Novel framework for quantifying dam construction, climate change, and land-use change impacts on flow regime: A case study in Ganjiang River Basin, China

Abstract

Study regionThis study was conducted in the Ganjiang River Basin, situated in eastern China. Study focusPrevious studies often quantified the impacts of climate change, land use, and dam construction on flow regime by only focusing on two of these factors at one time. In addition, the previous method used to quantify the deviation in the timing of annual extreme water conditions has a flaw. Therefore, this study improved the formula for calculating the deviation in the timing of annual extreme water conditions. Moreover, we proposed a novel framework for quantifying the impacts of dam construction, climate change, and land-use change on flow regime. New hydrological insights for the regionThe study observed significant alterations in the flow regime of the Ganjiang River Basin. These modifications were predominantly influenced by dam construction and climate change. Dam construction led to a notable increase in dry season flow and minimum flow indicators, while decreasing maximum flow indicators. Conversely, climate change resulted in a reduction of minimum flow indicators and an increase in maximum flow indicators. Climate change has also led to an increase in the frequency and duration of flow pulses. Intriguingly, dam construction and climate change played offsetting roles for 77 % of the indicators. Considering the global climate change context, judicious dam operation could to mitigate the impact of climate change on the flow regime.