Joep Schyns

University of Twente | UT · Department of Water Engineering and Management

Crop production has the largest water footprint (WF) of all economic sectors and ranks as a leading cause of water scarcity. Despite this, our understanding of historical changes in global WFs of crops remains limited. In this study, we analyse the recently published dataset on green and blue WFs of 175 individual crops in 1990–2019. We explore the...

The water footprint of a crop (WF) is a common metric for assessing agricultural water consumption and productivity. To provide an update and methodological enhancement of existing WF datasets, we apply a global process-based crop model to quantify consumptive WFs of 175 individual crops at a 5 arcminute resolution over the 1990–2019 period. This m...

Food systems are the largest users of land and water resources worldwide. Using a multi-model approach to track food through the global trade network, we calculated the land footprint (LF) and water footprint (WF) of food consumption in the European Union (EU). We estimated the EU LF as 140–222 Mha yr⁻¹ and WF as 569–918 km³ yr⁻¹. These amounts are...

Capital assets such as machinery and infrastructure contribute substantially to CO2 emissions over their lifetime. Unique features of capital assets such as their long durability complicate the assignment of capital-associated CO2 emissions to final beneficiaries. Whereas conventional approaches allocate emissions required to produce capital assets...

In this study, we simulate the crop yield and water footprint (WF) of major food crops of Iran on irrigated and rainfed croplands for the historical and the future climate. We assess the effects of three agricultural adaptation strategies to climate change in terms of potential blue water savings. We then evaluate to what extent these savings can r...

Today, human activities are highly dependent on fossil fuels and industrialized forms of agriculture and have reached a level that could damage the Earth’s systems [...]

Several studies addressed the water footprint (WF) of countries and virtual water (VW) trade in agricultural and industrial products, but freshwater use associated with wood products has received little attention. Yet, international trade in wood products has been growing, and forestry competes with other forest ecosystem services over limited fres...

Crop water productivity is a key element of water and food security in the world and can be quantified by the water footprint (WF). Previous studies have looked at the spatially explicit distribution of crop WFs, but little is known about their temporal dynamics. Here, we present AquaCrop-Earth@lternatives (ACEA), a new process-based global gridded...

Lacking systematic supply-use information of agricultural biomass and food products within China makes the existing provincial environmental pressure assessments (e.g., water consumption) either not detailed enough (e.g., by the input-output table-based approach) or not comprehensive enough (e.g., by the process-based approach). This study develops...

This chapter describes how to assess and reduce food systems’ pressure on global freshwater resources through the Water Footprint Assessment framework. First, we describe how to model the green and blue water footprint of growing a crop according to recent advances in the field of study. Second, we summarize methods to assess the environmental sust...

On 18 November 2019, the life of Arjen Y [...]

Freshwater resources are used to produce commodities that are traded and consumed elsewhere, which generate virtual water flows. The relation between regional blue water scarcity levels―the degree of competition over limited surface and groundwater flows―and inter-regional virtual water flows has been studied. However, the effects of production fra...

Potential climate-related impacts on future crop yield are a major societal concern. Previous projections of the Agricultural Model Intercomparison and Improvement Project’s Global Gridded Crop Model Intercomparison based on the Coupled Model Intercomparison Project Phase 5 identified substantial climate impacts on all major crops, but associated u...

The amount of groundwater and surface water consumed in a river basin constitutes the blue water footprint (BWF). To safeguard the environment, it has been suggested to set a cap to the BWF based on blue water availability (BWA). BWA depends on the precipitation that becomes runoff and the need to reserve environmental flow requirements. Previous s...

The paper presents insights from carrying out a pan-EU sustainability assessment using Farm Accountancy Data Network (FADN) data (the old wine) with societal metabolism accounting (SMA) processes (the new bottles). The SMA was deployed as part of a transdisciplinary study with EU policy stakeholders of how EU policy may need to change to deliver su...

Crop water productivity is a key element of water and food security in the world and can be quantified by the water footprint (WF). Previous studies have looked at the spatially explicit distribution of crop WFs but little is known about the temporal dynamics. We develop a new global gridded crop model – AquaCrop-Earth@lternatives (ACEA) – that can...

