Project

Back to overview

Global agricultural green and blue water consumptive uses and virtual water flows in the context of water scarcity and climate change

English title Global agricultural green and blue water consumptive uses and virtual water flows in the context of water scarcity and climate change
Applicant Yang Hong
Number 122479
Funding scheme Interdisciplinary projects
Research institution CIRUS Innovation research in utility sectors Eawag Swiss Federal Institut of Aquatic Science and Technology
Institution of higher education Swiss Federal Institute of Aquatic Science and Technology - EAWAG
Main discipline Social geography and ecology
Start/End 01.02.2009 - 31.01.2012
Approved amount 155'725.00
Show all

All Disciplines (2)

Discipline
Social geography and ecology
Hydrology, Limnology, Glaciology

Keywords (6)

green water; food security; climate change; water scarcity; crop yield; agricultural water use

Lay Summary (English)

Lead
Lay summary
Agriculture, including rainfed and irrigated systems, is the single largest water user amongst all the economic sectors. There is an intrinsic linkage between water availability, food production and food trade. Earlier studies of water-food-trade relations had mainly focused on addressing constraint of blue water scarcity on expanding irrigated agriculture. Recent years have seen a growing attention on rainfed systems which rely on green water stored in unsaturated soils. There have been increasing research interests in assessing blue and green water uses in agriculture and in virtual water flows associated with food trade. Meanwhile, rapid advances in integrating GIS techniques in numerical models have enabled recent studies to account for spatial variations of relevant factors and visualize results on high spatial resolutions. The GIS-based EPIC (Environmental Policy Integrated Climate) model (GEPIC hereafter) developed by the group of the main applicant under a SNF project has been one of such examples (Liu et al., 2007).This proposed study is a continuation of our longstanding effort in the water-food-trade relations research. The overall objective of the project is to take a green and blue water perspective in the investigation of water-food-trade relations across different geographical regions and on a high spatial resolution with a global coverage. The concrete research tasks include: 1) investigation into green and blue water consumptive uses in food production with a focus on major staple food crops for the last 15-20 years. Impacts of blue and green water variability on crop yield and food production are elaborated; 2) assessment of virtual water flows and relations with green and blue water availability and uses in food importing and exporting countries, taking into consideration other factors influencing virtual water trade; 3) projection of impacts of climate change on food production and virtual water flows under the IPCC climate and socio-economic scenarios with a focus on water scarcity and temporal and spatial variations. Regions of high risk in water and food insecurity will be highlighted. Uncertainties will be addressed and quantified wherever possible in the analysis.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Effects of ecological and conventional agricultural intensification practices on maize yields in sub-Saharan Africa
Folberth C. Yang H. Gaiser T. Liu J.G. Wang X.Y. Williams J. Schulin R.. 2014. (2014), Effects of ecological and conventional agricultural intensification practices on maize yields in sub-Saharan Africa, in Environmental Research Letter, 9(4), 1-12.
Modeling maize yield responses to improvement in nutrient, water and cultivar inputs in sub-Saharan Africa.
Folberth C. Yang H. Gaiser T. Abbaspour K.C. Schulin R. (2013), Modeling maize yield responses to improvement in nutrient, water and cultivar inputs in sub-Saharan Africa., in Agricultural Systems, 119, 22-34.
Regionalization of a large-scale crop growth model for sub-Saharan Africa: Model setup, evaluation, and estimation of maize yields
Folberth Christian, Gaiser Thomas, Abbaspour Karim C., Schulin Rainer, Yang Hong (2012), Regionalization of a large-scale crop growth model for sub-Saharan Africa: Model setup, evaluation, and estimation of maize yields, in Agriculture, Ecosystems & Environment, 151(0), 21-33.

