A composite index coupling five key elements of water cycle for drought analysis in Pearl River basin, China

Tian Wang; Xinjun Tu; Vijay P Singh; Xiaohong Chen; Kairong Lin

doi:10.1016/j.jenvman.2022.115813

A composite index coupling five key elements of water cycle for drought analysis in Pearl River basin, China

J Environ Manage. 2022 Oct 15:320:115813. doi: 10.1016/j.jenvman.2022.115813. Epub 2022 Aug 11.

Authors

Tian Wang¹, Xinjun Tu², Vijay P Singh³, Xiaohong Chen¹, Kairong Lin¹

Affiliations

¹ Center of Water Resources and Environment, School of Civil Engineering, Sun Yat-sen University, Guangzhou, 510275, China.
² Center of Water Resources and Environment, School of Civil Engineering, Sun Yat-sen University, Guangzhou, 510275, China; Center of Water Security Engineering and Technology in Southern China of Guangdong, Guangzhou, 510275, China; Guangdong Laboratory of Southern Ocean Science and Engineering, Zhuhai, 519000, China. Electronic address: eestxj@mail.sysu.edu.cn.
³ Department of Biological and Agricultural Engineering, Texas A&M University, 2117 College Station, TX, 77843, USA; Zachry Department of Civil Engineering, Texas A&M University, 2117 College Station, TX, 77843, USA; National Water & Energy Center, UAE University, Al Ain, United Arab Emirates.

PMID: 35963070
DOI: 10.1016/j.jenvman.2022.115813

Abstract

Drought, as a natural disaster, has widespread consequences and is notoriously difficult to manage. Critical to developing a drought management strategy is the identification and assessment of drought. To that end, this study developed a new composite index, called the standardized water cycle index (SWCI) based on the water cycle and water balance. The SWCI couplesd the key elements of the water cycle, including precipitation, evapotranspiration, leaf area index, surface runoff, and subsurface runoff, and requires the joint distribution of these elements which was determined using the D-vine copula. The Kendall transform was used to reduce the dimensionality of the five-element joint probability density function, which was then inversed to obtain the SWCI which was then evaluated with the data from the Pearl River basin obtained using the CMIP6. Results showed that the SWCI satisfactorily evaluated drought conditions, while reflecting the drought-mitigating effect of vegetation and subsurface runoff. The SWCI was also able to evaluate drought in areas with a high level of human activity.

Keywords: CMIP6; D-vine copula; Drought; Kendall distribution transform; Pearl river basin; Standardized water cycle index.

MeSH terms

China
Droughts*
Human Activities
Humans
Rivers*
Water Cycle