Evaluating water resource sustainability from the perspective of water resource carrying capacity, a case study of the Yongding River watershed in Beijing-Tianjin-Hebei region, China

Water resource sustainable use assessment methodology and an impact factor analysis framework for SDG 6-oriented river basins: evidence from the Yellow River basin (Shaanxi section) in China

The rapid growth of developing countries has placed unprecedented pressure on water resources, severely hindering the realization of sustainable development goal 6 (SDG 6) in river basins. In this study, sustainable water resource utilization (SWRU) in the Yellow River basin (Shaanxi section) from 2005 to 2019 is evaluated through an analysis of water resource overload combined with the water footprint (WF) and the water planetary boundary (WPB) and an analysis of water resource utilization quality combined with the WF and city development index (CDI) based on the coupled coordination model. Then, the results are incorporated into the drive-pressure-state-impact-response framework to analyze the impacts of the socioeconomic system on SWRU and the feedback effect of related policies. The results show that there were obvious differences in the spatiotemporal evolution characteristics of the WF in different geographical units. The WF of Guanzhong first increased and then decreased, and the WF of Northern Shaanxi grew continuously. The water deficit state is increasing. Although the coordination level between the WF and CDI in the basin increased by 500.31%, it was characterized by nonequilibrium and volatility. Compared to water resource endowment, socioeconomic development and government policies have greater impacts on SWRU; furthermore, the influencing factors demonstrate spatial variability, revealing the complexity of achieving SDG 6 in the basin. As policy implications, adaptive water resource policies should be formulated on the basis of strengthening the overall basin management. This study provides a scientific basis for promoting the realization of SDG 6 through watershed water management.

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.

Collaborative optimal allocation of water resources and sewage discharge rights in watershed cities: considering equity among water sectors

Water supply systems in watershed cities face challenges due to increasing water demand and arbitrary sewage discharge allocations. Previous studies have primarily focused on water resource allocation and sewage discharge rights, neglecting the intricate interactions between the two. This study introduces a novel approach by integrating sewage discharge rights into the watershed's water resource allocation mechanism. A multi-objective optimization model was developed, employing the Gini coefficient to balance the equitable and economic aspects across various water sectors. This model takes into account the distinct water demands and sewage discharge requirements of different sectors. The findings of this study are as follows: (a) the Gini coefficients for water demand allocation and sewage discharge rights allocation exhibit simultaneous optimization and display consistent trends; (b) when the importance of sewage discharge relative to other water users increases, the return on investment for domestic and industrial water use decreases, but the fairness of water distribution improves; (c) proper allocation of sewage discharge rights can effectively enhance the economic value of agricultural water use. Overall, this strategy has the potential to enhance both the equality and economic benefits of the water supply system while ensuring the sustainable utilization of water and sewage rights in the basin cities.

The Distribution Characteristics and Ecological Risks of Alkylphenols and the Relationships between Alkylphenols and Different Types of Land Use

In this study, the spatial distribution characteristics of nine alkylphenols (APs) in the Yongding River and Beiyun River were analyzed. The differences in the concentrations and spatial distribution patterns of nine APs were systematically evaluated using principal component analysis (PCA). The relationships between the concentration distribution patterns and the risks associated with nine APs were investigated under various categories of land use conditions in the region. The results demonstrated that the APs were widely present in both rivers, and the pollution risks associated with the APs were more severe in the Yongding River than in the Beiyun River. The results show that the contamination risks associated with 4-NP were the most serious in the two rivers, with detection percentages of 100% and 96.3%, respectively. In the Yongding River, the APs showed a tendency of low concentration levels in the upper reaches and high levels in the middle and lower regions. Meanwhile, the overall concentration levels of the APs in the Beiyun River were relatively high. However, despite the differences between the upper and middle regions of the Yongding River, the distribution pattern of the APs in the Beiyun River was basically stable. The concentration levels and risk quotient of the APs were negatively correlated with the vegetation cover land use type and positively correlated with the cropland and unused land use types within 500 m, 1 km, and 2 km. The purpose of this study was to provide theoretical data support and a basis for AP pollution risk evaluations in the Yongding River and Beiyun River.

