Water Environmental Carrying Capacity Research Articles

Regional Water Environmental Carrying Capacity: Changing Trends and Direction, Obstacle Factors, and Implications

Regional Water Environmental Carrying Capacity: Changing Trends and Direction, Obstacle Factors, and Implications

An optimization framework for basin-scale water environmental carrying capacity

The interaction between water environment and social economy at a basin scale is complex and challenging to quantify. To address this issue, this study proposes an integrated framework that builds parametric connections among water, contaminants, administrative regions, and social activities. The framework, known as the water environmental carrying capacity (WECC) optimization framework, effectively captures the intricacy of the interaction and integrates socio-economic parameter structure relationships, a water environmental model, a WECC optimization model, and a sensitivity analysis of regulatory parameters. Applied to the Anhui-Huaihe Basin in mid-eastern China, the framework considers nine administrative regions and three economic factors: industry, agriculture, and GDP per capita (pGDP). Results show that the current water environmental carrying capacity of the watershed is insufficient to meet socio-economic development requirements. After optimization, the WECC for industry, agriculture, and pGDP in the region increased by 22.40%, 26.59%, and 15.08% respectively. Overall COD and NH4–N discharge decreased by 13.6% and 14.7% respectively, effectively reducing pollution loads in rivers and enhancing sustainable development potential. At the regional scale, optimization for industry, agriculture, and pGDP exhibited different characteristics, but all aimed to improve efficiency by reducing the K value (pollution discharge/output value ratio). Regions with industrial treatment rates (αwt) below 0.8 should prioritize increasing treatment rates, while those above 0.8 should consider industrial upgrading for enhanced efficiency. For agriculture, important sensitive parameters for farming and livestock breeding are the proportion of high standard farmland (αs) and the scale breeding ratio (αb), which should be increased to above 0.15 and 0.83 respectively for all regions to achieve agricultural optimization. For pGDP optimization, the focus is on improving living environments and reducing pollution discharge, with crucial measures including collecting and treating rural domestic sewage, where the rural toilet improvement rate (αt) in each region should be increased to 0.78 or above. The results emphasize the need for both interregional allocation and intraregional planning to achieve comprehensive basin optimization and a harmonious balance between regional development and water environment.

Effects of a proposed hydraulic project on the surface water connectivity in Poyang Lake floodplain system, China: Numerical simulation and geostatistical analysis

Study RegionPoyang Lake, the largest freshwater lake in China, has been experiencing persistent shrinkage in recent years. Study FocusThe Poyang Lake Hydraulic Project (PLHP) was proposed to improve water resource and environment carrying capacity, its hydrological effects remain under investigation. This study combined a hydrodynamic model with geostatistical connectivity analysis, to quantify the influence of the PLHP on surface water connectivity in Poyang Lake. New Hydrological Insights for the RegionThe PLHP enlarges inundated areas most in the recession period (September-November), accounting for 85% of the total increase throughout the operating period (September-March), and enhances the interconnection probability within these inundated regions. Statistical analysis reveals that the Connectivity Function (CF) in low connectivity conditions (CF <0.4) can be significantly increased by 0.1–0.9, primarily in areas with lower topographies. While for the saucer-shaped sub-lakes, the PLHP can rarely extend the connecting processes between the main lake and sub-lakes in low-water-level conditions below 13 m, which is the lowest threshold height of most sub-lakes. Moreover, most isolated sub-lakes have merged into the main lake when the water level is higher than 14 m, thus the PLHP is no longer effective in this condition. Therefore, the enhancement effect of the PLHP on the connectivity of sub-lakes is restricted in both high- and low-water-level years, and is most pronounced in the medium-water-level year.

