Impact of climate change on irrigation water requirements for coffee plants in the fruit development stage: a case study of Dak Lak and Gia Lai provinces in the Central Highlands of Vietnam

This research study investigates the impact of climate change on the irrigation water requirements for coffee plants in the fruit development stage in Gia Lai and Dak Lak provinces, Vietnam. Observation data were collected from four meteorological stations, namely, An Khe, Pleiku, Buon Ma Thuot, and Buon Ho. To simulate future scenarios, five CMIP6 models (BBC-CSM2-MR, CanESM5, GFDL-ESM4, MIROC6, and MPI-ESM1.2-HR) were used with the SSP2–4.5 scenario for the years 2030–2049 and 2080–2099. The irrigation water requirements were calculated by the Crop Water Requirement model (CROPWAT) version 8.0. For 2030–2049, the simulation results of BCC-CSM2-MR at An Khe showed the highest increase of approximately 90 mm, while CanESM5 displayed only a 4 mm rise. On the other hand, both MIROC6 and MPI-ESM1.2-HR indicated a slight reduction, ranging from 4 to 10 mm at all stations. For 2080–2099, the BBC-CSM2-MR model at An Khe recorded the highest increase of 100 mm, whereas the GFDL-ESM4 model showed a decline of 90 mm at Buon Ho. Other models showed a fluctuation increase from 40 to 60 mm. This means that climate change has a significant impact on the irrigation water requirements for coffee plants in the Central Highlands of Vietnam.