Forecasting and Assessing Water Demand and Rice Production in An Giang Province in 2024 by Using the CROPWAT and ORYZA Models†

Abstract

In early 2024, the Mekong Delta in Vietnam faced significant saltwater intrusion, exceeding average levels. Between February and March, the region experienced three periods of increased saltwater intrusion, primarily driven by the El Niño phenomenon, which resulted in a striking lack of rainfall (60%–95% below normal levels). Extended sunny days led to considerable evaporation from fields, canals, rivers, and lakes. Concurrently, reduced upstream water flow into the Delta and heightened spring tide levels pushed saltwater deeper into rice fields, severely impacting local livelihoods and agriculture. To address this issue, the study aims to predict evapotranspiration and water demand using the CROPWAT 8.0 model in combination with simulating the growth and development of rice crops in An Giang province by utilizing the ORYZA model. This research will focus on the three main rice growing seasons: Winter–Spring, Summer-Autumn, and Autumn-Winter, utilizing a rice variety with a growth duration of 95–100 days. Forecasts for 2024 will rely on drought data from 2019, projecting continuous high temperatures (0.5 °C above 2019 levels) and no rainfall from January to May in 2024. It can be seen that agricultural activities in 2024, particularly during the Summer-Autumn season, could face severe consequences. © 2025 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC.