River Ecosystem Services Research Articles

Evaluating Ecosystem Services Incorporation in River Policy: A Multidimensional Framework Applied to China's River Chief System

ABSTRACTThis study develops a comprehensive evaluation framework to assess the incorporation of river ecosystem services (ESs) into policy content, focusing on China's River Chief System (RCS) policy. The framework introduces a quantitative tool that bridges the gap between policy formulation evaluation and policy effect evaluation by integrating a hierarchical indicator system, reference values, and a method for quantifying ES incorporation. Key findings from 32 province‐level RCS policy documents revealed selective incorporation of certain ES indicators, significant mismatches between policy focus and the typical structure of river ESs, and notable regional disparities. Provisioning services (i.e., water supply) and regulating services (i.e., pollution mitigation) are prioritized, while critical regulating services (e.g., flood mitigation and habitat maintenance) and cultural services (e.g., education and science) are underrepresented. Stakeholder and relationship indicators are limited, primarily focusing on managers and spatial relationships, while the value of river ESs is largely ignored. Policy optimization should emphasize expanding the coverage of ESs, incorporating broader stakeholder involvement, and integrating financial incentives. Drawing on international river policies, policymakers could create a more flexible and adaptive river governance structure. While the study offers a quantitative framework for policy evaluation, it acknowledges limitations, including reliance on textual data and potential biases in the reference values. Future research should include stakeholder perspectives and dynamically adjust reference values as new data become available.

Emergy-Based Evaluation of Xiaolangdi Reservoir’s Impact on the Ecosystem Health and Services of the Lower Yellow River

The disturbance in river ecosystems caused by reservoirs and dams has become a critical topic, attracting increasing attention. However, the extent to which reservoir and dam construction and operation impact downstream river ecosystem health and ecosystem service functions is not fully understood. This research examines the Xiaolangdi Reservoir and the Lower Yellow River (LYR) ecosystem in China as a case study. We analyzed the complex material and energy flows in the LYR ecosystem using emergy theory and developed a set of emergy-based indicators for the quantitative assessment of river ecosystem health and services under reservoir operation interference. The results indicate that the total natural capital and environmental endowments of the LYR ecosystem have remained relatively stable after the operation of the Xiaolangdi Reservoir, with an increase in renewable emergy input. The ecosystem’s vigor decreased slightly, while the biomass emergy diversity index remained stable. However, the total emergy inputs increased significantly, with external feedback inputs becoming the most important emergy source for the LYR ecosystem. The resilience of the LYR ecosystem improved, with a significant increase in emergy density and a decrease in the emergy sustainability index. These findings suggest that although the river ecosystem continues to provide supporting services to human society, the extent of these services has diminished compared to pre-perturbation levels. In this research, a methodology for analyzing the impact of key reservoir operations on the ecosystem health and services of a large river is proposed to provide support for large river sustainable development studies.

Preliminary assessment of river ecosystem services in the volcanic area of Mount Merapi, Indonesia

River ecosystem services (RES) are vulnerable to landscape changes mainly by volcanic eruptions. Therefore, this study aims to assess RES in the volcanic area which was affected by the major and minor eruptions of Mount Merapi, Indonesia. The RES referred to the regulating and supporting services of the Krasak River in Jogjakarta. The research involved collecting water and biodiversity samples from two distinct Merapi’s hazard zones (KRB I and KRB II) along the river. Parameters related to regulating services, such as particulate, organic, and nutrient purification, biological control, as well as supporting services like primary productivity, were quantified. We conducted an analysis to understand how landscape conditions interacted with these parameters and employed the t-test to assess differences in RES between the two KRBs. Our findings revealed that the Krasak River exhibited a range of values, including 2.40–5.95 mg/l for Biological Oxygen Demand (BOD), 0.61–3.41 mg/l for nitrate, 0.02–0.11 mg/l for phosphate, 160–60,000 MPN/100 ml for coliform, and 156.3–937 µg/l for chlorophyll-A. These values demonstrated the river’s capacity to perform both regulation and support services. However, certain segments showed variations in ecosystem services, possibly due to the presence of autochthonous matter from aquatic organisms and decomposing organic matters. This showed that volcanic eruption and landscape are closely linked with the water quality and aquatic biodiversity, which affect the ecosystem services.

