考虑地表-土壤-作物水分联合亏缺的综合旱情指数研究

区域干旱发生发展受地表水、土壤水、作物水等多种缺水过程的共同影响，以往基于单一缺水过程构建的干旱指数难以反映实际旱情，综合考虑多种缺水过程构建综合旱情指数，对有效开展区域旱情监测具有重要的意义。基于水文作物耦合模型(VIC-EPIC)模拟数据，通过线性加权集成标准化径流指数(SRI)、土壤含水量距平指数(SMAPI)和作物缺水指数(CWDI),构建了反映地表-土壤-作物水分联合亏缺的综合旱情指数(CDSI),并采用1981—2020年数据在湘江流域开展了应用研究。结果表明，基于CDSI提取的旱情特征序列与流域内35个县1990—2007年受旱率相关性在0.4～0.8之间，82.9%通过5%显著性水平检验，与反映单一水分亏缺的SRI、SMAPI和CWDI相比，相关性整体上有较大提升。CDSI能够较好地反映区域实际旱情发生发展，可为大范围旱情准确识别和评估提供有效支撑。

Study of comprehensive drought index based on water deficits of surface, soil, and crop

The occurrence and development of regional drought are affected by various water shortage processes such as surface water, soil water and crop water. The drought index based on a single water shortage process in the past is difficult to reflect the actual drought. It is of great significance to effectively carry out regional drought monitoring by comprehensively considering various water shortage processes to construct a comprehensive drought index. Based on the simulation data of hydrological crop coupling model (VIC-EPIC), a comprehensive drought index (CDSI) reflecting the combined water deficit of surface-soil-crop was constructed by linear weighted integrated standardized runoff index (SRI), soil water content anomaly index (SMAPI) and crop water deficit index (CWDI). The application research was carried out in Xiangjiang River Basin based on the data from 1981 to 2020. The results showed that the correlation between the drought characteristic sequence based on CDSI and the drought rate of 35 counties in the basin from 1990 to 2007 was between 0.4 and 0.8, and 82.9% of them passed the 5% significance level test. Compared with SRI, SMAPI and CWDI, which reflect a single water deficit, the correlation has been greatly improved. CDSI can better reflect the occurrence and development of regional actual drought, and can provide effective support for accurate identification and evaluation of large-scale drought.