Response of regional agricultural water use to the change of climate and plantation structure in the typical agricultural region of China

Climate is one of the main factors affecting agricultural water use. The variation of different climate factors will have a great impact on the balance of water supply, which will significantly aggravate the water-related threats to the sustainability of agricultural production. As a typical agricultural area of China, the Huang-Huai-Hai region is one of the major grain-producing areas. In order to evaluate the response of future agricultural water use to future uncertain changeable factors, this study assessed future agricultural water use with the coupling effect of climate change, irrigation efficiency and plantation structure change. The results showed that the temperature and precipitation both increased to different degrees under the two greenhouse gas emission and radiation forcing scenarios, which have great impacts on the crop water requirement (ETc) of main crops. Under RCP (Representative Concentration Pathways) 8.5, a 10% increase in the irrigation water utilization coefficient will reduce the regional irrigation water requirement by about 13 Gm(3), and the adjustment of plantation structure will reduce the irrigation water consumption by about 11 Gm(3). The quantitative analysis suggests that the improvement of the irrigation efficiency and the expansion of water-saving crop plantation areas in the future will moderate the adverse impact of climate change on agricultural water use. This study provides a reference for the management of agricultural water and the rational distribution of water resources under the future climate change.