Towards the sustainable development of water security: A new copula-based risk assessment system

Abstract

Water security is deeply intertwined with ecosystems, society and the economy, and is a frequent focal point of sustainable development. This study investigates the water security (WS) of Inner Mongolia, a dryland region in northern China. Specifically, an indicator system integrating the principles of Stability (S), Cooperation (C), and Resilience (R) was constructed to quantitatively and comprehensively assess water security. Risk probability was calculated by the constructed system by combining its output with a copula function. The findings revealed that: (1) WS-SCR levels in the study area gradually increased from 2001 to 2021. The periods multi-year average was 0.42, which is at the threshold level of security; (2) Based on a standard deviation ellipse, the spatial distribution of WS-SCR levels changed from northeast to southwest and back to northeast. The centroid of change shifted from east to west and back to east; (3) Key drivers influencing water security included GDP per capita (S3), agricultural irrigation water consumption per unit area (C4), comprehensive water use per capita (C5), reclaimed water use rate (C8), fertilizer application per unit of farmland (R4), and population density (R5); (4) The S-C, S-R, and C-R relationships within the study area were best modelled by the Clayton copula function, whereas the S-C-R relationship was most accurately modelled by using a Frank copula function. The three-dimensional joint risk probability S-C-R (S≤0.4, C≤0.4, R≤0.4) is 0.226; the probability that R was insecure increased with increasing S or C index values. This study provides a scientific foundation for the long-term planning and management of sustainable water security development in Eurasian drylands.

Keywords

• Copula function
• Risk assessment
• Sustainable development
• Stability-cooperation-resilience (S-C-R)
• Water security