Assessment of the water supply:demand ratios in a Mediterranean basin under different global change scenarios and mitigation alternatives

Will vegetation restoration affect the supply-demand relationship of water yield in an arid and semi-arid watershed?

Natural processes, combined with human activities, determine the inherent quality of regional water supply and demand. However, the interaction between artificial vegetation restoration and water supply-demand dynamics remains insufficiently understood, particularly in arid and semi-arid regions. This study focuses on the Jinghe River Basin (JRB) in the central Loess Plateau, aiming to investigate the changes in supply and demand of ecosystem water yield services and analyze factors affecting the water supply-demand relationship during the vegetation restoration, using the InVEST model, scenario analysis, and the Geodetector. The key findings are as follows: (1) Water shortages in the basin are concentrated in the southern and northern areas, while the southwestern and central areas exhibit water surpluses. Between 2000 and 2020, the water supply showed a first decline and then increase trend, whereas water demand exhibited an opposite trend, with 2009 and 2013 as turning points, respectively. These changes mitigated the basin's water scarcity. (2) Assuming constant meteorological factors and fixed water use indicators, water supply in the vegetation restoration areas decreased by 47.4 million m3, but water demand decreased by 89 million m3, indicating that vegetation restoration did not threaten human water availability. (3) Water supply is primarily influenced by meteorological factors, while water demand and the water supply-demand ratio (WSDR) are mainly driven by socio-economic factors. The influence of precipitation on water yield (q = 0.69) outweighs that of land use (q = 0.14), indicating that the reduction in water yield due to vegetation restoration is offset by the increased precipitation. This study provides insights into the spatiotemporal dynamics of water yield services and the relationship between vegetation restoration and water supply-demand in the arid and semi-arid regions.

Growing mismatches of supply and demand of ecosystem services in the Netherlands

A sufficient supply of goods and services from ecosystems is vital to ensure human well-being. This study evaluates whether the demand for goods and services within the Netherlands is met by Dutch ecosystems, could otherwise be provided through technology and/or by imports, or remains (partially) unmet. Additionally, this study shows the dynamics of supply and demand of these services over time. The results reveal that no ecosystem service supply is fully meeting the total demand provided by Dutch ecosystems. Additionally, for the majority of the services (10 out of 17), the gap between supply and demand widened over the last two decades, indicating a growing mismatch. Imports and technology only partly close the gap between supply and demand. The growing mismatch between supply and demand is expected to lead to increasing negative impacts on human well-being, such as poor air and water quality, heat stress in urban areas, increasing flood risks, limiting opportunities for outdoor recreation and loss of biodiversity. Our findings show that current policy goals to maintain and restore ecosystem services are not on track in the Netherlands. Urgent action is necessary to enhance the sustainable utilization of natural resources and to optimize the balance between supply and demand. Priority should be given to goods and services facing unmet demand where imports or technological solutions are not feasible, particularly those where the gap between supply and demand is widening.

Long-term hydroclimatic projections and climate change scenarios at regional scale in Morocco

Morocco urgently needs an updated understanding of its water resources, considering the current knowledge's insufficient and uncertain state. Incorporating the latest Shared Socioeconomic Pathways (SSPs) is crucial for a more accurate and informed assessment. This study aims to bridge this gap by examining the hydrological dynamics of major basins, offering insights vital for strategic water resource management. To unravel Morocco's hydrological future, we employed an integrative methodology encompassing advanced spatial analyses, watershed hydrological modeling through the 'Water Yield' module of InVEST, and climate change scenario projections from CMIP6. Leveraging reputable databases for land cover, soil, and climate data, we ensured a robust foundation for the projections applied. This comprehensive approach facilitated a nuanced examination of water availability, considering the intricate interplay of various factors. The findings unveil a concerning projection, anticipating water yield declines between 23% and 51% by 2080 and 43%-61% by 2100 across the 12 basins. The northwest and north areas, currently endowed with better water availability, face the most substantial reductions. Economic repercussions loom, with potential losses ranging from -0.8 to -8.5 billion USD by 2100, urging strategic interventions to avert potential GDP declines of 2.8%-17.1%. The study highlights the scenario-dependent sensitivity of water supply to varying levels of climate change. In the context of the North African region, Morocco's hydroclimatic challenges assume heightened significance. As a pivotal player in the region, Morocco's water resource management impacts its socio-economic landscape as well as resonates regionally. The outcome of proactive measures and strategic planning can potentially set a precedent for neighboring countries grappling with similar hydrological uncertainties, fostering regional resilience in the face of escalating water stress. The study's insights, therefore, carry broader implications, positioning Morocco as a key influencer in shaping sustainable water management practices across North Africa.

Identifying priority areas for freshwater supply conservation integrating multi-scale freshwater flows

Identifying priority areas for conservation is an effective measurement for the sustainable provision of ecosystem services (ESs) under threats globally. Although many approaches have been developed to identify conservation priority areas by combining supply and demand of ESs, the integration of ESs flows into the identification still need further exploration. For ESs like freshwater supply services, the processes of freshwater flows across multiple scales are crucial. This study aimed to propose a new study framework to identify priority areas for freshwater supply conservation by integrating the multi-scale (i.e., sub-watershed, tributary, and mainstream) freshwater flows, using the Yangtze River Delta as the study area. The results suggested that spatial mismatches between the supply and demand of freshwater supply services existed at different scales. There were approximately 129, 58, and 55 pairs of freshwater flows in sub-watersheds, tributaries, and mainstreams, respectively, which transported 5.98 × 1010 m3, 2.07 × 1010 m3 and 2.50 × 1010 m3 of freshwater. The results of multi-scale freshwater flows were integrated into conservation target goals, and the identified priority areas for freshwater supply conservation were selected at three scales. The priority areas selected at the sub-watershed scale were the largest. Compared with the traditional method of identifying priority areas without considering freshwater flows, the priority areas identified in this study included both sites with a high supply capacity and sites with a relatively low supply capacity, as they were significant for meeting the local freshwater demand. The increasing understanding of freshwater flows and the integration of the flows for the identification of priority areas for freshwater supply conservation are important for the development of more practical and rational policies or ecological management for the sustainable conservation of ESs.

Understanding supply-demand mismatches in ecosystem services and interactive effects of drivers to support spatial planning in Tianjin metropolis, China

Metropolitan areas are being challenged by the disparity between growing societal needs and dwindling natural resource provision. Understanding the supply-demand mismatches of ecosystem services (ES) and their drivers is essential for landscape planning and decision-making. However, integrating such information into spatial planning remains challenging due to the complex nature of urban ecosystems and their intrinsic interactions. In this study, we first assessed and mapped the supply, demand, and mismatches of six typical ES in Tianjin, China. We then clustered numerous townships based on their corresponding spatial characteristic of ES supply-demand mismatches. We also used Random Forest regression to examine the relative importance of drivers and applied Partial Least Squares structural equation modelling to decouple their interactions. The results showed that, the distribution of ES supply and demand showed obvious spatial heterogeneity, with a common surplus of ES supply in highly natural mountainous region and an excess of demand in urban centre. Additionally, all towns were classified into four spatial clusters with homogeneous states of supply-demand mismatches, serving as basic units for spatial optimization. Moreover, the interactions between drivers affected ES supply-demand mismatches in a coupled manner, including the direct effects of the socioeconomic factor (-0.821) and landscape composition (0.234), as well as the indirect effects of the biophysical factor (0.151) and landscape configuration (0.082). Finally, we discussed the utility of analysing the spatial mismatches between ES supply and demand for integrated territorial planning and coordinated decision-making.

Water security assessment and driving mechanism in the ecosystem service flow condition

Water resources are the foundation of human survival and development. Thus, it is essential to quantify the relationship between water supply and demand and assess water security to ensure sustainable use of water resources. In this study, we quantified the relationship between water supply and demand in the Yiluo River Basin (YRB) using the InVEST model, constructed a spatial flow model of water provision service at the sub-watershed scale, and analyzed the water security index (WSI) under static and dynamic conditions. Subsequently, we used geographic detectors to identify the explanatory power of the main influencing factors of the WSI. The results showed that (1) from 2005 to 2018, the water supply decreased continuously and the water demand first increased and then decreased in the YRB; (2) the spatial pattern of WSI showed that it was high in the southwest and low in the northeast, wherein the highest and lowest WSI values occurred in 2005 and 2018, respectively. From 2005 to 2018, the mean values of the static and dynamic WSI decreased from 0.77 to 0.60 and 1.56 to 1.20, respectively. (3) The precipitation factor from the supply dimension and the gross domestic product (GDP) factor from the demand dimension had the strongest explanatory power for the static WSI. For the dynamic WSI, the flow quantity of the water provision service flow had the strongest explanatory power. This study provided a reference for governments to formulate sustainable water resource management.

Analysis of the relationship between supply-demand matching of selected ecosystem services and urban spatial governance: a case study of Suzhou, China

The mismatch between the supply and demand of ecosystem services has become a critical cause of the decline of urban ecological security. Studying the supply-demand matching of ecosystem services and exploring its association with urban spatial governance are imperative for ensuring sustainable urbanization. Taking Suzhou City as a case, the supply and demand values and matching degrees of five selected ecosystem services were assessed. Additionally, we explored the relationship between ecosystem services and urban spatial governance, with a focus on urban functional zoning. The findings indicate that first, the supply value of water production, food production, carbon sequestration, and tourism and leisure fall short of the demand value, while the supply value of air purification exceeds the demand value. The spatial matching of supply and demand shows a typical circular structure, with areas in short supply predominantly located in the downtown area and its vicinity. Second, the degree of coupling coordination between the supply-demand ratio of selected ecosystem services and the intensity of ecological control is low. Urban functional zoning can affect the supply-demand relationship of selected ecosystem services, and intensified development efforts can exacerbate the mismatch between supply and demand. Third, research on the supply-demand matching of selected ecosystem services can facilitate the assessment and regulation of urban functional zoning. Urban spatial governance can be regulated based on land use, industry, and population, with a focus on achieving a better supply-demand matching of ecosystem services. Through the analysis, this paper is aimed to provide reference for mitigating urban environmental problems and formulating sustainable urban development strategies.

Landscape Pattern Change and Ecological Effect in a Typical Mountain-Oasis-Desert Region in the Northwest Region of China

China has experienced dramatic changes in its land use and landscape pattern in the past few decades. At present, a large number of studies have carried out in-depth and systematic analyses on the landscape variation and its ecological effects in Central and Eastern China, but research on the northwest arid region is relatively deficient. In the present study, the city of Hami, which is located in the northwest arid region of China, was selected as the study area to investigate the responses in the habitat quality, water yield and carbon storage to land use and cover change during 2000-2020. We found that (1) during the entire study period (2000-2020), the variation intensity of the first decade (2000-2010) was significantly greater than that of the second decade (2010-2020), and the conversion between desert and grassland played a dominant role in the conversion among these land types. (2) The maximum value of the habitat degradation degree in Hami city increased during the study period, indicating that the habitat presented a trend of degradation. (3) The total carbon storage in Hami city was approximately 11.03 × 10⁶ t, 11.16 × 10⁶ t and 11.17 × 10⁶ t in 2000, 2010 and 2020, respectively, which indicated an increasing trend. (4) According to the calculation, the average water yield and the total water conservation showed a decreasing trend in the study area. The corresponding results will help to formulate protective measures that are conducive to the restoration of ecosystem functions in extremely arid regions.

Mediating Effect of Heat Waves between Ecosystem Services and Heat-Related Mortality of Characteristic Populations: Evidence from Jiangsu Province, China

In the context of climate change, heat waves are a serious hazard having significant impacts on human health, especially vulnerable populations. Many studies have researched the association between extreme heat and mortality. In the context of urban planning, many studies have explored the cooling effect of green roofs, parks, urban forests and urban gardens. Nevertheless, few studies have analyzed the effect mechanism of specific ecosystem services (Ess) as mitigation measures to heat waves. This study aimed to determine the relationship among Ess, heat waves and the heat-related mortality risk of different groups by diseases, age and sex. The research was conducted in three cities in Jiangsu Province, including Nanjing, Suzhou and Yancheng. We quantified five ecosystem services, i.e., water supply service, carbon sequestration service, cooling service, biodiversity and cultural service. Based on the previous studies, we took the frequency of heat waves into account, extending the concept of the Heat Wave Magnitude Index (HWMI). A distributed lag nonlinear model (DLNM) was applied to estimate the effect of extreme heat on mortality. Then, the study used the process analysis method to explore the relationship among Ess, heat waves and heat-related mortality risks. The results indicated that (i) water supply service, carbon sequestration service, cooling service and biodiversity can reduce heat-related mortality while cultural service increases; (ii) the effects of carbon sequestration service and cultural service are stronger than other Ess; (iii) the effects of Ess on cardiorespiratory disease, stroke and chronic obstructive pulmonary disease (COPD) mortality risks are higher than others; and (iv) women and elderly heat-related mortality risks are more affected by the Ess. This study can provide a theoretical support for policy makers to mitigate heatwave events, thus limiting heat-related mortality.

Relations between physical and ecosystem service flows of freshwater are critical for water resource security in large dryland river basin

Freshwater ecosystem services are the link between ecological systems and social systems, which is an important guarantee of the freshwater safety particularly in dryland regions. However, more quantitative research has been based on the freshwater ecosystem services of static situations, and less on the flow conditions. We established a comprehensive modeling framework for the analysis of water security pattern based on the physical flow (PF) and ecosystem service flow (ESF) of freshwater. The results for Yellow River Basin showed that the water-scarce area have reduced in the past two decades. The PF of freshwater relieves water stress on an average of 52.1 % of the static water in scarce areas per year. The problem in water-deficient areas meanly lies on the water supply side. These results highlight the importance of PF from the upstream to downstream, which is critical for formulating sustainable management strategies in safeguarding long-term regional freshwater resource security.

Assessment of Supply and Demand of Regional Flood Regulation Ecosystem Services and Zoning Management in Response to Flood Disasters: A Case Study of Fujian Delta

Global climate change has led to flood disasters increasing in terms of frequency and damage caused, which seriously threatens urban and rural security. The flood regulation (FR) service function of the ecosystem plays an important role in mitigating flood disaster risk. Previous studies on flood regulation ecosystem services (FRES) are still lacking in a cross-scale assessment of supply and demand, refined simulation of regional complex hydrology, and application of spatial zoning management. Taking the Fujian Delta as an example, this study established a cross-scale research framework based on the social-ecosystem principle. The SWAT model was used to simulate the regional hydrological runoff and calculate the macro-scale supply of FRES. Taking patches of land as units, a flood risk assessment model was constructed to calculate the micro-scale demand for FRES for urban and rural society. Through a comparison of supply and demand across spatial scales, a zoning management scheme to deal with flood disaster risk was proposed. The results showed that: (1) The supply of FRES differed greatly among the sub-basins, and the sub-basins with low supply were mostly distributed in the lower reaches of Jiulong River and the coastal areas. (2) The demand for FRES was concentrated in high-density urban built-up areas. (3) By comparing the supply and demand of FRES in sub-basin units, 2153 km² ecological space was identified as the primary ecological protection area, and 914 km² cultivated land and bare land were identified as the primary ecological restoration area. (4) By comparing the supply and demand of FRES of land patch units, 65.42 km² of construction land was identified as the primary intervention area. This study provides a decision-making basis for regional flood disaster management from the perspective of FRES.

Spatiotemporal Variation and Driving Factors of Water Supply Services in the Three Gorges Reservoir Area of China Based on Supply-Demand Balance

Water supply services (WSSs) are critical to human survival and development. The Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) model enables an integrated, dynamic, and visual assessment of ecosystem services at different scales. In addition, Geodetector is an effective tool for identifying the main driving factors of spatial heterogeneity of ecosystem services. Therefore, this article takes the Three Gorges Reservoir Area (TGRA), the most prominent strategic reserve of freshwater resources in China, as the study area and uses the InVEST model to simulate the spatiotemporal heterogeneity of the supply-demand balance of WSSs and freshwater security patterns in 2005, 2010, 2015, and 2018, and explores the key driving factors of freshwater security index (FSI) with Geodetector. The total supply of WSSs in the TGRA decreased by 1.05% overall between 2005 and 2018, with the head and tail areas being low-value regions for water yield and the central part of the belly areas being high-value regions for water yield. The total demand for WSSs in the TGRA increased by 9.1%, with the tail zones and the central part of the belly zones being the high water consumption areas. In contrast, the head zones are of low water consumption. The multi-year average FSI of the TGRA is 0.12, 0.1, 0.21, and 0.16, showing an upward trend. The key ecological function areas in the TGRA are high-value FSI regions, while the tail zones in the key development areas are low-value FSI regions. Industrial water consumption significantly impacts FSI, with a multi-year average q value of 0.82. Meanwhile, the q value of industrial and domestic water consumption on FSI in 2018 increased by 43.54% and 30%, respectively, compared with 2005. This study analyzes the spatiotemporal variation of WSSs and detects the drivers in the natural-economic-social perspective and innovation in ecosystem services research. The study results can guide water resource security management in other large reservoirs or specific reservoir areas.

GIS-AHP Ensembles for Multi-Actor Multi-Criteria Site Selection Processes: Application to Groundwater Management under Climate Change

A possible adaptation pathway for water suppliers in Germany who face a climatically driven increase in water stress is the development of aquifers which are not used at their full potential. However, identifying suitable sites for aquifer development can go along with severe conflict potential due to the great variety of stakeholders who are involved in the decision-making process. We approach this multi-actor and multi-criteria decision-making problem by developing a geoinformation system-based analytic hierarchy process ensemble (GIS-AHP ensemble). As opposed to the classic GIS-AHP method that yields ratings of site suitability based on a single expert evaluation, the here proposed new GIS-AHP ensemble method respects multiple expert evaluations and allows for quantifying the robustness of yielded site ratings in multi-actor contexts, which helps to mitigate conflict potential. The respectively derived GIS-AHP ensemble site ratings for northwest Germany are successfully checked for plausibility in the framework of the study by using long-established groundwater abstraction areas as indicators for good site conditions. The GIS-AHP ensemble site ratings are further tested regarding their usability for long-term water supply planning by integrating a groundwater recharge scenario under climate change for the period 2020 to 2050. The proposed GIS-AHP ensemble methodology proves useful in the given case study for fostering integrated environmental decision-making and exhibits a high transferability to other, thematically differing site selection problems.

Integrating Water Quality Restoration Cost with Ecosystem Service Flow to Quantify an Ecological Compensation Standard: A Case Study of the Taoxi Creek Watershed

Watershed ecological compensation is an important economic tool for solving the protection–development conflict. However, establishing a sound ecological compensation plan for rational water resource use at the watershed scale remains challenging. Monthly water samples were collected between April 2019 and July 2020 at 28 points to analyze the spatiotemporal variation in water quality in the Taoxi Creek watershed, which is important for local water security. The Soil and Water Assessment Tool was used to simulate water supply, demand, and spatial flow at the watershed scale. Water quality restoration cost was integrated with ecosystem service flow to quantify the watershed ecological compensation. The ecological compensation using water quality restoration cost based on pollutant treatment cost and water quality target level was CNY 11.9 million (USD 188 million). Taoxi Creek was identified as the major supplier of water ecosystem services for downstream residents, and the ecological compensation based on ecosystem service flow was CNY 18.9–47.2 million (USD 3.0–7.5 million). Combining both calculations, the watershed should annually receive CNY 30.8–59.1 million (USD 4.9–9.3 million) of economic compensation from downstream ecosystem beneficiaries. This study provides a scientific basis for improving the ecological compensation scheme in the Taoxi Creek watershed and a reference for ecological compensation formulation in other watersheds.

An ecological perspective for understanding regional integration based on ecosystem service budgets, bundles, and flows: A case study of the Jinan metropolitan area in China

Regional integration can contribute to co-occurring benefits of different parts of an urban agglomeration by managing these parts as a whole. However, current regional integration mainly focuses on the socioeconomic rather than the ecological dimension. To interpret regional ecological integration, we firstly selected six typical ecosystem services (ESs) to represent ecological benefits that potentially need to be improved by ecological integration for further analysis. Then we used ES budgets, bundles, and flows to investigate the potential, basic analysis unit, and occurring manners of ecological integration, respectively. Our results show that supply-demand mismatches were observed in all the ES types. Meanwhile, coexisting ES surpluses and deficits on the town scale were found in supporting biodiversity, soil retention, water yield, green space recreation, and crop yield, which indicates that their supply-demand mismatches can be mitigated with ecological integration. Furthermore, all the towns were classified into five spatial clusters with distinct ES budget bundles, which acted as the basic analysis unit of ecological integration. ES flows with three flow characteristic types were observed between different clusters, and all the clusters had ES provider-beneficiary relationships with each other. Based on the ES approach, we provided an ecological perspective for understanding regional integration, which has the potential to promote regional ecological sustainability.

Impact of urbanization on the food-water-land-ecosystem nexus: A study of Shenzhen, China

The food-water-land-ecosystem (FWLE) nexus is fundamental for achieving sustainable development. This study examines the influence of urbanization on the FWLE nexus. Toward this end, land was deemed as an entry point. Therefore, the impact of urbanization on the nexus was explored based on changes in land use. We selected Shenzhen, a city in China, as the study area. First, a land change modeler was employed to analyze historical land-use changes from 2000 to 2010, to build transition potential submodels, and to project future land-use patterns for 2030 under a business-as-usual scenario. Second, based on land-use maps, we assessed habitat quality, water yield, and water supply from 2000 to 2030 using Integrated Valuation of Ecosystem Services and Tradeoffs. Moreover, crop production was estimated according to statistical materials. Finally, the study presents the analyses and discussion of the impacts of urbanization on ecosystem services related to the FWLE nexus. The results of land-use changes indicated that a significant expansion of artificial surfaces occurred in Shenzhen with varying degrees of decrease in cultivated land, forest, and grassland. Furthermore, habitat quality, water supply, and crop production decreased evidently due to rapid urbanization. In contrast, the total water yield indicated an upward trend owing to the increased water yield from increasing artificial surfaces, whereas water yield from other land-use areas declined, such as the forest and grassland. The results demonstrated a significant positive correlation between artificial surfaces and total water yield. However, negative correlations were observed in the interaction among habitat quality, water supply, and crop production. The study presented temporal and spatial assessments to provide an effective and convenient means of exploring the interactions and tradeoffs within the FWLE nexus, which, thus, contributed to the sustainable transformation of urbanization.

A framework of freshwater services flow model into assessment on water security and quantification of transboundary flow: A case study in northeast China

Ecosystem service flow dynamics which establish the linkage between human and nature is essential in an ecosystem service assessment. This study constructed an ecosystem service flow model of freshwater flow then utilized it to assess the water-related ecosystem services in northeast China. We included the provision, consumption, and spatial flow of freshwater services in an index to assess the water security condition and quantified the services trans-boundary flow from the northeast forest belt (NFB) in northeast China. Our results showed that large areas (50.54%, 55.10% and 52.90%, respectively) of northeast China received upstream freshwater service in three years. The water security condition of northeast China deteriorated from 2005 to 2015 with the change of water security index considering water flow (WSI_flow), mainly influenced by precipitation and agriculture water consumption. Approximately 4.16 billion m³ of freshwater service were delivered from NFB to surrounding regions demonstrating the importance of NFB in terms of ecosystem service provision. In addition, 73 key watersheds (4.71% of total area) within NFB that significantly affect the trans-boundary flow were further identified. We suggested that local government should advocate develop water-saving agriculture and livestock water quotas. Moreover, priorities should be given to protect the key watersheds within NFB in order to maintain the supply of freshwater service. This study provided a framework for exploring suitable strategies for managing water resources and laid a foundation for promoting the ecological compensation in the future.

