Arjen Hoekstra

• PhD
• Professor (Full) at University of Twente

Within the context of Earth’s limited natural resources and assimilation capacity, the current environmental footprint of humankind is not sustainable. Assessing land, water, energy, material, and other footprints along supply chains is paramount in understanding the sustainability, efficiency, and equity of resource use from the perspective of pro...

Freshwater scarcity is increasingly perceived as a global systemic risk. Previous global water scarcity assessments, measuring water scarcity annually, have underestimated experienced water scarcity by failing to capture the seasonal fluctuations in water consumption and availability. We assess blue water scarcity globally at a high spatial resolut...

This study quantifies and maps the water footprint (WF) of humanity at a high spatial resolution. It reports on consumptive use of rainwater (green WF) and ground and surface water (blue WF) and volumes of water polluted (gray WF). Water footprints are estimated per nation from both a production and consumption perspective. International virtual wa...

The increase in the consumption of animal products is likely to put further pressure on the world’s freshwater resources. This paper provides a comprehensive account of the water footprint of animal products, considering different production systems and feed composition per animal type and country. Nearly one-third of the total water footprint of a...

When water problems extend beyond the borders of local communities, the river basin is generally seen as the most appropriate unit for analysis, planning, and institutional arrangements. In this paper it is argued that addressing water problems at the river basin level is not always sufficient. Many of today’s seemingly local water issues carry a (...

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...

Water shortages pose significant threats to local water security and food production around the world. Water managers have resorted to various water resources planning measures to overcome these challenges. For the first time and for a case study in Iran, we provide a comparative analysis of two such measures: physical and virtual inter-basin water...

Phosphorus (P) losses from fertilized croplands to inland water bodies cause serious environmental problems. During wet years, high precipitation disproportionately contributes to P losses. We combine simulations of a gridded crop model and outputs from a number of hydrological and climate models to assess global impacts of changes in precipitation...

Feeding a growing population with global natural-resource constraints becomes an increasingly challenging task. Changing spatial cropping patterns could contribute to sustaining crop production and mitigating water scarcity. Previous studies on water saving through international food trade focussed either on comparing water productivities among foo...

The U.S.‐China trade conflict has already considerably reshaped China's food imports, and should the conflict continue, it might have substantial impacts on global food supply dynamics as well as China's food supply sources. We address these implications by analyzing recent trends in China's food imports and associated use of land and water resourc...

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 paper analyzed the impact of land use and its spatial configuration on streamflow in the Samin catchment (278 km 2), Indonesia. Historic land use was reconstructed based on satellite images for the years 1982, 1994, 2000, 2006, and 2013. A calibrated and validated Soil and Water Assessment Tool (SWAT) simulated the catchment hydrology of the s...

Undernutrition, obesity, climate change, and freshwater depletion share food and agricultural systems as an underlying driver. Efforts to more closely align dietary patterns with sustainability and health goals could be better informed with data covering the spectrum of countries characterized by over- and undernutrition. Here, we model the greenho...

Trade in commodities implies trade in virtual water (VW), which refers to the water that was used to produce the traded goods. Various studies have quantified international or inter-provincial virtual water (VW) flows related to the trade in crops and animal products. Until date, however, no effort has been undertaken to understand how the water em...

Global demand for livestock products is rising, resulting in a growing demand for feed and potentially burdening freshwater resources to produce this feed. To offset this increased pressure on water resources, the environmental performance of livestock sector should continue to improve. Over the last few decades, product output per animal and feeds...

The development of 'greening' cities introduces an uneasy tension between more green spaces and the increased use of scarce blue water resources to maintain this greenness, particularly in dry regions. This paper presents the first estimate of the blue water footprint (WF) of urban greenery. We estimated total water consumption of a 10-hectare pa...

The number of publications on environmental footprint indicators has been growing rapidly, but with limited efforts to integrate different footprints into a coherent framework. Such integration is important for comprehensive understanding of environmental issues, policy formulation and assessment of trade-offs between different environmental concer...

We introduce ten studies in the field of water footprint assessment (WFA) that are representative of the type of papers currently being published in this broad interdisciplinary field. WFA is the study of freshwater use, scarcity, and pollution in relation to consumption, production, and trade patterns. The reliable availability of sufficient and c...

