Modelling Changes in Water Consumption by Agricultural Crops Under Different Climate Change Scenarios

Abstract

Monitoring water consumption trends in the agricultural sector (as the largest consumer of available water resources), especially considering climate change effects, is one of the most essential requirements for long-term water resource planning. This study aims to evaluate the effects of climate change on agricultural crop water consumption in the Marun catchment, which is located in southwest Iran. For this purpose, temperature and precipitation climate scenarios were generated under representative concentration path (RCP) scenarios (RCP2.6, RCP4.5 and RCP8.5) from the fifth report of the International Panel on Climate Change (IPCC) for the future interval (2016–2040). Then, by gathering meteorological data in the region and using temperature and precipitation scenarios as inputs in the Cropwat model, the changes in the water required for the agricultural sector were calculated. The results of Cropwat show that the total water demand in the agricultural sector under the RCP2.6, RCP4.5 and RCP8.5 scenarios will increase by 38%, 39% and 40%, respectively, in the future period (2016–2040) compared with the baseline. Understanding the effects of temperature and precipitation changes on water and crop irrigation requirements is essential for policy-makers to develop more accurate and realistic long-term policies regarding water resources and agricultural product supplies, especially in climate change.