Identifying ecosystem service bundles and the spatiotemporal characteristics of trade-offs and synergies in coal mining areas with a high groundwater table

Understanding the spatiotemporal characteristics of the interactions among ecosystem services (ESs) is a crucial but challenging task for maintaining human well-being and achieving sustainable regional development. However, understanding the spatiotemporal interactions of multiple ESs at different grid scales and within different ecosystem services bundles (ESBs) is relatively limited, particularly in coal mining areas with a high groundwater table (CMA-HGT) where the land use has drastically changed as a result of mining subsidence. This study examines CMA-HGT in Huainan, aiming to identify ESBs and explore the spatiotemporal characteristics of trade-offs/synergies among ESs at distinct grid scales and ESBs. Five ESs relating to provisioning, regulation, and maintenance, including food production (FP), water yield (WY), soil conservation (SC), carbon sequestration (CS), and biodiversity maintenance (BM) were quantified using different biological models during the period 1987-2018. Spatiotemporal trade-offs/synergies among ESs were explored using correlation analysis and significance tests at different scales. The spatiotemporal distributions and main characteristics of distinct ESBs were identified using a self-organizing map (SOM) and Calinski criterion. The interactions among ESs in different ESBs were detected. Relationships between ESs and land use or coal production (CP) were explored using redundancy analysis (RDA). The results demonstrate that spatiotemporal trade-offs were generally observed among provisioning services at distinct grid scales and within different ESBs. Meanwhile, spatiotemporal synergies generally appeared between regulation and maintenance services at distinct grid scales. Interactions among ESs presented temporal dynamic, spatial heterogeneity and scales dependence due to the relationships of FP-BM or SC-CS had changed with the increasing of research scales. Three ESBs-ESB1, ESB2, and ESB3-were identified at a grid of scale of 1000 m, and their spatial locations varied across different periods, but the areas of variation covered less than 24% of the study area. BM was synergistic with FP, WY, SC, and CS; while WY had only a trade-off relationship with FP in ESB1. WY had trade-off relationships with FP, SC, CS, and BM in ESB2. In ESB3, BM was synergistic with FP, SC, and CS; while it was in a trade-off relationship with WY. Cultivated land, construction land and CP were the main driving factors in the WSA, ESB1, ESB2 and ESB3. There was a certain degree of change in the relationships between ESs and land use/CP, and the relationships among ESs at different grid scales and ESBs over time and space, which indicates strong regional heterogeneity and scale dependence. These results can provide detailed guidelines for formulating spatially targeted ecosystem management, restoration programs and ES payment policies.

Evaluation of Water Provision Ecosystem Services Associated with Land Use/Cover and Climate Variability in the Winike Watershed, Omo Gibe Basin of Ethiopia

The provision of freshwater is essential for sustaining human life. Understanding the water provision modelling associated with the Land Use/Cover (LUC) change and climatic factors is vital for landscape water resource management. The Winike watershed is the largest tributary in the upper Omo Gibe basin of Ethiopia. This research aims to analyze the spatial and temporal change in the water yield to investigate the water yield contribution from the watershed based on the variation in input parameters. The Integrated Valuation of Ecosystem Services and Tradeoffs Tool (InVEST) water yield model was used to evaluate the spatial and temporal variation of the water yield in different years (1988, 1998, 2008 and 2018). The data required for this model include LUC data from satellite images, reference evapotranspiration, root depth, plant available water, precipitation, season factor (Z), and a biophysical table. The analysis of LUC change shows a rapid conversion of grazing land, shrubland, and forest land into cultivated land. There has been a significant variation in water provision, which increased from 1.83 × 10⁹ m³ in 1988 to 3.35 × 10⁹ m³ in 2018. Sub-watersheds 31, 32, and 39 in the eastern part of the watershed contributed more water due to higher precipitation and lower reference evapotranspiration. The major increase in the contribution of water yield was in built-up land by 207.4%, followed by bare land, 148.54%, and forest land by 63%. Precipitation had a greater impact on water yield estimation compared with the other input parameters. Hence, this research helps decision-makers to make informed decisions regarding new policies for LUC change improvement to maintain the water resources in the Winike watershed.

Precipitation and urban expansion caused jointly the spatiotemporal dislocation between supply and demand of water provision service

A clear quantification and spatial mapping between supply and demand of water provision service in relation to climate change and urban expansion can provide some guidance to water resources management. Nevertheless, so far, most researches ignored the dynamic changes and influences of supply-demand coupling correlations. In this study, water yield and water demand were quantified and mapped in the Xiangjiang River Basin (XRB) from 2000 to 2018 by using the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) and water-demand models, then the spatial distribution characteristics and their matching relationship were identified by using the univariate local autocorrelation analysis and the common logarithm of water supply-demand ratio (WSDR). With that, the contributions of climate and socio-economic factors to the above-mentioned changes were explored by using geographic detector. Results showed that the annual water yield increased by 20.20% in 2000-2015 and decreased by 33.92% in 2015-2018 affected by precipitation and land use changes; Changsha-Zhuzhou- Xiangtan urban agglomeration (CZX) and Southwest of Yongzhou were the high value areas of water yield (>338 m³/hm²). Due to the urban expansion, the water demand increased by 40.50% from 2000 to 2005 and decreased by 36.39% after 2005; From 2000 to 2018, high value areas of water demand (>53566 m³/hm²) mainly appeared in midstream and downstream with high urbanization level, dense population and developed industry. Under the joint action of precipitation (prep) and urban expansion, the overall state of supply and demand in the upper reaches was surplus, and more than 90% of the regions in midstream and downstream were at the middle and high level of supply shortage, especially in Hengyang and Chenzhou. Consequently, the increasing needs of human beings should be emphasized from the overall perspective of the basin, the growth rate of construction land and the necessary green infrastructure should be controlled reasonably and configured for achieving win-win goals of coordinating environmental protection and urban development.

Multiscale research on spatial supply-demand mismatches and synergic strategies of multifunctional cultivated land

Multifunctional cultivated land has both sides of supply and demand, and their matches are very important to boost the high-quality development of agriculture and rural areas. The supply-demand match index and GIS spatial analysis were employed to explore the supply-demand mismatches and synergic strategies of multifunctional cultivated land. Taking the Wuhan Metropolitan Area (WMA), China as an example, we obtained the following results: (1) There were obvious supply-demand mismatches of multifunctional cultivated land in the production function, ecological function, and landscape culture function. The spatial distribution of supply-demand mismatches of the three different functions of cultivated land is different. The supply of cultivated land production function is less than the demand, while the supply of landscape culture function is greater than the demand. The supply matches the demand of cultivated land in the ecological function. (2) The supply-demand mismatches of multifunctional cultivated land have scale effects. From the 1 km × 1 km grid scale to the township, county (district), and prefecture-level city scales, the proportion of deficit regions of production function and ecological function decreases with increasing scale. In contrast, the deficit regions of landscape culture function are always concentrated in the center of the WMA. It is considered that we should improve the supply of cultivated land in the production function, protect ecological function and enhance the demand of landscape culture function. Moreover, the management of multifunctional cultivated land needs to strengthen the multiscale spatial linkage and differential strategies of the supply side and demand side.

Linking Ecosystem Service Supply–Demand Risks and Regional Spatial Management in the Yihe River Basin, Central China

The continuous supply of ecosystem services is the foundation of the sustainable development of human society. The identification of the supply–demand relationships and risks of ecosystem services is of considerable importance to the management of regional ecosystems and the effective allocation of resources. This paper took the Yihe River Basin as the research area and selected water yield, carbon sequestration, food production, and soil conservation to assess changes in the supply and demand of ecosystem services and their matching status from 2000 to 2018. Risk identification and management zoning were also conducted. Results show the following: (1) The spatial distribution of the four ecosystems service supply and demand in the Yihe River Basin was mismatched. The food production supply levels in the middle and lower reaches and the upstream water yield, carbon sequestration, and soil conservation supply levels were high. However, most of the areas with high demand for ecosystem services were concentrated downstream. (2) From 2000 to 2018, the supply of water yield and carbon sequestration in the Yihe River Basin decreased, while that of food production and soil conservation increased. The demand for the four ecosystem services also increased. (3) Water yield faced considerable supply–demand risks. Fifty percent of the sub-basins were at a high-risk level, and the risk areas were concentrated in the middle and lower reaches. The three remaining services were mainly at low-risk levels. The Yihe River Basin was divided into eight types of supply–demand risk spatial management zones based on the ecosystem service supply and demand levels, which will help promote refined regional ecosystem management and sustainable development. The supply and demand assessment of ecosystem services from a risk perspective can integrate the information of natural ecosystems and socio-economic systems and provide scientific support for watershed spatial management.

