Carrying Capacity Of Water Resources Research Articles

Comprehensive quantitative evaluation of the water resource carrying capacity in Wuhan City based on the “human–water–city” framework: Past, present and future

Given China's rapid urbanization process, the study of water resource carrying capacity (WRCC) has important theoretical and practical significance for urban sustainable development. In this paper, a “human–water–city” (HWC) framework was proposed that offers a comprehensive consideration of the development of human society, water quality and quantity, and the progress of urban construction. Based on this framework, we established an HWC evaluation indicator system and constructed the WRCC-HWC approach, to assess, compare, and forecast the WRCC. Taking Wuhan, China, as an example, principal component analysis (PCA) was adopted to evaluate the current (2009–2019) and future (2020–2030) WRCC-HWC. Specifically, global climate models (GCMs) and a grey model, GM (1,1), were used to forecast the value of the future index system. The results show that the WRCC-HWC in Wuhan gradually increased from −3.04 to 3.23 during 2009–2019, being mainly affected by the income of urban residents, per capita GDP, reuse ratio of water used by industry, built-up area, and the output value of new and high-tech industry. With a rapid growth rate from 2011 to 2016, the WRCC-HWC reached the Grade I (excellent) state in 2016. In addition, the forecast results show that, with the exceptions of precipitation and good air quality rate, all HWC indicators show upward trends from 2020 to 2030 in Wuhan. In particular, the per capita disposable income of urban residents (N1), per capita GDP (N2), and the output value of new and high-tech industry (N11) have faster growth rates, with relative growth rates from 2020 to 2030 exceeding 100%. Correspondingly, the WRCC-HWC from 2020 to 2030 were predicted to grow steadily each year, with a higher absolute growth rate starting in 2025. This study supports a comprehensive understanding of the current and future situation for WRCC-HWC in Wuhan and can provide a reference for the formulation of scientific and sustainable development strategies.

Predictive analysis of water resource carrying capacity based on system dynamics and improved fuzzy comprehensive evaluation method in Henan Province.

The water resource carrying capacity (WRCC) is a carrying capacity of natural resources. It affects the application and expansion of the carrying capacity of water resources. This subject involves various elements, such as water resources, the ecological environment system, humans and their economic and social systems, and a wider range of biological groups and their survival needs. Based on the objective recognition of the complex relationship between the water resource system, ecological environment system, and economic and social system, the support scale of water resources and the ecological environment for economic and social development is studied. Current research on the carrying capacity of water resources has mostly shifted from the previously limited support capacity of water resources to include factors such as the population, economy, and ecology, establishing the internal relationships between the economics, water resources, and ecological environment. This reflects the comprehensive carrying capacity of the entire region (or river basin) of water resources and the ecological environment system on an overall economic and social scale. Based on the conceptual connotation of the WRCC and the actual problems facing water resources in Henan Province, the paper uses a system dynamics method to develop information feedback between the four subsystems of Henan Province: economic, population, water resource, and water environment subsystems. The index system of the WRCC in Henan Province is also determined. The weight of each index is comprehensively determined by a combination weighting method of the analytic hierarchy process and an entropy weight method, and then a fuzzy comprehensive evaluation method is used to evaluate the WRCC of Henan Province under four different development models. The validation period of the model is 2010-2020, and the forecast period is 2021-2030. The results indicate that during the period 2021-2030, the WRCC of Henan Province showed a slight upward trend overall under the four models, but the increase rates were different under the different models. Among the four models, the comprehensive model's benefit was the best, which not only maintained the healthy and stable development of the economy and society but also improved the pressure on the water resources and the quality of the water environment.

