Modelling the Impact of Vegetation Change on Hydrological Processes in Bayin River Basin, Northwest China

Xin Jin,Yanxiang Jin,Jingya Zhai,Xufeng Mao,Di Fu

doi:10.3390/w13192787

Abstract

Vegetation change in arid areas may lead to the redistribution of regional water resources, which can intensify the competition between ecosystems and humans for water resources. This study aimed to accurately model the impact of vegetation change on hydrological processes in an arid endorheic river watershed undergoing revegetation, namely, the middle and lower reaches of the Bayin River basin, China. A LU-SWAT-MODFLOW model was developed by integrating dynamic hydrological response units with a coupled SWAT-MODFLOW model, which can reflect actual land cover changes in the basin. The LU-SWAT-MODFLOW model outperformed the original SWAT-MODFLOW model in simulating the impact of human activity as well as the leaf area index, evapotranspiration, and groundwater table depth. After regional revegetation, evapotranspiration and groundwater recharge in different sub-basins increased significantly. In addition, the direction and amount of surface-water–groundwater exchange changed considerably in areas where revegetation involved converting low-coverage grassland and bare land to forestland.

Highlights

Changes in vegetation and related management practices in arid areas may lead to the redistribution of regional water resources, which can intensify the competition between ecosystems and humans for water resources [1,4]
In this study, we developed a LU-SWAT-MODFLOW model by integrating a coupled SWAT-MODFLOW model with dynamic hydrological response unit (HRU), which can overcome the limitation of considering the vegetation change compared to the original HRUs for the middle and lower reaches of the Bayin River basin, a typical arid endorheic river, where there are frequent surface-water–groundwater interactions and evident vegetation changes
The results indicate that revegetation and rela irrigation not change the trend monthly

Summary

Introduction

Arid areas, which account for 40% of the world’s land area, are characterised by water shortages and uneven spatiotemporal distributions of water resources [3]. Changes in vegetation and related management practices (e.g., irrigation) in arid areas may lead to the redistribution of regional water resources, which can intensify the competition between ecosystems and humans for water resources [1,4]. In this context, the water demand and water consumption characteristics of vegetation change in arid areas are of particular concern [5,6]

Objectives

Methods

Results

Discussion

Conclusion