Investigating tradeoffs between supply, use and demand of ecosystem services and their effective drivers for sustainable environmental management

Ecosystems have a huge impact on social systems through providing diverse services. Sustainable management of social and ecological systems requires the quantification of spatial relationships between the supply, demand, and use of these ecosystem services. The main purpose of this paper was to provide a framework addressing all the complicated relationships of ecosystem services between ecological and social systems. Sustainable management cannot be achieved without considering these complex relationships. To simplify these complexities, management priorities must be identified. In this study, spatial changes of supply, use, and demand of ecosystem services and their main drivers were investigated. A Public Participation Geographic Information System was used to map the supply, demand and use of 19 ecosystem services in semiarid landscapes of Iran. Multi Criteria Decision Making methods were also used to link ecosystem services to social well-being. The main drivers of tradeoffs between supply, use, and demand of ecosystem services were determined using General Linear Method. The results showed that there was a synergy between supply, demand and use of ecosystem services in highlands. The deficit zones of ecosystem services were concentrated in lowlands. Provisioning services were the most important services for social well-being. The framework presented in this paper revealed all the complex relationships that the environmental management is faced with in ecosystem and social systems. Simplifying integrated relationships in both ecosystems (supply) and social systems (demand and use) helps sustainable management of ecosystems under environmental and social changes.

Evaluation of water conservation function of Danjiang River Basin in Qinling Mountains, China based on InVEST model

With the shortage of water resources becoming a global concern, the water conservation function has become one of the most important service functions and the key factor in the sustainable development of watershed ecosystem. The Danjiang River Basin as an important source of water for the middle route of China's South-to-North Water Diversion Project, its water conservation function has attracted extensive public attention under global climate change. In this study, InVEST water yield model based on Budyko hydrological method was employed to analyze the spatio-temporal dynamics of water conservation, and the response of water conservation to climate, land use and soil changes for the period from 2000 to 2019. The results show that the water conservation of Danjiang River Basin tends to decrease under the comprehensive influence of various factors. The spatial analysis of the importance of water conservation identified Shangnan County, the southern part of Danfeng County and the northern part of Shanyang County as important water conservation areas in the study area, which should be regarded as the key and priority protection areas in the regional water resource and ecological protection. The study provides insights for sustainable water management and ecological protection policies, and the InVEST model with localized parameters can also be applied to other areas lacking climate, hydrological and geological data.

Using the InVEST Model to Assess the Impacts of Climate and Land Use Changes on Water Yield in the Upstream Regions of the Shule River Basin

Water yield is a key ecosystem function index, directly impacting the sustainable development of the basin economy and ecosystem. Climate and land use/land cover (LULC) changes are the main driving factors affecting water yield. In the context of global climate change, assessing the impacts of climate and LULC changes on water yield in the alpine regions of the Qinghai–Tibet Plateau (QTP) is essential for formulating rational management and development strategies for water resources. On the basis of the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, we simulated and analyzed the spatiotemporal variations and the impacts of LULC and climate changes on water yield from 2001 to 2019 in the upstream regions of the Shule River Basin (USRB) on the northeastern margin of the QTP. Three scenarios were designed in the InVEST model to clearly analyze the contributions of climate and LULC changes on the variation of water yield. The first scenario integrated climate and LULC change into the model according to the actual conditions. The second scenario was simulation without LULC change, and the third scenario was without climate change. The results showed that (1) the InVEST model had a good performance in estimating water yield (coefficient of determination (R2) = 0.986; root mean square error (RMSE) = 3.012, p < 0.05); (2) the water yield significantly increased in the temporal scale from 2001 to 2019, especially in the high altitude of the marginal regions (accounting for 32.01%), while the northwest regions significantly decreased and accounted for only 8.39% (p < 0.05); (3) the spatial distribution of water yield increased from the middle low-altitude regions to the marginal high-altitude regions; and (4) through the analysis of the three scenarios, the impact of climate change on water yield was 90.56%, while that of LULC change was only 9.44%. This study reveals that climate warming has a positive impact on water yield, which will provide valuable references for the integrated assessment and management of water resources in the Shule River Basin.

Changes in supply and demand mediate the effects of land-use change on freshwater ecosystem services flows

Land-use change alters the dynamics of freshwater ecosystem services flows by affecting both service supply (by influencing hydrological processes and runoff) and demand (via changes in human water use). However, few studies have considered the wide range of effects of land-use change on freshwater ecosystem services' flows. In this study, we distinguished the impacts of changing water supply and demand in the Aojiang River watershed, Fujian Province, China, an important water resource for more than seven million people. Rapid urbanization between 1991 and 2015 led to a minor increase of 2.5% in the supply of freshwater ecosystem services. However, demand increased by 96.3%, leading to a 25.7% overall decrease in freshwater ecosystem services flows. Downstream demand for freshwater increased substantially due to large shifts in agricultural, urban, and industrial activities. Our analysis provides detailed information on freshwater ecosystem services flows from supply to beneficiaries within a watershed, thus facilitating integrated watershed management and decision making. This study demonstrates how land-use change and ecosystem services' flows can be integrated both at local and regional scales for land-use management, water reallocation, and ecological compensation, thus promoting the sustainability of freshwater ecosystems.

Considering the Environmental Impacts of Bioenergy Technologies to Support German Energy Transition

Clean energy for all, as listed in the United Nation’s SDG7, is a key component for sustainable environmental development. Therefore, it is imperative to uncover the environmental implications of alternative energy technologies. SustainableGAS project simulates different process chains for the substitution of natural gas with renewable energies in the German gas market. The project follows an interdisciplinary approach, taking into account techno-social and environmental variabilities. However, this research highlights the project results from the environmental perspective. So far, a detailed assessment of the environmental costs of alternative gas technologies with a focus on the process of energy transition has remained rare. Although such data constitute key inputs for decision-making, this study helps to bridge a substantial knowledge gap. Competing land-use systems are examined to secure central ecosystem services. To fulfill this obligation, an Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) serves as the modelling tool. InVEST assesses ecosystem services (ES) that are or may be affected by alternative bioenergy technologies. Spatially explicit model results include the water provisioning from the Water Yield Model (WYM), soil erosion and sedimentation described by the Sediment Delivery Ratio (SDR), and nutrient fluxes (N) in response to changing land use are obtained through the Nutrient Delivery Ratio (NDR). The detailed model results are finally extrapolated, which provides a comprehensive image of the environmental impacts associated with bioenergy expansion in Germany from our combination of unique Renewable Gas Plants (RGPs). The final result shows that nutrient load will reduce in southern Germany by the year 2050 compared to the reference state, and biomass use reduced by 46% crops.

Matching Ecosystem Services Supply and Demand through Land Use Optimization: A Study of the Guangdong-Hong Kong-Macao Megacity

Shortfalls and mismatches between the supply and demand of ecosystem services (ES) can be detrimental to human wellbeing. Studies focused on these problems have increased in recent decades, but few have applied land use optimization to reduce such spatial mismatches. This study developed a methodology to identify ES mismatches and then use these mismatches as objectives for land use optimization. The methodology was applied to the Guangdong-Hong Kong-Macao "Greater Bay Area" (GBA), a megacity of over 70 million people and one of the world's largest urban agglomerations. Considering the demand for a healthy and secure living environment among city-dwellers, we focused on three ES: heat mitigation, flood mitigation, and recreational services. The results showed large spatial heterogeneity in supply and demand for these three ES. However, compared to current conditions in the GBA, our model showed that optimized land use allocation could better match the supply and demand for heat mitigation (number of beneficiaries increased by 15%), flood mitigation (amount of population exposed to flood damage decreased by 37%), and recreation (number of beneficiaries increased by 14%). By integrating land use allocation and spatial mismatch analysis, this methodology provides a feasible way to align ES supply and demand to advance urban and regional sustainability.

