Grey Water Footprint Research Articles

THE WATER FOOTPRINT IN CONTEXT OF CIRCULAR ECONOMY

Fresh water is the most used natural resource among the products we consume daily. Everything we eat or buy contains. But do we know how much water is needed to produce these goods? The concept of water footprint can help us find the answer to this question. Researcher at the University of Twente (Netherlands), Arjen Hoekstra, developed this concept in 2002. His goal was to show the impact on the amount of water that products in our lives contains. For a single product, the water footprint means the amount of water consumed and/or polluted at all stages of its production. It is measured in units of volume giving us an idea of the impact that a particular item has on the use of fresh water. Therefore, it takes into account the water used directly in production and the indirect part used in raw materials. The water footprint assessment method represents the volume of drinking water used either by a consumer or by a producer throughout the supply chain. By using this method, the volume of water is calculated by type of source, as well as the amount of water polluted, depending on the type of pollution, all these elements being specified spatially and temporally. The total water footprint of a product consists of three components: blue, green and gray water footprint. Assessing the water footprint of products and services is a good step towards evaluation of water circularity. The water footprint assessment must be integrated into the concepts of the circular economy by insisting on what happens to water after use and how circular and sustainable it is.

Distribution of Water Footprint Components of University Students and Detecting the Factors that Affect Those Components

20% of world population face the risk of disease and death due to the lack of access to healthy drinking water. A certain portion of water resources can no longer be used because of being polluted while some other parts pose danger for public health because of substructure incapacity. Water footprint is a remarkably crucial concept in terms of sustainable water management. Within the context of this study, consumption habits of university students and related changes in water footprint values have been investigated. Water Footprint Survey has been administered to participant university students and water footprint profiles of the students have been designed based on water footprint values computed according to survey results. At the end of the conducted analyses in Istanbul University-Cerrahpasa Avcilar Campus, mean annual rate of water footprint per person has been computed as 1848.78 m3 for students. Components of this water footprint has been designated as; green water footprint 1329 m3/per person/year, blue water footprint 199 m3/per person/year, grey water footprint 320.78 m3/per person/year. In addition, by transferring the data attained from surveys to IBM SPSS environment, presence and/or absence of a significant relationship between variables has been analyzed. It was then observed that parallel to the rise in students' income level a corresponding climb emerged in general water footprint.

Different Approaches to Assessing Pollution Load: The Case of Nitrogen-Related Grey Water Footprint of Barley and Soybean in Argentina

Agriculture is among the main causes of water pollution. Currently, 75% of global anthropogenic nitrogen (N) loads come from leaching/runoff from cropland. The grey water footprint (GWF) is an indicator of water resource pollution, which allows for the evaluation and monitoring of pollutant loads (L) that can affect water. However, in the literature, there are different approaches to estimating L and thus contrasting GWF estimates: (A1) leaching/runoff fraction approach, (A2) surplus approach and (A3) soil nitrogen balance approach. This study compares these approaches for the first time to assess which one is best adapted to real crop production conditions and optimises GWF calculation. The three approaches are applied to assess N-related GWF in barley and soybean. For barley in 2019, A3 estimated a GWF value 285 to 196% higher than A1, while in 2020, the A3 estimate was 135 to 81% higher. Soybean did not produce a GWF due to the crop characteristics. A3 incorporated N partitioning within the agroecosystem and considered different N inputs beyond fertilization, improving the accuracy of L and GWF estimation. Providing robust GWF results to decision-makers may help to prevent or reduce the impacts of activities that threaten the world’s water ecosystems and supply.

Spatiotemporal variations of agricultural water footprint and its economic benefits in Xinjiang, northwestern China

Agriculture is the largest water user and is the main driving force behind water stress in Xinjiang, northwestern China. In this study, the water footprint (WF) (blue, green and gray WF) of main crop production and their temporal and spatial characteristics in Xinjiang were estimated in 2006, 2010, 2014 and 2018. The blue water footprint deficit (BWFd) was conducted and food productivity and economic benefits of WF were also analyzed via the water consumption per output value (food productivity and economic benefits). The results reveal that the WF increased from 22.75 to 44.16 billion m3 during 2006–2018 in Xinjiang, of which cotton, corn and wheat are main contributors of WF. In terms of different regions, corn has the largest WF in north Xinjiang and cotton has the largest WF in south and east Xinjiang. The BWFd broadened from − 11.51 to + 13.26 billion m3 in Xinjiang with the largest increased BWFd in Kashgar (from − 3.35 to 1.40 billion m3) and Aksu (from − 2.92 to 2.23 billion m3) of south Xinjiang and in Shihezi (from − 0.11 to 2.90 billion m3) of north Xinjiang. In addition, the water footprint food productivity does not well correspond with the water footprint economic benefits in prefectures of Xinjiang. It means we should consider the food yields priority and economic benefits priority to formulate a scientific and effective supervisor mode to realize the sustainable management of agricultural water in prefectures of Xinjiang.

