A Developed Method of Water Pollution Control Based on Environmental Capacity and Environmental Flow in Luanhe River Basin

Xiaoxuan Li,Xiaolan Zhang,Chunhui Li,Yujun Yi,Xuan Wang,Qiang Liu

doi:10.3390/w14050730

Xiaoxuan Li, Xiaolan Zhang + Show 4 more

Open Access

https://doi.org/10.3390/w14050730

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Abstract

To solve increasingly serious water pollution problems, it is necessary to systematically manage water resources, water environment, and water ecology as elements of a watershed. Comprehensive watershed water pollution control should regard the basin as a whole, respect the natural laws of the river and lake system, and focus on the protection and restoration of its natural ecological environment so that the comprehensive ecological service functions of rivers and lakes can be fully realized. Based on the concepts of environmental capacity (EC) and environmental flow (EF), this study established watershed water pollution control scheme prediction and evaluation methods to explore the changes in the water environment and water ecology in the basin under different water pollution control schemes. The MIKE11 model was used to construct a hydrologic and water quality model of the study area, the one-dimensional water quality model was used to calculate the water environmental capacity, and the Tennant method was used to evaluate the environmental flow. In this study, the method was applied to the Luanhe River Basin of Chengde, Hebei Province, China. It simulated the concentration changes of four pollutants—namely, NH3-N, COD, TN, and TP—under eight different water pollution control schemes, and the responses of EC and EF were compared and analyzed. Some conclusions are as follows: (1) Reducing point source pollution has the most obvious effect on water pollution prevention, especially on NH3-N and COD, while reducing nonpoint source pollution is weaker and the effect of increasing upstream water is the weakest. (2) The increase in up-stream water inflow and reducing point source pollution can greatly increase the EC of NH3-N and COD. The EC of TN can be greatly increased by reducing point source pollution, and the EC of TP can be greatly increased by reducing nonpoint source pollution. (3) The increase in upstream water inflow can improve the EF level to a certain extent. This method can also be applied to other similar river basins, providing valuable suggestions for rationally formulating water environmental management strategies and for promoting the sustainable development of the ecological environment and social economy in the river basin.

Highlights

River has sufficient flow in July, which can meet the demand under different simulation scenarios and can provide a good habitat and growth environment for aquatic animals and plants
Based on the concepts of the environmental capacity (EC) and environmental flow (EF) and the MIKE11 model, a simulated evaluation method of the basin water pollution control scheme was established to explore the changes in the water environment and water ecology in the basin under different water pollution control schemes, and the method was applied to the Luanhe River Basin in Chengde, Hebei
Reducing point source pollution, reducing nonpoint source pollution, and increasing upstream water were selected to be combined into eight water pollution control schemes

Summary

Introduction

Water is the most important link between different geographical units and ecosystems in a watershed, and it is a carrier for the migration of soil, nutrients, pollutants, and species within the watershed [2]. People usually managed watersheds as a single element through a single government agency, which makes it difficult to solve the complex problems of mutual influence and interweaving between the watershed water, ecological environment, and social economy [4]. With the popularization of sustainable development, it is generally recognized that the effective way to solve the increasingly serious problems of overpopulation, natural resource shortages, and environmental degradation in the process of development is to carry out the systematic and comprehensive management scheme of natural resources, ecological environment, and social economy in the basin as a unit

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Conclusion