Increased flood susceptibility in the Tibetan Plateau with climate and land use changes

Abstract

Most of the current studies on the flood susceptibility of the Tibetan Plateau (TP) have relied on historical observations, lacking future projections and are not conductive to adaptive strategy optimization. Here, we examine the dynamics of flood susceptibility using a logistic regression model. When combined with climate and land use changes, the flood susceptibility in the TP is projected to increase under three Shared Socioeconomic Pathways (SSP). By the 2090 s, compared to the baseline period (1960–2020), the areas classified as very highly susceptible will experience an increase of 3.63 %, 6.17 %, and 15.26 % under the SSP126, SSP245, and SSP585 scenarios, respectively. The regions with high (4.98 %) and very high (6.88 %) flood susceptibility are primarily concentrated in densely populated areas located in the eastern and southern parts of the TP. As significant factors influencing flood susceptibility, the mean annual precipitation in the TP is expected to increase by 114 mm, 135 mm, and 223 mm from the baseline to the 2090 s under the SSP126, SSP245, and SSP585 scenarios, respectively. Additionally, the mean annual temperature is projected to rise by 2.2 ℃, 3.5 ℃, and 7.1 ℃, respectively. Furthermore, there will be a substantial expansion in the built-up area within the TP, with the percentage of built-up area increasing from 0.12 % in 2020 to 0.32 % by 2095. Our findings provide a quantitative assessment of how both natural environmental factors and human disturbances contribute to the susceptibility of the TP to flooding. Moving forward, it is expected that the built-up area on the northeastern edge of the TP will experience significant growth, resulting in an increased vulnerability to floods. Therefore, it is imperative to implement rational land use and land cover planning measures in order to mitigate the impact of flood disasters.