Grey water footprint assessment of geothermal water resources in the southeastern Anatolia region

Grey water footprint assessment of geothermal water resources in the southeastern Anatolia region

Analysis of Water Resources and Water Environmental Carrying Capacity of Animal Husbandry in China—Based on Water Footprint Theory

Water shortage and water pollution have become the key factors restricting the sustainable development of animal husbandry in China. In this study, the water footprint model was used to analyze the water resource carrying capacity and water environment bearing pressure of animal husbandry in 31 provinces of China from 2001 to 2019. The findings indicate that: (1) The development of animal husbandry has exacerbated the regional water deficiency problem. Shandong, Henan, Hebei, and Liaoning have become the most serious water deficit areas of animal husbandry in China. The decreasing water resource carrying capacity indicates that water resources are difficult in supporting the growth of animal husbandry; (2) the change of animal feeding structures has led to the decrease of gray water footprint and the alleviation of the water environment bearing pressure; however, the water environment of animal husbandry in northern China and the northwest is still overburdened, which poses a major challenge to the control of agricultural non-point source pollution; (3) furthermore, according to the spatial and temporal characteristics of the water resource carrying capacity and water environment bearing pressure, the main livestock-producing areas in the north are facing a profound “water-livestock” contradiction and showing an increasing trend. The research results will help decision-makers to adjust the development mode of animal husbandry, optimize resource allocation, and promote the sustainable development of resource-saving and environment-friendly animal husbandry.

Virtual nitrogen and phosphorus flow associated with interprovincial crop trade and its effect on grey water stress in China

The grey water footprint (GWF) is defined as freshwater requirements for diluting pollutants in receiving water bodies. It is widely used to measure the impact of pollutant loads on water resources. GWF can be transferred from one area to another through trade. Although pollution flow has previously been investigated at the national level, there has been no explicit study on the extent to which crop trade affects GWF across regions and the associated changes in grey water stress (GWS). This study analyzes pollution flow associated with interprovincial crop trade based on nitrogen (N) and phosphorus (P) loss intensity of three major crops, namely, maize, rice and wheat, which is simulated by a grid-based crop model for the period 2008–2012, and evaluates the spatial patterns of GWS across China. The results indicate that the integrated national GWF for N and P was 1271 billion m3 yr−1, with maize, rice, and wheat contributing 39%, 37%, and 24%, respectively. Through interprovincial crop trade, southern China outsourced substantial N and P losses to the north, leading to a 30% GWS increase in northern China and 66% GWS mitigation in southern China. Specifically, Jilin, Henan, and Heilongjiang Provinces in the northern China showed increases in GWS by 161%, 114%, and 55%, respectively, while Fujian, Shanghai, and Zhejiang in the south had GWS reductions of 83%, 85%, and 80%, respectively. It was found that the interprovincial crop trade led to reduced national GWF and GWS. Insights into GWF and GWS can form the basis for policy developments on N and P pollution mitigation across regions in China.

Blue Water Footprint and Grey Water Footprint Assessment of Block-Printed Batik-Making Process Coloured by Indigo (Indigofera sp.), Tingi (Ceriops sp.) and Mahogany (Swietenia sp.) Dyes

The Indonesian batik, which is usually produced by small and medium enterprises (SMEs) often consumes a lot of water and causing environmental pollution. Therefore, a study to map the water use for batik production is required. This study examines the Blue Water Footprint (BWF) and Grey Water Footprint (GWF) of block-printed batik making-process coloured by Indigo (Indigofera sp.), Mahogany (Swietenia sp.) and Tingi (Ceriops sp.) dyes produced by a batik SME in Jarum village of Klaten Regency, Indonesia. The average BWF of block-printed batik making-process coloured by natural dyes was lower than the GWF and Indigo consumes more water in dyeing, followed by Tingi and Mahogany. The dyeing process consumes less water for BWF (2.96 L/pc), while the biggest portion of BWF was contributed from the wax removal process (152.81 L/pc). Implementation of cleaner production by managing the grey water, such as the implementation of communal Wastewater Treatment Plant, adopting water conservation strategies and educating the craftsmen are necessary to achieve batik and water resource sustainability.