Evaluation and valuation of tajan river basin ecosystem services

Rivers as a blue ecosystem have a lot of ecosystem services that awareness of the value of their services will protect them as much as possible and communities will benefit from their environmental services. In this study, Tajan river basin ecosystem services in the north of Iran was valuated. To valuate, the choice experiment method was used to estimate willingness to pay. Tajan river basin ecosystem services attributes including regulating, supporting, provisioning and cultural services and a price attribute at three levels were determined. Data from 239 resident households of Mazandaran province were used in 2017. The empirical analysis did by the conditional logit model and mixed logit model. Also, multi criteria decision making including techniques Entropy, TOPSIS and SAW used for evaluating the role and importance of the Tajan river basin ecosystem services. The findings indicated that residents were willing to pay for the conservation of Tajan river basin ecosystem services, 13.77 USD per year. It was for regulating, supporting, provisioning and cultural services of Tajan river basin, 2.62, 6.30, 2.50 and 2.35 USD per year to move away from the status quo to the improvement status respectively. Also, findings of weighting and prioritization of Tajan river basin ecosystem services with TOPSIS and SAW methods showed that supporting and provisioning services had the highest weight for the evaluation Tajan river basin ecosystem services. In other words, the residents prefer the services as the most important Tajan river basin ecosystem services. Results showed that willingness to pay can be introduced as a useful tool to investigated people's preference for conservation of river basin ecosystem services under various activities. Therefore, by determining the value of river ecosystem services, community will understand that river services are of great importance, and the application of its value in calculations related to comprehensive management of basin water resources will provide a suitable economic solution to increase user utility the river.

Human interventions alter morphodynamics of meandering channels: Insights from decadal to pre-industrial observations in the Yangtze River

Human activities, such as reservoir construction and bank revetment, significantly alter downstream flow and sediment regimes and river channel changes, impacting river ecosystem services. However, our understanding of how intense human activities affect morphodynamics of meandering channels in big river systems remains incomplete due to the lack of high-resolution in-situ data. Here, we use comprehensive data encompassing hydrology and sediment, historical channel maps, and high-resolution river bathymetry to investigate the evolution of meandering bends in the Middle Yangtze River (MYR) across three distinct phases: the natural period (1490–1975), the bank revetment period (1975–2002), and the post-dam period (2003–2018). The study revealed that, in the absence of human intervention, the meandering channels of the MYR naturally experienced inner bank deposition and outer bank erosion, largely governed by curvature-induced secondary flow patterns in flow and sediment transport mode. In 1975–2002, outer-bank revetments reduced erodibility, stabilizing outer banks, while inner banks continued to experience lateral and vertical deposition, causing a narrower and deeper channel hydraulic geometry. Conversely, meandering bends had exhibited an unusual pattern of ‘outer bank deposition and inner bank erosion’ in 2003–2018. Channel morphological changes characterized by channel incision and widening were driven by changes from erodible bank boundaries to solidified bank boundaries, substantial reduction in suspended sediment concentration, and an altered and extended effective flow range (10,000–25,000 m3/s). Our findings highlight that human interventions such as damming and bank revetments can alter the conventional erosion–deposition morphodynamics of meandering bends in large river systems, carrying vital implications for sustainable river management in the Anthropocene.

Identification of River Ecosystem Services through Water Utilization at Merapi Volcano, Indonesia

