Assessment of Flood and Drought Likelihood Using Extreme Rainfall Indices Under Climate Change: A Case Study of Yom River Basin

Abstract

Floods and droughts have been occurring frequently in the Yom River Basin lately, which has a major effect on locals' lives and property. The severity and frequency of water-related disasters have increased due to climate change, especially the variance of extreme rainfall patterns that are rising, such as the length of dry spells and heavy rainfall. Therefore, utilizing extreme rainfall indices in assessing the probability of floods and droughts is essential for future water management planning. The purpose of this study is to analyze flood and drought indices from extreme rainfall indices under climate change in the Yom River Basin and assess the probability of floods and droughts in sub-basin areas. The methods used in the research include calculating extreme rainfall indices that are related to the bias-corrected global climate model's present and projected precipitation data, analyzing how extreme rainfall indices change using statistical techniques, and assessing the probability of spatial floods and droughts using determined flood and drought index criteria. The study results indicate that the overall drought risk in the Yom River Basin is projected to decrease slightly in the near and mid future, with a more substantial decrease anticipated in the far future. At the sub-basin level, the upper Yom sub-basin is expected to see a slight decrease in drought risk in the near future, a slight increase in the mid future, and a significant decrease in the far future. In the middle Yom sub-basin, drought risk is projected to slightly decline in the near future and continue to decrease throughout the mid and far future, reflecting a long-term trend of reduced drought severity. For the lower Yom sub-basin, a slight decrease is anticipated in the near and mid futures, with a more pronounced reduction in the far future.