Although several studies have revealed that the consumption-based water footprint (WF) is unequal in space, the contributing factors to this spatial inequality have rarely been quantified. This study addresses this need by quantifying the effects that determine the difference of one region's WF per capita and a benchmark average value. A decomposition framework is developed. Using provincial water uses in China as a case study, this framework breaks down the deviation of one province's per capita WF from the national average value into effects of five key factors, namely, the actual-requisite WF difference, direct water use intensity, economic production structure, consumption level and consumption structure. The structural decomposition analysis is adapted to investigate differences between the provincial WFs and national average value, in contrast to its conventional use for examining changes of an environmental variable over time. The results indicate that the drivers of a high or low WF level in different provinces are diverse. The dominant factors are most often the direct water use intensity and consumption level, which may contribute over 1000 and 400 m3 of per capita WFs per year, respectively. The results assist in the diagnosis of per capita WF for each province. Policy suggestions highlighting feasible institutional or technological arrangements are made for each province, which have the potential to reduce consumption-based WF inequality without compromising living standards of inhabitants.
Keywords: Driving forces; Input-output table; Spatial comparison; Structural decomposition analysis; Water footprint.
Copyright © 2018 Elsevier B.V. All rights reserved.