IRRIGATION WATER REQUIREMENTS IN THE TROPICAL BASIN USING CROPWAT 8.0 MODEL: A CASE STUDY OF THE BA RIVER BASIN, VIETNAM

In the context of climate change and the current scarcity of water resources, assessing and forecasting irrigation water requirements are crucial for water resource management in tropical river basins. This research applied the CROPWAT 8.0 model together with ArcGIS software and CMhyd model to determine the current irrigation water requirement for crops in four sub-basins in the Ba River basin and projected it until 2100 under the scenarios of the CMIP6 model. Under the impact of climate change, the irrigation water requirement tends to increase, especially during the dry months in sub-basin 4 in the lower Ba River basin. Rice is the crop with the highest water requirement among all four sub-basins. This presents a significant challenge for the local managers. The results of this research can serve as a basis for planning irrigation strategies that align with the characteristics of crops, natural conditions, socio-economic factors, and adaptation to climate change. Additionally, this research can be used as a reference to support decision-makers in the rational management and use of water resources in tropical basins, select appropriate irrigation methods for each type of crop, and consider economic calculations in national planning to determine an effective crop structure for each river basin.