Water Use Sectors Research Articles

National water use of coal-fired power generation: Hybrid life cycle assessment in China

Previous studies of water use for coal-fired power generation may have overlooked inter-sectoral impacts in the supply chain. Indeed, to devise effective water conservation strategies during the ongoing energy transition, it is of utmost importance to analyze the sectoral water use structures and flows in the supply chain and identify the sources of water scarcity. Therefore, based on the power sector-split environmentally extended input‒output (EEIO) model and the life cycle assessment (LCA) idea, we comprehensively analyze the nexus between coal-fired power generation and water use from a sectoral perspective. Our findings reveal a complex and diverse water use structure in coal-fired power generation. The technology of production inherently determines the high intensity of water withdrawal, and the close intersectoral linkages, particularly with agriculture, construction, and some industrial sectors, in the production process result in an intricate web of indirect water withdrawal and blue water footprint (WF). Moreover, the grey WF, primarily sourced from coal mining and indirectly tied to tertiary industries, underscores critical areas for attention in water pollution management. Finally, water use in the coal-fired power sector is projected to remain at elevated levels in the short to medium term under various transition strategies. Following an in-depth exploration of the coal-fired power‒water use nexus, the findings can offer new perspectives and specific entry points for sustainable energy development and water resource management.

Water Scarcity Assessment of Hydropower Plants in China under Climate Change, Sectoral Competition, and Energy Expansion.

Hydropower plays a pivotal role in low-carbon electricity generation, yet many projects are situated in regions facing heightened water scarcity risks. This research devised a plant-level Hydropower Water Scarcity Index (HWSI), derived from the ratio of water demand for electricity generation to basin-scale available runoff water. We assessed the water scarcity of 1736 hydropower plants in China for the baseline year 2018 and projected into the future from 2025 to 2060. The results indicate a notable increase in hydropower generation facing moderate to severe water scarcity (HWSI >0.05), rising from 10% in 2018 to 24-34% of the national total (430-630 TWh), with a projected peak in the 2030s-2040s under the most pessimistic scenarios. Hotspots of risk are situated in the southwest and northern regions, primarily driven by decreased river basin runoff and intensified sectoral water use, rather than by hydropower demand expansion. Comparative analysis of four adaptation strategies revealed that sectoral water savings and enhancing power generation efficiency are the most effective, potentially mitigating a high of 16% of hydropower risks in China. This study provides insights for formulating region-specific adaptation strategies and assessing energy-water security in the face of evolving environmental and societal challenges.

Evolution of spatiotemporal pattern of virtual water in the Yangtze River economic belt

Cross-regional water allocation within the river basin, coupled with the development of specialized industries based on comparative advantages, can effectively mediate overall water use efficiency. The uneven distribution of water resources and structural contradictions in water usage hinder the sustainable development of water resources in the Yangtze River Economic Belt (YEB). This study aims to address these issues from the perspective of virtual water trade, to facilitate cross-regional water resource allocation and guide structural adjustments in industrial water use, ensuring water security. In this study, we developed a dynamic multi-regional input–output model (MRIO) to explore dynamic change of virtual water trade pattern in the YEB that evolves over time. This model sheds light on evolving virtual water transfer patterns and the nuances of water resource pressure transmission. Additionally, it quantifies sectoral water use variations, pinpointing the cornerstone industries across different regions. The findings are as follows: (1) The pattern of virtual water transfer predominantly towards the developed downstream regions remains unchanged, but regional disparities are gradually diminishing. (2) The upstream regions of the YEB transfer more water resource pressures externally, while the downstream regions do not experience excessive external transfers of water resource pressures. (3) The pattern of Agriculture-driven virtual water transfers is gradually being disrupted. While the upstream regions continue to rely on Agriculture as their pillar industries, the downstream regions are progressively shifting towards tertiary industries such as Service. These results indicate that economic development is the primary driver of changes in the the pattern of virtual water transfer, and economic disparities are a key factor in shaping the latest virtual water transfer. Based on existing policies, there is a need for comprehensive coordination of water resource allocation and strengthening of virtual water trade exchanges between regions to address the uneven distribution of water resources. Additionally, it is necessary to resolve structural water use conflicts by developing specialized economic strengths based on the main industries for virtual water in each region.