Regional complex system simulation optimization through linking governance and environment performance: A case study of water environmental carrying capacity based on the SDES model

The resolution of issues related to sustainable development in regions and urbans is closely related to the complex systems, which lie not only in the numerous subsystems and spatial hierarchy, but also in the complex relationships between humans, socioeconomic, environmental and governance.The system dynamics (SD) model has been widely used in modeling regional and urban complex systems which involve multi-dimensional socio-economic and environmental issues. However, most simulations have focused on the state variables, such as the end-state social-economic and environmental situation, while the interaction between governance and their consequences on complex systems has been scarce. In addition, the social-ecological system (SES) framework has been endorsed worldwide because of its ability to explicitly recognize the complex interactions among socioeconomic-ecological-governance subsystems. To date, there have been few studies that combine the SES framework and complex systems models to quantitatively simulate the environmental performance of governance. In this research, we try to fill this gap by combining both to create a SDES model to quantitatively simulate the impacts of stakeholders' actions on environmental performance, and the feasibility of SDES model is verified by simulating the impacts of stakeholders' actions on water environment carrying capacity (WECC) in Liyang City, China. Moreover, we establish a cost-benefit analytical framework to identify the most cost-effective action to improve WECC based on the SDES model. Findings of this research contribute new theoretical and methodological insights into addressing environmental issues while we are facing a more complex regional and urban system and fragmented governance.

Surface water environmental carrying capacity and surface water quality based on economy-society-environment nexus – Evidence from China

Impacts of economy-society-environment on surface water resource in China are complex and unclear. Revealing these connections is vital to understand responses of surface water quality to anthropogenic activities. This study made an attempt to explore potential indications on surface water quality from economic, social and environmental factors in eight separate regions of China during the period of 2000–2019. Five machine learning models were employed including Greedy Thick Thinning Bayesian Belief Network, Naive Bayes, Augmented Naive Bayes (ANB), Logistic Regression and Random Forest. A total of 8 economic variables, 5 social variables and 8 environmental variables were introduced into the models. Results showed that ANB presented the best performance in estimating the surface water quality class with the highest accuracies of 81%, 75% and 87% for three surface water quality groups (Class I–III, Class IV–V and worse than Class V), respectively. The higher the surface water environmental carrying capacity in a region, the better the estimation performance of ANB on the surface water quality class. Surface water quality with Class I–III was more closely related to economic and social development, while environmental variables largely interpreted the quality of surface water with Class IV–V in most regions. The critical factors filtered by the importance analysis were indicative on surface water quality. This study provided a feasible framework in revealing the economy-society-environment nexus in the context of comprehensive management on regional surface water quality.

Spatial-temporal variation characteristics and coupling coordination of the “water resources – water environment – water ecology” carrying capacity in the Three Gorges Reservoir Area

The coordinated control and management of water resources, the water environment, and water ecology are essential for optimizing the management of water resources, improving the water environment, rehabilitating water ecosystems, and achieving sustainable development. Most studies conducted to investigate the water carrying capacity have focused primarily on water resources or water environment. However, it is challenging to conduct such research in areas where the interactions between water resources, the environment, and ecology are intricate. In this study, an evaluation indicator system for the water resources - water environment - water ecology carrying capacity (WCC) was constructed, and a coupling coordination model and GeoDetector were employed to systematically analyze the coupling coordination indices (CCI) among the water resource carrying capacity (WRECC), water environment carrying capacity (WENCC), and water ecology carrying capacity (WECCC), as well as the main influencing factors in the Three Gorges Reservoir Area (TGRA) from 2005 to 2018. The results showed that the numbers of counties and districts with a high CCI class gradually increased over this period. The percentage of Class V fluctuated from 0% to 7.7%, and the stability of the water system steadily increased. Spatially, the overall distribution pattern gradually increased from southwest to northeast, and both the single and interactive effects of anthropogenic factors on water systems gradually increased. The CCI was predominantly affected by factors such as the amount of surface water resources per capita, indices of water conservation, forest coverage, discharge of domestic sewage per capita, and water replenishment of the ecosystem. These results show that coordination between the WCC components should be strengthened to further improve water use and domestic water treatment efficiency. To achieve superior-class, effective, and environmentally friendly scientific governance, the productivity of water resources should be increased in areas where the disparity between water availability and the demand for socioeconomic development is severe, and sewage treatment processes should be closely regulated. It is also important to combine resource development and utilization with water ecological protection and management.