Renewable energy sources can help combat climate change but knowing the land, water and carbon implications of different renewable energy production mixes becomes a key. This paper systematically applies land, water and carbon footprint accounting methods to calculate resource appropriation and CO 2 eq GHG emissions of two energy scenarios. The '10...

It has become common practice to speak about ‘green’ versus ‘blue’ water consumption, in order to distinguish between consumption of rainwater versus groundwater or surface water. The two sources of water differ in terms of possibilities for storage and use. Whereas industrial, municipal and livestock water supply primarily depend on blue water, cr...

Water and food security are fundamental policies for most nations. However, implementing sustainable plans for food security is not necessarily in line with short-term solutions for water resources management particularly in semi-arid and arid regions. Adaptive sustainable agricultural practices need to be taken to lessening the stress on renewable...

Water and food security are fundamental policies for most nations. However, implementing sustainable plans for food security is not necessarily in line with short-term solutions for water resources management particularly in semi-arid and arid regions. Adaptive sustainable agricultural practices need to be taken to lessening the stress on renewable...

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...

- This is the first study on the water saving effect of mulching and drip irrigation at catchment scale. - Mulching and drip irrigation will reduce the blue water footprint in Upper Litani Basin (ULB) by 5%. - Additional measures will be needed to lower the water footprint in the ULB to sustainable level. - Mulching reduces the water footprint o...

6) Institute of Geography, Urban and Regional Planning, University of Peshawar, Pakistan Over the last few decades, the demand for agricultural products has increased due to population and economic growth. This has exerted immense pressure on the available water resources of Pakistan. In this study, the annual blue and green water footprint (WF) of...

Urban water security is a major concern in the context of urbanization and climate change. Water security goes beyond having good infrastructure or good governance. Systems thinking can help in understanding the mechanisms that influence the long-term water security of a city. Therefore, we developed a dashboard of 56 indicators based on the pressu...

Population growth paired with growing freshwater scarcity in various parts of the world will reduce the potential of food self-sufficiency in many countries. Today, two thirds of the global population are already living in areas facing severe water scarcity at least one month of the year. This raises the importance of addressing the relationship be...

Driven by biofuel policies, which aim to reduce greenhouse gas (GHG) emissions and increase domestic energy supply, global production and consumption of bioethanol have doubled between 2007 and 2016, with rapid growth in corn-based bioethanol in the US and sugarcane-based bioethanol in Brazil. Advances in crop yields, energy use efficiency in ferti...

This research is the first to assess the impact of alternative agricultural practices on the blue water saving and the variation in water footprint (WF) of crop production affected by prime factors controlling yield and water consumption. These alternative practices consist of mulching and drip irrigation for summer crops. Unlike most water footpri...

We compare two rationales for the management of social-ecological systems under uncertainty: control and resilience. The first focuses at system performance, the second at system capacity to cope with change. The two schools of thought promote their own legitimacy, but undertake little effort to transcend their own perspective. Though, different sc...

Water issues in many river basins associated with droughts, water over-exploitation and pollution are increasingly being driven by remote pressures through intensified virtual water (VW) flows. However, little attention has been paid to the internal trade-offs between the (physical and virtual) water flows and the associated economic benefits and i...

The blue water footprint (WF) measures the consumption of runoff in a river basin. In order to ensure sustainable water consumption, setting a monthly blue WF cap, that is an upper-limit to the blue WF in a river basin each month, can be a suitable policy instrument. The blue WF cap in a river basin depends on the precipitation that becomes runoff...

The formulation of water footprint (WF) benchmarks in crop production – i.e. identifying reference levels of reasonable amounts of water consumption and pollution per tonne of crop produced – has been suggested as a promising strategy to counter inefficient water use and pollution. The current study is the first to show how setting WF benchmarks ma...

Hydrological response to expected future changes in land use and climate in the Samin catchment (278 km²) in Java, Indonesia, was simulated using the Soil and Water Assessment Tool model. We analysed changes between the baseline period 1983–2005 and the future period 2030–2050 under both land-use change and climate change. We used the outputs of a...

Although corporate social responsibility in general and corporate water stewardship specifically are of increasing concern to businesses, investors are lagging behind in fostering water sustainable investment practices – despite the large impact their investment decisions have on the state and shape of tomorrow's water resources. This paper is the...