Merapi volcano is renowned as one of the world’s most active and densely populated volcanoes. Despite the constant high risk it presents, local residents continue to inhabit the Merapi slopes, primarily due to the ecosystem services that sustain their lives. River ecosystem services in this area are particularly vulnerable to landscape changes, largely driven by volcanic eruptions and human activities. This study aims to define the river ecosystem services by exploring the water utilization in Krasak River, which has been affected by Merapi eruptions from 2010 to 2023. The evaluation of water utilization was conducted using an ecosystem services approach, involving semi-structured interviews with 42 informants in six villages located along the upstream, middle stream, and downstream of the Krasak River. Content analysis was employed to explore water utilization practices and categorize river ecosystem services. The results revealed that water utilization in Krasak watershed comprises the use of springs and wells for supplying drinking needs and domestic needs as well as the use of rivers for irrigation water, fish ponds and recreation activities. Variations in Krasak River water utilization in different segments were influenced by water quality, quantity, accessibility, and the availability of alternative water sources. Based on local perspectives, the prominent river services encompass provisioning (e.g., irrigation, fish ponds, rural water supply, sand and stones), regulating (e.g., water quality maintenance, groundwater quantity), supporting (e.g., primary productivity), and cultural (e.g., recreation, aesthetic value) services. Challenges to river ecosystem services include concerns about river water utilization’s impact on perceptions of the river’s value and the roles of local communities and government in Krasak River management. These findings would contribute valuable insights for enhancing sustainable water resource management in the Merapi area.

The multiscale nexus among land use-land cover changes and water quality in the Suquía River Basin, a semi-arid region of Argentina

Agricultural intensification and urban sprawl have led to significant alterations in riverscapes, and one of the critical consequences is the deterioration of water quality with significant implications for public health. Therefore, the objectives of this study were the assessment of the water quality of the Suquía River, the assessment of LULC change at different spatial scales, and the analysis of the potential seasonal correlation among LULC change and Water Quality Index (WQI). The Sample Sites (SS) 1 and 2 before Cordoba city had the highest WQI values while from SS3 the WQI decreased, with the lowest WQI close to the wastewater treatment plant (SS7) after Cordoba city. From SS8 in a agricultural context, the WQI increases but does not reach the original values. In light of analysis carried out, the correlation between water quality variables and the different LULC classes at the local and regional scales demonstrated that WQI is negatively affected by agricultural and urban activities, while natural classes impacted positively. The spatialization of the results can help strongly in assessing and managing the diffusion of point and non-point pollution along the riverscape. The knowledge gained from this research can play a crucial role in water resources management, which supports the provision of river ecosystem services essential for the well-being of local populations.

Scaling from global to regional river flow with global hydrological models: Choice matters

High-resolution global flow discharge datasets are critical to understand the terrestrial water cycle and river ecosystem services. Recently, a number of global hydrological models have been developed to capture global river flow dynamics at locally relevant scales. However, the relative accuracy of these simulated flow discharges is largely unknown. In this paper, using the largest observed streamflow datasets from > 26,000 gauging stations, we evaluated the performance of monthly and sub-monthly flow variation (1980–2014) generated from five major global hydrological models, Catchment-based Macro-scale Floodplain model (CaMa-Flood), Global Flood Awareness System (GloFAS-reanalysis), Global Reach-level Flood Reanalysis (GRFR), PCRaster GLOBal Water Balance model (PCR-GLOBWB), and Water Global Assessment and Prognosis (WaterGAP). Significant spatial heterogeneity in model performance was identified. We found that estimates by all five discharge datasets have a relatively high correlation with the observations (medians > 0.6). But none of them showed adequate correlations between simulated and observed flows for systems in Southwest or Central U.S.A., South Africa, or South Australia. Across all models, overestimation of monthly mean flow was more common than underestimation and high flows at a sub-monthly scale were more accurately characterized than low flows. Performance of all models was poor in Africa and Oceania. No single model performed universally best at all gauging stations, but GRFR showed the best estimate at around 40 % of the locations. None of the models provided satisfying estimates for rivers and streams in arid regions. We also found a significant negative effect of flow regulation on the predictive accuracy of all models. Our study highlights the importance of thorough evaluation of global discharge datasets before their local and regional application and provides guidance for future enhancement of global hydrological models.

Impact of Environmental Flow Policy on Power System Balancing Costs and River Ecosystem Service Benefits: A Case Study of the Ossauskoski Hydropower Plant in the Kemijoki River, Finland

Impact of Environmental Flow Policy on Power System Balancing Costs and River Ecosystem Service Benefits: A Case Study of the Ossauskoski Hydropower Plant in the Kemijoki River, Finland

Does the Value of Water-Related Ecosystem Services Capture Water Scarcity? Application to Rice Farming in the Mekong Delta of Vietnam?

