Indirect Water Footprint Research Articles

A feasibility study to estimate household water footprint in Iran: Adaptation and application of a localized questionnaire

Iran, grappling with the challenges common to arid and semi-arid regions, is confronting a significant freshwater scarcity that exacerbates its water crisis. Central to this issue is the provision of an adequate domestic water supply. This study embarked on adapting a localized water footprint questionnaire to gauge individual household water footprints within the Iranian context. Utilizing a cross-sectional approach, we adapted and validated a water footprint questionnaire tool tailored for Iranian consumers. The original questionnaire, derived from watercalculator.org, comprises 35 questions encompassing direct household water use, direct non-household water use, and indirect water use. Following its translation, cultural adaptation, and validation, the questionnaire was deployed for data collection. The investigation unveiled average water footprints as follows: a direct indoor water footprint (DWFin) of 133.31±65.54 lpcd, a direct outdoor water footprint (DWFout) of 1.89±1.73 lpcd, and an indirect water footprint (IWF) of 4284.94±714.33 lpcd, culminating in an overall average water footprint (WF) of 4420.14 ± 695.17 lpcd. Despite the study's limitations, including a sample that may not fully capture all provincial demographics, the findings underscore the practicability of employing this methodology in Iran and the significant potential for water conservation through heightened awareness and the policy-driven implementation of water-efficient practices at the household level.

The water footprint of pig farms in Ireland based on commercial farm data

Livestock production is getting increased attention due to its impact on natural resources, and freshwater is one such limited resource. To reduce the pressure on freshwater use and develop sustainable livestock systems from farm-to-fork we need to study the whole production cycle, and look for hotspots of major freshwater use. Considering this, we chose intensive pork production as our focal livestock system, since it is one the most eaten meats globally. We focused on pork production in Ireland and studied the freshwater use (green and blue) from cradle-to-farm gate using the water footprint (WFP) method. Detailed farm data (e.g. diet composition, production data) were combined with on-farm water meter data to explore variations in water consumption between farms, and potential explanatory variables for differences in consumption between farms. So far, there have been no WFP studies in pork production that explored this, and insight into variation could help to identify options for improvement. We analyzed the direct (on-farm) and indirect (off-farm) green and blue water footprint of 10 Irish pig farms. Our results show that the average total WFP, including the direct and indirect water footprint, was 2537 L/kg pork, which is at the low end of previously published studies. The indirect green water footprint related to the production of purchased feed was responsible for the largest share (99 %) of the total WFP. The direct blue water footprint formed only a minor component of the total WFP (14 L/kg pork), with drinking water playing the major role. We can conclude from this study that variation in WFP between the least and most efficient farms was small (Q3-Q1 = 181 L/kg pork); nevertheless, this indicates that efficiencies of around 7 % could be gained by the least efficient cohort of farms by adjusting on-farm management practices. We also found a weak negative correlation between WFP and farm size, and WFP and meat produced. Overall, this study suggests that to reduce the burden on freshwater resources and reduce the pork WFP, future research should focus on the feed related impacts.

Water Footprints of Dairy Milk Processing Industry: A Case Study of Punjab (India)

A robust assessment of water used in agriculture, including livestock production systems and supply chains, is critical to inform diversification and the development of productivity and sustainable food production systems. This paper presents a detailed analysis of water used and consumed in nine dairy milk processing plants spread across Punjab, India’s leading dairy milk-producing state. Over the five years (2015–2019), the direct water use (DWU) was quantified at 3.31 L of groundwater per kg of milk processed. Only about 26% of the direct water used was consumed, including evaporative losses in various milk processing operations, while the remaining 74% was returned as effluent discharges. The average total water footprint (TWF), accounting for both direct and indirect water consumption, was quantified at 9.0 L of water per kg of milk processed. The majority share (~89%) of the total water footprint was contributed by the indirect water footprint associated with the consumption of electricity (energy) in dairy milk processing activities. The plant’s milk processing capacity and processing products mix also affected significant seasonal and annual variations in the direct and indirect water footprints of dairy milk processing. The analysis also found an inverse relationship between the average total water footprint and the average monthly amount of milk processed in the study plants. Therefore, efforts to reduce the indirect water footprint (associated with energy consumption), the treatment and recycling of effluent discharges, and the optimization of milk processing capacity, the dairy processing product mix, and the locations of dairy processing plants are expected to help reduce the water footprint of dairy processing in the state.

