Assessing the sustainability of freshwater consumption based on developing 3D water footprint: A case of China

Abstract

Sustainable development requires that resources use should be kept within boundary values. This paper provided a complete explanation of the theoretical concepts of the three-dimensional water footprint model (3D WF model) and improved the 3D WF model by extending it to both water quantity and water quality assessment perspectives. Size and depth of blue water footprint (BWF) and grey water footprint (GWF) help assess the sustainability of regional water resources in terms of both source and sink appropriation, which emphasizing the importance of freshwater resources as critical natural capital. Then, the improved 3D WF model was used to explore the sustainability of regional freshwater resource utilization by taking the freshwater resource utilization status of 31 provinces in mainland China as an example. The values of blue water footprint size (BWFsize) and grey water footprint size (GWFsize) in China from 2003 to 2015 were 575.6 billion m³ and 1552.3 billion m³, corresponding to the dominant factors of agricultural sources (64.0%) and domestic sources (75.3%), respectively. The high value areas of blue water footprint depth (BWFdepth) and grey water footprint depth (GWFdepth) were mainly located in North, East and Northwest China, with a high mismatch between freshwater resource stock and flow possession. After clustering, Xinjiang was in a source deficit dominated region; Beijing, Tianjin, Shaanxi, Shanghai and Henan were in a sink deficit dominated region; Ningxia, Hebei, Liaoning and Shandong were in a dual source and sink deficit region. The water footprint size (WFsize) and water footprint depth (WFdepth) reflect the intra- and intergenerational equity in the sustainable use of regional water resources, and the improved 3D WF distinguishes types of unsustainable regional water resources (source shortage or sink shortage, or both), which is important for raising awareness of water conservation among residents and helping managers to tailor water management policies to local conditions.