Coupling research on spatio-temporal differentiation of water resources carrying capacity in mature mining cities

Abstract Long-term unreasonable mining has seriously affected the water resources quality of mature mining cities, but mining development is an important economic pillar of those cities. The problems between sustainable development of mining cities and environmental protection of water resources need to be solved urgently. Based on the state-danger-immunity (SDI) conceptual framework, this paper constructs the evaluation system of water resources carrying capacity (WRCC), and calculates the temporal and spatial differentiation of WRCC of mature mining cities from 2013 to 2019 by combining the criteria importance through intercriteria correlation (CRITIC) method, catastrophe progression model and coupling degree model. The results show that: (1) except that the WRCC grade of Bozhou rose to overload, the WRCC grade of other cities remained unchanged. Huainan, Chuzhou and Xuancheng all showed a downward trend, Suzhou and Chizhou were relatively stable, and Bozhou showed an upward trend. (2) The WRCC of mature mining cities showed an oblique N-type fluctuation. The change range of water resources quality state was small, and the changes in water resources security danger and water resources risk immunity were completely opposite. (3) The coordinated development of mature mining cities as a whole with Chuzhou and Xuancheng has changed from primary imbalance to severe imbalance. Other cities have been in severe imbalance.

Evaluation of Agricultural Water Resources Carrying Capacity and Its Influencing Factors: A Case Study of Townships in the Arid Region of Northwest China

The water resources carrying capacity (WRCC) strongly determines the agricultural development in arid areas. Evaluation of WRCC is important in balancing the availability of water resources with society’s economic and environmental demands. Given the demand for sustainable utilization of agricultural water resources, we combine the water stress index and comprehensive index of WRCC and use multi-source data to evaluate agricultural WRCC and its influencing factors at the township scale. It makes up for the deficiencies of current research, such as the existence of single-index evaluation systems, limited calibration data, and a lack of a sub-watershed (i.e., township) scale. By applying multi-source data, this study expands the spatial scale of WRCC assessment and establishes a multidimensional evaluation framework for the water resources in dryland agriculture. The results indicate water stress index ranges from 0.52 to 1.67, and the comprehensive index of WRCC ranges from 0.25 to 0.70, which are significantly different in different types of irrigation areas and townships. Water quantity and water management are key factors influencing WRCC, the water ecosystem is an area requiring improvement, and the water environment is not a current constraint. Different irrigation areas and different types of townships should implement targeted measures to improve WRCC.

An Assessment of the Water Resources Carrying Capacity in Xinjiang

The water resource shortage is a crucial factor in restraining the development of society and the economy in Xinjiang, where there is drought and little rain. The assessment of the water resources carrying capacity (WRCC) is a prerequisite for socioeconomic sustainable development in Xinjiang. In this paper, a convenient and effective model is established for assessing the WRCC under the influence of social welfare and water use efficiency. Meanwhile, a pedigree chart for WRCC is put forward. Then the developed approach is applied to investigate the sustainable utilization of water resources in Xinjiang. The results indicate that the WRCC of Xinjiang is not overloaded in 2018. The status of the WRCC is worse in northern Xinjiang than in southern Xinjiang, especially in Karamay, Shihezi, and Urumchi. The areas with potential water resource exploitation in Xinjiang are mainly located in the Yili Kazak Autonomous Prefecture and Altay Prefecture. The efficiency of agricultural water use is of vital importance to the WRCC in Xinjiang. The WRCC of Xinjiang can be improved by saving agricultural water, water recycling, and optimizing industrial structures. The maximum population carried by the water resources in Xinjiang is predicted to be 33.63 million and 35.80 million in 2035 and 2050, respectively. The assessment of the WRCC provides a valuable reference for the sustainable utilization of water resources in Xinjiang.

Sustainability assessment in the anthropocentric watershed based on emergy and decomposition methods: A case study of Erhai Lake Basin, southwest China

Assessment of anthropocentric watersheds’ sustainability and its driving forces is important for regional natural resources management and sustainable development. However, the impact of natural resources use on watersheds’ sustainability needs deeper exploration. This study employs emergy accounting and decomposition analysis methods to evaluate the sustainability and related key factors of Erhai Lake Basin (ELB) of Yunnan province in China -- a watershed facing urgently sustainable issues. Major results show that the environmental sustainability index (ESI) of ELB decreased with low production efficiency -- emergy yield ratio (EYR), and high environmental pressure -- environmental loading ratio (ELR) from 2000 to 2015. Four factors within the decomposition analysis have been identified, namely the emergy intensity factor (ΔUG), resource factor (ΔRF), water supporting factor (ΔWN) and water efficiency factor (ΔPW), as the major drivers of ESI changes. The economic development in ELB highly exceeded the carrying capacity of natural water resources, relying on imported resources and, in so doing, affecting sustainability levels. Accordingly, several suggestions are proposed which are helpful for sustainable watersheds governance.

