Mapping global agricultural economic water scarcity to identify target areas for sustainable irrigation expansion

2020 ◽  
Author(s):  
Lorenzo Rosa ◽  
Davide Danilo Chiarelli ◽  
Maria Cristina Rulli ◽  
Jampel Dell'Angelo ◽  
Paolo D'Odorico
Keyword(s):  
Food Security ◽  
Agricultural Economic ◽  
Water Scarcity ◽  
Food Production ◽  
Sub Saharan Africa ◽  
Green Water ◽  
Blue Water ◽  
Water Scarce ◽  
Sustainable Irrigation ◽  
Water And Food Security

<p>With continuing growth in food demand and limited potential for cropland expansion, sustainable irrigation becomes an increasingly important strategy to ensure a reliable and resilient global supply of food in a changing climate. We here define and introduce the original concept of ‘agricultural economic water scarcity’ as the condition whereby croplands exposed to green water scarcity are not irrigated even though a sufficient amount of renewable blue water resources for irrigation is locally available. These conditions occur for instance as a result of a variety of socio-economic and political factors that impede irrigation. To date, little attention has been given to the analysis of this phenomenon and its role in the global geography of water scarcity. Here, we develop and apply a monthly agro-hydrological model to quantify and map croplands affected by agricultural green, blue, and economic water scarcity. By doing so we firstly provide a comprehensive, spatially explicit, global mapping of agricultural economic water scarcity across the global croplands. We then assess the water and food security implications of increased food production from irrigation expansion over economically water scarce croplands. Our results show that up to 25% of global croplands face agricultural economic water scarcity. Two thirds of economically water scarce lands are located in Sub-Saharan Africa, Eastern Europe, and Central Asia. Here, a sustainable irrigation expansion could increase food production and feed an additional 850 million people, while preventing further aggravation of blue water scarcity. The application of the concept of agricultural economic water scarcity has the potential to identify target areas for sustainable water and food security policies at global, regional, national, and local scales.</p>

scholarly journals Global agricultural economic water scarcity

2020 ◽  
Vol 6 (18) ◽  
pp. eaaz6031 ◽  
Author(s):  
Lorenzo Rosa ◽  
Davide Danilo Chiarelli ◽  
Maria Cristina Rulli ◽  
Jampel Dell’Angelo ◽  
Paolo D’Odorico
Keyword(s):  
Agricultural Economic ◽  
Water Scarcity ◽  
Sub Saharan Africa ◽  
Ecosystem Functions ◽  
Sub Saharan ◽  
Productivity Potential ◽  
Water Scarce ◽  
Sustainable Irrigation ◽  
Agricultural Regions ◽  
Economic Capacity

Water scarcity raises major concerns on the sustainable future of humanity and the conservation of important ecosystem functions. To meet the increasing food demand without expanding cultivated areas, agriculture will likely need to introduce irrigation in croplands that are currently rain-fed but where enough water would be available for irrigation. “Agricultural economic water scarcity” is, here, defined as lack of irrigation due to limited institutional and economic capacity instead of hydrologic constraints. To date, the location and productivity potential of economically water scarce croplands remain unknown. We develop a monthly agrohydrological analysis to map agricultural regions affected by agricultural economic water scarcity. We find these regions account for up to 25% of the global croplands, mostly across Sub-Saharan Africa, Eastern Europe, and Central Asia. Sustainable irrigation of economically water scarce croplands could feed an additional 840 million people while preventing further aggravation of blue water scarcity.

scholarly journals Climate-driven interannual variability of water scarcity in food production potential: a global analysis

2014 ◽  
Vol 18 (2) ◽  
pp. 447-461 ◽  
Author(s):  
M. Kummu ◽  
D. Gerten ◽  
J. Heinke ◽  
M. Konzmann ◽  
O. Varis
Keyword(s):  
Water Availability ◽  
Water Scarcity ◽  
Food Production ◽  
Global Analysis ◽  
Reference Conditions ◽  
Food Storage ◽  
Blue Water ◽  
Animal Products ◽  
Hydroclimatic Variability ◽  
Water Scarce