Analysis and Evaluation of Variation Characteristics in Groundwater Resources Carrying Capacity in Beijing between 2010 and 2020

The problems of water shortages and groundwater overexploitation are serious in Beijing. Resources are over-exploited to meet the industrial needs of various sectors, and the capacity of groundwater resources to support economic development is also reduced. Therefore, it is of great significance to study the evaluation of regional groundwater resources carrying capacity from the perspective of time and space. This study evaluates the groundwater resource carrying capacity of Beijing from time and space by using the function between water use efficiency and groundwater availability constructed by regional water supply, consumption data and GDP data. The results show that: The proportion of groundwater in water supply in Beijing has decreased and it was still one of the main sources of water supply from 2010 to 2020. From the perspective of time, when the degree of groundwater exploitation (De) was greater than 1, the contribution rate of exploitation degree of economic development (Dg) reached 60% from 2010 to 2015, indicating that the economic development of Beijing is highly dependent on groundwater resources. From 2015 to 2020, the De was less than 1, but the Dg value kept increasing and approaching 90% and the total overload rate was 81.8%. The supporting capacity of groundwater resources will become more fragile. At the spatial scale, only the Dongcheng and the Xicheng regions were overloaded whose rates were 58.48% and 69.92%. The research shows that the degree of groundwater exploitation has approached the saturation state, the economic development is highly dependent on groundwater resources and there is a large space for water saving. Improving the utilization efficiency of water resources cannot improve the carrying capacity of groundwater resources, so it is still necessary to increase the amount of groundwater resources by recharging the groundwater through a series of comprehensive over-exploitation control measures, which is of great significance to the management and sustainable development of regional groundwater.

Trend analysis and obstacle factor of inter provincial water resources carrying capacity in China: from the perspective of decoupling pressure and support capacity

The high distribution of water resources among provinces in China considerably impacts the development of society and economy in each region. Thus, it is of great practical significance to examine the water resources carrying capacity (WRCC) of each Chinese province. This paper constructs a comprehensive evaluation index system for the WRCC from two aspects: pressure and support. First, it analyzes dynamic changes in the WRCC of 31 Chinese provinces in China by using the decoupling model (DM). Second, it analyzes the key factors that hinder the improvement of WRCC by using the obstacle degree model (ODM). The study found that there are significant inter-provincial differences in China's WRCC. Provinces with greater natural water resources have a higher WRCC. Under the condition of similar natural water resources, WRCC in economically developed provinces is higher. From 2008 to 2015, China's overall WRCC has been increasing. Moreover, three-fifth of China's provinces can be classified as Upward-type (Upward I, Upward II, and Upward III) provinces and their WRCC is in a good state by considering the decoupling type and trend of WRCC in two periods together. The main obstacle factors hindering the improvement of the WRCC are total water resources ([Formula: see text]), water supply per capita ([Formula: see text]), total water supply ([Formula: see text]), forest cover rate ([Formula: see text]), soil erosion control area ([Formula: see text]), water consumption saving ([Formula: see text]), and water usage penetration rate ([Formula: see text]). This study can provide a scientific basis for understanding change trend of WRCC in Chinese provinces and improve their WRCC.

Occurrence and distribution characteristics of heavy metals in the surface water of Yongding River Basin, China

