scholarly journals Global Water Availability and Requirements for Future Food Production

2011 ◽  
Vol 12 (5) ◽  
pp. 885-899 ◽  
Author(s):  
D. Gerten ◽  
J. Heinke ◽  
H. Hoff ◽  
H. Biemans ◽  
M. Fader ◽  
...  
Keyword(s):  
Water Availability ◽  
Water Scarcity ◽  
Food Production ◽  
General Circulation ◽  
Population Change ◽  
Water Productivity ◽  
General Circulation Models ◽  
Water Requirements ◽  
Balanced Diet ◽  
Per Capita

Abstract This study compares, spatially explicitly and at global scale, per capita water availability and water requirements for food production presently (1971–2000) and in the future given climate and population change (2070–99). A vegetation and hydrology model Lund–Potsdam–Jena managed Land (LPJmL) was used to calculate green and blue water availability per capita, water requirements to produce a balanced diet representing a benchmark for hunger alleviation [3000 kilocalories per capita per day (1 kilocalorie = 4184 joules), here assumed to consist of 80% vegetal food and 20% animal products], and a new water scarcity indicator that relates the two at country scale. A country was considered water-scarce if its water availability fell below the water requirement for the specified diet, which is presently the case especially in North and East Africa and in southwestern Asia. Under climate (derived from 17 general circulation models) and population change (A2 and B1 emissions and population scenarios), water availability per person will most probably diminish in many regions. At the same time the calorie-specific water requirements tend to decrease, due mainly to the positive effect of rising atmospheric CO2 concentration on crop water productivity—which, however, is very uncertain to be fully realized in most regions. As a net effect of climate, CO2, and population change, water scarcity will become aggravated in many countries, and a number of additional countries are at risk of losing their present capacity to produce a balanced diet for their inhabitants.

scholarly journals Analysis of intra-country virtual water trade strategy to alleviate water scarcity in Iran

2010 ◽  
Vol 7 (2) ◽  
pp. 2609-2649 ◽  
Author(s):  
M. Faramarzi ◽  
H. Yang ◽  
J. Mousavi ◽  
R. Schulin ◽  
C. R. Binder ◽  
...  
Keyword(s):  
Water Scarcity ◽  
Food Production ◽  
Water Productivity ◽  
National Level ◽  
Virtual Water ◽  
Mixed Integer ◽  
Baseline Scenario ◽  
Cropping Pattern ◽  
Virtual Water Trade ◽  
Cereal Production

Abstract. Increasing water scarcity has posed a major constraint to sustain food production in many parts of the world. To study the situation at the regional level, we took Iran as an example and analyzed how an intra-country "virtual water trade strategy" (VWTS) may help improve cereal production as well as alleviate the water scarcity problem. This strategy calls, in part, for the adjustment of the structure of cropping pattern (ASCP) and interregional food trade where crop yield and crop water productivity as well as local economic and social conditions are taken into account. We constructed a systematic framework to assess ASCP at the provincial level under various driving forces and constraints. A mixed-integer, multi-objective, linear optimization model was developed and solved by linear programming. Data from 1990–2004 were used to account for yearly fluctuations of water availability and food production. Five scenarios were designed aimed at maximizing the national cereal production while meeting certain levels of wheat self-sufficiency under various water and land constraints in individual provinces. The results show that under the baseline scenario, which assumes a continuation of the existing water use and food policy at the national level, some ASCP scenarios could produce more wheat with less water. Based on different scenarios in ASCP, we calculated that 31% to 100% of the total wheat shortage in the deficit provinces could be supplied by the wheat surplus provinces. As a result, wheat deficit provinces would receive 3.5 billion m3 to 5.5 billion m3 of virtual water by importing wheat from surplus provinces.

How water scarcity will shape the new century

2001 ◽  
Vol 43 (4) ◽  
pp. 17-22 ◽  
Author(s):  
Lester R. Brown
Keyword(s):  
Water Resources ◽  
Water Scarcity ◽  
Food Production ◽  
Protein Production ◽  
Water Productivity ◽  
Animal Protein ◽  
Scarce Resource

Water resources are increasingly being overexploited, such that current food production, which relies heavily on irrigation schemes, is unsustainable. Many steps, including improved irrigation techniques, more water-efficient crops and animal protein production, etc., will be needed to raise water productivity across the board. Water must in future be recognised as a scarce resource and not taken for granted.