Research on water resources carrying capacity evaluation based on innovative RCC method

Scientific assessment of water resources carrying capacity (WRCC) is the basis for implementing water resources protection measures. To make the evaluation more objective and reasonable, this study created a WRCC evaluation method based on R-clustering-variance coefficient method coupled with cloud model (RCC) for the state study of WRCC in a specific region. The study collected and summarized the available indicators through the review of existing studies to build a database of extensively selected indicators, and also combined with the characteristics of the study area to construct the initial indicators database. Then the indicators were categorized into 12 factor layers under the concept of water resources carrying subjects and objects, and the R clustering-variance coefficient method was introduced to screen the indicators to construct a concise and effective evaluation index system. Finally, combined with the cloud model to identify the comprehensive state of WRCC, the quantitative expression of WRCC was realized. Taking Henan Province of China as the research area, a total of 81 available indicators were collected, and an evaluation index system composed of 30 indicators was constructed after screening. During the evaluation years of 2005–2017, the WRCC level in Henan Province gradually raised from level IV (overload) to level II (weakly bearable), and the results of the study were stable and consistent with the changing trend of existing studies. The study can provide new ideas for the evaluation indicators selection and quantitative evaluation of water resources carrying capacity or other carrying capacity for a specific county, city, or provincial study area.

Analysis of Water Supply-Demand Based on Socioeconomic Efficiency

Water resource is an important factor restricting social-economic development. Hebei Province is one of the regions suffering from severe water shortage in China. Based on the Water Resources Assessment and Planning model, population growth, economic growth, water-saving, and integrated scenarios were established. The water demand and supply in Hebei Province in 2025 and 2035 were forecasted in this study. The research results show that agriculture is the main unmet water demand sector. In the absence of large-scale population inflows, the local population growth has little impact on the changes in water supply-demand. Economic development is one of the main factors affecting water balance. The water-saving scenario has the greatest impact on water supply-demand. Compared to population and economic growth scenarios, the simulation results of water demand and unmet water demand were the smallest. Under an integrated scenario, the current situation of water shortage in Hebei has been greatly improved, but there is still a demand shortage of44.12×108 m3 in 2030. It is necessary to take measures to improve the carrying capacity of water resources in various regions of Hebei Province and narrow the regional gap. This study provided a reference for the rational utilization of water resources.

An Algorithm for Optimal Allocation of Water Resources in Receiving Areas Based on Adaptive Decreasing Inertia Weights

As the biggest rigid constraint for high-quality economic and social development, how to improve the carrying capacity of water resources, realize the stable and coordinated development of water resources-ecological environment-economic and social integrated system, and provide water resources guarantee for regional transformation and upgrading development is a major issue in the current social development. This paper firstly selects the minimum loss of water resources allocation as the objective function for mathematical modelling, chooses the particle swarm algorithm as the objective algorithm, and proposes a particle swarm algorithm based on the standard particle swarm algorithm with improved adaptive decreasing inertia weights. It is a time-varying process for the inertia weights and acceleration factors of the standard particle swarm algorithm so that they change nonlinearly with the continuous advancement of the iterative optimization seeking process, thus improving the convergence accuracy and speed of the algorithm and reducing the risk of falling into local optimum solutions at a later stage. Finally, based on the actual installation of the current water distribution reactive power compensation device, the shunt distributor set is selected as the reactive power compensation device, sensitivity analysis is applied to the load nodes for sensitivity calculation, and the nodes requiring compensation are connected to the shunt distributor set for flexible and optimal configuration. The stronger local search capability of the inertia weight adaptive decreasing algorithm is utilized in the generation process of new particles to perform a local search operation for particles, which avoids premature convergence and improves the search performance of the algorithm. To realize the rational allocation of water resources, a multiobjective receiving area water resources optimization allocation model with maximum water supply benefit, minimum regional water shortage, and minimum pollutant emission is established.

Oasis sustainability assessment in arid areas using GRACE satellite data.

