Water resources assessment in the Minqin Basin: an arid inland river basin under intensive irrigation in northwest China

Abstract

The Minqin Basin is at the lower reach of the Shiyang River of Gansu province in northwest China. Dramatic decline in groundwater level has resulted from over-abstraction of groundwater since the late 1950s to satisfy increasing irrigation and other demands. Severe water shortage led to environmental degradation. To better understand the spatial-temporal variation of groundwater levels and to evaluate the groundwater resources in the region, a three-dimensional regional groundwater flow model was built and calibrated under transient condition. The MODFLOW program was used and the research area was discretized as a square network with cell size of 400 9 400 m. The model showed that the aquifer was under destructive stress, with a groundwater resource deficit of 260 million cubic meters per year (Mm 3 /year) on average. Since the inflow of surface water from the upstream basin has declined to about 100-150 Mm 3 /year in recent decades, the irrigation return flow had become the main recharge and accounted for 60.6% of total recharge; meanwhile, abstraction by pumping wells took 99.2% from the total groundwater discharge.

Human settlement and changes in the distribution of river systems in the Minqin Basin over the past 2000 years in Northwest China

“…The Shiyang River Basin (SRB), located in the eastern part of the Hexi Corridor in Gansu Province, Northwest China, is an area that has experienced most severe water supply-demand conflicts in the country over the past 2000 years. The Minqin Basin is in the lower reach of the SRB, and over the recent centuries, the increasing human activities have brought many ecological problems such as declining groundwater level (Xiao et al 2007;Sun et al 2009;Zhang et al 2012;Chen and Feng 2013), the disappearing terminal lakes and the reducing vegetation (Xiao et al 2007;Feng et al 2011). As a microcosm of the arid areas in Northwest China, the Minqin Basin is an ideal place for studying the dynamic relationship between human activities and drainage patterns and environmental changes during the past 2000 years.…”

Comparative evaluation of crop water use efficiency, economic analysis and net household profit simulation in arid Northwest China

“…Rainfall is rare and the average precipitation is 110 mm per year, a majority of which comes from June to August. The annual mean evaporation of 2650 mm greatly exceeds the annual precipitation (Ma et al, 2008;Zhang et al, 2012). In order to offset the water deficit and maintain a high crop yield, irrigation is a critical constraint to agricultural production in this region.…”

Effects of ecological restoration‐induced land‐use change and improved management on grassland net primary productivity in the Shiyanghe River Basin, north‐west China

“…Adverse human activities, such as the overexploitation of surface water and ground water for irrigation, overgrazing and grassland‐to‐cropland conversion, caused large‐scale land degradation across the Shiyanghe River Basin (Zhang et al ., ). Shiyanghe River, located at the eastern Hexi corridor of north‐west China, is an ecologically vulnerable area.…”