水足迹研究进展

水为生命之源,水资源的合理分配与科学管理是区域可持续发展与流域综合管理的核心环节;水足迹作为一种全面核算人类活动对水资源真实占用的综合指标,将人类消费终端与水资源利用密切关联,为维护流域水资源安全、提高区域水资源利用效率提供了重要的科学依据,已成为当前国际水资源管理的前沿研究领域。在明确水足迹及水资源生态足迹相关概念的基础上,对比分析了水足迹与生态足迹、水资源生态足迹模型的异同,明晰了过程、产品及区域等不同研究对象的水足迹核算方法,系统梳理了产品和区域水足迹评价、基于水足迹的区域水资源安全研究、区域水足迹可持续性分析等水足迹主要研究内容的近今进展,并展望了进一步的重点研究方向,即水足迹综合研究、水足迹评价不确定性分析、水足迹与物质流核算的关联研究,以及基于足迹整合的可持续发展多维测度等。

Research progress on water footprint

The rational and appropriate allocation as well as scientific management of water resource is the cardinal and crucial part of the sustainability of regional development and integrated watershed management.Water footprint, as a comprehensive accounting indicator, reflecting the consumption of water resource due to human activities, connects human water expenditure directly and tightly with water utilization, which can translates human appropriation of fresh water into the volume or mass of water, and thus provides vital scientific analysis grounds of the maintenance of watershed water resource security and the improvement of regional water utilization efficiency, and has already become one of the frontier research fields of international water resources management.Firstly, based on the definitions of water footprint and water ecological footprint, which are the derivations of ecological footprint, and have already been the two main models used to calculate human use of water resource, this paper made comparative studies on water footprint, ecological footprint and water ecological footprint.Their similarities and differences are analyzed from the following four aspects: the origins and aims, fundamentals, footprint components and model applications.The results show that ecological footprint model, especially in its accounts setting idea, has significant impacts on both water footprint and water ecological footprint model, and water ecological footprint is regarded as a new emerged component of ecological footprint.However, compared with water ecological footprint, water footprint is a more comprehensive indicator to calculate the total annual volume of fresh water used to produce goods and services for consumption, and thus it can play a more important role in water resource management.Furthermore, the methods to calculate water footprint in process, product and region dimensions were explicated.Secondly, this paper reviewed the recent main research progresses on water footprint both in China and overseas from the following several aspects: (1) the assessments of water footprint in product and region.More water footprints of processes and products are calculated and analyzed by foreign scholars, while case study of a region's water footprint are booming all over the world; (2) regional water resource security researches based on deep analyses of water footprint and some derived indices; (3) the sustainability assessments of regional water footprint by comparing the blue, green water footprint with available fresh water resource and comparing the grey water footprint with assimilative capacity of the watershed.Thirdly, this study proposed the key issues for further research, and the themes are as follows: (1) to make more comprehensive and integrated study on water footprint, including calculating and analyzing the quantity and structure of footprint, and then assessing the environmental, social and economic sustainability of water footprint, and finally making response plans, which are usually ignored; (2) to make further study on the uncertainty of water footprint calculation, which could enable scientists to make precise statements about the degree of confidence they have in their evaluation and simulation-based predictions; (3) to study the relationships between material flow accounting and water footprint, and make a joint research by integrating advantages from both of them; (4) to develop a multi-dimensional measure of sustainable development based on "footprint family", including ecological footprint, carbon footprint and water footprint, then human appropriation of natural capital like land resource, water resource and energy resource can be fully accounted.