Abstract. Interannual climatic and hydrologic variability has been substantial during the past decades in many regions. While climate variability and its impacts on precipitation and soil moisture have been studied intensively, less is known on subsequent implications for global food production. In this paper we quantify effects of hydroclimatic variability on global "green" and "blue" water availability and demand in global agriculture, and thus complement former studies that have focused merely on long-term averages. Moreover, we assess some options to overcome chronic or sporadic water scarcity. The analysis is based on historical climate forcing data sets over the period 1977–2006, while demography, diet composition and land use are fixed to reference conditions (year 2000). In doing so, we isolate the effect of interannual hydroclimatic variability from other factors that drive food production. We analyse the potential of food production units (FPUs) to produce a reference diet for their inhabitants (3000 kcal cap−1 day−1, with 80% vegetal food and 20% animal products). We applied the LPJmL vegetation and hydrology model to calculate the variation in green-blue water availability and the water requirements to produce that very diet. An FPU was considered water scarce if its water availability was not sufficient to produce the diet (i.e. assuming food self-sufficiency to estimate dependency on trade from elsewhere). We found that 24% of the world's population lives in chronically water-scarce FPUs (i.e. water is scarce every year), while an additional 19% live under occasional water scarcity (water is scarce in some years). Among these 2.6 billion people altogether, 55% would have to rely on international trade to reach the reference diet, while for 24% domestic trade would be enough. For the remaining 21% of the population exposed to some degree of water scarcity, local food storage and/or intermittent trade would be enough to secure the reference diet over the occasional dry years.

scholarly journals The Impact of Water-Related Challenges on Rural Communities Food Security Initiatives

2021 ◽  
Vol 7 (1) ◽  
pp. 11-23
Author(s):  
Ndivhoniswani Nephawe ◽  
Marizvikuru Mwale ◽  
Jethro Zuwarimwe ◽  
Malose Moses Tjale
Keyword(s):  
Food Security ◽  
Rural Communities ◽  
Water Scarcity ◽  
Food Production ◽  
Agricultural Sector ◽  
Water Security ◽  
Research Areas ◽  
Water Scarce ◽  
The Impact ◽  
Practical Implications

Water scarcity has been a critical concern in many countries of the world. The same concern has been discussed, analyzed and researched at different platforms to find better solutions to the challenges of water scarcity, and in most cases water scarcity directly influence food security in terms of food production. South Africa, being one of the water scarce countries that derives its food from the agricultural sector; water scarcity remains at the centre stage of the national socioeconomic debate. Water scarcity is one of the major challenges in many countries such as Zimbabwe and Ethiopia particularly for the farmers. However, there is insufficient information on the impact of water scarcity challenges on rural communities’ food security initiatives. This review is focused on unearthing water scarcity challenges in rural communities, their impact on agriculture and ultimately food security initiatives. This paves way for possible research areas, practical implications and strategies to mitigate water security effects on food security.

Green Water and Food Security

2018 ◽  
pp. 44-60 ◽  
Author(s):  
Garrison Sposito
Keyword(s):  
Food Security ◽  
Food Production ◽  
Agricultural Land ◽  
Green Water ◽  
World Food ◽  
The World ◽  
Global Increase ◽  
Water And Food Security ◽  
Crop Biomass

Green water is defined as the water in soil that is potentially available to plants for uptake and subsequent transpiration. Despite the fact that crop biomass is directly related to transpiration and the global transpiration flow alone matches that of all the rivers in the world, green water has until recently been largely neglected in research on food security. That long neglect is redressed by a review of recent research on the role of green water in the production of agricultural commodities to meet current and future world food demand, including how the differences in water requirement between plant-based and animal-based commodities play out in respect to the food-water nexus. Informed by current literature, a case is made for optimizing green water management to achieve a global increase in food production from 20 to 40 percent without an expansion of either agricultural land use or the volume of water withdrawn for irrigation.