Scheme simulation and predictive analysis of water environment carrying capacity in Shanxi Province based on system dynamics and DPSIR model

A key influence factor of sustainable regional development is the water environment carrying capacity (WECC), which is a prerequisite for ecological security and harmonious regional development. Utilizing the benefits of the dynamic analysis of system dynamics (SD) and the Driver-Pressure-State-Impact-Response (DPSIR) framework system, we constructed a water environment carrying capacity-system dynamics (WECC-SD) model and evaluation index system for Shanxi Province. Five possible future development schemes were designed to predict the changes in WECC from 2020 to 2030. Further, we analyzed the system coordination with the coupling coordination degree model. The results manifest that the comprehensive ranking of WECC under different schemes is: comprehensive scheme > water environment protection scheme > water conservation scheme > status quo scheme > economic development scheme. The economic development scheme performs the worst in WECC and coupling coordination performance, the water conservation and water environment protection schemes can both improve WECC to varying degrees but promote coordinated system development to a very limited extent, the comprehensive scheme can significantly improve WECC and system coordination and is the best strategy to realize the coordinated and steady development of regional economic activities and the water environment. In future development, economic development should be moderated on the premise that the quality of the water environment will gradually enhance and the consumption of water resources will continue to decline, so that a benign relationship between population – economy – water resources – water environment can be created and a steady increase in the level of coordinated regional development can be promoted. The study reveals complex impact relationships within the WECC system and informs the development of future regional planning and environmental policy.

Evaluation of Development Policy through Water Environmental Carrying Capacity Analysis in North Kendeng Mountain, Indonesia

North Kendeng Mountain has abundant limestone that can potentially be utilized for cement material, cosmetics, paint, and other commercial products. This area also provides water resource storage widely utilized for household use and crop irrigation for local people. This condition has sparked conflict between the government and investors on one side with local people and academicians on the other side. The government and investors, prefer this area for commercial uses while the cons prefer for conservation area. The Strategic Environmental Assessment (SEA) for the North Kendeng ecosystem found that spatial planning and mid-term development planning by the provincial government and related regency governments are oriented toward natural resources utilization and prioritize the area for mining. This paper analyses water environmental carrying capacity implications if the government’s policy and planning are implemented. The type of research is descriptive analysis. The data collection techniques include informal interviews, observation, and literature review. The qualitative data on the development policies are analyzed with content analysis technique including descriptive, interpretative, and explanative. The comparison analysis also conducted to understand the interaction between proposed development activities and the existing environmental condition based on water environmental carrying capacity (WECC) result, and to analyze policy orientation on North Kendeng Mountain Area. After comparing the water demand and availabilityboth with and without government’s policy, this study found that condition of water environmental carrying capacity comparing the demand and availability both with and without policy and planning are deficit for all regencies, except Lamongan regency. This development policy potentially worsens water deficit for all regencies. Therefore, it is suggested that revising the policy and updating the planning are required to achieve sustainable utilization of the North Kendeng Mountain Area. 

Overloading risk assessment of water environment-water resources carrying capacity based on a novel Bayesian methodology

Water environment-water resources carrying capacity (WERCC) is a sustainability indicator, rendering it significant to measure the water systems covering the water environment and water resources. Currently, water environment carrying capacity (WECC) accounting and assessment mostly tend to the deterministic results of a single element under a design hydrological condition. However, the WERCC, as well as its components WECC and water resources carrying capacity (WRCC), is a random variable with a certain probability distribution. To account for that, we established a Bayesian network-based WERCC overloading risk assessment method system. It can calculate the water system carrying state and its corresponding probability after determining the WECC and WRCC probability distributions. Among them, the probability distributions of the WECC and WRCC were determined by the Bayesian formula, and the spatiotemporal law, respectively. Additionally, based on the above quantitative uncertainty analysis in the basin, a Bayesian network-based WERCC overloading risk assessment path was built by modeling the causal chain of the WERCC internal impact mechanism, and the risk assessment results were obtained by the software Netica. Taking the North Canal Basin in China as an example, the results of WERCC overloading risk zoning showed that CU6 and CU9 were severe risk areas; CU2, CU7, CU8, and CU10 had moderate risks; and the remaining 40% control units were slight or mild risks. According to the overloading risk characteristics, the uncertain quantitative assessment has provided a scientific basis for ensuring the sustainable development of the North Canal from the perspective of reducing the water environment pressure (WEP) and improving the WERCC.