This study utilized the contingent valuation method to estimate the value of water-related ecosystem services (ES) in Vietnam, focusing on provisioning and regulating services for addressing water scarcity (WS) in rice farming. By incorporating gender and climate change perceptions, it expanded the existing literature on valuing river ecosystem services. The findings showed a significant number of households experiencing severe water scarcity in the past five years, with over 70% facing occasional or regular WS in the last 12 months. Rice farmers were willing to adopt coping measures and preventive practices to preserve water-related ES, recognizing their importance for sustaining rice cultivation. Farmers demonstrated willingness to contribute financially to restore and maintain water-related ES in rivers and canals. The median willingness to pay for restoration was VND188,300/ha, with estimated values of US$2,898,133 for a 10% affected area and US$23,185,068 for an 80% affected area over five years. Perception of WS severity and associated risk positively influenced households’ decisions to contribute financially. These findings have policy implications and provide insights for effective coping strategies against WS, enhancing water-resilient agriculture in the Lower Mekong Basin.

Large-scale stresses, decay of River Jamuna and resilience strategies in the Anthropocene

In the recent decades, many worlds' large rivers have been exceptionally modified by human interference. The principal objective of this study is to investigate the causes and consequences of decay of river Jamuna (distributary of river Bhagirathi-Hooghly). The entire investigation was conducted by the data of historical maps like Rennel's map of Bengal, Hunter's map, digital version of US army map, landsat satellite imageries (1980-MSS, 1990-TM, 2000-TM, 2010-ETM+ and 2020-OLI) and fluvio-hydrological study. Maximum likelihood classification algorithm was used to delineate the land use and land cover classes and Kappa based accuracy assessment indices were also used for the validation. There is no scientific work on this historically important river and afterward, millions of people are also underprivileged from this river ecosystem services due to severe degeneration. In this milieu, it is a genuine research gap. Novelty of the work is exposed the authentic causes of river decay and anthropogenic stressors. Result showed that the average width of river Jamuna has been significantly decreased whereas maximum average width of the channel was recorded in the year 1956 (319.81 m) and the present channel is flowing comparatively within narrow path (69.27 m). Rate of siltation (average rate of siltation 0.23 m/year) on channel bed has been increased due to impacts of channelization. Channel bed, natural levee and proximity floodplain have been encroached by large scale human intervention. LULC patterns showed that the urban built-up area is rapidly amplified from 2000 (22.26%) to 2020 (31.50%) whereas, agricultural and swampy land turned into built up area. Off-take of Jamuna is completely detached from the parent river Bhagirathi-Hooghly in the early 1956 and gradual anthropogenic interferences within river corridor accelerate river decaying processes. River restoration is highly required for sustainable river ecosystem health management and environmental development. Some management strategies have been recommended such as reconnecting of river Jamuna with Bhagirathi-Hooghly, dredging, decommissioning of culvert and sluice gate, cleaning of fishing pool and water hyacinth and sustainable land-use planning.

Simulation of land use trends and assessment of scale effects on ecosystem service values in the Huaihe River basin, China.

Land use demand change in the Huaihe River basin (HRB) and ecosystem service values (ESVs) in watersheds are important for the sustainable development and use of land resources. This paper takes the HRB as the research object, and using remote sensing images of land use as the data source adopts the comprehensive evaluation analysis method of ESVs based on equivalent factors and sensitivity analysis of the performance characteristics of ESV changes of different land use types. The PLUS model is used to predict spatiotemporal land use change characteristics to 2030 combining inertial development, ecological development, and cultivated land development. The spatial distribution and aggregation of ESVs at each scale were also explored by analyzing ESVs at municipal, county, and grid scales. Considering also hotspots, the contribution of land use conversion to ESVs was quantified. The results showed that (1) from 2000 to 2020, cultivated land decreased sharply to 28,344.6875 km2, while construction land increased sharply to 26,914.563 km2, and the change of other land types was small. (2) The ESVs in the HRB were 222,019 × 1012 CNY in 2000, 235,015 × 1012 CNY in 2005, 234,419 × 1012 CNY in 2010, 229,885 × 1012 CNY in 2015, and 224,759 × 1012 CNY in 2020, with an overall fluctuation, first increasing and then decreasing. (3) The ESVs were 219,977 × 1012 CNY, 218,098 × 1012 CNY, 219,757 × 1012 CNY, and 213,985 × 1012 CNY under the four simulation scenarios of inertial development, ecological development, cultivated land development, and urban development, respectively. At different scales, the high-value areas decreased, and the low-value areas increased. (4) The hot and cold spots of ESV values were relatively clustered, with the former mainly clustered in the southeast region and the latter mainly clustered in the northwest region. The sensitivity of ecological value was lower than 1, while the ESV was inelastic to the ecological coefficient, and the results were plausible. The mutual conversion of cultivated land to water contributed the most to ESVs. Based on the multi-scenario simulation of land use in the HRB by the PLUS model, we identified the spatial distribution characteristics of ESVs at different scales, which can provide a scientific basis and multiple perspectives for the optimization of land use structure and socio-economic development decisions.