Impacts of water constraints on economic outputs and trade: A multi-regional input-output analysis in China

Water resource constraints pose significant challenges to sustainable development of economy, environment, and human society. This study addresses the existing gap in understanding the impacts of water resource constraints on economic outputs and inter-provincial trade in China. A water-use constrained multi-regional input-output (MRIO) model is developed to analyze the impacts on economic outputs resulting from different water constraints imposed on economic sectors. A series of scenarios are designed to represent different levels of sectoral water use restrictions based on short-term water policy and water stress alleviation targets. Results reveal that regions experience different levels of water stress displaying diverse economic impacts due to future water restrictions. Overall, national economic outputs will experience a 0.76–1.14% decrease compared to the baseline scenario, that is, the “business-as-usual” scenario. Provinces with lower levels of economic development tend to be less resilient to the economic losses arising from water constraints. As such, Ningxia and Shanxi show with the greatest relative economic impact, accounting for 7.09% and 4.21% of their respective provinces’ economic outputs under the baseline scenario. Furthermore, the direction of net bilateral trade, such as net trade between Henan and Shaanxi or between Henan and Hunan, would reverse under water constraint scenarios from the baseline scenario. This underscores the importance of considering the cascading effects of local water constraints on inter-provincial trade. Our study highlights the trade-offs between water conservation and economic development, emphasizing the need for region-specific water-saving measures.

Water governance for water security: analysing institutional strengths and challenges in Finland

ABSTRACT The relationship between water security and water governance across different water-using sectors remains under-researched. We apply the Organisation for Economic Co-operation and Development’s (OECD) Water Governance Indicator Framework with revised principles and criteria to analyse three sectors critical to water security in Finland: bioeconomy, mining and water infrastructure. Our findings indicate that water security as a concept helps to both assess and clarify governance priorities, while well-functioning governance with engagement of key actors is a prerequisite for broader water security. Given the differing interests and emerging pressures related to water, ensuring water security requires well-resourced public sector agencies to coordinate interaction across sectors and actors.

Implications for sustainable water consumption in Africa by simulating five decades (1965–2014) of groundwater recharge

Groundwater stands as a vital water resource for both present and future generations in Africa. This underscores the importance of examining the sustainability of current groundwater consumption across the continent, along with its capacity to fulfill the current human and essential environmental water needs. Groundwater sustainable yield is a suitable indicator for assessing groundwater sustainability but has not yet been quantified properly across Africa. A thorough quantification of groundwater sustainable yield necessitates a profound comprehension of the spatio-temporal fluctuations in surface hydrology, groundwater recharge, environmental flow, and sectoral water use. In this study, high spatial resolution (10 km) land surface hydrology was simulated for five decades (1965–2014) across Africa by the Community Land Model version 5 at half-hourly time step and aggregated to monthly and annual temporal resolutions. Then, groundwater recharge and environmental flow were quantified based on the water balance approach for the whole continent. Finally, by including African sectoral water use data available for four decades (1971–2010) we obtained the long-term average of groundwater sustainable yield. Based on extensive simulations of long-term land surface hydrology, we discovered that the groundwater system in Africa experienced an average annual recharge of 57.8 mm yr−1 (with a standard deviation of 110.8 mm yr−1 serving as an indicator of spatial variability), corresponding roughly to an annual recharge volume of 1793.6 km3 yr−1. Furthermore, our analysis revealed that the entire continent possesses an annual average potential sustainable yield (with standard deviations) of 4.5 mm yr−1 (10.2), 20.6 mm yr−1 (42.9), and 37.3 mm yr−1 (75.7) under conservative, optimum, and suitable water consumption scenarios, respectively. This calculated annual groundwater sustainable yield corresponds to 141.9 km3 yr−1, 643.1 km3 yr−1, and 1160.5 km3 yr−1 for the conservative, optimum, and suitable scenarios, respectively. Furthermore, the calculated sustainable yield volume is contrasted with the total water storage figures documented for 50 countries throughout Africa. The outcomes illustrate that our calculated annual sustainable yield equates to roughly 0.02%, 0.1%, and 0.17% of the reported groundwater storage across the entire continent. Based on the estimated long-term average sustainable yield and the reported total water storage at the national level, our conclusion is that the accessible groundwater resources could potentially satisfy the current water requirements of both humans and the environment in African countries. This study offers the first model-based estimation of groundwater availability across Africa, potentially serving as a catalyst to inspire further progress toward adopting more sustainable approaches to groundwater usage on the continent.