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 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 Projection of Water Availability and Sustainability in Nigeria Due to Climate Change

2021 ◽  
Vol 13 (11) ◽  
pp. 6284
Author(s):  
Mohammed Sanusi Shiru ◽  
Shamsuddin Shahid ◽  
Inhwan Park
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
General Circulation ◽  
Water Storage ◽  
Coupled Model ◽  
General Circulation Models ◽  
Research Unit ◽  
Wet Season ◽  
Spatiotemporal Changes ◽  
Terrestrial Water

This study projects water availability and sustainability in Nigeria due to climate change. This study used Gravity Recovery and Climate Experiment (GRACE) terrestrial water storage data (TWS), Global Precipitation Climatology Center (GPCC) precipitation data and Climate Research Unit (CRU) temperature data. Four general circulation models (GCMs) of the Coupled Model Intercomparison Project 5 were downscaled using the best of four downscaling methods. Two machine learning (ML) models, RF and SVM, were developed to simulate GRACE TWS data for the period 2002–2016 and were then used for the projection of spatiotemporal changes in TWS. The projected TWS data were used to assess the spatiotemporal changes in water availability and sustainability based on the reliability–resiliency–vulnerability (RRV) concept. This study revealed that linear scaling was the best for downscaling over Nigeria. RF had better performance than SVM in modeling TWS for the study area. This study also revealed there would be decreases in water storage during the wet season (June–September) and increases in the dry season (January–May). Decreases in projected water availability were in the range of 0–12 mm for the periods 2010–2039, 2040–2069, and 2070–2099 under RCP2.6 and in the range of 0–17 mm under RCP8.5 during the wet season. Spatially, annual changes in water storage are expected to increase in the northern part and decrease in the south, particularly in the country’s southeast. Groundwater sustainability was higher during the period 2070–2099 under all RCPs compared to the other periods and this can be attributed to the expected increases in rainfall during this period.

scholarly journals Optimal water allocation of the Zayandeh-Roud Reservoir in Iran based on inflow projection under climate change scenarios

2021 ◽  
Author(s):  
Fatemeh Saedi ◽  
Azadeh Ahmadi ◽  
Karim C. Abbaspour
Keyword(s):  
Climate Change ◽  
Water Availability ◽  
Climate Change Impact ◽  
General Circulation ◽  
Assessment Tool ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Climate Change Scenarios ◽  
Change Impact ◽  
The Impact

Abstract The climate change impact on water availability has become a significant cause for concern in the Zayandeh-Roud Reservoir in Iran and similar reservoirs in arid regions. This study investigates the climate change impact on supplying water and water availability in the Zayandeh-Roud River Basin. For better management, the Soil & Water Assessment Tool (SWAT) was used to develop a hydrologic model of the Basin. The model then was calibrated and validated for two upstream stations using the SUFI-2 algorithm in the SWAT-CUP software. The impact of climate change was modeled by using data derived from five Inter-Sectoral Impact Model Intercomparison Project general circulation models under four Representative Concentration Pathways (RCPs). For calibration (1991–2008), the Nash–Sutcliffe efficiency (NSE) values of 0.75 and 0.61 at the Ghaleshahrokh and Eskandari stations were obtained, respectively. For validation (2009–2015), the NSE values were 0.80 and 0.82, respectively. The reservoir inflow would probably reduce by 40–50% during the period of 2020–2045 relative to the base period of 1981–2006. To evaluate the reservoir's future performance, a nonlinear optimization model was used to minimize water deficits. The highest annual water deficit would likely be around 847 MCM. The lowest reservoir reliability and the highest vulnerability occurred under the extreme RCP8.5 pathway.

Projected climate conditions to 2100 for Regina, Saskatchewan

2010 ◽  
Vol 37 (9) ◽  
pp. 1247-1260 ◽  
Author(s):  
Andrew deJong ◽  
Edward McBean ◽  
Bahram Gharabaghi
Keyword(s):  
Water Availability ◽  
General Circulation ◽  
Historical Data ◽  
Potential Evapotranspiration ◽  
General Circulation Models ◽  
Climate Conditions ◽  
Temperature And Precipitation ◽  
Aerosol Emissions ◽  
Increasing Trends ◽  
Precipitation Projections

Possible trends of climate (temperature, precipitation, and potential evapotranspiration (PET)) for Regina, Saskatchewan are described, premised on comparisons of both projections from historical data and calculations from use of four general circulation models (GCMs). Results derived from GCMs of CGCM3.1, CCSM3, HadGEM1 and MIROC3.2, along with a series of storylines describing the relationships between the forces driving greenhouse gas and aerosol emissions during the 21st century, are employed which demonstrate increasing trends in temperature and precipitation. Unlike the identifiable and divergent projections of mean annual temperatures, there are relatively small differences in total annual precipitation projections using a number of projected scenarios of emissions. Further, although the projections indicate higher rates of precipitation are expected, there will not be increased water availability due to greater projected increases in PET, translating to there being less water available in the next century.

scholarly journals A coupled human–natural system analysis of freshwater security under climate and population change