Optimizing the Combined Allocation of Land and Water to Agriculture in the Omo-Gibe River Basin Considering the Water-Energy-Food-Nexus and Environmental Constraints

This study applied the Gebre optimization model to optimize the land and water usage in the Omo-Gibe river basin, Ethiopia, where competition among stakeholders and growing demands pose a challenge. This model was applied through a nexus approach to maximize benefits and minimize conflicting trade-offs. The main objective was to maximize the economic benefit from land and water allocation with the framework of the land-water-food-energy-environment nexus under climate change mitigation and river ecosystem services (LWFEEN). This model takes into account multiple dimensions, including economic, environmental, social, and technical factors, going beyond ordinary optimization models. It also incorporates an innovative crop succession allocation concept not often seen in the literature. This crop succession proposal includes sequences of cropping patterns and fallow land use options that closely resemble real-world farming practices. The results demonstrated that the Gebre optimization model effectively resolves the existing constraint conflicts and maximizes economic benefits by reducing costs, penalties, and environmental impacts, promoting sustainable use of natural resources in the Omo-Gibe river basin and avoiding conflicts among stakeholders. Therefore, this study offered decision-makers a strategic perspective on how to apply the Gebre-model within the context of the land-water-food-energy-environment nexus(LWFEEN) approach in river basins such as the Omo-Gibe, with the ultimate goal of achieving sustainable development.

Operationalizing equity in multipurpose water systems

Abstract. Participatory decision-making is a well-established approach to address the increasing pressure on water systems induced by growing multi-sectoral demands and increased competition among different water users. However, most existing approaches search for system-wise efficient solutions and do not quantify their distributional effect among the stakeholders. In this work, we investigate how to operationalize equity principles to design improved water systems operations that better balance efficiency and justice. More specifically, we explore the extent to which the inclusion of equity principles reshapes the space of efficient solutions. Numerical experiments are conducted on the Lake Como system, Italy, operated primarily for flood control and irrigation water supply while also providing recreation and river ecosystem services. Our results show how incorporating equity considerations into the design of water system operations enriches the solution space by generating more compromise solutions than those obtained using a traditional multi-objective optimization. Moreover, we find that including equity in the operating policy design can indirectly improve the performance of marginalized sectors, such as recreation and ecosystem, which are not explicitly considered by the current lake operation. Lastly, we illustrate how the aggregation of multi-sectoral interests into an equity index strongly shapes our results. Thus, eliciting the preference structure of stakeholders and policymakers becomes paramount for the identification of a fair balance across competing interests. This work bridges the gap between multi-objective optimization approaches and equity-informed decision-making for real-world water resources planning and management, providing an effective tool to promote efficient and equitable policies.