Agent-based modelling of water balance in a social-ecological system: A multidisciplinary approach for mountain catchments

The European Alps are known as the 'water towers of Europe'. However, climatic and socioeconomic changes influence both water supply and demand, increasing the need to manage this limited and valuable resource properly to avoid user conflicts and water scarcity. Two major challenges emerge when assessing water scarcity in the Alps: Firstly, mountainous regions are very heterogeneous regarding water availability and demand over space and time, and therefore water scarcity assessments need to be done at low temporal and spatial scales. Secondly, the tight coupling of the natural and the social sphere necessitate an integrative approach considering dynamics and interactions of the social-ecological system. Hence, we applied the agent-based water supply and demand model Aqua.MORE, which is designed for catchment scale and sub-daily temporal resolution, to a case study site in the Italian Alps. In the model, the water supply, the local water managers and water users are represented by interacting model agents. We estimated the water supply by refining the annual runoff data provided by the InVEST water yield model for within-year variations. Local stakeholders contributed to the development of quantitative and spatially-explicit scenarios for land use and tourism evolution. To evaluate water supply and demand dynamics, we assessed six scenarios for the period of 2015 to 2050: three different socio-economic policy pathways, both alone and in combination with a climate change scenario. In all six scenarios, the water demand:supply (D:S) ratio continuously rises from 2015 to 2050.The highest D:S ratio values are prognosed at the beginning of the irrigation period in May. In all scenarios considering climatic changes, the D:S ratio exceeds 20% for several days, indicating potential water scarcity. The simulation results reinforce the importance of analysing water balances at a high temporal resolution and can support management processes and stakeholder dialogues for sustainable watershed management.

Ecosystem service potential, flow, demand and their spatial associations: a comparison of the nutrient retention service between a human- and a nature-dominated watershed

Nutrient regulation is an important ecosystem regulating service in watersheds. However, systematic investigations of the spatial associations between the potential, flow, and demand of the nutrient regulation service are still lacking. Therefore, we performed a case study comparing the total phosphorus (TP) retention in the Dianchi Lake (DL) watershed (human-dominated) with that in the Lower Reach of the Zi River (LRZR) watershed (nature-dominated). We used four indicators-TP retention potential, TP retention, TP load, and TP export-to represent the potential, flow, demand, and flow-demand budget of the TP retention service, respectively. We estimated the TP retention and export using the InVEST tool, mapped the four TP indicators and calculated their correlations, and estimated the contributions of different ecosystem types and terrain ranges to TP retention and export. We determined the following: (1) the incongruity between the spatial distribution of the TP retention potential and the other three TP indicators was smaller in the LRZR watershed than in the DL watershed; (2) the TP retention potentials generally increased-while the other three TP indicators decreased-with increases in the elevation gradient in the DL watershed and the slope gradients in both study areas; and (3) paddy fields exhibited the highest TP retention intensity and residential areas exhibited the highest TP export intensity among the major ecosystem types in both study areas. Moreover, the TP retention intensities of dryland crops and residential areas in the DL watershed were much higher than they were in the LRZR watershed. Our findings imply that the flow of the nutrient retention service is influenced more by the service demand than by the service potential and that it is influenced by both landscape composition and pattern. Because of the limitations and uncertainties in the modeling outputs, our results should be carefully used in other studies or in decision-making.

Integrating the InVEST and SDSM Model for Estimating Water Provision Services in Response to Future Climate Change in Monsoon Basins of South China

An assessment of how future climate change will impact water provision services is important for formulating rational water resources management and development strategies as well as for ecosystem protection. The East Asian monsoon is an important component of the Asian climate and its changes affect the climate in East Asia and seriously affect the provision of water services. In this study, through the coupling of the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and Statistical Downscaling Technique Model (SDSM), we evaluated the impact of future climate change on water provisions in a typical East Asian monsoon basin of South China. The results demonstrate the applicability of the InVEST model combined with the SDSM model over the East Asian monsoon river basins. Under representative concentration pathway 4.5 scenario (RCP4.5), the annual average maximum and minimum temperatures would continually increase far into the future (2080–2095). However, the maximum and minimum temperatures slightly decreased under representative concentration pathway 2.6 scenario (RCP2.6) in the far future (2080–2095). The annual average precipitation and reference evapotranspiration experienced slight but steady increasing trends under the RCP2.6 and RCP4.5 scenarios. Based on the InVEST model simulation, annual average water yield would increase by 19.3% (33.5%) far in the future (2080–2095) under RCP2.6 (4.5) scenario. This study provides a valuable reference for studying future climate change impacts on water provisions in East Asian monsoon basins.

Regional Spatial Management Based on Supply-Demand Risk of Ecosystem Services-A Case Study of the Fenghe River Watershed

The supply–demand risk assessment of ecosystem services (ES) can identify the supply–demand risk level, which is very important for the sustainable management of regional ES. In this study, taking the Fenghe River watershed (FRW) as a case, based on the status and the change trend of the supply–demand ratio of ES, and the ES supply change trend, the supply–demand risk level of food provision (FP), water yield (WY), soil retention (SR), and climate regulation (CR) are evaluated, and the risk management zones of the FRW are divided using spatial superposition. The results show that: (1) The supply and demand of SR are spatially matched, while the other three ES are spatially mismatched. (2) From 2000 to 2015, the supply amount of FP, WY, and SR increases by 11.59%, 1.25% and 55%, respectively, while the supply amount of CR decreases by 5.15%. At the same time, the demand amount of FP, WY, SR and CR increases by 39.97%, 53.88%, 36.3% and 215.5%, respectively. (3) The supply–demand ratio means of four ES in the FRW are all greater than 0, but there are some areas within that are less than 0. (4) In terms of sub-watershed scale, except for SR, there are critically endangered areas for the other three ES. Moreover, the FRW is divided into 11 supply–demand risk management zones, such as FS-WY-CR critically endangered zone, WY-CR critically endangered and FS vulnerable zone. The supply–demand risk management zones based on multiple ES can identify the risk level of each ES in each zone. These results and conclusions can provide the basis for rational allocation of resources and sustainable management of ES.

Integrating Ecosystem Services Supply–Demand and Spatial Relationships for Intercity Cooperation: A Case Study of the Yangtze River Delta

Transboundary environmental problems caused by urban expansion and economic growth cannot be solved by individual cities. Successful intercity environmental cooperation relies on the clear identification and definition of the rights and obligations of each city. An Ecosystem services (ES) approach not only budgets the ES supply and demand of a city, but also defines the spatial relationships between Services Provisioning Areas (SPA) and Services Benefiting Areas (SBA). However, to date, quantitative studies integrating ES budgets and spatial relations have been scarce. This study integrates ecosystem services supply–demand budgeting with flow direction analysis to identify intercity environmental cooperation in the highly urbanized Yangtze River Delta (YRD) region of China for water-related ecosystem services (flood protection, erosion regulation and water purification). The results demonstrated that there were significant spatial mismatches in the supply and demand of three water-related ES among 16 core cities in the YRD region: five to six cities in the southern part of the region had significant service surpluses, while ten to 11 cities in the north–central part had significant service deficits. We then went on to offer definitions for Ecosystem Services Surplus City, Ecosystem Services Deficit City and Ecosystem Services Balance City, as well as Service Provisioning City, Service Benefiting City and Service Connecting City in which to categorize cities in the YRD Region. Furthermore, we identified two intercity cooperation types and two non-cooperation types. This framework can be used to promote ecological integration in highly urbanized regions to advance sustainable development.