Blue, green, and grey water footprints assessment for paddy irrigation-drainage system

Water footprint (WF) quantifies the impact of paddy field evapotranspiration (ET) and non-point source pollution on water resources and is an evaluation index for water sustainability. However, it is difficult to measure accurately using the existing method, which is based on parameter assumption without considering the field water conditions. In this study, a generic and physically based method for blue, green, and grey water accounting in paddy rice cultivation is introduced. We conducted field experiments using the common flood irrigation (CFI) and water-saving irrigation (SWI) modes in Nanjing, East China. By tracing the sources of ET and the migration process of multiple pollutants (TN, TP, NH4+-N, and NO3−-N), the characteristics of blue-green water consumption and the actual amount of water required to dilute pollutants at different growth stages of rice under CFI and SWI were analyzed. The WF of paddy rice was 1000 m3/t (49% WFgreen, 17% WFblue, 34% WFgrey) and 910 m3/t (50% WFgreen, 10% WFblue, 40% WFgrey) for CFI and SWI, respectively. The WF for paddy rice production was reduced by approximately 9% under SWI compared to CFI, with declines of 47% for WFblue and 8% for WFgreen. The SWI mode changed the ratio of blue to green water fluxes in field water by reducing irrigation during non-critical periods, and green water was used preferentially to enhance its utility. This conceptual method is the first to describe the formation mechanism of blue, green, and grey WFs in paddy systems. It can be extended to different scales and agro-ecosystems that show the influence of crop cultivation on water resources.

Water footprint of lemon production in Argentina

This work comes to fill a knowledge gap regarding the sustainability of the lemon industry. The motivation is the prominent role of the citrus sector in the economy of the northwest of Argentina and in the world: Argentina is the eighth largest producer of fresh citrus fruits, one of the four leading lemon-producing countries and the world's first lemon processor. A water footprint study is conducted to obtain relevant information on the water consumption and degradation associated with citrus production, according to the Water Footprint Network guidelines. A remarkable aspect is that most data used come mainly from actual practices and sources considering daily weather data of seven weather stations from 2012 to 2018. The green, blue and grey water footprints linked to the primary production of lemons are evaluated every year. The water footprint is distributed approximately in 69% (234 m3t−1) green, 8% (30 m3t−1) blue and 23% (82 m3t−1) grey. In addition, the Available Water Remaining (AWARE) indicator is used for outlining the blue water sustainability, resulting in a potential for blue water deprivation of 102 m3 world eq. per tonne of harvested lemons. This work is expected to serve as a baseline to provide diagnosis and improvement opportunities in the lemon sector for public and private stakeholders.

Assessment of water pollution in the Tibetan Plateau with contributions from agricultural and economic sectors: a case study of Lhasa River Basin.

The freshwater environment of watersheds in the Tibetan Plateau is bound with the safety of the Asian Water Tower. In this study, nitrogen (N) and phosphorus (P) loads delivered to freshwater and the associated gray water footprint (GWF) in the agriculture, tourism, domestic life, and industrial sectors were estimated to assess the seasonal and annual characteristics of the water pollution levels (WPLs) in the Lhasa River Basin from 2006 to 2018, and WPL calculations were compared with actual water quality measurements from 2017 to 2018. We found that more than 90% of the GWF came from anthropogenic sources. From the perspective of the whole basin, domestic life was the largest contributor to both N-related GWFs (52%) and P-related GWFs (50%), followed by agriculture for N-related GWFs (32%) and tourism industry for P-related GWFs (30%). The N emissions into the freshwater environment exceeded the maximum assimilation capacity of the watersheds in individual years at both seasonal and annual scales, while P emissions were completely within the pollution assimilative capacity. Besides, we found the serious N pollution near irrigation areas at the seasonal scale (WPL = 2.7 and TN = 1.11 mg/L). The prosperity of tourism has led to a tenfold increase in N-related GWFs and a fivefold increase in P-related GWFs for the tourism industry near the Lhasa city. The strict top-down unified management for ecological environmental protection in plateaus may be an effective method.