An oasis is an important habitat for humans, plants, and wildlife in arid desert areas. The sustainability of an oasis is crucial for a smooth regional ecological functioning and healthy economic development. However, the overexploitation of groundwater will result in unsustainable oasis development. Due to the lack of long-term groundwater monitoring data, the impact of groundwater level changes on the sustainability of an oasis has not been studied extensively. In the present study, we used the ground water storage anomaly (GWSA) in combination with the Gravity Recovery and Climate Experiment (GRACE) and the Global Land Data Assimilation System (GLDAS) for the rapid identification of oasis sustainability, which has been tested and evaluated in Hotan and Qira oasis located in arid areas. The results showed that (1) the GWSA is a suitable and reliable indicator for trend change analysis in small-scale oasis and, (2) additionally, M-K test results for long-term trend change of GWSA showed a positive correlation with water resource carrying capacity (WRCC). These results suggest that GWSA can be used as a reliable index for the rapid assessment of oasis sustainability status in arid areas. Moreover, the potential applicability of GRACE satellite data in evaluating the groundwater sustainability in arid areas lacking proper data has also been proved in this study. These findings have provided a foundation to evaluate the sustainability status of an oasis and set a reference point to formulate future policies for the oasis.

An improved method of using two-dimensional model to evaluate the carrying capacity of regional water resource in Inner Mongolia of China

The evaluation of regional water resource carrying capacity has been repeatedly conducted to provide a scientific basis for the local water resource management and the sustainable development, in particular in the water-limited regions. However, the definition of regional water resource carrying capacity and its evaluation method are still arguable. Through a case study of Inner Mongolia, located in the arid and semi-arid northern China, this paper developed an improved method to calculate regional water resource carrying capacity by the combination of the water supply-demand analysis and the S-shaped curve threshold analysis. The spatial and temporal patterns of the regional water resource carrying capacity in Inner Mongolia during 2000–2019 was evaluated at three scales, namely the province scale, the basin scale and the city scale. The results showed that the average regional water resource carrying capacity of the whole province was 0.25 (the full mark is 1.00); at the basin scale, the Yellow River Basin had the lowest regional water resource carrying capacity (0.17) among all the basins, showing that the utilization of the water resources was unreasonable; at the city scale, the average regional water resource carrying capacities in Hulunbuir and Xilingol were both over 0.25, while those in Alxa, BayanNur and Wuhai were below 0.1; Hulunbuir had 25.48 billion m3 water surplus, while BayanNur suffered from an average water deficit of 4.51 billion m3 from 2000 to 2019. This paper has provided a reasonable way to measure the regional water resource carrying capacity using an improved method by incorporating S-shaped curve threshold analysis, which may have a wider application for the clustering and optimization of regional water management. In addition, the spatial and temporal patterns of regional water carrying capacity are beneficial for policymakers in the implementation of the effective water usage.

Quantitative Evaluation and Diagnosis of Water Resources Carrying Capacity (WRCC) Based on Dynamic Difference Degree Coefficient in the Yellow River Irrigation District

In order to effectively deal with the uncertainty between evaluation samples and evaluation criteria, and quantitatively identify the water resources carrying capacity (WRCC) and its obstacle factors in the Yellow River irrigation district, a calculation method of dynamic difference degree coefficient varying with evaluation sample was proposed, and then an evaluation and diagnosis model of WRCC was established. The results applied to the Dagong irrigation district showed that the overall WRCC of five counties in the irrigation district were improved from 2010 to 2017, especially since 2013. The improvement magnitudes of Changyuan County, Fengqiu County, and Hua County were significantly higher than those of Xun County and Neihuang County. In 2017, Fengqiu County, Changyuan County, Hua County, Xun County, and Neihuang County were in water resources critical overloaded status, and the connection number values were 0.231, 0.163, 0.120, −0.293, and −0.331, respectively, which is consistent with the fact that their distances become farther from the main stream of the Yellow River. In addition, the utilization ratio of water resources, available water resources amount per capita, GDP per capita, and water deficient ratio in each county belonged to the middle or strong obstacle index over a long period of time. They were the crucial obstacle factors of WRCC in the Dagong irrigation district, as well as the core and difficult points of water resources management. In some counties, the effective irrigation area ratio, effective utilization coefficient of irrigation water, and water consumption ratio of the ecological environment gradually developed from strong obstacle to weak or strong promotion index. These were important reasons for the improvement of their carrying situation, reflecting their control of agricultural and ecological water consumption. In short, the results of the case study suggest that the model established in this study is conducive to the identification of water resources’ carrying status and its key obstacle factors in the Yellow River irrigation district, and can be applied to the evaluation and regulation of resources and environment carrying capacity.

