Adaptive Water Resources Management In Arid Inland River Basins Under A Background Of Climate Change

Dual impacts from climate change and human activities have led to variation on regional hydrology,with profound influences on water resources formation and distribution,and also the effectiveness on land surface ecology under high-level exploitation of the water.The Shiyang River Basin,located in northwestern China,a representative example in China's inland river basins for its spatially differential hydro-geomorphology and geographic-ecological characteristics.Our study focuses on the three diverse regions from upper mountainous to lower plain in the basin,considering the distinction between oasis and desert in the plain area,for comparative analysis.Contents in our study include variation of regional hydrometeorology and land use/cover(LUC),along with the variability of the mountainous discharges and dynamics of the underground system in plain areas under regulations of irrigation.Based on the above,basin hydrological variability,along with its water-ecological effectiveness,was comprehensively discussed for adaptive water resources management in the arid water-scarce region of China's inland river basins.Statistics resulted in an overall increase in regional air temperature,precipitation and the mountainous discharges,during the period from 1981 to 2010.Simultaneously,the potential evapotranspiration(ET0)and the actual evapotranspiration(AET)in the three diverse regions also showed increasing trends.Analysis revealed that three climatic factors including air temperature,relative humidity and net solar radiation dominated contributions of ET0's increase,especially the uprising of air temperature and net solar radiation in the past several decades.The arid level presented remission to some extent with non-significant trend.The LUC's classification across the basin resulted in a satisfactory precision.Vegetation dynamics was found strengthened from 2001 to 2015.LUC area increase occurred in forest and grassland in upper mountains,arable land in middle oasis and transition zones in the middle and lower plains,while that of arable land in lower oasis and desert in middle and lower plains shrunk.Although the strengthened vegetation dynamics led to increase of regional AET,the incremental precipitation made an offset,the mountainous discharge presented increased during the time period from 1981 to 2015.The increased of mountainous discharges could not match the huge deficit to AET requirement in middle and lower oasis,abstraction of groundwater was also vital components of the gross water utilization.Over abstraction made groundwater level declined continuously,although the land surface ecology showed greener,an ecological effectiveness of the increased precipitation in the area.Primarily quantitative analysis for groundwater level recovery revealed that adaptive management in water utilization would be necessary in the basin.Application of water saving technologies,along with moderate shrinkage of arable land are suitable for the Wuwei oasis,while that for the Minqin oasis might be emphasized with higher level,with complete implementation of water saving approaches and more reduction of cultivation.As an industry-dominated area in the basin,the Jinchang oasis also faces to severe water supply situation and a declined groundwater system.Irrigation scale should be controlled along with the complete application of new watering technologies.Additionally,the promotion of industrial water efficiency is another one that should be emphasized in the area.