Global scenarios of irrigation water use for bioenergy production: a systematic review

Abstract. Many scenarios of future climate evolution and its anthropogenic drivers include considerable amounts of bioenergy as fuel source, negative emission technology, or for final energy production. The associated freshwater requirements for irrigation of dedicated biomass plantations might be substantial and therefore potentially increase water limitation and stress in affected regions; however, assumptions and quantities of water use provided in the literature vary strongly. This paper reviews existing global assessments of freshwater requirements for such bioenergy production and puts these estimates into the context of scenarios for other water use sectors. We scanned the available literature and (out of 430 initial hits) found 16 publications (partly including several scenarios) with reported values on global water demand for irrigation of biomass plantations, suggesting a range of 125–11,350 km3 yr−1 water use (consumption), compared to about 1,100–11,600 km3 yr−1 for other (agricultural, industrial, and domestic) water withdrawals. To provide an understanding of the origins of this large range, we present the diverse underlying assumptions, discuss major study differences, and make the freshwater amounts involved comparable by estimating the original biomass harvests from reported final energy or negative emissions. We conclude that due to the potentially high water demands and the trade-offs that might go along with them, bioenergy should be an integral part of global assessments of freshwater demand and use. For interpreting and comparing reported estimates of possible future bioenergy water demands, full disclosure of parameters and assumptions is crucial. A minimum set should include annual blue water consumption and withdrawal, bioenergy crop species, rainfed as well as irrigated bioenergy plantation locations (including total area), and total bioenergy harvest amounts.

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Global scenarios of irrigation water abstractions for bioenergy production: a systematic review

Hydrology and Earth System Sciences ◽

10.5194/hess-25-1711-2021 ◽

2021 ◽

Vol 25 (4) ◽

pp. 1711-1726

Author(s):

Fabian Stenzel ◽

Dieter Gerten ◽

Naota Hanasaki

Keyword(s):

Water Use ◽

Irrigation Water ◽

High Water ◽

Green Water ◽

Total Biomass ◽

Domestic Water ◽

Crop Species ◽

Biomass Harvest ◽

Bioenergy Production ◽

Water Withdrawals

Abstract. Many scenarios of future climate evolution and its anthropogenic drivers include considerable amounts of bioenergy as a fuel source, as a negative emission technology, and for providing electricity. The associated freshwater abstractions for irrigation of dedicated biomass plantations might be substantial and therefore potentially increase water limitation and stress in affected regions; however, assumptions and quantities of water use provided in the literature vary strongly. This paper reviews existing global assessments of freshwater abstractions for bioenergy production and puts these estimates into the context of scenarios of other water-use sectors. We scanned the available literature and (out of 430 initial hits) found 16 publications (some of which include several bioenergy-water-use scenarios) with reported values on global irrigation water abstractions for biomass plantations, suggesting water withdrawals in the range of 128.4 to 9000 km3 yr−1, which would come on top of (or compete with) agricultural, industrial, and domestic water withdrawals. To provide an understanding of the origins of this large range, we present the diverse underlying assumptions, discuss major study differences, and calculate an inverse water-use efficiency (iwue), which facilitates comparison of the required freshwater amounts per produced biomass harvest. We conclude that due to the potentially high water demands and the tradeoffs that might go along with them, bioenergy should be an integral part of global assessments of freshwater demand and use. For interpreting and comparing reported estimates of possible future bioenergy water abstractions, full disclosure of parameters and assumptions is crucial. A minimum set should include the complete water balances of bioenergy production systems (including partitioning of blue and green water), bioenergy crop species and associated water-use efficiencies, rainfed and irrigated bioenergy plantation locations (including total area and meteorological conditions), and total biomass harvest amounts. In the future, a model intercomparison project with standardized parameters and scenarios would be helpful.

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Bioenergy potentials from recently abandoned cropland under the land-energy-water nexus

10.5194/egusphere-egu21-16111 ◽

2021 ◽

Author(s):

Jan Sandstad Næss ◽

Otavio Cavalett ◽

Francesco Cherubini

Keyword(s):

