Temporal and spatial variation and driving factors of water consumption in the middle Heihe river basin before and after the implementation of the"97 water diversion scheme"

Abstract

Irrational allocation of irrigation water resources aggravates water shortages, affecting the sustainable development of agriculture, especially in arid regions. The expansion of the cultivated area in the middle Heihe river basin (HRB) will not necessarily increase the water consumption, despite the increase in the water-saving irrigation area. In this study, the temporal and spatial distribution, and the driving factors related to water consumption, including evapotranspiration (ET), transpiration (T), evapotranspiration ratio (T/ET), and precipitation deficit (ET-P), were investigated in the middle HRB using linear trend, piecewise fitting, and multiple linear regression method. The results show that the "97 WDS" has prominent impacts on the temporal and spatial trends and the driving factors in ET and T in the middle HRB. Water consumption does not necessarily increase under the centralized water allocation with improved irrigation efficiency and increased cultivated area. The result provides new evidence for increasing T/ET to decrease water consumption in response to the expanding cultivated area, while helping decision-makers to reduce water consumption in the middle HRB, and evaluate “97 WDS”.