Sectoral water use responses to droughts and heatwaves: analyses from local to global scales for 1990–2019

Water use for various sectors (e.g. irrigation, livestock, domestic, energy and manufacturing) is increasing due to a growing global population and economic development. Additionally, increases in frequency and severity of droughts, heatwaves and compound drought-heatwave events, also lead to responses in sectoral water use and a reduction in water availability, intensifying water scarcity. However, limited knowledge exists on the responses in sectoral water use during these hydroclimatic extremes. In this study we quantify the impacts of droughts, heatwaves and compound events on water use of irrigation, livestock, domestic, energy and manufacturing sectors at global, country and local scales. To achieve this, datasets of reported and downscaled sectoral water use (i.e. withdrawal and consumption) were evaluated during these hydroclimatic extremes and compared to normal (non-extreme) periods for 1990–2019. Our analysis shows that these hydroclimatic extremes affect water use patterns differently per sector and region. Reported data show that domestic and irrigation water use increases during heatwaves in Eastern Europe and central continental United States, while water use decreases for thermoelectric sector, particularly in Europe while it increases in north and Eastern Asia. Additionally, global water use response patterns reveal that irrigation and domestic sectors are mostly prioritized over livestock, thermoelectric and manufacturing. Reported local-scale data reveal that for most sectors and regions/locations, stronger water use responses are found for heatwaves and compound events compared to impacts during hydrological droughts. Our outcomes provide improved understanding of sectoral water use behaviour under hydroclimatic extremes. Nonetheless, given the future threats to water availability and the limited accessible information of water use, there is an urgency to collect more monitored-driven data of sectoral water use for improved assessments of water scarcity under these extremes. Consequently, this research reveals the necessity of more realistic water use models to better represent the sectoral responses to hydroclimatic extremes.

Comparative analysis of local adaptation processes in the future across peri-urban India to support transformations to sustainability

Peri-urban transformations in emerging economies like India demand scientific attention given their impact on global environmental change processes. Some studies examine past or ongoing peri-urban adaptation processes, but insight into future adaptation needs and aspirations of peri-urban communities is lacking. Also, it is unknown how the high degree of informality that characterizes peri-urban areas, interacts with formal institutions to shape or enable more sustainable adaptation pathways. This study addresses these scientific gaps, using an existing typology of adaptation processes to investigate plausible future adaptation pathways in three peri-urban villages in India, near Pune, Hyderabad, and Kolkata cities. On-site field research followed by a Delphi-study were used to develop normative adaptation pathways for livelihood and household water use with local actors. The pathways represent development trajectories and adaptation strategies over the next 15 years in the livelihood and household water sectors. Pathways data was thereafter analyzed and compared in terms of drivers of vulnerability and opportunity, adaptation processes, and formal and informal institutions. Our ex-ante study identifies general and context specific drivers of vulnerability and opportunity shaping different peri-urban transformations. Results reveal similarities in future drivers, whose impact on peri-urban livelihoods and household water is context dependent. This comparative analysis contributes a deeper understanding of future adaptation needs by highlighting patterns in locally preferred adaptation processes for different drivers and water-use sectors. This normative understanding reveals preferences of local communities who are otherwise marginalized from decision-making arenas. A combination of adaptation processes will be needed to respond to the various drivers, only some of which are achievable through informal institutions. Formal government intervention will be essential for stimulating innovation, intensification, and revitalization forms of adaptation. Institutional adjustments will be key to shaping local agency and future adaptive capacity away from a business-as-usual trajectory.

Spatiotemporal characteristics of water use change and its driving factors in China’s urban agglomerations

Under the background of water scarcity, water use change is a vital indicator for coordinated development of socioeconomic and eco-environmental system, especially in China’s urban agglomerations which are “markers” that identify water use change across the country. Therefore, this study adopts detailed data for irrigation, industrial, and domestic subsectors at the prefecture-level city scale to reveal the spatiotemporal characteristics of water use changes across and within China’s urban agglomerations during 2000–2020. Meanwhile, the contributions of nine socioeconomic drivers are quantitatively dissected by Logarithmic Mean Divisia Index (LMDI). The results show that, total water use in China’s urban agglomerations experienced a trend of rising first and then declining, but it remained about 360 billion m3 over the whole period. Total and sectoral water use changes across and within China’s 19 urban agglomerations showed significant differences. The activity and structure effects increased water use by 160 billion m3 and 10 billion m3 for China’s urban agglomerations over the whole period, while the intensity effects decreased water use by 170 billion m3. Most urban agglomerations and prefecture-level cities had the same dominant driving factors as the overall situation of China’s urban agglomerations, belonging to the intensity-driven and activity-driven type. The results could serve as scientific supports to propose targeted water management policies and development pathways for China’s urban agglomerations.