Nature Conservation ◽

Water Use ◽

Soil Characteristics ◽

Agricultural Management ◽

Site Specific ◽

Bioenergy Production ◽

Trade Offs ◽

Irrigation Water Use ◽

Land Availability ◽

Abandoned Cropland

Bioenergy plays a key role in scenarios limiting global warming below 2&#176;C in 2100 relative to pre-industrial times. Land availability for bioenergy production is constrained due to competition with agriculture, nature conservation and other land uses. Utilizing recently abandoned cropland to produce bioenergy is a promising option for gradual bioenergy deployment with lower risks of potential trade-offs on food security and the environment. Up until now, the global extent of abandoned cropland has been unclear. Furthermore, there is a need to better map bioenergy potentials, taking into account site-specific conditions such as local climate, soil characteristics, agricultural management and water use.Our study spatially quantify global bioenergy potentials from recently abandoned cropland under the land-energy-water nexus. We integrate a recently developed high-resolution satellite-derived land cover product (European Space Agency Climate Change Initiative Land Cover) with an agro-ecological crop yield model (Global Agro-Ecological Zones 3.0). Abandoned cropland is mapped as pixels transitioning from cropland to non-urban classes. We further identify candidate areas for nature conservation and areas with increased pressure on water resources. Based on climatic conditions, soil characteristics and agricultural management levels, we spatially model bioenergy yields and irrigation water use on abandoned cropland for three perennial grasses. We compute and analyze bioenergy potentials for 296 different variants of management factors and land and water use constraints. By assessing key energy, water and land indicators, we identify optimal bioenergy production strategies and site-specific trade-offs.We found 83 million hectares of abandoned cropland between 1992 and 2015, equivalent of 5% of today&#8217;s cropland area. Bioenergy potentials range between 6-39 exajoules per year (EJ yr-1) (11-68% of today&#8217;s bioenergy demand), depending on agricultural management, land availability and irrigation water use. We further show and extensively discuss site-specific trade-offs between increased bioenergy production, land-use and water-use. Our high-end estimate (39 EJ yr-1) relies on complete irrigation and land availability. When acknowledging site-specific trade-offs on water resources and nature conservation, a potential of 20 EJ yr-1 is achievable without production in biodiversity hotspots or irrigation in water scarce areas. This is equal to 8-23% of median projected bioenergy demand in 2050 for 1.5&#176;C scenarios across different Shared Socio-economic Pathways. The associated land and water requirements are equal to 3% of current global cropland extent and 8% of today&#8217;s global agricultural water use, respectively.

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China's water sustainability in the 21st century: a climate-informed water risk assessment covering multi-sector water demands

Hydrology and Earth System Sciences ◽

10.5194/hess-18-1653-2014 ◽

2014 ◽

Vol 18 (5) ◽

pp. 1653-1662 ◽

Cited By ~ 12

Author(s):

X. Chen ◽

D. Naresh ◽

L. Upmanu ◽

Z. Hao ◽

L. Dong ◽

...

Keyword(s):

Water Stress ◽

Risk Measures ◽

Rainfall Variability ◽

Political Process ◽

Temporal Distribution ◽

High Water ◽

Annual Rainfall ◽

Water Sustainability ◽

Domestic Water ◽

Water Demands

Abstract. China is facing a water resources crisis with growing concerns as to the reliable supply of water for agricultural, industrial and domestic needs. High inter-annual rainfall variability and increasing consumptive use across the country exacerbates the situation further and is a constraint on future development. For water sustainability, it is necessary to examine the differences in water demand and supply and their spatio-temporal distribution in order to quantify the dimensions of the water risk. Here, a detailed quantitative assessment of water risk as measured by the spatial distribution of cumulated deficits for China is presented. Considering daily precipitation and temperature variability over fifty years and the current water demands, risk measures are developed to inform county level water deficits that account for both within-year and across-year variations in climate. We choose political rather than watershed boundaries since economic activity and water use are organized by county and the political process is best informed through that unit. As expected, the risk measures highlight North China Plain counties as highly water stressed. Regions with high water stress have high inter-annual variability in rainfall and now have depleted groundwater aquifers. The stress components due to agricultural, industrial and domestic water demands are illustrated separately to assess the vulnerability of particular sectors within the country to provide a basis for targeted policy analysis for reducing water stress.

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China's water sustainability in the 21st century: a climate informed water risk assessment covering multi-sector water demands

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-10-11129-2013 ◽

2013 ◽

Vol 10 (8) ◽

pp. 11129-11150 ◽

Cited By ~ 5

Author(s):

X. Chen ◽

N. Devineni ◽

U. Lall ◽

Z. Hao ◽

L. Dong ◽

...

Keyword(s):

Water Stress ◽

Risk Measures ◽

Rainfall Variability ◽

Political Process ◽

Temporal Distribution ◽

High Water ◽

Annual Rainfall ◽

Water Sustainability ◽

Domestic Water ◽

Water Demands

Abstract. China is facing a water resources crisis with growing concerns as to the reliable supply of water for agricultural, industrial and domestic needs. High inter-annual rainfall variability and increasing consumptive use across the country exacerbates the situation further and is a constraint on future development. For water sustainability, it is necessary to examine the differences in water demand and supply and their spatio-temporal distribution in order to quantify the dimensions of the water risk. Here, a detailed quantitative assessment of water risk as measured by the distribution of cumulated deficits for China is presented. Considering daily precipitation and temperature variability over fifty years and the current water demands, risk measures are developed to inform county level water deficits that account for both within year and across year variations in climate. We choose political rather than watershed boundaries since economic activity and water use are organized by county and the political process is best informed through that unit. The risk measures highlight North China Plain counties as highly water stressed. Regions with high water stress are typically the regions with high inter-annual variability in rainfall and now have depleted groundwater aquifers. The stress components due to agricultural, industrial and domestic water demands are illustrated separately to assess the vulnerability of particular sectors within the country to provide a basis for targeted policy analysis for reducing water stress.