Aquatic plants entrap different size of plastics in indoor flume experiments

Plastics accumulate in the environment affecting biota and ecosystems. Although rivers are vectors of land-based plastics to the sea, macroplastics and microplastics in rivers are recently studied. Most studies focused on floating plastic transport to the sea through rivers considering only abiotic hydromorphological factors. In this view, among biotic factors, vegetation has recently been found to entrap plastics. Indeed, the role of vegetation is pivotal in affecting riverine plastic transport. While marine vegetation blocking plastics has been studied, research in freshwater ecosystems is neglected. Since hydrological factors have a pivotal role in riverine plastic transport and few is known on plant entrapment, the interaction between hydrological variables and plastic entrapment by vegetation has not yet been investigated. Given that the composition, transport, and fate of “submerged” plastics in the water column are neglected, we aimed at investigating the behaviour of plants in entrapping plastics within a specific laboratory flume tank. Specifically, we assessed whether (i) aquatic plants block different plastic sizes within the water column and (ii) different factors (e.g. water level, density of plants) affect plastic entrapment. Our results showed that, according to plant density, the higher the plant density the higher the entrapment of plastics by plants - independently of plastic size. Considering the water level, macro-, meso-, and microplastics were trapped similarly. Moreover, Potamogeton crispus blocked fewer microplastics compared with Myriophyllum spicatum. Our results might have impact as plants acted as temporary plastic trappers and can be used as tools for mitigating plastic pollution. Future research might investigate if this laboratory approach can be applied in field for recollecting plastics and consequently mitigating the problem. In conclusion, good management of plants in watercourses, canals, and rivers should be ideal for enhancing river functionality and ecosystem services for human well-being (i.e. the plastic entrapment service by plants).

Pathologies of the Riverside Built Environment Versus Success Indicators of Functional Performance

Abstract The paper focuses on the downtown built environment (downtown waterfronts) and also on individual architectural objects which have an important function in such a space. The quality of the built environment affects its surroundings not only in a physical but also in a social way. To find the most appropriate ways of preventing the occurrence of the built environment pathologies in downtown areas, the study used the diagnostic technique of functional performance understood, among other things, as the ability to satisfy the stakeholders' needs and the impact of stakeholders' actions on their living environment. During the research, a comparative platform was found for the functional performance, the imperative of sustainable development and the ecosystem services of rivers and reservoirs. The investigations resulted in the creation of success indicators illustrated by examples of six voivodeship capital cities in Poland which have the strongest connection with the downtown built environment in waterfront areas, namely: Gdańsk, Szczecin, Warszawa (Warsaw), Kraków (Cracow), Wrocław and Poznań.

Florix, an index to assess plant species in floodplains for nature conservation – Developed and tested along the river Danube

Natural floodplains are ecosystems with a diverse mosaic of habitats and site conditions, but also highly threatened due to anthropogenic pressures. Plant species occur in all habitat types and can indicate their value for nature conservation. To improve sustainable management of rivers and floodplains, several indices such as the River Ecosystem Service Index (RESI) have been developed. However, there are so far no assessment schemes for the entire range of floodplain plants. The common assessment approaches like biological integrity, achievement rates or threatened species (Red list), applying to other species groups or other ecosystems, are not appropriate in floodplains. Legal obligations and the need to restore floodplains clearly call for an index assessing the ecological value in a reference area which can be combined with a 5-scale assessment in accordance to established assessments like RESI or the Water Framework Directive.Five typical characteristics describing vascular plants’ adaptation to floodplain habitats were identified. These can be derived from published data sets available for all species in Germany. We checked these indicators for multicollinearity and selected three of them: species number, hydrodynamic indicators, nature conservation indicators. Species number highly correlate with habitat indicators and geographic occurrence. For the selected three indicators we determined thresholds to group habitats and their indicator rate to five classes (very low to very high value for nature conservation). These thresholds are valid for the river Danube and for the habitat types scrutinized in this study.The Florix approach was sensitive in data sets testing active against former floodplains and protected against unprotected areas: For the entire reference region ‘Danube floodplain’, Florix values were higher in the active floodplain and in the protected areas. Only the habitat type ‘water bodies’ showed better scores for habitats in the former floodplain, for ‘softwood forests’ the status of being part of a protected area had no effect. Florix results were validated in two case studies differing in land use intensity. The region with dominant agricultural use showed significantly lower values than that with a higher portion of forests and grasslands.Florix can be used for a floristic conservation status assessment at single habitat level or for the entity of a study region in comparison to a reference region. It allows to identify main pressures and to complement a habitat-type based evaluation. To achieve higher comparability, we should strive for a generalized monitoring in Europe like it is common in aquatic ecosystem monitoring.

