The Effect of Land Use on Availability of Japanese Freshwater Resources and Its Significance for Water Footprinting

Masaharu Motoshita,Matthias Finkbeiner,Yuya Ono,Atsushi Inaba

doi:10.3390/su8010086

Abstract

All relevant effects on water must be assessed in water footprinting for identifying hotspots and managing the impacts of products, processes, and services throughout the life cycle. Although several studies have focused on physical water scarcity and degradation of water quality, the relevance of land use in water footprinting has not been widely addressed. Here, we aimed to verify the extent of land-use effect in the context of water footprinting. Intensity factors of land use regarding the loss of freshwater availability are modeled by calculating water balance at grid scale in Japan. A water footprint inventory and impacts related to land use are assessed by applying the developed intensity factors and comparing them with those related to water consumption and degradation. Artificial land use such as urban area results in the loss of many parts of available freshwater input by precipitation. When considering water footprint inventory, the dominance of land use is less than that of water consumption. However, the effect of land use is relevant to the assessment of water footprint impact by differentiating stress on water resources. The exclusion of land use effect underestimates the water footprint of goods produced in Japan by an average of around 37%.

Highlights

Freshwater is a necessary resource for sustaining healthy human life and ecosystems
A special type of Life Cycle Assessment (LCA) that focuses on the potential environmental impacts relevant to water use has attracted attention as water footprinting
Water balance model calculation quantitatively reveals that land cover change attributed to artificial land use may cause loss of freshwater availability in surface and groundwater by affecting surface flow and groundwater recharge

Summary

Introduction

Freshwater is a necessary resource for sustaining healthy human life and ecosystems. water covers major parts of the globe, available freshwater resources are only limited to ~0.8% of total water resources [1]. Imbalance of demand and supply of freshwater has various environmental impacts owing to freshwater use Both availability and demand of freshwater resources vary by region, which means that the stress of freshwater scarcity is not geographically uniform. Recent globalized supply chains of products and services increases the complexity and difficulties of identifying and managing critical environmental impacts of water use in those chains. In this context, a special type of Life Cycle Assessment (LCA) that focuses on the potential environmental impacts relevant to water use has attracted attention as water footprinting. Water footprinting can be a tool for tracing the environmental impacts of water use through life cycle of products, processes and organizations and expected to contribute to improved water management in terms of environmental impacts

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