Tracking indirect water footprints, virtual water flows, and burden shifts related to inputs and supply chains for croplands: A case for maize in China

Increasing crop yields to ensure an adequate food supply under water and land scarcity is dependent on intensive agricultural inputs (such as fertilizers, pesticides, agri-films, or energy) which consume water resources and generate water pollution. However, the burden shifting of water quantity and quality stress from producers to importer and consumers through agricultural input production, trade, and consumption have been largely overlooked. Here, taking maize in China as the study case, we mapped step-by-step indirect water footprint (IWF) of maize production, virtual water (VW) flows related to inputs driven by maize consumption, and the resulting burden shifting of water quantity and quality. Bottom-up WF accounting approach was applied. The maize consumption was intercepted into two stages: the crop production stage (CPS) from raw materials to the farm, and the crop trade stage (CTS) from farm to fork. Results show that the national average blue and grey IWF of maize production was 3.91 and 26.86 m3/t, respectively. In the CPS, the input-related VW flowed from the west and east coast to the north. In the CTS, the VW flows from the north to the south. Blue and grey VW flows in CTS caused by secondary flows of VW in CPS accounted for 48% and 18% of the total flows, respectively. In total VW flows along the maize supply chain, 63% of blue VW and 71% of grey VW net exports occurred in the north of severe water scarcity and water pollution levels. The analysis highlights the impact of the crop supply chain on water quantity and water quality in the consumption of agricultural inputs, the importance of step-by-step supply chain analysis for regional crop water conservation management, and the urgent need for integrated management of agricultural and industrial water resources.

Evaluation of water footprint of urban renewal projects. Case study in Seville, Andalusia

This publication presents a methodology for the evaluation of the water footprint of urban renewal projects. The indirect water footprint is obtained by adding together the embodied or virtual water of the materials incorporated in the 12-month project, while the direct footprint is mainly due to the green areas and rainwater collection system over its 40-year life span. The methodology, originally defined for the agricultural sector, is adapted to an urban system that includes gardens and sustainable urban drainage systems. In an innovative way, the present work analyses the amortisation of the indirect water footprint of the construction products by improvements in the city water cycle. The project involves street renewal with water-sensitive criteria, with five green areas, and road and pavement construction. The methodology identifies changes in garden designs, soil drainage, and rainwater-collecting systems in terms of blue, green, and grey water footprints. Five scenarios of a project in Seville, Spain are studied. The indirect water footprint of the project is 2.6 times higher than that in a standard project, but, due to annual savings of 65% in its direct water footprint, the breakeven point is reached in the 10th year.

Water footprint and virtual water flows embodied in China's supply chain

ABSTRACT Due to the increasingly serious water shortage in China, water conservation becomes more and more important. This paper analyzes the amount of water consumption in every link of the goods supply to explore the water conservation feasibility in every link. This paper establishes an EIO-LCA model based on the life cycle assessment method for water consumption from supply chains in various sectors, and decomposes the water footprint of the inter-sector supply chain into six levels and calculates the water consumption at each level. The results show that the total water footprint of China's supply chain increases by 6.5% from 2007 to 2017; industrial sector is the core sector for indirect water footprint consumption. China is an importing country of virtual water, imported intermediate products are the main source of imported virtual water and re-exported products account for an increasing proportion of exported virtual water.

Assessing Water Footprint of Copper Production by Pyrometallurgy

As an important tool for water resource environmental impact assessment, the application of water footprint assessment method in copper production process is conducive to more accurate assessment of water resource environmental impact in copper production process. The water footprint assessment method released by the Water Footprint Network was used to study the water footprint of the production process of cathode copper products produced by pyrometallurgy. It was found that the water footprint of 1 ton of copper produced by pyrometallurgy was 242m3, of which the blue water footprint accounted for 60%, the grey water footprint accounted for 40%. The direct water footprint accounted for 67% and the indirect water footprint accounted for 33%. The characteristics of water footprint contribution at each process were compared, which provided data support and reference for enterprises to better understand the water resource environmental impact of copper by pyrometallurgy and to choose the water resource utilization mode with their own production characteristics.