Future climate change could reduce irrigated and rainfed wheat water footprint in arid environments

The concept of water footprint (WF) has been used to manage freshwater resources for the past two decades and is considered as indicator of the sustainability of agricultural systems. Accordingly, the current study aimed to quantify WF and its components in the future climate for rainfed and irrigated wheat agro-ecosystems in 17 provinces of Iran located in arid or semi-arid environments. The provinces were divided into five climate classes. The simulations were conducted under current (1980–2010) and future climate (2040–2070) using the Agricultural Production Systems sIMulator (APSIM) crop model, following the Agricultural Model Intercomparison and Improvement Project (AgMIP) protocol. Baseline simulations indicated that the total WF, averaged across all climate classes, was 1148 m3 t−1 for irrigated and 1155 m3 t−1 for rainfed wheat. WF was projected to decline in the future compared to baseline in both irrigated and rainfed systems mostly because of increases in yield of +9% in rainfed systems and 3.5% in irrigated systems, and decreases in water consumption by −5.4% and −10.1%, respectively. However, the share of gray water footprint (WFgray) was projected to increase in the near future for both rainfed (+5.4%) and irrigated (+6.9%) systems. These findings suggest that cleaner and more sustainable production (i.e. obtaining grain yield under optimal water and nitrogen consumption) could be achieved in irrigated and rainfed wheat ago-ecosystems if optimal N fertilizer management is adopted. Additionally, rainfed cultivation can be further expanded in some areas which is expected to result in a substantial reduction in blue water (i.e. less irrigation), especially in sub-humid and semi-arid cool areas.

Yield, technological quality and water footprints of wheat under Mediterranean climate conditions: A field experiment to evaluate the effects of irrigation and nitrogen fertilization strategies

The evaluation of the role of different agronomic strategies in achieving sustainable wheat yields under variable Mediterranean climate conditions may involve the use of resource-use indicators that combine productivity and environmental impact. A two-seasons field experiment was conducted in South Portugal to study the effect of water regimes and nitrogen fertilization on wheat yield, grain quality and water use evaluated with water productivity and water footprint indicators. The water regime treatments were full irrigation, supplemental irrigation, and rainfed. Nitrogen fertilizer treatments, including conventional and enhanced efficiency fertilizers (EEF) were distinguished by N splitting and timing over the crop cycle. Contrasting meteorological variables in the two years caused distinct wheat productive responses. Although leading to lower grain yields, supplemental irrigation guaranteed a water productivity similar to full irrigation. The use of EEFs in which 50% of the total nitrogen was applied at the booting phase had a positive significant effect on grain protein content and on dough rheologic properties, indicating that late nitrogen applications benefit the technological quality of wheat. The average total water footprints estimated for the two seasons showed no relevant differences but the partition of the green, blue and grey components in irrigated wheat varied, with an increased importance of blue water consumptive use in the second year of the experiment. In fact, the ratio blue water footprint/green water footprint increased from 0.40 to 2.00 due to higher irrigation requirements. High grey water footprint in rainfed wheat was mostly influenced by lower yields in 2018–2019, and by an advantageous rainfall distribution during the 2017–2018 season. No significant reduction in grey water footprint was observed when using EEFs. A multivariate statistical approach through factor analysis (FA) and multivariate linear regression (MLR) was used to examine the data structure and correlation. FA resulted in three-factor models of yield and water use, yield components and wheat quality, in the first season. In the second, drier, season, variables most related with irrigation water use were clustered in one detached factor. The stepwise MLR pointed to a good prediction capability of water footprints from NDVI measured with proximal sensors at booting, anthesis, maturation and/or tillering.

Modeling climate change impacts on blue, green, and grey water footprints and crop yields in the Texas High Plains, USA

