珠江流域1981—2020年水文干旱时空特征分析

基于VIC模型和汇流模型生成的1981—2020年5 km×5 km网格模拟流量数据，构建了长历时、网格化的标准化径流干旱指数(SRDI),对珠江流域水文干旱时空演变特征进行了评估。结果表明：基于模拟流量构建的网格化SRDI能够较好地模拟珠江流域干旱时空演变过程；珠江流域水文干旱的时间演变特征明显，干旱集中发生在夏季，秋季可能发生大范围的水文干旱，季节尺度上一年四季均有可能发生极端干旱；珠江流域水文干旱在空间格局上呈现为自东向西由干旱高频区向干旱长历时、高烈度区过渡分布。

Temporal and spatial characteristics of hydrological drought in the Pearl River Basin from 1981 to 2020

With the simulated runoff data at the 5.km×5.km grid cells from 1981 to 2020 based on the VIC model and the confluence model, a long-term and grid SRDI (standardized runoff drought index) was constructed. Then, the spatiotemporal evolution characteristics of drought in the Pearl River Basin were analyzed. The results show that: the grid SRDI based on simulated runoff can better simulate the spatiotemporal variation of drought in the Pearl River Basin; the temporal evolution characteristics of drought are obvious, hydrological drought mainly occurs in summer, and a large-scale drought may probably occur in autumn; on the seasonal scale, it is possible that extreme drought occurs all the year around; spatially speaking, the hydrological droughts in the Pearl River Basin present a transitional distribution from the east with high-frequency, to the west with long-duration and high-intensity.