Water Crisis in India: Concept of Nexus-Regional Solution

In India, which ranks first in the world in terms of population size in 2023, rapid technological and economic development is combined with an increased scarcity of natural resources, which is especially acute in the lack of water resources. Increase of water consumption (90% of water is consumed by irrigation and agriculture), growing competition for water resources from energy, industry, urbanization, etc. require a transition from sectoral water use management to management based on the concept of nexus (latin)–linkage between sectors. The central is Water–Energy–Food nexus which has been studied since the early 2010s. In developing the new National Water Policy of India, attention is focused on the development of the Water–Energy–Food production nexus. The article is based on a review of scientific publications, a critical analysis of forecasts and scenarios, and the use of statistical databases. The most acute problems of water availability and rationalization of its use are discussed at the state level and at the level of large river basins (project “Pure Ganges”). Technological and managerial decisions made in India aimed at rationalizing water use based on an unsophisticated approach are considered. A new driving force is the accelerated development of renewable energy sources. The problems of the Water–Energy–Food production nexus can be successfully solved only in the context of integral regional development, which becomes more complicated under the climate change.

Global monthly sectoral water use for 2010–2100 at 0.5° resolution across alternative futures

Water usage is closely linked with societal goals that are both local and global in scale, such as sustainable development and economic growth. It is therefore of value, particularly for long-term planning, to understand how future sectoral water usage could evolve on a global scale at fine resolution. Additionally, future water usage could be strongly shaped by global forces, such as socioeconomic and climate change, and the multi-sector dynamic interactions those forces create. We generate a novel global gridded monthly sectoral water withdrawal and consumption dataset at 0.5° resolution for 2010–2100 for a diverse range of 75 scenarios. The scenarios are harmonized with the five Shared Socioeconomic Pathways (SSPs) and four Representative Concentration Pathways (RCPs) scenarios to support its usage in studies evaluating the implications of uncertain human and earth system change for future global and regional dynamics. To generate the data, we couple the Global Change Analysis Model (GCAM) with a land use spatial downscaling model (Demeter), a global hydrologic framework (Xanthos), and a water withdrawal downscaling model (Tethys).

The Influencing Factors of Water Uses in the Yellow River Basin: A Physical, Production-Based, and Consumption-Based Water Footprint Analysis by the Random Forest Model

The strategy of “Basing city, land, population and production on water resources”, clarifying the water uses of each province and the influencing factors are crucial to the conservation and intensive use of water resources for the Yellow River basin. In this study, physical water use, the production-based water footprint, and the consumption-based water footprint of nine provinces in the Yellow River Basin from 2007 to 2017 are measured. Then, the key influencing factors of three kinds of water use are analyzed by the random forest model. The results show that (1) the three kinds of water use in the Yellow River basin all showed a trend of first increasing and then decreasing. Physical water use and the production-based water footprint present the geographical differentiation in the declining order from the upper reach to the lower reach, and then the middle reach, while the order for the consumption-based water footprint is the lower reach, the upper reach, and the middle reach. (2) Agriculture, forestry, animal husbandry, fisheries, electricity and hot water production, supply, and chemicals are the dominant sectors of physical water use. Agriculture, forestry, animal husbandry, fisheries, food processing, tobacco, and construction are the key sectors for production-based and consumption-based water footprints. (3) The results of the random forest model show the influencing factors and their interactions of three kinds of water use in the Yellow River basin present obvious sectoral differences. The key influencing factors exhibit a linear or nonlinear response to water use in the three perspectives. The influencing factors of water use are also differentiated among the three perspectives.

Global spread of water scarcity risk through trade

Water scarcity is increasingly perceived as a great challenge to the sustainable development of human society. The economic output loss due to water scarcity is defined as water scarcity risk (WSR), which constitutes local water scarcity risk (LWSR, local economic output loss in water-using sectors due to water scarcity) and virtual water scarcity risk (VWSR, the spread of LWSR through trade systems). However, the traditional water stress index used in the existing WSR assessment research is limited in its accuracy and descriptiveness. Here we address these limitations by quantifying the LWSR with the consideration of environmental flow requirement, water intensity, economic output, and further assessing the VWSR. Results show that the WSR of the world is around 2.7 trillion US dollars in 2016. We also identify the hotspots of WSR at the national and sectoral levels. Our findings help lay the foundation for nations to develop strategies for mitigating WSR.