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Socioeconomic potential for rainwater harvesting systems in southern Brazilian municipalities

Water Science & Technology Water Supply ◽

10.2166/ws.2021.291 ◽

2021 ◽

Author(s):

L. C. Tavares ◽

J. M. Bravo ◽

R. Tassi ◽

I. R. Almeida ◽

D. Wartchow

Keyword(s):

Rainwater Harvesting ◽

High Water ◽

Economic Benefits ◽

Point Of View ◽

Technology Selection ◽

Domestic Water ◽

Water Demands ◽

Harvesting Systems ◽

Residential Demand ◽

Economic Constraints

Abstract The implementation of rainwater harvesting (RWH) systems depends on technical and socioeconomic assessments. However, most studies do not consider socioeconomic aspects, which could lead to different degrees of RWH implementation and technology selection due to economic constraints and local regulations. We evaluated the socioeconomic potential for RWH as an alternative for water supply of 24 Southern Brazilian municipalities with less than 50,000 inhabitants. A total of 10,080 RWH configurations were assessed and a reliability analysis was carried out to define the RWH system configurations potentially implementable (RWH+) in each municipality. RWH economic benefits were estimated from a social point of view, based on the reduction of the monthly water payment. Overall, RWH+ supplying higher demands with higher economics savings were feasible, as expected. However, several municipalities that showed RWH+ supplying 100% of the domestic water demands obtained lower economic savings, due to low water tariff and water consumption. Still, a set of municipalities presented RWH+ for rainwater demand replacing 50% to 60% of the residential demand, for which the high-water tariffs reflected in higher economics savings. The advantages of using the RWH systems outstand even more when the investments at Federal and Local levels are considered.

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Irrigation Water Use in the Danube Basin: Facts, Governance and Approach to Sustainability

Journal of Environmental Geography ◽

10.2478/jengeo-2019-0007 ◽

2019 ◽

Vol 12 (3-4) ◽

pp. 1-12

Author(s):

Diana Dogaru ◽

Wolfram Mauser ◽

Dan Balteanu ◽

Tatjana Krimly ◽

Christian Lippert ◽

...

Keyword(s):

Water Use ◽

Irrigation Water ◽

Irrigation Management ◽

Field Studies ◽

Management Plan ◽

Transdisciplinary Research ◽

Integrative Approach ◽

Danube Basin ◽

Trade Offs ◽

Irrigation Water Use

Abstract In this paper we assess the irrigation water use in the Danube Basin, highlight its complexity, identify future challenges and show the relevance for a basin-wide integrative irrigation management plan as part of a more holistic and coherent resource policy. In this sense, we base our integrative regional assessments of the water-food-energy nexus on insights from an extensive review and scientific synthesis of the Danube Basin and region, experimental field studies on irrigation and agricultural water consumption, current irrigation related policies and strategies in most of the Danube countries, and regulatory frameworks on resources at European Union level. We show that a basin-wide integrative approach to water use calls for the evaluation of resource use trade-offs, resonates with the need for transdisciplinary research in addressing nexus challenges and supports integrative resource management policies within which irrigation water use represents an inherent part. In this respect, we propose a transdisciplinary research framework on sustainable irrigation water use in the Danube Basin. The findings were summarized into four interconnected problem areas in the Danube Basin, which directly or indirectly relate to irrigation strategies and resource policies: prospective water scarcity and Danube water connectedness, agricultural droughts, present and future level of potential yields, and science based proactive decision-making.

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Efficient water conservation in agriculture for growing urban water demands in Jordan

Water Policy ◽

10.2166/wp.2010.066 ◽

2011 ◽

Vol 13 (1) ◽

pp. 102-124 ◽

Cited By ~ 5

Author(s):

Octavio A. Ramírez ◽

Frank A. Ward ◽

Raed Al-Tabini ◽

Richard Phillips

Keyword(s):

Water Use ◽

Water Conservation ◽

High Price ◽

Irrigated Agriculture ◽

Urban Water ◽

Economic Productivity ◽

Water Demands ◽

Irrigation Water Use ◽

The Face ◽

Scarce Water

A significant worldwide challenge is to increase the food supply to accommodate a population growing to 9,000,000,000 in the face of climate change. Per capita water supply in Jordan is among the world's lowest. Despite this scarcity, three-quarters of Jordan's water use is consumed by irrigated agriculture, while producing low economic values from additional water used compared to urban uses. However, irrigated agriculture supports Jordan's food security, so its policymakers continue to examine measures to produce more crop per drop in irrigated agriculture, to permit scarce water to meet growing urban demands. This paper examines economically efficient measures to conserve water in irrigated agriculture to sustain growing urban water demands. Using a sample of one-third of the farms in Jordan's Mafraq Basin, an econometric model is formulated to identify factors influencing irrigation water use and economic productivity. Findings show that the price of water is the overarching factor influencing both. A low water price discourages water conservation even if other institutions promote it. A high price of water encourages conservation even in the presence of other discouraging factors. Results suggest that water-conserving policies in Jordan's irrigated agriculture can be more effectively implemented where water institutions and programs are designed to be compatible with the underlying economic scarcity of water. Results carry significant implications for the design and implementation of development programs affecting the use of water in the world's dry areas.

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