Research on regional water environmental carrying capacity based on GIS and TOPSIS comprehensive evaluation model.

Water environmental carrying capacity (WECC) is an important indicator for assessing the coordination between the water environment and the social-economic-resources and environment subsystems. In this study, to determine the WECC of Changsha-Zhuzhou-Xiangtan urban agglomeration in Xiang River Basin, a three-level index system was established using an analytic hierarchy process. Because the previous evaluation system lacked continuous indicators, the results could not reflect the differences of WECC within the administrative units, thus, this study selected 4 continuous indicators, and finally an evaluation index system including 15 indicators was established. Based on the TOPSIS model and logistic regression model, the current situation and change trend of WECC in the study area were obtained in ArcGIS. The results showed that the comprehensive WECC in this region was inferior in 2020, particularly in urban concentrated areas, and it was extremely uneven in spatial distribution. The WECC decreased significantly from 2011 to 2014 and gradually improved from 2014 to 2020. According to the prediction results, the WECC will increase in the future, with an average value of 0.54 in 2025 and 0.60 in 2035. This study will have important guiding implications for the protection and improvement of the water environment in the study area and related areas.

Systematic Evaluation and Influencing Factors Analysis of Water Environmental Carrying Capacity in Taihu Basin, China

Systematic evaluation of water environment carrying capacity (WECC) is a prerequisite for achieving sustainable development, which reflects the water environment comprehensive condition of lake basin under the current economic development scenario. Therefore, taking the Taihu Basin as a case study, a scientific comprehensive evaluation index system of WECC was established based on the Pressure-State-Response (PSR) assessment framework, which included water resources (WR), pollution emission (PE), water quality (WQ), water ecology (WE), and land use (LU) sub-systems. An expert group was invited to determine the weights of each indicator using the group analytic hierarchy process (G-AHP) method, and the indicators in the WR, PE, WQ, WE, and LU sub-systems were 6.5%, 21.8%, 27.9%, 11.1%, and 32.9%, respectively. According to the evaluation results, the WECC index of Taihu Basin increased by 51.4% from 2007 to 2019, but it still slightly exceeded the carrying capacity of the water environment; the water quality and pollution discharge indices had the most significant improvement. Algal blooms are a major factor challenging WECC in the Taihu Basin. Therefore, the overall restoration of the water eco-system must receive more attention in the future.

Comprehensive evaluation of water resources and environmental carrying capacity based on dualistic water cycle analysis and its application in the Tuo River Basin, China

Maintaining water quantity and quality are two problems that occur during water resource development. Considering the reciprocal relationship, the threshold of water resource development urgently needs to be evaluated to guarantee environmental water function. In this study, the water resources and environmental carrying capacity (WRECC) evaluation method was proposed based on dualistic water cycle analysis. Nine indicators from 4 aspects, including the water resource utilization proportion, water use efficiency, pollutant treatment efficiency, river flow, and mutual coupling in the dualistic water cycle processes, were selected to represent the comprehensive WRECC. The first-order tributary of the Yangtze River, the Tuo River Basin, was chosen to validate the method. During the year 2009 to 2018, the water environment quality was improving in the study area, and WRECC evaluation results were in accordance with the change in the water system, which showed a decreasing trend during the study periods. WRECC revealed that the upstream area had severer water pressure than the middle area, mainly coming from insufficient freshwater to support social development and provide dilution capacity. The study proposed a human water cycle intervention scenario by increasing the recycled water use rate and wastewater treatment rate to improve the WRECC, and the improvement effects can reach 30%. The WRECC method provides a useful tool for water environment management and water resource planning.