Quality matters: Pollution exacerbates water scarcity and sectoral output risks in China

Pollution exacerbates a region's water scarcity by making water unfit for different uses and reducing freshwater availability. Local water scarcity may lead to economic output losses, and the risk can be transmitted to downstream sectors through reduced input supplies. Previous studies focus on quantity-based water scarcity assessment. It is still unknown how water quality constraints may amplify economic risks of local water-use sectors and distant economies. Here we introduce an integrated method and assess the impacts of both quantity and quality-based local physical water scarcity risks (LWSR) and virtual water scarcity risks (VWSR) in domestic trade system in China. We find in 2017 quality-based LWSR and VWSR in China are ∼593 and ∼240 billion US$. Inclusion of water pollution constraints almost doubles the risks of economic losses due to insufficient clean water supply. We then identify critical regions and sectors that are highly risky or vulnerable to the supply chains. We find water pollution makes risky VWSR exporters more centralized in a few Northern provinces where available freshwater resources are already limited, e.g. the agriculture sector in Hebei province. VWSR importers span broadly, but water pollution increases concentrations of upstream suppliers that face local water scarcity for most provinces, decreasing overall resilience of China's domestic trade network. Our results underscore the needs to alleviate overall scarcity risks by conserving physical water resources and improving water quality simultaneously.

Water resources management of large hydrological basins in semi-arid regions: Spatial and temporal variability of water footprint of the Upper Euphrates River basin

The existing water accounts for large-scale, semi-arid and transboundary river basins are usually lack of sufficient spatial-temporal elements of water use, a prerequisite for identifying potential water savings and for sustainable management of scarce water resources. This study aims to demonstrate value of water footprint (WF) accounting framework for such river basins with the case study of the Upper Euphrates River basin which is not only used as major food and energy production resource in Turkey but also a focal point for international conflict, diplomacy and dialogue in Middle East. The methodology is based on Water Footprint Assessment Manual which is published by Water Footprint Network. The study maps spatial-temporal variations of sectoral water use in the study area for the agriculture, domestic water supply and industry for the period of 2008–2019. The water footprint of the Upper Euphrates River basin is calculated as 27.4 Gm3, most of which is related to the agricultural activities. The downstream and lower plains of the study area exhibited a considerably high blue and grey agricultural WF, reaching 2397 and 349 mm, respectively. Several crops have substantially large WFs in the region such as cotton, wheat, pistachio, and barley. The analysis given in this study revealed importance of spatial-temporal disaggregated information in water accounting for sustainable management of water resources. These accounts can provide insights that were not available to the decision makers before, such as water saving opportunities, potential water efficiency and productivity benchmarks, strategic planning for various climatic conditions etc. These are the major values that water footprint accounting can introduce in water management in a large scale, semi-arid transboundary river basins.

Integrated model for Food-Energy-Water (FEW) nexus to study global sustainability: The water compartments and water stress analysis.

Analysis of global sustainability is incomplete without an examination of the FEW nexus. Here, we modify the Generalized Global Sustainability Model (GGSM) to incorporate the global water system and project water stress on the global and regional levels. Five key water-consuming sectors considered here are agricultural, municipal, energy, industry, and livestock. The regions are created based on the continents, namely, Africa, Asia, Europe, North America, Oceania, and South America. The sectoral water use intensities and geographical distribution of the water demand were parameterized using historical data. A more realistic and novel indicator is proposed to assess the water situation: net water stress. It considers the water whose utility can be harvested, within economic and technological considerations, rather than the total renewable water resources. Simulation results indicate that overall global water availability is adequate to support the rising water demand in the next century. However, regional heterogeneity of water availability leads to high water stress in Africa. Africa's maximum net water stress is 140%, so the water demand is expected to be more than total exploitable water resources. Africa might soon cross the 100% threshold/breakeven in 2022. For a population explosion scenario, the intensity of the water crisis for Africa and Asia is expected to rise further, and the maximum net water stress would reach 149% and 97%, respectively. The water use efficiency improvement for the agricultural sector, which reduces the water demand by 30%, could help to delay this crisis significantly.

