An Environmental Flow Framework for Riverine Macroinvertebrates During Dry and Wet Seasons Through Non-linear Ecological Modeling

Qingyi Luo,Ming-Chih Chiu,Lu Tan,Qinghua Cai

doi:10.3389/fevo.2021.734716

Abstract

A suitable environmental flow is critical for the functional maintenance of riverine ecosystems. Hydropower plants alter the flow regime by decreasing or even drying up the streamflow downstream of the dams, thereby affecting ecosystem sustainability. In this study, we aimed to develop a robust environmental flow framework that can provide scientific evidence for sustainable water resource management. Using ecological niche modeling based on non-linear responses of species to habitat factors, we assessed the environmental flow in the Xiangxi River Basin of Central China during dry and wet seasons from a multi-year perspective. The most abundant macroinvertebrate taxon (i.e.,Baetis) was selected for model testing. The results showed seasonal differences in the minimum ecological water requirements and optimal environmental flow. These two hydrological metrics were higher during the wet season than during the dry season. During the dry season, the minimum ecological water requirement ofBaetiswas 1.3 m3·s−1, and the optimal environmental flow was 1.6 m3·s−1. During the wet season, the minimum ecological water requirement ofBaetiswas 2.5 m3·s−1, and the optimal environmental flow was 2.6 m3·s−1. This study provides a theoretical basis for the robust management of water resources in river basins.

Highlights

River ecosystems have an enormous capacity to provide food and shelter for aquatic species and offer a wide range of ecosystem services that directly affect human well-being (Kuriqi et al, 2021)
The construction of small hydropower plants has a small impact on the chemical factors, but it has a large impact on physical factors such as the flow velocity and water depth of the stream (Wang et al, 2013)
The habitat suitability during the dry and wet seasons changed with the same trend under the influence of water depth

Summary

Introduction

River ecosystems have an enormous capacity to provide food and shelter for aquatic species and offer a wide range of ecosystem services that directly affect human well-being (Kuriqi et al, 2021). Environmental Flow Framework for Macroinvertebrates gap among regions, the construction of hydropower plants and other water conservancy projects in mountain streams has undoubtedly solved the huge problem of economic development (Pang et al, 2015; Wang, 2019). In China, the construction of small hydropower plants reduced the similarity of macroinvertebrate communities in different river sections; the reservoir area is the region where the impact is the largest (Zhao et al, 2015). Suitable environmental flow can provide a technical route for mitigating the damage caused by hydropower plants in river and stream ecosystems (Alsterberg et al, 2017; Hong et al, 2018)

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