DPSRE model framework for dynamic evaluation of the water environmental carrying capacity in a river network area of Taihu Lake, East China

DPSRE model framework for dynamic evaluation of the water environmental carrying capacity in a river network area of Taihu Lake, East China

Linking hydrological, hydraulic and water quality models for river water environmental capacity assessment.

The water environment of a river network can self-clean to a certain extent; however, when the wastewater discharge load exceeds a certain threshold, the balance of nature is disrupted, leading to water pollution. This emphasises the urgent need to evaluate river water environmental capacity (RWEC) as a necessary parameter for sustainable development. However, to quantify the RWEC, it is important to estimate the hydrological and hydrodynamic factors in the basin, leading to the linking of these models. The present investigation aims to propose an integrated framework, named RWEC, consisting of hydrological and hydrodynamic models, a database system, and GIS to evaluate the water environmental carrying capacity of the selected river network. The rain - runoff (RR), hydrodynamic (HD), ecological (ECO), and RWEC models were used. Groups of data, including meteorology, hydrology, and the environment, combined with topographic data and waste sources, were applied. Groups of models and data were integrated into a seven-step framework to calculate the RWEC. The case study is a basin in Binh Duong Province, Vietnam and four pollutants were selected: NH4+, BOD5, NO3-, PO43-. The flow and water quality factors in the river basin in the study area were measured based on hydraulic models, and the water quality was calibrated. The role of hydrological, hydraulic, and water quality models in the RWEC calculation was clarified. According to the baseline and forecast scenarios, the calculation of the RWEC for the scenarios was performed. In the baseline scenario, RWECNH4+ is in the range (-283, -22) kg/day, RWECBOD5 ranges from (143, 3126) kg/day, RWECNO3- is in the range (-778, 2166) kg/day, and RWECPO43- is in the range (-31, 46) kg/day. The dependence of RWEC on environmental factors, self-cleaning factors, and the difference between the baseline and forecast scenarios were clarified.

Assessment of water environmental carrying capacity of Thuy Trieu lagoon, Cam Ranh, Khanh Hoa

Assessment of water environmental carrying capacity of Thuy Trieu lagoon, Cam Ranh, Khanh Hoa

A Neighborhood-Based Urban Water Carrying Capacity Assessment: Analysis of the Relationship between Spatial-Demographic Factors and Water Consumption Patterns in Tehran, Iran

The upward trajectory of urbanization, coupled with the ever-growing demand for more water resources, has led to increased pressure on limited water resources, particularly in cities with dry climates such as Tehran. Since the balance of Tehran’s water ecosystems has been disturbed, and the quality and quantity of water resources have been affected in recent years, conducting an assessment of water environment carrying capacity (WECC) seemed vital for this city. WECC was used as the basis of water supply sustainability evaluation concerning Tehran’s land use and demographic characteristics on a neighborhood scale. Therefore, the effect size and correlation of 12 types of land use and six variables derived from the literature with water consumption patterns were examined in warm and cold seasons. The results show that land use, population density, percentage of deteriorated area, percentage of buildings over 30 years old, residential–commercial land use, and green spaces correlate significantly with water consumption. The percentage of deteriorated areas and buildings over 30 years old has a negative, and the rest has a positive impact on water consumption. It is also recommended to use the research findings to improve Tehran’s water environment carrying capacity and apply the proposed evaluation procedure to other cities. The results of this research can be used in planning large and densely populated cities with a neighborhood-oriented approach, in which local institutions play an essential role in attracting people’s participation and inclusive urban planning.

