Assessing the impact of climate change on the water resources in the Kon - Ha Thanh river basin, Binh Dinh province

Abstract

Climate change and its impacts on water resources are urgent issues that are receiving significant attention. The assessment of climate change's impact on the water resources of the Kon - Ha Thanh river basin was conducted using the MIKE NAM hydrological model, combined with two climate change scenarios, RCP 4.5 and RCP 8.5, published by the Ministry of Natural Resources and Environment in 2020. The model parameters were developed based on a data series from 1985 to 2022, to calculate annual flow, flood season flow, and dry season flow under the influence of climate change. Specifically, the parameters were calculated for three periods in the 21^st century: Early (2016 - 2035), mid (2046 - 2065), and late (2080 - 2099). The accuracy of the MIKE NAM hydrological model was demonstrated to be good, with a NASH coefficient achieving a high score above 0.8 after calibration and validation. The study results indicate that climate change in the area significantly impacts water resources, as evidenced by the uneven distribution of annual flow (+4 %), flood season flow (+6 %), and dry season flow (-3 %) under both RCP 4.5 and RCP 8.5 scenarios. This research can provide a foundation to support the management, exploitation, use, and sustainable development of water resources in the Kon - Ha Thanh river basin in the future.