During the recent drought in California, shade plastic balls, pictured, were released in the Los Angeles reservoir to reduce evaporation. By using the water footprint indicator that covers the entire supply chain of the shade balls, Haghighi et al. assess the extent to which using them is sustainable. https://www.nature.com/natsustain/volumes/1/is...

The interest in quick technologic fixes to complex water problems increases during extreme hydroclimatic events. However, past evidence shows that such fixes might be associated with unintended consequences. We revisit the idea of using shade balls in the Los Angeles reservoir to reduce evaporation during the recent drought in California, and quest...

Grey water footprint (WF) reduction is essential given the increasing water pollution associated with food production and the limited assimilation capacity of fresh water. Fertilizer application can contribute significantly to the grey WF as a result of nutrient leaching to groundwater and runoff to streams. The objective of this study is to explor...

In irrigated crop production, nitrogen (N) is often applied at high rates in order to maximize crop yield. With such high rates, the blue water footprint (WF) per unit of crop is low, but the N-related grey WF per unit of crop yield is relatively high. This study explores the trade-off between blue and grey WF at different N-application rates (from...

We review the increasing body of research on urban water security. First, we reflect on the four different focusses in water security literature: welfare, equity, sustainability and water-related risks. Second, we make an inventory of the multiple perspectives on urban water security: disciplinary perspectives (e.g. engineering, environmental, publ...

While most studies assessing the effects of land use change on hydrological processes have focused on the impact of changes in the relative occurrence of different land use types, less attention has been paid to the impacts of changes in spatial land use configuration (e.g. shape and connectivity of land use types). The impacts of the spatial land...

This study presents the first estimate of the blue and green water footprint of urban greenery. The blue water scarcity is not only an emerging challenge in agriculture but also in the urban, particularly in dry regions. The necessity of improving the wellbeing of citizens by recent movements in smart green cities introduces an uneasy tension betwe...

Global food trade entails virtual flows of agricultural resources and pollution across countries. Here we performed a global-scale assessment of impacts of international food trade on blue water use, total water use, and nitrogen (N) inputs and on N losses in maize, rice, and wheat production. We simulated baseline conditions for the year 2000 and...

The United States is the largest producer of goods and services in the world. Rainfall, surface water supplies, and groundwater aquifers represent a fundamental input to economic production. Despite the importance of water resources to economic activity, we do not have consistent information on water use for specific locations and economic sectors....

Target 6.4 of the recently adopted Sustainable Development Goals (SDGs) deals with the reduction of water scarcity. To monitor progress towards this target, two indicators are used: Indicator 6.4.1 measuring water use efficiency and 6.4.2 measuring the level of water stress (WS). This paper aims to identify whether the currently proposed indicator...

Growing water demands put increasing pressure on local water resources, especially in water-short countries. Virtual water trade can play a key role in filling the gap between local demand and supply of water-intensive commodities. This study aims to analyse the dynamics in virtual water trade of Tunisia in relation to environmental and socio-econo...

For centuries, humans have resorted to building dams to gain control over freshwater available for human consumption. Although dams and their reservoirs have made many important contributions to human development, they receive negative attention as well, because of the large amounts of water they can consume through evaporation. We estimate the blu...

Future hydrological processes in the Samin catchment (278 km2) in Java, Indonesia have been simulated using the Soil and Water Assessment Tool (SWAT) model using inputs from predicted land use distributions in the period 2030-2050, bias corrected Regional Climate Model (RCM) output and output of six Global Climate Models (GCMs) to include climate m...

We estimate the global anthropogenic phosphorus (P) loads to freshwater and the associated grey water footprints (GWFs) for the period 2002-2010, at a spatial resolution of 5 × 5 arc minute, and compare the GWF per river basin to runoff to assess the P-related water pollution level (WPL). The global anthropogenic P load to freshwater systems from b...

Numerous studies have been published on water footprints (WFs) of agricultural products, but much less on WFs of industrial products. The latter are often composed of various basic materials. Already the basic materials follow from a chain of processes, each with its specific water consumption (blue WF) and pollution (grey WF). We assess blue and g...

Iran’s focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water consumption in relation to food production, consumption, and trade, we carried ou...