Collaboration

Group / person Country
Types of collaboration
Potsdam Institute for Climate Change Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Associated projects

Number Title Start Funding scheme
146430 Application of a Spatially Explicit Bio-physical Crop Model to Assess Drought Impact on Crop Yield and Crop-Drought Vulnerability in Sub-Saharan Africa 01.12.2013 Interdisciplinary projects
138608 Spatially explicit modeling of impacts of adaptive agronomic measures on crop water productivity and yields in the context of water scarcity and climate change in Sub-Saharan Africa 01.02.2012 Interdisciplinary projects
103600 Water Scarcity - Its Measurement and Implications for Virtual Water Import 01.04.2004 Project funding (Div. I-III)
113890 An Assessment of Regional Water Endowments, Crop Water Productivity, and Implications for Intra-country Virtual Water Trade in Iran 01.10.2006 Project funding (Div. I-III)
128754 UP-IPAZIA: “UPgrade and full deployment of the Empa/Eawag computational cluster IPAZIA: towards an interdisciplinary on-site resource for computational sciences” 01.04.2010 R'EQUIP

Abstract

Agriculture, including rainfed and irrigated systems, is the single largest water user amongst all the economic sectors. There is an intrinsic linkage between water availability, food production and food trade. The virtual water concept, emerged in the mid 1990s, specifically addresses this linkage from the perspective of food trade as a means of redistributing global water resources and as a possible policy option in managing local water resources, particularly in water scarce countries and regions (Allan, 1996; Zehnder, 1997; Oki and Kanae, 2004; Hoekstra and Hung, 2005; Yang et al., 2006). Earlier studies of water-food-trade relations had mainly focused on addressing constraint of blue water scarcity on expanding irrigated agriculture. Recent years have seen a growing attention on rainfed systems which rely on green water stored in unsaturated soils (Falkenmark and Rockström, 2006). There have been increasing research interests in assessing blue and green water uses in agriculture and in virtual water flows associated with food trade. Meanwhile, rapid advances in integrating GIS techniques in numerical models have enabled recent studies to account for spatial variations of relevant factors and visualize results on high spatial resolutions. The GIS-based EPIC (Environmental Policy Integrated Climate) model (GEPIC hereafter) developed by the applicants under the SNF project (No. 205121-103600) has been one of such examples (Liu et al., 2007). Despite the tremendous efforts and remarkable progress made in the previous studies, research gaps and shortcomings remain. One of them is that hitherto estimations of global green and blue water uses in agriculture production have generally been conducted in an aggregate manner. The results do not provide specific information for individual crops, notably staple crops crucial for food security. Another shortcoming is that until now studies of relations between water availability, food production and virtual water trade have not been able to appropriately incorporate green water in the analysis. Furthermore, so far no study has probed possible implications of climate change for future global virtual water flows. Uncertainties involved in various aspects of the analysis and results have not been addressed adequately, in some cases even completely ignored. This proposed study is a continuation of our longstanding effort in the water-food-trade relations research. The overall objective of the project is to take a green and blue water perspective in the investigation of water-food-trade relations across different geographical regions and on a high spatial resolution with a global coverage. The concrete research tasks include: 1) investigation into green and blue water consumptive uses in food production with a focus on major staple food crops for the last 15-20 years. Impacts of blue and green water variability on crop yield and food production will be examined; 2) assessment of virtual water flows and relations with green and blue water availability and uses in food importing and exporting countries, taking into consideration other natural and socio-economic factors influencing virtual water trade; 3) projection of impacts of climate change on food production and virtual water flows under the IPCC climate and socio-economic scenarios with a focus on water scarcity and temporal and spatial variations. Regions of high risk in water and food insecurity will be highlighted. Uncertainties will be addressed and quantified wherever possible in the analysis. However, investigating the trend in climate change and uncertainties in climate modeling itself is not the task of this study. The GEPIC model will be used as the core model in the analysis. An econometric approach will be taken to probe water related factors in explaining virtual water trade. The Soil and Water Assessment Tool (hereafter SWAT), a hydrological model currently used in several projects at Eawag, is planned to provide hydrological support to the analysis. The data required for the proposed study have been mostly collected through the previous and on-going projects at Eawag. This proposed project is in close links with two international initiatives: Green and Blue Water Initiative and Global Catchments Initiative, where the main applicant of this proposed project is actively involved. Additional expertise and data required will be obtained from the collaboration with other international research teams involved in the two initiatives and from additional sources if needed.
-