Simulating the impacts of future climate change on water footprints and crop production allows for selecting alternative crops for mitigating climate change effects. In this study, climate change impacts on irrigated grain corn, grain sorghum, winter wheat, and dryland (rainfed) winter wheat in the Palo Duro watershed of the Texas High Plains were assessed using an improved Soil and Water Assessment Tool (SWAT) model with an enhanced irrigation representation of management allowed depletion (MAD) irrigation scheduling. Climate change analyses in this study used the Coupled Model Intercomparison Project Phase 5 (CMIP5) climate projections of 11 General Circulation Models (GCMs) under four Representative Concentration Pathway (RCP) emission scenarios of RCP2.6, 4.5, 6.0, and 8.5 during two 30-year periods of the middle (2040-2069) and end (2070-2099) of the 21st century to compare to a baseline period of 1970-1999. For the irrigated summer crops of corn and sorghum, all 11 GCMs predicted the reductions of future irrigation, crop evapotranspiration (ETc), and yields compared to the baseline period. According to an ensemble of 11 GCMs, the simulated reductions in average annual irrigation, ETc, and yield for the irrigated corn were 63%, 34%, and 13%, respectively, at the end of the 21st century under the severe emission scenario of RCP8.5. Those values were 80%, 34%, and 34% under the irrigated sorghum land use. As for the irrigated winter wheat, the decreases in future irrigation and ETc were also identified in all GCMs relative to the baseline period. However, irrigated wheat yields were increased in the future climate. The changes in dryland wheat ETc were consistent with the rainfall variation under all climate change scenarios. Generally, the future climate could benefit the dryland wheat yields. A large uncertainty was found for the surface runoff simulations under both irrigated and dryland wheat according to various GCMs.

Water footprint in gold extraction: A case-study in Suárez, Cauca, Colombia

This research deepens the analysis of the mineral water footprint, especially that of gold, in regions that are understudied and where mining has been an intensified extractive activity since the colonial era, as is the case in the northern part of department of Cauca in Colombia. Thus, the purpose was to estimate the water footprint indicators in gold mining in Suárez (Cauca, Colombia), to quantify the impacts generated by the non-returned water in the production process and the levels of pollutants in the wastewater, aimed to strength public policies, control strategies and mitigation that generates reductions in the impacts from mining activities on the environment. The blue water footprint was estimated in 79.91 m3 per kg of gold extracted and the gray water footprint was found to be in the range of 272,125.39 to 404,825.11 m3 per kg of gold extracted. The water footprint values obtained were compared with other mines with similar operations. These results generate a baseline for decision making, providing elements for environmental strategic planning, regulations and showing the great environmental pressure that gold activity exerts on water resources and the territories.

Global-scale impact analysis of mine tailings dam failures: 1915–2020

Tailings are the waste materials generated from mining activities and are typically stored in large man-made earthen dams in the form of slurry. Failures of such tailings dams can have deleterious effects on the environment and even impact areas that are miles away from the failed dam. In this study, we updated the existing tailings dam failure database developed by the International Commission on Large Dams and World Information Service on Energy and analyzed the impacts of dam failure over the past hundred years from a global perspective. In addition, we prepared a tailings dam spatial database. The impact of mine tailings dam failure on aquatic environments was also investigated using a proxy environmental indicator—the gray water footprint. The resulting information from the historical overview of dam failures, was used to map the risk associated with existing tailings dams as well as the magnitude of tailings dam failures. Furthermore, we integrated mining commodity production data and the tailings dam failure data. This revealed that the number of failures is rising once again, and the trajectory of dam failures has shifted from developed to developing countries. Only a few dam failure incidents have had significant impacts. Although safer technologies are available to manage mine waste, most extractive industries are yet to adopt such technologies into their standard practices. Moreover, the reluctance of mining companies for the public disclosure of information related to tailings dams and dam failures hinders efforts to establish a complete tailings dam database. We have provided up-to-date tailings dam information, which may be useful for extractive industries.

Carbon Footprint and Water Footprint of Cashmere Fabrics

Given the serious problems of climate change, water shortage and water pollution, researchers have paid increasing attention to the concepts of the carbon footprint and water footprint as useful indices to quantify and evaluate the environmental impacts of the textile industry. In this study, assessment of the carbon footprints and water footprints of ten kinds of cashmere fabrics was conducted based on the PAS 2050 specification, the Water Footprint Network approach and the ISO 14046 standard. The results showed that knitted cashmere fabrics had a greater carbon footprint than woven cashmere fabrics. Contrarily, woven cashmere fabrics had a greater water footprint than knitted cashmere fabrics. The blue water footprint, grey water footprint and water scarcity footprint of combed sliver dyed woven cashmere fabric were the largest among the ten kinds of cashmere fabrics. The main pollutants that caused the grey water footprints of cashmere fabrics were total phosphorus (TP), chlorine dioxide, hexavalent chromium (Cr (VI)) and sulfide. The leading contributors to the water eutrophication footprint were total nitrogen, ammonia nitrogen, chemical oxygen demand and TP. These typical pollutants contributed 39% ~ 48%, 23% ~ 28%, 12% ~ 24% and 12% ~ 14% to each cashmere product’s water eutrophication footprint, respectively. The leading contributors to the water ecotoxicity footprint were aniline, Cr (VI) and absorbable organic halogens discharged in the dyeing and finishing process.