Identifying Dynamic Changes in Ecosystem Services Supply and Demand for Urban Sustainability: Insights from a Rapidly Urbanizing City in Central China

Identifying the balance and dynamic changes in supply and demand of ecosystem services (ES) can help maintain the sustainability of the regional ecosystem and improve human well-being. To achieve a sustainable ecological management regime in Zhengzhou City, this study presented a comprehensive framework for identifying dynamic changes of ES supply and demand and managing ES. Using land use data of Zhengzhou City in 1995, 2005, and 2015 and incorporating expert knowledge and the ES evaluation matrix, we evaluated the spatiotemporal changes in the ES supply and demand in Zhengzhou. Gradient analysis was conducted to identify urban–rural patterns in the budgets of ES supply and demand. Spatial autocorrelation analysis was employed to identify the hotspot areas of ES surpluses or deficits. The research results show the following: (1) In the past 20 years, the supply-and-demand relationship of ES in Zhengzhou has gradually evolved in a direction where supply falls short of demand. The average budget index of Zhengzhou’s ES supply and demand decreased from 7.30 in 1995 to −4.89 in 2015. Changes in the supply and demand status of ES in Zhengzhou corresponded to the background of rapid urbanization. (2) Urban–rural gradient differences exist in the budgets of ES supply and demand in Zhengzhou. Core development areas, such as the Zhengzhou urban areas, are in deficit, whereas a balance or surplus can be observed in rural areas far from urban centers. (3) The surplus hotspots of ES budgets were mainly distributed in the western and southern mountainous areas of Zhengzhou, and they were scattered and the scope shrank, with a decrease of 2.73 times in 20 years, whereas the deficit hotspots expanded outward with each urban area as the center, with an increase of 5.77%. Ecological management zoning (ecological conservation area, ecological improvement area, and ecological reconstruction area) with the effective guidance of ecological and economic policies could comprehensively improve ES management and achieve urban sustainability. The framework in this study can easily and quickly assess the supply and demand status of ES and provide scientific support for the ecological management in rapidly urbanizing areas.

Evaluating Ecosystem Services Supply and Demand Dynamics and Ecological Zoning Management in Wuhan, China

The concept of ecosystem services (ES) supply and demand has attracted increasing attention in science and policy making because it effectively links ecosystem services to human well-being. The imbalance of ES supply and demand in urban areas has become a key issue in regional sustainable development. In this context, we calculated ES supply and demand for Wuhan City, China, using the ES supply and demand ratio (ESDR) and the comprehensive ES supply–demand ratio (CESDR) to express the relationship between ES supply and demand. Ecological zoning was proposed according to the spatial differentiation of the ES supply–demand relationship, and policy recommendations are made. The results show that from the perspective of total ES supply and demand, the water yield supply (S_WY), grain yield supply (S_GY), and recreation services supply (S_RS) are greater than the water yield demand (D_WY), grain yield demand (D_GY), and recreation services demand (D_RS), and that the climate regulation supply (S_CR) is less than the climate regulation demand (D_CR). From a spatial perspective, there are imbalances and mismatches in ES supply and demand, especially in urban central areas. The values of S_WY, S_GY, S_CS, and S_RS per unit area are less than their respective demand values, and the area of mismatch has expanded with the gradual increase of the built-up area. The spatial pattern of ES supply and demand is circular, with the form of “deficit zone–relative equilibrium zone–surplus zone”, which corresponds to “urban central area–near suburbs–distant suburbs and rural areas”.

Integrating ecosystem services flows into water security simulations in water scarce areas: Present and future

Water resources are indispensable resources for human survival. Researchers have used different methods to evaluate regional water security situations to ensure sustainable development. However, existing water security assessment models focus on the current status of water security in a static state and do not introduce flow characteristics of water resources into regional water security assessments. On the other hand, the quality of water resources should be reflected in not only current water security situations but also change trends of water security. Therefore, this paper attempts to integrate ecosystem service flows into a water security simulation using a simplified service path attribution networks (SPANs) model. Simultaneously, by simulating future scenarios and comparing future and current water security statuses, this paper systematically evaluates regional water security status and provides water security management and control suggestions that meet the requirements of regional development. The results show that water security in Henan Province and Shandong Province is lacking, and water resource management and control measures need to be strengthened to improve the water security in these areas. The water security assessment framework established in this paper not only reasonably assesses the status of water security but also provides a development model that meets the needs of the study area through a multiple scenario analysis. This study provides a scientific basis for government departments to formulate water management policies.

Spatial imbalance and changes in supply and demand of ecosystem services in China

Human activities and regional land development have caused intense interference to ecosystems. With rapid development of economy and urgent needs of life quality improvements in China, sustainable ecosystem management is crucial for national ecological civilization construction. However, few studies have focused on supply-demand patterns of ecosystem services on a national scale in China. The aim of this study was to analyze the spatial-temporal patterns and changes in the supply-demand of ecosystem services and to explore their interactive relationship in the context of economic development and urbanization drivers. The ecosystem services provision index (ESPI) and land development index (LDI) were proposed to indicate the supply and demand for ecosystem services. The results indicated that the Low supply-High demand (L-H) pattern accounted for 3.27% of the total land area in China and was mainly concentrated in developed regions and some capital cities, where 28.95% of the total population and 51.93% of the country's GDP was generated in 2015. The spatial imbalance in the supply-demand of ecosystem services was obvious. From 2000 to 2015, the imbalance was shrinking, and regions with negative changes in supply-demand patterns were declining. During 2000-2008, there was an obvious transformation from Low supply-Low demand (L-L) to High supply-Low demand (H-L), which accounted for 12.44% of the total land area due to Grain for Green and other ecological protection policies. The proportion of ecological land to total land area, vegetation cover and elevation were significantly correlated with the supply of ecosystem services. In the meantime, ESPI was negatively correlated with LDI in most regions in China. There were also regional differences in their relationships. The rapid economic growth and the intensive land development resulted in a more significant decrease in ESPI in the developed regions than that in the undeveloped North and Northeast China. The results of this study could contribute to sustainable ecosystem management and decision-making for Chinese ecological civilization construction.

Land conservation can mitigate freshwater ecosystem services degradation due to climate change in a semiarid catchment: The case of the Portneuf River catchment, Idaho, USA

There is increasing evidence of environmental change impacts on freshwater ecosystem services especially through land use and climate change. However, little is known about how land conservation could help mitigate adverse water-sustainability impacts. In this paper, we utilized the InVEST tool and the Residual Trends method to assess the joint effects and relative contributions of climate change and land conservation on freshwater ecosystem services in the Portneuf River catchment in Idaho, USA. We developed five hypothesized scenarios regarding gain and loss in the enrollment of Conservation Reserve Program (CRP), the largest agricultural land-retirement program in the U.S., plus riparian buffer and assessed their interactions with climate change. Results suggest that the realized water yield in the Portneuf River catchment would possibly be 56% less due to climate change and 24% less due to the decline of CRP enrollment. On the contrary, if CRP enrollment is promoted by ~30% and riparian buffer protection is implemented, the water supply reduction in the year 2050 could be changed from 56% to 26%, the total phosphorus (TP) and total nitrogen (TN) export would be reduced by 10% and 11%, and the total suspended sediment (TSS) reduced by 17%. This study suggests that increasing implementation of the CRP would likely preserve key freshwater ecosystem services and assist proactive mitigation, especially for semiarid regions vulnerable to changing climate conditions.

Temporal variation and spatial scale dependency of the trade-offs and synergies among multiple ecosystem services in the Taihu Lake Basin of China

Grasping the temporal-spatial characteristics of interactions and spatial scales of multiple ecosystem services is the foundation for sustainable ecosystem management. Eight ecosystem services, including crop production, freshwater supply, aquatic production, net primary production, soil conservation, water retention, flood regulation, and forest recreation were measured at the 1-km² pixel scale in the Taihu Lake Basin (TLB) of China from 1990 to 2010. Furthermore, we quantified the trade-offs and synergies of services at different periods of urbanization and across the 1-km² pixel scale and the county scale. We aim to find which ecosystem services interactions temporally vary and depend on spatial scale. Our results found that: 1). Tremendous amount of cultivated lands were converted to construction land, and rapidly shrank from 1990 to 2010. 2). Determined by land use, different ecosystem services had spatial heterogeneity of their strength. Ecosystem services hot spots experienced an increasing trend while cold spots showed a trend of decreasing first and then increasing from 1990 to 2010. 3). Trade-offs between provisioning services and regulating services at the 1-km² pixel scale changed over time. There was a new synergy between freshwater supply and aquatic production at the 1-km² pixel scale in 2010 with the human demand. 4). From 1990 to 2010, the changes of provisioning services led to trade-offs among provisioning services, regulating services and cultural services at two scales. Taking temporal variation and scale dependence into account, this research is helpful to the delineation of "Ecological Conservation Redline" and implement the project of "Grain for Green". We also provide suggestions for maintaining ecosystem services with economic growth in China's Yangtze River Economic Belt for land use policies and decision making.