Evaluating water resource carrying capacity using the deep learning method: a case study of Yunnan, Southwest China.

Water resource carrying capacity (WRCC) is an important index for measuring the relations between water resource systems and socio-economic-environmental development. In view of the difficulty in describing the complex and nonlinear relationships between the WRCC and indicators using traditional methods, this study introduces deep learning theory and proposes a novel deep neural network named WRCC-Net for WRCC assessment. Unlike typical network structures, we constructed a hierarchical structure that can indicate the index system in WRCC evaluation. Furthermore, we utilized a residual learning technique to increase the network depth for fitting the complex relationship between the WRCC state and indicators. The proposed deep learning method was applied to solve the real-world WRCC problem by taking the Yunnan province (Southwest China) as the case area. The WRCC was assessed from the following five dimensions: the water resources, social, economic, ecological environment, and coordination subsystems. Performance evaluation shows the advantages of the proposed WRCC-Net over the typical deep feed-forward network and shallow methods. Therefore, the proposed method provides a new way of evaluating the WRCC state and has potential for WRCC research. Overall, the WRCC evaluation using the WRCC-Net shows that the state of the WRCC in Yunnan constantly decreased from 2008 to 2018. These central-eastern areas in the Yunnan province, such as Kunming, Qujing, and Yuxi, are under an unfavorable capacity state. Measures, such as improving water resources management and increasing water utilization efficiency, should be considered in water resource planning in Yunnan province for the sustainable development of water resources.

Risk Assessment of the Water Resources Carrying Capacity: A Case Study in North China

AbstractEvaluating the water resources carrying capacity (WRCC) is the prerequisite and foundation for the planning and management of water resources. In this paper, according to risk theory, a framework for the risk assessment of WRCC was proposed based on the fragility of damage‐affected bodies and the damage posed by disaster‐inducing factors. Then, based on water quantity, water quality, water area, and water flow, a fragility index system was constructed from the water resources, economy, and society category. Additionally, the damage was analyzed in terms of climate change, urbanization, and industrialization. Finally, a model for the risk assessment of the WRCC was established by combining the fragility of the water resources carrying system with the compound damage posed by climate change, urbanization, and industrialization. The developed model was then applied to assess the risk of the WRCC in North China in 2017. The results indicate that the fragility of the WRCC was the highest in the Beijing–Tianjin–Hebei region, and the compound damage showed an increasing trend from the southeast to the northwest in North China. Meanwhile, the risk of the WRCC decreased from the southeast to the northwest, the highest risk was observed in Hebei Province, and the lowest risk was observed in Inner Mongolia. This research provides an important technical guideline for the sustainable utilization of water resources and the coordinated development of the economy and society.

Evaluation of the Water Resource Carrying Capacity on the North Slope of the Tianshan Mountains, Northwest China

Water resource carrying capacity (WRCC) is essential for characterizing the harmony between humans and water resources in an area. Investigation of the WRCC is useful for guiding the sustainable development of a region. The northern slope of the Tianshan Mountains is an important area for the economic development of Xinjiang, China. In recent years, the supply of water in the area barely satisfies the demand. To quantitatively evaluate the WRCC, data for four indicators including the water resources, social and economic development, and ecological environment of the area were utilized. The comprehensive weighting method, which combines the entropy and analytic hierarchy processes, was used to assess these indicators. A fuzzy comprehensive evaluation model was employed to evaluate the urban WRCC of the northern slope of the Tianshan Mountain for 2018. The results showed urban WRCC values varying between good and moderate for the northern slope of the Tianshan Mountains, and this indicates that the study area is in a loadable state. Although the water supply can meet the development of cities on the northern slope of the Tianshan Mountains to a certain extent at this stage, because it is located in the arid region of western China, the shortage and uneven distribution of water resources are one of the biggest limiting factors for the future development of this region. The findings of the present study provide a basis for the development, rational allocation, and sustainable utilization of urban water resources on the northern slope of the Tianshan Mountains.