Reducing water scarcity by improving water productivity in the United States

Nearly one-sixth of U.S. river basins are unable to consistently meet societal water demands while also providing sufficient water for the environment. Water scarcity is expected to intensify and spread as populations increase, new water demands emerge, and climate changes. Improving water productivity by meeting realistic benchmarks for all water users could allow U.S. communities to expand economic activity and improve environmental flows. Here we utilize a spatially detailed database of water productivity to set realistic benchmarks for over 400 industries and products. We assess unrealized water savings achievable by each industry in each river basin within the conterminous U.S. by bringing all water users up to industry- and region-specific water productivity benchmarks. Some of the most water stressed areas throughout the U.S. West and South have the greatest potential for water savings, with around half of these water savings obtained by improving water productivity in the production of corn, cotton, and alfalfa. By incorporating benchmark-meeting water savings within a national hydrological model (WaSSI), we demonstrate that depletion of river flows across Western U.S. regions can be reduced on average by 6.2–23.2%, without reducing economic production. Lastly, we employ an environmentally extended input-output model to identify the U.S. industries and locations that can make the biggest impact by working with their suppliers to reduce water use ‘upstream’ in their supply chain. The agriculture and manufacturing sectors have the largest indirect water footprint due to their reliance on water-intensive inputs but these sectors also show the greatest capacity to reduce water consumption throughout their supply chains.

Water Footprint and Water Pinch Analysis in Ethanol Industrial Production for Water Management

Fuel ethanol is considered to be a clean alternative fuel to meet increasing energy demands and mitigate environmental pollution. Faced with challenges in terms of energy security and environmental pollution, China is vigorously developing fuel ethanol. However, ethanol-manufacturing is a water-intensive industry; it consumes large volumes of fresh water and generates a corresponding amount of waste water. Expansion of this industry can reduce water quality and cause water stress. This study aims to combine the water footprint (WF) with a water pinch analysis technique to manage water consumption and sewage discharge systematically in an ethanol plant. A well-operated cassava ethanol plant in China was chosen as a case study. The WF of industrial ethanol production was evaluated. The total WF was 17.08 L/L ethanol, comprised of a 7.69 L blue water footprint (BWF), and a 9.39 L gray water footprint (GWF). The direct WF was 16.38 L/L ethanol, and the indirect WF was 0.70 L/L ethanol. Thereafter, a water pinch analysis was conducted, and the optimal direct water reuse scheme was studied. After the water network was optimized, the BWF was reduced by 0.98 L/L ethanol, while the GWF was reduced by 1.47 L/L ethanol. These results indicate that the combined use of WF and pinch analysis can provide the starch-based ethanol industry with an effective tool to improve its water management.

Water footprint of regional products: the case of white cachama (Piaractus brachypomus)

In response to the demand for water resources, the ecological indicator “Water Footprint” appears, which is measured in terms of the water consumed and / or contaminated per liter of water / kg / harvest. The Water Footprint helps to optimize the use of water resources by reducing water changes, increasing planting densities, employing closed systems with recirculation and / or green water technologies. For the calculation of the Water Footprint in fish ponds in the Piedmont Llanero, the climatology, meteorology and hydrological regime in the municipality of Restrepo-Meta-Colombia were characterized. Calculations of potential evapotranspiration were carried out, as well as effective precipitation. The volume necessary for the assimilation of the contaminants by the water bodies and the virtual water for the elaboration of the concentrate was also considered. For the cultivation of white cachama (Piaractus brachypomus), a Water Footprint of 3848.5 L of water / kg / harvest was calculated, a value lower than that reported for other fish cultures and, even, for other agricultural activities. It was also found that the Indirect Water Footprint (2913.3 L / kg) is the one that contributes the most to the total value of Water Footprint. This demonstrates the difference in water consumption in cachama production, bringing it closer to a sustainable production system.

Direct and indirect urban water footprints of the United States

AbstractThe water footprint of the urban environment is not limited to direct water consumption (i.e., municipal supplies); embedded water in imported resources, or virtual water transfers, provides an additional component of the urban water footprint. Using empirical data, our analysis extends traditional urban water footprinting analysis to quantify both direct and indirect urban resources for the United States. We determine direct water volumes and their embedded energy through open records requests of water utilities. The indirect component of the urban water footprint includes water indirectly consumed through energy and food, relating to the food‐energy‐water nexus. We comprehensively quantify the indirect water footprint for 74 metropolitan statistical areas through the combination of various databases, including the Commodity Flow Survey of the U.S. Census Bureau, the U.S. Department of Agriculture, the Water Footprint Network, and the Energy Information Administration. We then analyze spatial heterogeneity in both direct and indirect water footprints, determining the average urban water footprint in the United States to be 1.64 million gallons of water per person per year [6200 m3/person/yr or 17,000 L/person/d], dominated by indirect water. Additionally, our study of the urban water cycle extends beyond considering only water resources to include embedded energy and equivalent carbon dioxide emissions. The inclusion of multiple sectors of the urban water cycle and their underlying processes provides important insights to the overall urban environment, the interdependencies of the food‐energy‐water nexus, and water resource sustainability. Our results provide opportunities for benchmarking the urban energy‐water nexus, water footprints, and climate change potential.

