This study aims to reveal the historical and future relationship between droughts in the Yangtze River basin and hydropower capacity in Zhejiang Province. Generally, the interannual variation of hydropower capacity is positively correlated with the 12-month timescale of the Standardized Precipitation Evapotranspiration Index (SPEI) over the Yangtze River basin during 1999–2018, so a more severe drought event in the Yangtze River basin leads to lower hydropower capacity in Zhejiang Province. Therefore, a linear regression model is constructed based on their year-to-year incremental relationship, which is significant at the 99% confidence level. Using five global climate models that are good simulations of the interannual variability of precipitation/surface air temperature over the Yangtze River basin, the results suggest that the severity and the frequency of drought would increase relative to 1999–2018, with a drought event (SPEI < −0.5) happening once every 2.7 and 2.2 years under 1.5 and 2.0°C warming scenarios, respectively. Based on the interannual incremental relationship between hydropower capacity and SPEI, the hydropower capacity in Zhejiang Province will decrease by 0.34 (1.23) billion kWh under the 1.5°C (2.0°C) warming target when only the meteorological conditions are considered. When further development of hydropower stations in the future is also considered, the hydropower capacity would increase by −0.28 (1.11) billion kWh under 1.5°C (2.0°C) warming using the logistic growth model. Consequently, the drought events and the development of the hydroelectric system would jointly influence the hydropower capacity in the Yangtze River basin, and the meteorological conditions of a drying trend would contribute to lower hydropower capacity in Zhejiang Province in the future.

本研究旨在揭示长江流域干旱与浙江省水电容量之间的历史和未来关系。通常，水电容量的年际变化与1999-2018年长江流域标准降水蒸散指数（SPEI）的12个月时间尺度呈正相关，因此长江流域更严重的干旱事件导致水电容量下降。浙江省水电容量。因此，基于它们的逐年增量关系构建线性回归模型，这在99％的置信度水平上非常重要。使用五个全球气候模型，它们很好地模拟了长江流域降水/地表气温的年际变化，结果表明，相对于1999-2018年，干旱的严重程度和频率将增加，干旱事件（SPEI <-0.5）分别在1.5和2.0°C的变暖情景下每2.7年和2.2年发生一次。根据水电容量和SPEI之间的年际增量关系，仅考虑气象条件，在1.5°C（2.0°C）的升温目标下，浙江省的水电容量将减少0.34（1.23）十亿千瓦时。如果考虑将来对水电站进行进一步开发，则使用逻辑增长模型在1.5°C（2.0°C）变暖的情况下，水电容量将增加-0.28（1.11）十亿千瓦时。所以，