Yongding River is a vital socioeconomic zone in China in providing daily usage for humans, animals, and running of industries and agriculture. This study first provides a comparative assessment for the heavy metal pollution in the surface water from 82 estuarine locations along the basin, including the Guanting Reservoir and seven wastewater treatment plants (WWTPs). The occurrence, distribution, potential sources, and water quality relating to the detected heavy metals were addressed. Eleven typical elements (Pb, Cr, As, Cd, Sb, Ba, V, Ti, Zn, Ni, and Be) were investigated, and the results showed that all the measured concentrations were below the WHO guideline limits. Most heavy metals exhibited higher levels in the middle of Yongding River basin due to the discharge of WWTPs. Pb, Ti, Zn, and Cd in the surface water mainly originated from anthropogenic discharge, while Sb and V were mostly contributed to geogenic sources according to the principal component analysis. Three documented methods, water quality index (WQI), heavy metal pollution (HPI), and Nemerow pollution index (Pn) values, were used to evaluate the contamination monitoring of surface water. All the locations were classified as low and moderate risk except Y12, B2, and Y13 for their Pn values were higher than 1.0. The present study highlights the status of heavy metals in Yongding River basin which is helpful in providing fundamental data for assessment of water quality and the effective protection for Yongding River basin in the future.

Research on Comprehensive Evaluation and Coordinated Development of Water Resources Carrying Capacity in Qingjiang River Basin, China

The protection of a water resource’s ecological environment is one of the most important tasks in the watershed in China. The evaluation of water resources carrying capacity (WRCC) is the foundation for the suitability of territorial space development. It is necessary to further analyze the weaknesses of the coordinated development of various dimensions of WRCC and explore the basis of territorial space development and optimization. This paper considers Chinese unique policy tasks, namely, “three water management together”, the types of main function areas, “red lines” control, and national spatial suitability evaluation, to construct the evaluation index system of WRCC. Monomial evaluation, integrated evaluation, and coupling coordination analysis methods are used separately to evaluate the carrying index, comprehensive carrying index, and coupling coordination degree of WRCC in the Qingjiang River Basin. The results show that: (1) As far as monomial evaluation is concerned, water resource supplies are often overloaded on the overall economy, industrial, and agricultural development; (2) The comprehensive indices of WRCC of the counties in the southwest are obviously better than that of the counties in the northeast; (3) The degree of coupling coordination of WRCC in the Qingjiang River Basin is not high, and is essentially in the primary or barely coordinated level; (4) the short board of WRCC in the Qingjiang River Basin presents obvious spatial characteristics, which from west to east are water environment, water resources and water ecology lagging, respectively. This paper measures WRCC for industry, agriculture, life, and ecology, which is helpful in promoting the suitability evaluation of land space development. Meanwhile, the case study of the Qingjiang River Basin provides reference for other regions to implement the “double evaluation”.

Evaluating urban resource and environment carrying capacity by using an innovative indicator system based on eco-civilization-a case study of Guiyang

A city's sustainable development should occur via harmonious development of urban resource and environment carrying capacity (URECC) and economic growth. By following laws of harmonious development of man, nature, and society, ecological civilization refers to the sum total of material, spiritual, and institutional achievements made by mankind in promoting social, economic, and cultural development. It is an important way of realizing sustained development in China, which has been taken as an important way and method for solving the conflict between environmental problems and resources. In this study, an indicator system of URECC was built based on ecological civilization, which included 18 indicators chosen from 5 kinds of carrying capacities, which are water, land, atmospheric environment, energy, and solid waste. Then, the built index system was applied in a case study to evaluate URECC. Results showed that the indicator system could not only reveal the development tendency of URECC but also reveal changing situations of original bearing capacity, allowing the administration to take appropriate measures to improve URECC. Therefore, it can be guaranteed that economic and social development does not exceed URECC. It provides a good basis for building a more scientific, accurate, and comprehensive future assessment indicator system and also provides guidance and reference for rapid urban development. Consequently, this method not only addresses deficiencies in the existing researches but also provides a new method for assessing URECC.

