Pollution exacerbates China’s water scarcity and its regional inequality

TLDR

Water scarcity studies have largely focused on quantity, overlooking quality constraints that render water unsuitable for many uses and thereby worsen scarcity. The study aims to conduct a nationwide assessment of China’s water scarcity that incorporates quality requirements and emphasizes multi‑scale evaluation. The authors performed a nationwide assessment of water scarcity in China, explicitly integrating quality criteria for human uses. The assessment reveals that poor water quality worsens China’s water scarcity, with North China facing year‑round scarcity and South China experiencing seasonal scarcity, affecting over half the population and underscoring the need for better quantity and quality management.

Abstract

Inadequate water quality can mean that water is unsuitable for a variety of human uses, thus exacerbating freshwater scarcity. Previous large-scale water scarcity assessments mostly focused on the availability of sufficient freshwater quantity for providing supplies, but neglected the quality constraints on water usability. Here we report a comprehensive nationwide water scarcity assessment in China, which explicitly includes quality requirements for human water uses. We highlight the necessity of incorporating water scarcity assessment at multiple temporal and geographic scales. Our results show that inadequate water quality exacerbates China's water scarcity, which is unevenly distributed across the country. North China often suffers water scarcity throughout the year, whereas South China, despite sufficient quantities, experiences seasonal water scarcity due to inadequate quality. Over half of the population are affected by water scarcity, pointing to an urgent need for improving freshwater quantity and quality management to cope with water scarcity.