Water environmental pressure assessment in agricultural systems in Central Asia based on an Integrated Excess Nitrogen Load Model

Agricultural runoff is the main source of water pollution in Central Asia. Excessive nitrogen (N) inputs from overuse of chemical fertilizers are threatening regional water resources. However, the scarcity of quantitative data and simplified empirical models limit the reliability of grey water footprint (GWF), particularly in undeveloped regions. In this study, we developed an Integrated Excess Nitrogen Load Model (IENLM) to calculate excess N load and evaluate its potential water environmental pressure in Central Asia. The model optimized the biological N fixation and atmospheric N deposition modules by involving more environmental variables and human activities. Results showed that N fertilizer application contributed over 60% to total N input and was mainly responsible for 42.9% increase of total GWF from 101.5 to 145.0 billion m3 during 1992 - 2018. Water pollution level (WPL) increased from 0.55 in 1992 to 2.41 in 2018 and the pollution assimilation capacity of water systems has been fully consumed just by N load from agriculture since 2005. GWF intensity and grey water pollution – efficiency types in all Central Asian countries have improved in recent years except for Turkmenistan. N fertilizer application and agricultural economy development were the main driving factors induced N pollution. Results were validated by riverine nitrate concentrations and the estimates from prior studies. In future, combining the N fertilizer reduction with other farm management practices were projected to effectively improve the WPL. The modeling framework is favorable for N pollution research in data-scarce regions and provides a scientific basis for decision-making for agriculture and water resource managements.

Environmental impact of grain virtual water flows in China: From 1997 to 2014

The mismatching of grain production and consumption in space causes grain virtual water flow. Previous studies focused on the important role of virtual water trade in regional food security and its impact on water resource consumption, while this study focuses on the impact of virtual water flow on the environment. In this paper, two indexes of gray water footprint and carbon footprint were selected by footprint evaluation method to study the influence of virtual water flow on regional environment. The results show that the scale of grain virtual water flow gradually expanded, and the amount of virtual water flow increased from 67.14 Gm³ to 129.87 Gm³ from 1997 to 2014. The gray water footprint at a national scale showed a fluctuating trend, with obvious differences in temporal and spatial distribution. In addition, the total carbon footprint at the national scale increased from 290.2 Mton in 1997–430.4 Mton in 2014, basically showing a continuous increase trend. Provinces with larger gray water footprints are basically converted into import areas, and the total national gray water footprint reduced 64.74 Gm3. Meanwhile, the carbon footprint of the grain export region and import region changed significantly. Among the export areas, such as the Northeast region and the Huang-Huai-Hai region, the carbon footprint had an obvious downward trend. On the other hand, the carbon footprint of the import region in the south due to increasing of grain production to meet their own needs showed an increasing trend. Although virtual water flow reduced the gray water footprint and carbon footprint nationally, it increased the local environmental pressure on the export area. This study would be helpful in forming better water management policy and alleviating regional environment pressure.

Measurement and driving factors of grey water footprint efficiency in Yangtze River Basin

Water shortages and poor water quality have become an urgent problem that is constraining the sustainable development of China. Grey water has been found to bring greater stress on the water supply than freshwater consumption, and the grey water footprint (GWF) has received significant attention as a comprehensive indicator to assess wastewater pollution. In this study, we analysed the grey water footprint in the Yangtze River Basin from 2003 to 2017 and established a Logarithmic mean divisia index (LMDI) model to decompose the grey water footprint efficiency into six key factors. Our findings are as follows: (1) The average grey water footprint (AGWF) in the central regions was 40% higher than eastern region and 172% higher than western region; (2) Economic effects and capital deepening effects are the main factors affecting positive changes in grey water footprint efficiency; (3) Based on an analysis of the driving factors of greywater footprint efficiency in each province, we conducted a territorial classification according to the primary driving factors in each province. Our results reflect the spatial distribution characteristics of the influencing factors on the grey water footprint effect in the Yangtze River Basin and will enable the government to formulate relevant policies for each subregion.