Water scarcity and food security: alternative futures for the 21st century

2001 ◽  
Vol 43 (4) ◽  
pp. 61-70 ◽  
Author(s):  
M. W. Rosengrant ◽  
X. Cai
Keyword(s):  
Food Security ◽  
Water Availability ◽  
Water Scarcity ◽  
Food Production ◽  
Irrigated Agriculture ◽  
Modeling Framework ◽  
Alternative Futures ◽  
Water Demands ◽  
Agriculture And Food

Water availability for agriculture - the major water user worldwide - is one of the most critical factors for food security in many regions of the world. The role of water withdrawals in irrigated agriculture and food security has been receiving substantial attention in recent years. This paper addresses key questions regarding water availability and food security, including: How will water availability and water demand evolve over the next three decades, taking into account availability and variability in water resources, the water supply infrastructure, and irrigation and nonagricultural water demands? What are the relationships among water scarcity, food production, and food security? How much of future food production will come from rainfed and irrigated areas? A global modeling framework, IMPACT-Water, is applied to explore answers to these questions using analysis.

scholarly journals Dilemma of nitrogen management for future food security in sub-Saharan Africa – a review

Soil Research ◽  
2017 ◽  
Vol 55 (6) ◽  
pp. 425 ◽  
Author(s):  
Cargele Masso ◽  
Fredrick Baijukya ◽  
Peter Ebanyat ◽  
Sifi Bouaziz ◽  
John Wendt ◽  
...  
Keyword(s):  
Food Security ◽  
Food Production ◽  
Smallholder Farmers ◽  
Lake Victoria ◽  
Research Capacity ◽  
Sub Saharan Africa ◽  
N Recovery ◽  
Sub Saharan ◽  
Other World ◽  
N Use

Food security entails having sufficient, safe, and nutritious food to meet dietary needs. The need to optimise nitrogen (N) use for nutrition security while minimising environmental risks in sub-Saharan Africa (SSA) is overdue. Challenges related to managing N use in SSA can be associated with both insufficient use and excessive loss, and thus the continent must address the ‘too little’ and ‘too much’ paradox. Too little N is used in food production (80% of countries have N deficiencies), which has led to chronic food insecurity and malnutrition. Conversely, too much N load in water bodies due mainly to soil erosion, leaching, limited N recovery from wastewater, and atmospheric deposition contributes to eutrophication (152 Gg N year–1 in Lake Victoria, East Africa). Limited research has been conducted to improve N use for food production and adoption remains low, mainly because farming is generally practiced by resource-poor smallholder farmers. In addition, little has been done to effectively address the ‘too much’ issues, as a consequence of limited research capacity. This research gap must be addressed, and supportive policies operationalised, to maximise N benefits, while also minimising pollution. Innovation platforms involving key stakeholders are required to address N use efficiency along the food supply chain in SSA, as well as other world regions with similar challenges.

scholarly journals Optimizing cropland cover for stable food production in Sub-Saharan Africa using simulated yield and Modern Portfolio Theory

2014 ◽  
Vol 5 (2) ◽  
pp. 1571-1606 ◽  
Author(s):  
P. Bodin ◽  
S. Olin ◽  
T. A. M. Pugh ◽  
A. Arneth
Keyword(s):  
Food Security ◽  
Food Production ◽  
Local Food ◽  
Local Population ◽  
Portfolio Theory ◽  
Sub Saharan Africa ◽  
Modern Portfolio Theory ◽  
Local Food Production ◽  
Sub Saharan ◽  
Access To Food

Abstract. Food security can be defined as stable access to food of good nutritional quality. In Sub Saharan Africa access to food is strongly linked to local food production and the capacity to generate enough calories to sustain the local population. Therefore it is important in these regions to generate not only sufficiently high yields but also to reduce interannual variability in food production. Traditionally, climate impact simulation studies have focused on factors that underlie maximum productivity ignoring the variability in yield. By using Modern Portfolio Theory, a method stemming from economics, we here calculate optimum current and future crop selection that maintain current yield while minimizing variance, vs. maintaining variance while maximizing yield. Based on simulated yield using the LPJ-GUESS dynamic vegetation model, the results show that current cropland distribution for many crops is close to these optimum distributions. Even so, the optimizations displayed substantial potential to either increase food production and/or to decrease its variance regionally. Our approach can also be seen as a method to create future scenarios for the sown areas of crops in regions where local food production is important for food security.

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