River Ecosystem Resilience: Applying the Contingent Valuation Method in Vietnam

Mine water drainage interferes with ecosystems of the discharging river, whilst river ecosystem services in return affect the livelihoods and well-being of adjacent communities. In Ha Long, Vietnam, surface coal mining will be closed after 2025 following the national and provincial strategy toward sustainable development. This opens up an opportunity to rehabilitate the associated rivers to increase resilience in the surrounding social-ecological system (SES) heavily affected by water pollution from coal mines. Increasing resilience through rehabilitation is costly and policy makers often lack precise enough information on public benefits to make good decisions. In this study, we apply the concept of SESs to analyze the interrelationship between river ecosystems and human society with its institutions and local governance surrounding the Ha Long coal mining area. Applying a contingent valuation survey with 410 households living near to the mining operations, we assess the public benefits resulting from three different but partly combined projects to increase resilience. Results show that households are significantly willing to contribute to all proposed resilience increasing projects. Factors explaining willingness to pay (WTP) are diverse and are found to be related to common institutions and local governance. Through a comparison of the results for the three projects, we find the presence of embedding effects and identify factors leading to upward biased estimates of WTP. Our study contributes to a better understanding and valuation of public benefits in SES necessary for public policy towards increasing resilience in developing countries.

Correlation Between Community Knowledge Level of River Ecosystem Services and Littering Behavior in Belawan Hilir Sub-watershed

Belawan watershed is one of the watersheds that have a primary role in North Sumatra Province. The flow of the Belawan watershed crosses 2 (two) regencies/cities, i.e., Deli Serdang Regency and Medan City. In more detail, Medan City is located in the Belawan Hilir Sub-watershed. Several main rivers in Medan have been polluted and shallowed, as a result of people's habit of littering the river. People who live around the Belawan watershed have a significant role in the sustainability of the river and its ecosystem services. This study aims to analyze the level of community knowledge of river ecosystem services in the Belawan Hilir sub-watershed and to measure the correlation between the community knowledge level and the behavior of river littering. The respondents were sampled using Simple Random Sampling, while the number of samples was calculated using the Slovin formula. Data was collected through structured interviews by compiling a list of questions (questionnaires). The correlation between community knowledge levels and behavior of river littering was determined using spearman correlation analysis. The community knowledge level was 63% (good category). There was a moderate-positive correlation between the community knowledge level and the behavior of river littering (0.512 correlation coefficient). Community awareness can be increased through online-based socialization using social media or by providing more waste management training programs.

Prioritizing stakeholders’ preferences for policy scenarios of vulnerable ecosystems with spatial heterogeneity in choice experiment: Coupling stated preferences with elevation

Understanding public preferences and evaluating the river basin are essential for effective river basin management, and enhancing its environmental attributes can provide considerable non-market benefits. As such, the study explores the heterogeneity in people's preferences and rankings of river ecosystem services based on their willingness to pay (WTP) to upgrade these services. A research survey was conducted throughout the river basin using a choice experiment approach. In this study, we evaluated the impact of study area elevation (a spatial attribute) on residents' willingness to pay for rehabilitation of environmental attributes. The study incorporates 6 ecological attributes in order to examine the differences in people's willingness to pay at various elevation levels. A total of five cities and 33 surrounding villages and townships were surveyed, while five elevation groups were made on an ad hoc basis to split samples, i.e., 1000–1600 m, ≤1600–2200 m, ≤2200–2800 m, > 2800–3400 m, and 3400–4000 m. The results of the mixed logit model recognized that people living at different elevations value rehabilitation of varying environmental attributes differently. For example, the inhabitants in Group 1 (1000–1600 mm) are willing to pay RMB 6.70 per year for biodiversity upgrades; while the WTP of the people for the same attributes is RMB 32.68 in Group 5 (3400–4000 mm). The Krinsky Robb approach confirmed that agricultural product quality and greenhouse gases (GHGs) were the most highly valued attributes, with a willingness to pay of RMB 90.40 and RMB 47.17, respectively. Applying these results as a reference for sustainable improvements and uplift of deteriorated ecological qualities is an example of how they may be helpful in bettering the world.