Abstract

Drought is a recurring natural disaster, which significantly affects the economy and environment of diverse geographical area worldwide. Therefore, it is imperative to develop a new technique that enables comprehensive identification and monitoring of drought over a large spatial extent. In this study, a new drought index called Combined Terrestrial Evapotranspiration Index (CTEI) is developed by using a combination of Gravity Recovery and Climate Experiment (GRACE) data and meteorological parameters, i.e. precipitation (P) and potential evapotranspiration (PET) over the Indus, Ganga, and the Brahmaputra (IGB) river basins. Further, the results of CTEI are compared with pre-existing drought indices, which highlighted good correlation with GRACE Groundwater Drought Index (GGDI) (ρ = 0.88), Water storage deficit index (WSDI) (ρ = 0.96), Combined Climatologic Deviation Index (CCDI) (ρ = 0.97) and Standardized Precipitation-Evapotranspiration Index (SPEI) (ρ = 0.49). It also compared with In-situ Groundwater Drought Index (IGDI) derived by groundwater observation wells. The mean annual CTEI exhibited a strong correlation with IGDI (0.49 to 0.77) and climatic parameters (P, PET, and land surface temperature). Outcomes illustrated a significant potential of CTEI index and extended the utility of GRACE derived Terrestrial Water Storage observations for drought characterization as well as quantification of its severity.

摘要

干旱是一种反复发生的自然灾害，它严重影响着全球不同地理区域的经济和环境。因此，当务之急是开发一种能够在大空间范围内全面识别和监测干旱的新技术。在这项研究中，结合重力恢复和气候实验 (GRACE) 数据和气象参数，即印度河上的降水量 (P) 和潜在蒸散量 (PET)，开发了一种新的干旱指数，称为陆地蒸散组合指数 (CTEI)。 、恒河和雅鲁藏布江 (IGB) 河流域。此外，将 CTEI 的结果与预先存在的干旱指数进行比较，突出显示与 GRACE 地下水干旱指数 (GGDI) (ρ = 0.88)、蓄水不足指数 (WSDI) (ρ = 0.96)、综合气候偏差指数 (CCDI) (ρ = 0.97) 和标准化降水-蒸散指数 (SPEI) (ρ = 0.49)。它还与地下水观测井得出的原位地下水干旱指数（IGDI）进行了比较。年平均 CTEI 与 IGDI（0.49 至 0.77）和气候参数（P、PET 和地表温度）具有很强的相关性。结果说明了 CTEI 指数的巨大潜力，并扩展了 GRACE 衍生的陆地蓄水观测在干旱表征及其严重程度量化方面的效用。年平均 CTEI 与 IGDI（0.49 至 0.77）和气候参数（P、PET 和地表温度）具有很强的相关性。结果说明了 CTEI 指数的巨大潜力，并扩展了 GRACE 衍生的陆地蓄水观测在干旱表征及其严重程度量化方面的效用。年平均 CTEI 与 IGDI（0.49 至 0.77）和气候参数（P、PET 和地表温度）具有很强的相关性。结果说明了 CTEI 指数的巨大潜力，并扩展了 GRACE 衍生的陆地蓄水观测在干旱表征及其严重程度量化方面的效用。