Impact and mitigation of global change on freshwater-related ecosystem services in Southern Europe

Global change is severely impacting the biosphere that, through ecosystem services, sustains human well-being. Such impacts are expected to increase unless mitigation management actions are implemented. Despite the call from the scientific and political arenas for their implementation, few studies assess the effectiveness of actions on freshwater-related services. Here, by modeling water provisioning, water purification and erosion control under current and future conditions, we assess future trends of service provision with and without mitigation policies. In particular, two different storylines combine multiple climate, land use/land cover and agricultural management scenarios, and represent a pro-efficiency business as usual (myopic storyline) and a future that considers social and environmental sustainability (sustainable storyline). The mentioned services are modeled for the horizon 2050 and in three South European river basins: Ebro, Adige and Sava, which encompass the wide socio-environmental diversity of the region. Our results indicate that Mediterranean basins (Ebro) are extremely vulnerable to global change respect Alpine (Adige) or Continental (Sava) basins, as the Ebro might experience a decrease in water availability up to 40%, whereas the decrease is of only 2-4% in the Adige or negligible in the Sava. However, Mediterranean basins are also more sensitive to the implementation of mitigation actions, which would compensate the drop in water provisioning. Results also indicate that the regulating services of water purification and erosion control will gain more relevance in the future, as both services increased between 4 and 20% in both global change scenarios as a result of the expansion of agricultural and urban areas. Overall, the impact of global change is diverse among services and across river basins in Southern Europe, with the Mediterranean basins as the most vulnerable and the Continental as the least. The implementation of mitigation actions can compensate the impact and therefore deserves full political attention.

Modeling Water Yield: Assessing the Role of Site and Region-Specific Attributes in Determining Model Performance of the InVEST Seasonal Water Yield Model

Simple hydrological models, such as the Seasonal Water Yield Model developed by the Natural Capital Project (InVEST SWYM), are attractive as data requirements are relatively easy to satisfy. However, simple models may produce unrealistic results when the underlying hydrological processes are inadequately described. We used the variation in performance of the InVEST SWYM across watersheds to identify correlates of poorly modeled outcomes of InVEST SWYM. We grouped 749 watersheds from across North America into five bioclimatic regions using nine environmental variables. For each region, we compared the predicted flow patterns to actual flow conditions over a 15-year period. The correlation between the modeled and actual flows was highly dispersed and relatively poor, with 92% of r2 values less than 0.5 and 42% less than 0.1. We linked cryospheric variables to model performance in the bioclimatic region with the poorest model performance (the Low elevation Boreal Sub-humid region—LeBSh). After incorporating cryospheric conditions into the InVEST SWYM, predictions improved significantly in 30% of the LeBSh watersheds. We provide a relatively straightforward approach for identifying processes that simple hydrological models may not consider or which need further attention or refinement.

How to Detect Scale Effect of Ecosystem Services Supply? A Comprehensive Insight from Xilinhot in Inner Mongolia, China

Spatial scale plays a crucial role in the assessment and management of ecosystem services (ES), yet explicit information for identifying and understanding the scale effect on ES supply remains limited. In an attempt to detect scale effect on ES supply from a comprehensive perspective, this study developed a framework for integrating scale effect in three aspects, including individual ES patterns, pairwise ES interactions, and ecosystem service bundles (ESB). The framework was tested in Xilinhot, a prairie landscape city of Inner Mongolia, at four different levels of spatial scale. The results indicated that, most ES showed a decreasing clustering at coarser scales in terms of spatial pattern. At the same time, coarser scales resulted in fewer trade-offs and stronger synergies between pairwise ES. The identification of ESB varied greatly with scale, and this change reflected in the composition of ES variables and spatial distribution of bundles. We attributed the scale effect of the above three aspects to differences in social-ecological factors and their driving mechanisms at different scales. This comprehensive framework could support local managers to coordinate the management of multiple ES at different scales.

Multiple stressor effects on biological quality elements in the Ebro River: Present diagnosis and predicted responses

Multiple abiotic stressors affect the ecological status of water bodies. The status of waterbodies in the Ebro catchment (NE Spain) is evaluated using the biological quality elements (BQEs) of diatoms, invertebrates and macrophytes. The multi-stressor influence on the three BQEs was evaluated using the monitoring dataset available from the catchment water authority. Nutrient concentrations, especially total phosphorus (TP), affected most of the analyzed BQEs, while changes in mean discharge, water temperature, or river morphology did not show significant influences. Linear statistical models were used to evaluate the change of water bodies' ecological status under different combinations of future socioeconomic and climate scenarios. Changes in land use, rainfall, water temperature, mean discharge, TP and nitrate concentrations were modeled according to the future scenarios. These revealed an evolution of the abiotic stressors that could lead to a general decrease in the ecosystem quality of water bodies within the Ebro catchment. This deterioration was especially evidenced on the diatoms and invertebrate biological indices, mainly because of the foreseen increase in TP concentrations. Water bodies located in the headwaters were seen as the most sensitive to future changes.

Deriving spatially explicit water uses from land use change modelling results in four river basins across Europe

The objective of this study is to provide spatially distributed water use maps at a high spatial and thematic resolution as detailed input data for further modelling purposes. The maps were derived on the basis of official water statistics and land use maps to represent the current conditions in four European river basins affected by water scarcity (Adige, Ebro, Evrotas and Sava) and allow setting up reference scenarios. The present land use distribution was modelled based on CORINE data with the land use change model iCLUE. Modelling the land use allows to create dynamic land and water use maps adapted to the needs of eventual scenario analyses compared to using only observed land use maps. The availability of several CORINE datasets allowed calibrating and validating the results of the iCLUE model carrying out a three map comparison. Sectoral water uses were attributed to different land use classes and by this means located in space. Both the location and the magnitude of urban and agricultural water uses can be derived from the final maps. The created maps together with the corresponding land use data provide a coherent set of information crucial to most environmental modelling activities and often missing at this spatial and thematic resolution. This work also aims at visualizing and validating the water use statistics provided by official institutions such as the River Basin Management Plans. The results show that in some cases they are not consistent and underline the importance of harmonised data collection regarding water statistics, as otherwise comparisons within one study area and with others are hampered. This study is embedded in the EU-FP7 GLOBAQUA project which analyses the effects of stressors, such as changes of land and water use, on aquatic ecosystems in areas suffering water scarcity.

Optimal fresh water blending: A methodological approach to improve the resilience of water supply systems

Climate change and socioeconomic factors have increased the complexity of urban water supply systems. Thus, fresh water sources are being gradually diversified to improve the reliability and resilience of the systems. However, as the number of source blending options grows, optimization tools are needed to design drinking water supply systems that comply with indicators of cost, resilience, and water quality. This paper proposes a pioneering methodological approach, based on an ant-colony-optimization (ACO) algorithm, to optimize the blending of drinking water from different sources to minimize operational costs of a given system originating from a number of impaired water sources while complying with water quality standards. To evidence the potential of the ACO algorithm to solve such a system, a virtual case study was designed that considers eight fresh water sources, including seawater desalination and potable reuse. Seven scenarios were developed with different weightings to service outage, water conveyance and treatment costs while complying with water quality goals in regard to total organic carbon, nitrates, and total dissolved solids. It was shown that the cost per volumetric unit of water can vary considerably depending on the weightings of the three cost items. This paper provides a rigorous scientific approach to propose a methodology supporting the decision-making process of selecting a mixture of different sources to achieve the overall lowest system cost. Hence, this work contributes to improving the resilience and sustainability of urban water supplies.