An Integrated Hydrological Model for the Restoration of Ecosystems in Arid Regions: Application in Zhangye Basin of the Middle Heihe River Basin, Northwest China

Abstract

River basins in or across arid regions have been facing intensified water scarcity and ecological problems, mainly due to the intense irrigated agriculture. Integrating the multiprocesses in hydrological cycle is quite necessary to make reasonable management strategies. In this paper, an integrated multiprocess hydrological model was proposed by coupling river water flow, groundwater flow, canal conveyance, and vadose water flow processes. It was applied to the Zhangye basin of middle Heihe River basin for searching management strategies to restore the ecosystems (i.e., ensure surface runoff into downstream and also recover local groundwater levels). The integrated model was calibrated and validated during 2005‐2007 and 2008‐2010, respectively. Simulation of groundwater levels (GWLs, 32 wells) and surface runoff both matched well with the observed values, with Nash and Sutcliffe model efficiency > 0.38 and R2 > 0.57. Then various scenarios were designed with considering five alternatives of different farmland area decrease and three alternatives of groundwater exploitation. Responses of surface runoff and GWLs were predicted for 20 years. Surface runoff change was compared with the water diversion curve, and GWL recovery was also discussed. Results revealed that ecosystems could not be restored with current agricultural area, even shutting down groundwater abstraction for irrigation. A decrease of about 30% of farmland area and using surface river water instead of pumping groundwater for irrigation could satisfy water diversion demand with only a slight GWL decline. Furthermore, the extra irrigation with diverted surface water during nongrowing season could further lead to the recovery of GWLs while without causing negative effects on surface runoff.

Soil moisture variations of wetland at different altitudes in desert regions, China

“…The development and utilization of water resources in arid regions of Northwest China are expounded from the levels and zones of river hydrology and ecosystem [11][12]. Heihe River Basin in Northwest China has the most extended history, the most profound depth and the most investment in the study of human development of water resources and its impact on local ecology in arid areas which suffers severe ecological problems [13][14][15].…”

Methodologies and Management Framework for Restoration of Wetland Hydrologic Connectivity: A Synthesis

“…The interaction between surface water and groundwater is an important part of the hydrological cycle in a basin (Lago et al 2010; Maassen and Dagmar 2010). Many human activities cause interstitial sedimentation or damage to surface–groundwater hydrological connections, affecting the ecological processes between the two (Wei et al 2011; Cheng et al 2014; Liu et al 2018).…”

“…It is widely recognized that successful wetland rehabilitation must include the restoration of vertical links of surface water and groundwater (Kasahara and Hill 2006; Boulton 2007). For the excessive extraction of groundwater, the groundwater irrigation amount per hectare of farmland should be calculated to more accurately calculated the lost amount of groundwater and improve irrigation efficiency (Liu et al 2018; Li and Ren 2019). An increase in the amount of water replenished in the wetland, in turn, increases the amount of groundwater recharge for the wetland (Fan et al 2012).…”

Introduction to the Water‐Soil‐Air‐Plant‐Human Nexus: Modeling and Observing Complex Land Surface Systems at River Basin Scale

“…To investigate the interactions between groundwater, soil freezing and thawing process, and human water use, a high‐resolution land model CAS‐LSM including groundwater lateral flow and human water regulation was developed and applied for the entire HRB (Xie et al, ). For the agricultural oasis in the midstream area of the HRB, an integrated model coupling river water, groundwater, vadose zone waterflow, and canal conveyance was developed, and based on scenario analysis and model prediction, how to reduce agricultural water use and restore the natural ecosystem was proposed (Liu, Xu, et al, ).…”