2021 ◽  
Vol 118 (14) ◽  
pp. e2020431118
Author(s):  
Jim Yoon ◽  
Christian Klassert ◽  
Philip Selby ◽  
Thibaut Lachaut ◽  
Stephen Knox ◽  
...  
Keyword(s):  
Low Income ◽  
Water Availability ◽  
Large Scale ◽  
System Analysis ◽  
Population Change ◽  
Water Security ◽  
Well Being ◽  
Water Model ◽  
Systems Model ◽  
Per Capita

Limited water availability, population growth, and climate change have resulted in freshwater crises in many countries. Jordan’s situation is emblematic, compounded by conflict-induced population shocks. Integrating knowledge across hydrology, climatology, agriculture, political science, geography, and economics, we present the Jordan Water Model, a nationwide coupled human–natural-engineered systems model that is used to evaluate Jordan’s freshwater security under climate and socioeconomic changes. The complex systems model simulates the trajectory of Jordan’s water system, representing dynamic interactions between a hierarchy of actors and the natural and engineered water environment. A multiagent modeling approach enables the quantification of impacts at the level of thousands of representative agents across sectors, allowing for the evaluation of both systemwide and distributional outcomes translated into a suite of water-security metrics (vulnerability, equity, shortage duration, and economic well-being). Model results indicate severe, potentially destabilizing, declines in freshwater security. Per capita water availability decreases by approximately 50% by the end of the century. Without intervening measures, >90% of the low-income household population experiences critical insecurity by the end of the century, receiving <40 L per capita per day. Widening disparity in freshwater use, lengthening shortage durations, and declining economic welfare are prevalent across narratives. To gain a foothold on its freshwater future, Jordan must enact a sweeping portfolio of ambitious interventions that include large-scale desalinization and comprehensive water sector reform, with model results revealing exponential improvements in water security through the coordination of supply- and demand-side measures.

scholarly journals Climate change impacts on Central Asian water resources

2012 ◽  
Vol 32 ◽  
pp. 77-83 ◽  
Author(s):  
M. Malsy ◽  
T. Aus der Beek ◽  
S. Eisner ◽  
M. Flörke
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Water Availability ◽  
General Circulation ◽  
Input Data ◽  
Large Scale ◽  
General Circulation Models ◽  
Central Asian ◽  
Ipcc Sres ◽  
Asian Water

Abstract. Central Asia is in large parts dominated by low precipitation and, consequentially, by low water availability. Therefore, changes of natural water resources induced by climate change are of high interest. The aim of this study is to analyse the potential impact of climate change on Central Asian water resources until the end of the 21st century and to point out the main affected regions. Thus, simulations with the large-scale hydrology model WaterGAP3 for the baseline and scenario periods were performed with outputs from three General Circulation Models (GCMs: ECHAM5, IPSL-CM4, and CNRM-CM3) and two IPCC-SRES emission scenarios (A2 and B1). The results show that mean modelled annual water availability increases for all scenarios and GCMs while CNRM-CM3 induces the wettest water situation for the 2085s and ECHAM5 the lowest water availability. Furthermore, robust trends to wetter or dryer conditions could be found for many basins. A seasonal shift of mean modelled water availability could be derived for ECHAM5 which does not show a second peak during summer. The application of daily input data showed no improvement of modelled monthly river discharges for most Central Asian basins compared to monthly input data.

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

2013 ◽  
Vol 10 (6) ◽  
pp. 6931-6962 ◽  
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 ◽  
The Past ◽  
Hydroclimatic Variability

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 rather intensively studied, less is known on its impacts on freshwater availability and further implications for global food production. In this paper we quantify effects of hydroclimatic variability on global "green" and "blue" water availability and demand in agriculture. Analysis is based on climate forcing data for the past 30 yr with demography, diet composition and land use fixed to constant reference conditions. We thus assess how observed interannual hydroclimatic variability impacts on the ability of food production units (FPUs) to produce a given diet for their inhabitants, here focused on a benchmark for hunger alleviation (3000 kilocalories per capita per day, with 80% vegetal food and 20% animal products). We applied the LPJmL vegetation and hydrology model to calculate spatially explicitly 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 (neglecting trade from elsewhere, i.e. assuming food self-sufficiency). We found that altogether 24% of the global population lives in areas under chronic scarcity (i.e. water is scarce every year) while an additional 19% live under occasional water scarcity (i.e. water is scarce in some years). Of these 2.6 billion people under some degree of scarcity, 55% would have to rely on international trade to reach the reference diet while for 24% domestic trade would be enough (assuming present cropland extent and management). For the remaining 21% of population under scarcity, local food storage and/or intermittent trade would be enough secure the reference diet over the occasional dry years.

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