A regulation-allocation coupling approach for agricultural water resources management based on water quantity orientation

In water-scarce areas with low grain yields, people have to expand the farmland scale to gain more food. Rapid expansion of agricultural scale may lead to a higher risk of re-abandonment of wasteland due to waterless irrigation in water-deficient areas. Against this background, this study proposed a water resources regulation-allocation coupling model. The ‘regulation’ is to control the water consumption of agriculture and regulate the utilized scale with water resources as the main constraint; the ‘allocation’ is to optimize the water resources allocation among crops and arrange the crop planting system according to the water quota for different crops and the economic, social and ecological benefits brought by crops, so as to control the water resources among crops. Afterwards, taking an agro-pastoral ecotone in Northwest China as the study case, schemes of feasible agricultural scale and planting structure suitable for local conditions were obtained. Lastly, the matching patterns of land and water resources were raised gradually from ‘poor’ into ‘good’ degree from 2015 to 2030. This study is expected to provide a reference for controlling the ordered and balanced development of land and water resources of agriculture as well as effectively improving the sustainable development ability in water-deficient areas