Integrated water risk early warning framework of the semi-arid transitional zone based on the water environmental carrying capacity (WECC)

Integrated water risk early warning framework of the semi-arid transitional zone based on the water environmental carrying capacity (WECC)

Realizing Sustainable Development of Yellow River Basin by Horizontal Eco-Compensation Based on Integrated Water Rights (IWRs) Transactions

Horizontal/interregional eco-compensation is an important policy to promote regional ecological and environmental cooperation and realize sustainable development for river basins. To solve these problems, a horizontal compensation framework based on integrated water rights (IWRs) transaction has been established. Taking the Yellow River basin as an example, the IWRs scheme realizes sustainable development, to a certain extent, improving the current issues of shortages, the low utilization efficiency of water resources, and weak water environmental carrying capacity. Evidence for this improvement includes: (1) an increased revenue of USD 244.71; (2) the water use efficiency in the middle and upper streams (Qinghai, Gansu, Ningxia, Neimenggu, Shanxi) and the overall river basin being obviously improved (the maximum improvement value is 0.1273 m3/USD); (3) the overload situation of water resource carrying status being relieved in some subareas (Ningxia, Neimenggu, Henan, Shandong) and improved in the whole basin (from 0.6366 to 0.6124); (3) the water environmental carrying rate (COD and NH4+-N) of the middle and upper streams (Qinghai, Gansu, Ningxia, Neimenggu, Shanxi) and the whole river basin obviously decreasing (with maximum decreasing values of 0.43 and 1.14, respectively).

Evaluation of Regional Water Environmental Carrying Capacity and Diagnosis of Obstacle Factors Based on UMT Model

In order to promote the sustainable development of a social economy and ecology, the social–economic–natural compound ecosystem (SENCE) conceptual framework was used to construct the water environmental carrying capacity index system. Taking the Gansu section of the Yellow River basin as an example, 18 indexes were selected from the 3 subsystems of social, economic, and natural ecology. Based on the unascertained measure theory and the obstacle factor model, the comprehensive level of water environmental carrying capacity in the Gansu section of the Yellow River basin from 2015 to 2020 was empirically evaluated, and the obstacles that hindered the water environmental carrying capacity were identified and analyzed. The results showed that the comprehensive level of water environmental carrying capacity fluctuated and increased overall, and it was grade III (critical load) from 2015 to 2017 and in 2019 and grade IV (weak load) in 2018 and 2020. Considering the ranking of the obstacle degree of each index, the obstacle factors were concentrated in the natural ecological subsystem, among which the obstacle factors were the discharge of wastewater, the population density, the urbanization rate, and the water resources development and utilization rate, which should be examined in the future. The research results and methods described in this paper could provide a theoretical reference for the evaluation of water environmental carrying capacity for other rivers and lakes.

Dynamic assessment and influencing factors analysis of water environmental carrying capacity in the Yangtze River Economic Belt, China

Improving water environmental carrying capacity (WECC) is pivotal to support water sustainability and continued economic development. The improvement pathways of WECC based on both subsystem coupling and driving factors have not yet been identified. Therefore, taking the Yangtze River Economic Belt (YREB) as a case study, this paper firstly constructed a set of scientific comprehensive evaluation index system of WECC based on the coupling system of water resources-water environment-society-economy. Secondly, the improved catastrophe progression method was properly introduced to dynamically evaluate the level of provincial WECC from 2010 to 2018. Finally, the coupling coordination degree (CCD) and obstacle factor diagnosis model were creatively combined to identify the main influencing factors of WECC. The main findings were as follows: (1) The WECC of the YREB was generally low at the provincial and subsystem levels without any obvious upward trend. In comparison, the WECC was higher in Shanghai City, Zhejiang Province and the lower reaches of the YREB. (2) The CCD among the four subsystems was generally low in the YREB. Meanwhile, there was a significant positive correlation between the CCD and WECC in each provincial area, and thus the low CCD was a vital reason for the low WECC in the YREB. (3) Overall, the economic subsystem had the highest restriction on WECC improvement in the YREB, while that of the water resources subsystem had the least. Seen from the mean, the top five obstacle factors of WECC were proportion of ecological environment water consumption, urbanization rate, per capita GDP, proportion of tertiary industry and water consumption per unit of GDP respectively. Furthermore, the rankings of main obstacle factors showed a certain time fluctuation. In general, it could be found out that the CCD of subsystems and main obstacle factors should be focused on simultaneously when improving regional WECC. Additionally, this study has provided a new analytical framework for identifying the pathways of improving WECC, which is also applicable to find the improvement pathways for stability and safety of other complex systems.