Bioethanol production from non-crop based lignocellulosic material has reached the commercial scale and is advocated as a possible solution to decarbonize the transport sector. This study evaluates how much presently used transport related fossil fuels can be replaced with lignocellulosic bioethanol using crop residues, calculates greenhouse gas em...

Potential climate-related impacts on future crop yield are a major societal concern first surveyed in a harmonized multi-model effort in 2014. We report here on new 21st-century projections using ensembles of latest-generation crop and climate models. Results suggest markedly more pessimistic yield responses for maize, soybean, and rice compared to...

Plain Language Summary Around the world, people are using too much water from rivers, lakes, and streams. As a result, rivers run dry, lake levels drop, and fish and other animals and plants that depend on freshwater are being harmed. We therefore need to strike a better balance between how much water we use for ourselves and how much water we leav...

This report explores the complex issue of water scarcity in agriculture, particularly focusing on irrigation practices in the European Union (EU). It examines the role of two key EU policies: the Water Framework Directive (WFD) and the Common Agricultural Policy (CAP). While these policies guide water use in agriculture, they are not operationally...

Energy security for the EU is a priority of the European Commission. Although both blue and green water resources are increasingly scarce, the EU currently does not explicitly account for water resource use in its energy related policies. Here we quantify the freshwater resources required to produce the different energy sources in the EU, by means...

Significance Precipitation over land partitions into runoff via surface water and groundwater (blue water) and evapotranspiration (green water). We expand the traditional debate on water scarcity, which solely focuses on blue water, by assessing green water scarcity. The current debate on water scarcity is heavily skewed, since it leaves unnoticed...

The European Union (EU) aims at increasing the share of renewable energy use, of which nearly half originates from wood sources currently. An energy supply from wood sources strongly relies on green water resources, which are limited and also essential for food security and terrestrial biodiversity. We have estimated the water footprint (WF) of woo...

This paper presents the first estimate of global water use in the forestry sector related to roundwood production for lumber, pulp, paper, fuel and firewood. For the period 1961-2010, we estimate forest evaporation at a high spatial resolution level and attribute total water consumption to various forest products, including ecosystem services. Glob...

Forests play a central interlinked role in the 2030 Agenda on Sustainable Development. The Agenda aims at an increased share of renewable energy in the global energy mix (target 7.2) and restoration and sustainable management of forests (targets 6.6, 15.1 & 15.2). Forests also play a key role in the hydrological cycle accounting for the largest wat...

Poster presented at AGU Fall Meeting 2015 (H41G-1426)

Research on water scarcity has mainly focussed on blue water (ground- and surface water), but green water (soil moisture returning to the atmosphere through evaporation) is also scarce, because its availability is limited and there are competing demands for green water. Crop production, grazing lands, forestry and terrestrial ecosystems are all sus...

Jordan faces great internal water scarcity and pollution, conflict over trans-boundary waters, and strong dependency on external water resources through trade. This paper analyzes these issues and subsequently reviews options to reduce the risk of extreme water scarcity and dependency. Based on estimates of water footprint, water availability, and...

Research on water scarcity has mainly focused on blue water (surface- and groundwater), but green water (soil moisture directly returning to the atmosphere as evaporation) is also scarce, because its availability is limited and there are competing demands for green water. Crop production, grazing lands, forestry and terrestrial ecosystems are all s...

Une Evaluation d'Empreinte Eau est effectuée pour le Maroc, permettant une cartographie d'empreinte eau de différentes activités au niveau du bassin fluvial et sur une échelle mensuelle, en distinguant entre les eaux de surface et les eaux souterraines. Le document vise à démontrer la valeur ajoutée de l'analyse détaillée de l'empreinte eau humaine...

This report is an extended version of an article published in PLOS ONE (Schyns and Hoekstra, 2014) and provides a full Water Footprint Assessment for Morocco.

A Water Footprint Assessment is carried out for Morocco, mapping the water footprint of different activities at river basin and monthly scale, distinguishing between surface- and groundwater. The paper aims to demonstrate the added value of detailed analysis of the human water footprint within a country and thorough assessment of the virtual water...