Abstract

Significant population growth with rapid economic development have led to water scarcity problems around the world. Currently, most of the simple water scarcity assessment methods only refer to per capita water use, failing to take into account actual water availability and actual human domestic water use. Therefore, we have developed a simple and practical method to assess water scarcity, incorporating total water resources, water use efficiency, and the proportion of domestic water. In this approach, a new water scarcity index is employed to describe different levels of water scarcity using various thresholds based on the basic daily human water use per person. This may help to visualize the extent of water scarcity in a region while focusing on human interests. To illustrate this approach, we take China–the world’s largest developing country–as an example, analysing its nationwide water scarcity in 2021 while validating it with the results of other scholars on China’s water scarcity. The results show that our water scarcity assessment index is very accurate, revealing that in 2021, the disparity in water resources between the northern and southern regions of China remains substantial, with severe water scarcity still widely concentrated in northern China.

Introduction

Continuous water supply plays a vital role in daily life and social development ( Ethaib et al., 2022 ). However, increasing water consumption is due to the significant population growth and rapid economic development, resulting in extremely high water resource pressures, which cause water scarcity in numerous places around the world ( Liu et al., 2017 ). For instance, in regions such as Greater London with high population density, intense irrigation present in areas like the High Plains of the United States, and nations like India that exhibit both traits, there is a prevalent issue of water scarcity ( Mekonnen and Hoekstra, 2016 ). Nevertheless, in addition to direct water supply shortages caused by the forces of nature, human factors, as well as socio-political factors, are often overlooked, leading to the masking of the causes of scarcity. This complexity of water scarcity is labelled by Mehta as ‘real’ scarcity (related to socially and ecologically relevant physical phenomena like grass cover, fodder, distance to water for disadvantaged groups, cycles of natural resource abundance and scarcity, agro-meteorological hydrology, etc.) and ‘manufactured’ scarcity (constructing water scarcity as a perpetual and pervasive natural phenomenon, the industry of disaster relief and drought relief, and perverse benefits) ( Mehta, 2003 ). Moreover, there are also sudden and uncontrolled factors affecting water resources, such as the outbreak of the COVID-19 pandemic crisis, which has put many additional pressures on water resources, including the increase in local agricultural irrigation brought about by the localised production of food, and the parallel alteration of the virtual water trade caused by the changes that have taken place in the food trade ( Al-Saidi and Hussein, 2021 ).

Results

۳٫۱٫ Statistical analysis of the results

A comparison of the water scarcity index calculated using Eq. (1) for each region of China, with a threshold of 0.2 (no stress), is shown in Fig. 2 . The results show that most regions in China are still suffering from water problems, including some economically developed cities with heavy water problems, such as Beijing (0.01), Tianjin (0.008), and Shanghai (0.02). In contrast, Qinghai (1.43) and Xizang (10.56) have abundant water resources, which are significantly higher than in other regions.

۳٫۲٫ Spatial analysis of the results

In this study, ArcGIS Pro software was used to raster water resource data from various provinces in China in order to comprehensively and visually assess water scarcity across the country. As can be seen in Fig. 3 , the water scarcity index shows obvious spatial distribution differences, mainly between the northern and southern regions of China. Overall, the water scarcity index shows absolute scarcity in the north and no stress in the south. Specifically, a wide range of areas in northern China, including Inner Mongolia, Liaoning, and Shaanxi, exhibit water scarcity and some pressure on water resources. It is worth noting that some areas in the north also show absolute water scarcity, especially in Beijing, Tianjin, Hebei and Shanxi, indicating that the available water resources in these regions do not meet the minimum basic human needs of the region.