Analysis of Canada’s water use: tracing water flow from source to end use

Freshwater is a critical natural resource and fundamental to social and environmental activities, including industrial activities, food production, and residential needs. Hence, it is important to understand provincial water supply and demand. However, there are large gaps in provincial and sectoral water use data. This study provides estimates for disaggregated water use by regional subsectors and uses Sankey diagrams to depict the water flow from intake to consumption and discharge. The study uses a bottom-up method in the oil and gas and hydropower sectors and top-down methods in the residential, commercial and institutional, manufacturing, mining, agricultural, and power sectors. Surface and ground water are considered separately. Water use in the year 2017 was analyzed for British Columbia, Alberta, Saskatchewan, Manitoba, Ontario, Quebec, the Atlantic Provinces, and the Territories. Water-use intensities were also calculated by region and sector. A total of 40 billion m3 of water use is traced from source to either discharge or consumption. New disaggregated data is developed provincially and by sector for oil and gas, mining, and power generation. Water use in the oil and gas sector was disaggregated into 5 subsectors, with oil sands surface mining in Alberta as the largest consumer with 138 million m3 of water consumed. Hydro power was estimated to consume the most water out of all sectors, with 3393 million m3 of water consumed. Alberta was also found to have the largest consumptive water use per capita. The results provide important insights on water supply and demand in Canada. Such information supports both regional and federal governments in formulating appropriate regional and sectoral policies and can support water managers and the public in understanding water supply and demand in Canada. Modelling efforts requiring regional and sectoral water use can also use these results. Supplemental data for this article is available online at http://dx.doi.org/.

Integration of a Network-Based and an Economy-Wide Water Model to Support Decision Making on Water Resources Planning and Management in Northeastern Brazil

Allocation of Water Resources at the basin level is a critical issue for economic growth as well as for environmental sustainability. This study integrates network-based optimization with an Input-Output model, made available through a Spatial Decision Support System (HEAL), to support design and evaluation of water allocation policies. The innovative platform was applied to a case study using four-interlinked hydrographic basins in Northeastern of Brazil. The integrated modeling was able to measure broader socioeconomic impacts of decisions on reservoir volumes and water allocations at basin level, through indicators in a sectoral and regional scale, including ones associated with Sustainable Development Goals, such as the Water Use Efficiency (WUE) indicator. Results of the trade-offs between two scenarios, representative of the limits of performance of regulatory water instruments, were generated using the integrated modeling. They were compared with the Reference scenario for the base year (2011) and show that the economic sector most negatively affected by the regulatory instrument use is the industrial sector. Furthermore, the sugar and ethanol industry, main water users in the industrial sector (93.1% of the sector's water use) and less efficient (WUE 1.47 US$/m3 vs. 30.70 US$/m3 average of the sector) in the base year, maintain their percentage share of water use in the sector and even slightly expand it (93.2%), with slight efficiency gains (+2.3%). On the other hand, non-water-intensive industries, have their shares reduced (from 6.9 to 6.8%) and lose efficiency (−9.5%). Results of the same trade-offs by region showed that the largest proportional economic losses occur in the drier areas, damaging the economy, especially in the most industrialized municipalities with the highest GDPs. Integrated economic modeling can expand aspects involved in water security issues, assisting management by introducing socioeconomic impact measures, in a broader scale, associated with allocation decisions. Hydrological allocation criteria cannot distinguish between user efficiency and which economic sectors are using how much water. This results in economic and social losses. In water-scarce regions and with growing transfer needs, such as in the basins studied, adequate incentives, through management instruments designed based on economic theory, are essential to promote sustainable development.

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

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.

Dynamic analysis of residential and enterprise water supply and leakage efficiencies.

With per capita water resources at only around a quarter of the world average, China's water resources are limited and unevenly distributed. Past research on water resource utilization has mainly focused on industrial water use (agriculture and industry), water plant ownership efficiencies (private or public operation), or water resources and economic production; however, there have been few studies focused on water supply livelihood. Therefore, this paper considered both industrial production water services, non-production water services (public sector and residential water use), and water leakage losses, which is a water supply problem seldom mentioned in other studies. An undesirable directional distance function (DDF) dynamic data envelopment analysis (DEA) model was employed for the dynamic analysis as it was able to deal with both desirable and undesirable outputs at the same time. The model examined collected water supply and water leak efficiency data from 30 Chinese provinces/municipalities from 2007 to 2018, from which it was found that (1) Beijing, Gansu, Guangdong, and Ningxia had efficient water supply and water leak losses from 2007 to 2018 and the most improved province was Jiangxi; (2) the eastern provinces, in general, had better water efficiencies and the central and western provinces needed greater improvements; and (3) the lowest water leakage loss efficiencies were in Inner Mongolia, Jiangxi, and Heilongjiang, all of which required significant improvements.