The Water Footprint of Kathmandu Metropolitan City

The water footprint is consumption-based indicator of water use. Water footprint is defined as the total volume of both indirect and the direct freshwater used for producing goods and services consumed by individuals or inhabitants of community. There are many studies regarding the direct water use but studies incorporating both direct and indirect water use is deficient. This study tries to estimate total volume of water based on the consumption pattern of different commodities by individuals of Kathmandu Metropolitan city using extended water footprint calculator. The average water footprint of individuals appears to be 1145.52 m3/yr. The indirect and direct water footprint appears to be 1070.82 Mm3/yr and 46.59 Mm3/yr respectively which cumulatively give the total water footprint of Kathmandu Metropolitan City of 1117.40 Mm3/yr. This volume is equal to 2.27 times the annual flow the River Bagmati. The indirect water footprint includes food water footprint of 1055.60 Mm3/yr or 2.14 times the annual flow and industrial water use of 15.22 Mm3/yr or 0.03 times the annual flow while the direct water footprint includes domestic water use of 46.59 Mm3/yr or 0.09 times the annual flow. In food water footprint, cereals consumption shared the highest contribution of 34.82% followed by meat consumption with share of 32.62% in total water footprint. Per capita per day water use of inhabitants appears to be 3138 liters which includes water use in food items of 2965 liters, industrial water use of 43 liters and domestic water use of 131 liters. The per capita per day domestic water use is 90 liters more than supplement of 41 liters by the water operator of Kathmandu Valley. Per capita per day domestic water use is already 5 liters more than expected improvement in water supplement of 126 liters per capita per day in 2025 after accomplishment of Melamchi water project. And, it is expected to increase further observing the rapid urbanization of Kathmandu Metropolitan City. The study showed water footprint of individuals is directly related to food consumption behavior, life style and services used therefore it is necessary to initiate water offsetting measures at individual level and water operator to find environmentally sustainable alternatives along with ongoing water project to fulfill demand. J. Nat. Hist. Mus. Vol. 28, 2014: 73-80

基于投入产出表的中国水足迹走势分析

水足迹是近年来国内外研究水资源压力的常用方法。基于投入产出表的水足迹分析方法,分析了我国1997-2007年的水足迹状况,改进了耗水系数的计算方法,研究了基于稀释理论的灰水足迹计算方法,计算了外部水足迹及额外水足迹负重以及相应系数,分析了我国水足迹消费的商品(服务)结构。结果表明,1997-2007年我国年均水足迹总量为2.83万亿m³,总体呈现下降趋势,其中蓝水足迹为2183亿m³,灰水足迹为2.62万亿m³(以Ⅲ类水标准核算)。在水足迹总量中,间接水足迹占据比例达到90%,可见水资源压力的产生主要基于商品或服务的消费。我国水足迹基本上依靠自给,同时我国承担其他国家的水资源压力的比例很大,但是整体上呈现下降趋势。从水足迹消费商品(服务)结构上看,与饮食相关的商品或服务占较大比例。;Water footprint (WF) method is a common way to study the water resources pressure in recent years. The total water footprint of China from 1997 to 2002 were calculated by using water footprint method based on the input-output tables in this paper, the method for calculating the water consumption coefficients was improved, and the method for calculating the gray water footprint based on dilution theory was studied in the paper. The external water footprints, the extra water footprints and the corresponding coefficients were also calculated, and the goods (services) structures of the water footprint consumption were analyzed in this study. The results showed that the annual WF of China had a downward trend from 1997 to 2007, with an average annual of 2.83 trillion cubic meters, in which the blue WF was 218.3 billion cubic meters and the gray WF was 2.62 trillion cubic meters (accounting to the third level surface water quality standards). The indirect water footprint accounted for 90% of the total WF, which meant the pressure of water resources mainly comes from the consumption of goods or services. The WF of China depends on self-sufficiency largely, and at the same time China bears a large proportion of the water pressure of other countries, but which has a it shows a downward trend on the whole. In the sight of the structure of goods or services, the diet-related goods or services occupied a higher proportion of WF.