Multi-objective optimal allocation of agricultural water and land resources in the Heihe River Basin: Coupling of climate and land use change

Abstract

As important factors affecting agricultural activities, climate change and land use change are bound to affect agricultural production. Therefore, it is necessary to predict possible changes in these factors in the future and to ensure the safety of agricultural production through scientific agricultural planning. This study uses the CMIP6 and FLUS models to forecast climate change and land use change in the future. Building on this, a multi-objective planning model for agriculture is constructed to optimize the allocation of land and water resources in the middle reaches of the Heihe River. The Global Agro-Ecological Zones (GAEZ) model is used to simulate crop production potential. The results indicates that the area of wheat, corn, and vegetables are not expected to undergo significant changes. Corn is projected to remain the primary crop. However, crops spatial distribution will be changed, with crop planting areas shifting towards Gaotai county (GT) when water resources are abundant. In order to control carbon emissions, the focus for corn should be on controlling the energy consumption of its processing, while for wheat and vegetables the focus should be on controlling inputs such as fertilizers and pesticides and on maximizing the efficiency of irrigation water use. The GAEZ simulation results indicate that crops may be more suitable for cultivation in flat area around the main stream of the Heihe River in the future, such as the central and northern parts of the Gaotai county, the eastern part of Linze county (LZ), and the western part of Ganzhou county (GZ). This study incorporates land use change into the agricultural planning framework and addresses the spatial allocation of crops, offering a new perspective for agricultural planning.