In deciding what crops to grow, farmers will look at, among other things, the economicallymost productive use of the water and land resources that they have access to. However, optimizingwater and land use at the farm level may result in total water and land footprints at the catchmentlevel that are in conflict with sustainable resource use. This s...

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...

This paper reviews the evolvement of water footprint assessment (WFA) as a new research field over the past fifteen years. The research is rooted in four basic thoughts: (1) there is a global dimension to water management because water-intensive commodities are internationally traded, so we must study virtual water trade and the effects of countrie...

Changes in the stream flow of the Samin catchment (277.9 km2) in Java, Indonesia, have been attributed to land use change and climate change. Hydro-climatic data covering the period 1990-2013 and land use data acquired from Landsat satellite imageries for the years 1994 and 2013 were used and analysed. A quantitative measure is developed to attribu...

Reducing the water footprint (WF) of the process of growing irrigated crops is an indispensable element in water management, particularly in water-scarce areas. To achieve this, information on marginal cost curves (MCCs) that rank management packages according to their cost-effectiveness to reduce the WF need to support the decision making. MCCs en...

This special issue is a collection of recent papers in the field of Water Footprint Assessment (WFA), an emerging area of research focused on the analysis of freshwater use, scarcity, and pollution in relation to consumption, production, and trade. As increasing freshwater scarcity forms a major risk to the global economy, sustainable management of...

Abstract Meat production puts larger demands on water and land and results in larger greenhouse gas emissions than alternative forms of food. This study uses footprint indicators, the water, land and carbon footprint, to assess natural resources use and greenhouse gas emissions for sheep and chicken meat produced in Tunisia in different farming sys...

Changes in the water balance of the Samin catchment (277.9 km2) on Java, Indonesia, can be attributed to land use change using the Soil Water Assessment Tool (SWAT) model. A baseline-altered method was used in which the simulation period 1990 – 2013 was divided into four equal periods to represent baseline conditions (1990 – 1995) and altered land...

Grey water footprint (WF) reduction is essential given the increasing water pollution associated with food production and the limited assimilation capacity of fresh water. Fertilizer application can contribute significantly to the grey WF as a result of nutrient leaching to groundwater and runoff to streams. The objective of this study is to explor...

The depletion of water resources, in terms of both quantity and quality, has become a major concern both locally and globally. Ruminants, in particular, are under increased public scrutiny due to their relatively high water use per unit of meat or milk produced. Estimating the water footprint of livestock production is a relatively new field of res...

Abstract Iran is the second largest country in the Middle East and is facing a dangerous water crisis in the recent years. Agriculture is the biggest fresh water user in Iran, accounting for over 90% of national water abstraction, and therefore, inefficient water management in this sector is known as the main source of water shortage across the cou...

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...

Water scarcity is a major challenge in the coming decades. The increasing population and the changing pattern of water availability that results from global warming reduce the potential of sufficient food production in many countries over the world. Today, two thirds of the global population are already living under conditions of severe water scarc...

Impacts of land use change on the water balance of a catchment are still not fully understood due to climatic interferences. For tropical regions, only few studies have attempted to attribute changes in the water balance to land use change, where some of the results are contradictory and inconsistent, in particular for large catchments (> 100 km2)....

Hydrological models often require input data on soil-water retention (SWR), but obtaining such data is laborious and costly so that SWR in many places remains unknown. To fill the gap, a prediction of SWR using a pedotransfer function (PTF) is one of the alternatives. This study aims to select the most suitable existing PTFs in order to predict SWR...

Future freshwater supply, human water demand, and people's exposure to water stress are subject to multiple sources of uncertainty, including unknown future pathways of fossil fuel and water consumption, and 'irreducible' uncertainty arising from internal climate system variability. Such internal variability can conceal forced hydroclimatic changes...

The depletion of water resources, in terms of both quantity and quality, has become a major concern both locally and globally. Ruminants, in particular, are under increased public scrutiny due to their relatively high water use per unit of meat or milk produced. Estimating the water footprint of livestock production is a relatively new field of res...

This paper explores the effect of varying agricultural management practices on different water efficiency indicators: irrigation efficiency (IE), crop water use efficiency (WUE), and green and blue water footprint (WF). We take winter wheat in an experimental field in Northern China as a case study and consider a dry, average and wet year. We condu...