yalong River Basin, China. Results show that: (a) the EWFs in established, ongoing, proposed, and planning phases of 19 hydropower stations are 243, 123, 59, and 42 Mm3, respectively; (b) the PWF of 19 hydropower stations varies between 0.01 and 4.49 m3GJ−1, and the average PWF is 1.20 m3GJ−1. These values are quite small when compared with hydropower stations in other basins in the world, and the difference in PWF among different hydropower stations is mainly derived from energy efficiency factor; (c) all the BWS in the Yalong River Basin are below 100% (low blue water scarcity), in which the total blue water footprint is less than 20% of the natural flow, and environmental flow requirements are met. From the perspective of the water footprint method, the cumulative environmental effects of hydropower development and utilization in the Yalong River Basin will not affect the local environmental flow requirements.

Highlights

As a clean and renewable energy source, hydropower meets the growing energy needs of mankind while mitigating global warming trends [1]
In the situation including evaporated water footprint (EWF), we further considered the impact of hydropower station construction on environmental flow requirements in different phases and evaluated the cumulative environmental effects of hydropower stations (The relationship between the degree of hydropower development and utilization in the basin and the environment) in the basin
We took the Yalong River Basin as the research object, considered the four phases of hydropower development in the basin, calculated the evaporated water footprint (EWF), product water footprint (PWF), and the blue water scarcity (BWS), analyzed its influencing factors, and evaluated the cumulative environmental effects of hydropower stations based on the water footprint method

Summary

Introduction

As a clean and renewable energy source, hydropower meets the growing energy needs of mankind while mitigating global warming trends [1]. Hydropower continues to grow worldwide, especially in developing countries, such as China [2]. Large-scale hydropower development and construction has brought controversies [3,4,5,6,7], such as the effects on the water environment and the changes to the river hydrological, including runoff, flood peak flow, water temperature [8]; effects on the ecological environment, such as migratory fish breeding [9], environmental flow [10], and ecological compensation [11,12,13]; effects on the social environment, such as immigration issues and land occupation issues [14]. The traditional water resource index “water intake” can no longer truly measure the water consumption of hydropower stations and their positive and negative impacts on the environment, ecology, and society. How to objectively measure the comprehensive performance of cascade hydropower development is a difficult problem [17]

Methods

Results

Conclusion