Evaluation of Land Comprehensive Carrying Capacity and Spatio-Temporal Analysis of the Harbin-Changchun Urban Agglomeration

Land comprehensive carrying capacity (LCCC) reflects the limits of urban development that the land ground in the spatial area can bear under the constraints of society, economy, resources, and environment. An accurate and objective evaluation of LCCC is of great significance to the rational planning of urban space. Using the entropy method to obtain the weights of evaluation indexes, this study constructed an index system composed of four subsystems, i.e., urban construction (UC), social economy (SE), industry development (ID), and urban ecology (UE). Furthermore, calculating the index of 11 cities for the Harbin-Changchun urban agglomeration (HCUA) to analyze the influence of LCCC from diverse dimensions for the period 2004-2015. Lastly, the spatial and temporal differentiation characteristics between the neighboring units of LCCC were visualized through global and local spatial analysis. The results infer some novel findings as follows. (1) The overall tendency of the LCCC of the HCUA has gradually increased over the time window with the coordination of each subsystem. The urban ecological subsystem shows the highest rate of contribution and the social economy subsystem has the largest increase. Urban construction and industry development have a lower number of hot spot cities and lower clustering characteristics than social economy and urban ecology. (2) The core cities of the HCUA, Changchun and Harbin, demonstrate the reverse trend from 2010 to 2015, which reveals the states of excellent and good carrying capacity, respectively. In contrast, four cities are at the inferior state, and three cities are poor. Prioritizing the promotion of the industry development subsystem should be considered for these seven cities. (3) There is some spatial variation of LCCC in the HCUA, which shows the characteristic of "gradually decreasing from the core city to the surrounding area". Changchun and Jilin are high-high clustering areas that drive Siping from a cold spot to a hot spot. Focusing on the development of secondary growth pole cities, Jilin and Songyuan are forming complementary and mutual reinforcement with the core cities, which has a positive significance in promoting the sustainable development of the regional space of urban agglomeration.

Water Resource Carrying Capacity Based on Water Demand Prediction in Chang-Ji Economic Circle

In view of the large spatial difference in water resources, the water shortage and deterioration of water quality in the Chang-Ji Economic Circle located in northeast China, the water resource carrying capacity (WRCC) from the perspective of time and space is evaluated. We combine the gray correlation analysis and multiple linear regression models to quantitatively predict water supply and demand in different planning years, which provide the basis for quantitative analysis of the WRCC. The selection of research indicators also considers the interaction of social economy, water resources, and water environment. Combined with the fuzzy comprehensive evaluation method, the gray correlation analysis and multiple linear regression models to quantitatively and qualitatively evaluate the WRCC under different social development plans. The developmental trends were obtained from 2017 to 2030 using four plans designed for distinct purposes. It can be seen that the utilization of water resource is unreasonable now and maintains a poor level under a business-as-usual Plan I. Plan II and Plan III show that resource-based water shortage is the most critical issue in this region, and poor water quality cannot be ignored either. Compared with Plan I, the average index of WRCC in Plan IV increased by 51.8% and over 84% of the regions maintain a good level. Strengthening sewage treatment and properly using transit water resources are more conducive to the rapid development of Chang-Ji Economic Circle.

Dynamic Evaluation of Sustainable Water Resource Systems in Metropolitan Areas: A Case Study of the Beijing Megacity

Increasing water scarcity has made it difficult to meet global water demands, so the sustainable use of water resources is an important issue. In this study, the sustainable water resource system (SWRS) operating mechanism is discussed, considering three components: dynamics, resistance and coordination. According to the SWRS operating mechanism, a universal indicator system with three layers, including goal, criterion, and index layers, is constructed for SWRS evaluation. Additionally, considering the fuzziness of threshold values for grading standards, an SWRS evaluation model is constructed based on the set pair analysis (SPA), analytic hierarchy process (AHP) and attribute interval recognition methods. This model is conceptually simple and convenient. An evaluation indicator system is constructed for the SWRS in Beijing, and evaluation standards with five grades are established. The dynamics of the sustainability of the Beijing SWRS and corresponding operating mechanism are analyzed using the SPA evaluation model. The results suggest that the three components of the operating mechanism all have positive effects on the Beijing SWRS state, but the SWRS state has not yet been fundamentally changed. Therefore, considerable improvements can be achieved regarding the sustainability of the Beijing SWRS.