A composite drought index developed for detecting large-scale drought characteristics

• Published in: Journal of hydrology (Amsterdam) 2022-02, Vol.605, p.127308, Article 127308
• Main Authors: Faiz, Muhammad Abrar, Zhang, Yongqiang, Zhang, Xuanze, Ma, Ning, Aryal, Santosh K., Ha, Trinh Thi Viet, Baig, Faisal, Naz, Farah
• Format: Article
• Language: English
• Subjects: Composite drought index; Drought; PDSI; Precipitation; SPI
• ISSN: 0022-1694; 1879-2707
• DOI: 10.1016/j.jhydrol.2021.127308

•Proposed composite drought index is simple and easy to calculate.•Proposed index is reliable to detect soil moisture.•Index performs well in monitoring drought conditions. Numerous studies have projected that drought will become more severe under changing climatic conditions which will have a profound impact on terrestrial ecosystems around the world. While a wide range of drought indices has been extensively applied to assess droughts, various issues have been raised, such as over- or underestimation of drought conditions, feature extraction techniques, or transformations used to develop the indices. In this study, a new composite drought index (CDI) was developed using the integration of potential and actual evapotranspiration, climatic water balance, and precipitation. The proposed CDI was evaluated by comparing it with soil moisture, Palmer Drought Severity Index (PDSI), scaled crop yield index (sCYI), evaluation integrated drought index (EIDI), and standardized runoff index (SRI) in China. Our results demonstrate that together with PDSI, CDI performs well in monitoring drought over 2417 grid cells obtained from in-situ latitude and longitude. It was found that CDI performs better than the PDSI and EIDI for reliable soil moisture detection and stable drought monitoring in the study area. Compared to PDSI, CDI shows a more positive correlation with sCYI for seasonal maize and wheat. CDI has less false alarm ratio in the detection of mild to extreme drought events compared to PDSI.