Dynamic simulation and comprehensive evaluation of the water resources carrying capacity in Guangzhou city, China

The quantity and quality of water resources are of vital importance to the sustainable development of the social economy. Accordingly, research on the water resources carrying capacity (WRCC) has received wide attention from scholars. The WRCC system comprises multiple complex and nonlinear interactions related to society, economy, water resources and the water environment. A full understanding of its internal mechanism is conducive to the further improvement of the regional WRCC. In this study, the system dynamics (SD) model is applied to establish the dynamic feedback system of the WRCC. The quantitative and qualitative evaluation of WRCC is conducted by coupling the analytic hierarchy process (AHP), entropy weight method and multiobjective linear weighting function. Furthermore, the coupling coordination degree model is introduced to rate the coordination of the WRCC system. Five typical scenarios designed for distinct purposes are simulated by the constructed SD model in Guangzhou from 2021 to 2030. The results indicate that the rapid economic development scenario performs worst in terms of WRCC (0.39 in 2030) and coupling coordination degree (0.28 in 2030), the water environment protection scenario and water conservation scenario are considerably effective for improving WRCC and promoting its coordinated development, and the comprehensive scenario performs best in both aspects. Pearson correlation analysis shows that there is a strong positive correlation between WRCC and coupling coordination degree, with a correlation coefficient of 0.91. Thus, to further enhance WRCC, we must attach great importance to regional coordinated development. In view of the problems existing in Guangzhou, several feasible suggestions are put forward for improving water use efficiency, reducing pollutant emissions and developing high-tech industries. This research can provide a scientific reference for promoting regional sustainable development.

Spatial Equilibrium Evaluation of Regional Water Resources Carrying Capacity Based on Dynamic Weight Method and Dagum Gini Coefficient

With the rapid economic development and the acceleration of urbanization, the pressure on the water resources system is becoming intense. As an important indicator of water resources security and sustainable development, the water resources carrying capacity has become a hot issue. To overcome the limitation of commonly used methods for weight determination and to evaluate the regional water resources carrying capacity reasonably, the index weight determined by the Analytic Hierarchy Process method was revised by the subtraction set pair potential to calculate the dynamic index weight. Then, the dynamic weight was combined with the set pair analysis method to evaluate the regional water resources carrying capacity dynamically. In addition, the Dagum Gini coefficient and its decomposition method were used to analyze the overall difference of water resources carrying capacity in the whole region and the differences within and between subregions considering the lack of quantitative research in spatial equilibrium. Finally, a case study was carried out in Anhui Province, China. The results showed that from 2011 to 2018, most of the water resources carrying capacity for 16 cities in Anhui Province were in a critical state, with the strongest in the south of Anhui Province and the weakest in the north. The overall spatial difference of carrying capacity in Anhui Province showed an increasing trend from 2011 to 2018. Furthermore, the slightest difference within the subregion was in the north of Anhui Province, while the largest was in the south. The most significant difference between the subregions was between the south and the north of Anhui Province. The primary source of carrying capacity spatial difference in Anhui Province was from the difference between subregions. The results of the case study suggested that the method proposed in this paper are conducive to the early find of possible disadvantages of spatial equilibrium and can effectively identify the main source of regional spatial difference in water resources carrying capacity, which means that the method can be widely applied to similar issues.

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.

Evaluation method of regional water resources carrying capacity based on semipartial connection number and dynamic subtraction set pair potential

为准确和客观地评价区域水资源承载力，从水资源承载力评价样本与评价等级标准这一集对的复杂系统结构角度，应用集对分析半偏联系数和减法集对势方法，构造了定量反映和刻画集对联系数系统结构中联系数分量间微观运动的迁移率矩阵，提出了一种联系数分量值的修正方法，同时基于减法集对势和三角模糊数方法动态确定了差异度系数，构建了区域水资源承载力定量评价方法. 该方法在安徽省淮北市的应用结果表明：2011—2019年水资源承载力介于2~3级之间，承载力较差，系统态势总体上由偏反势向均势过渡，逐渐向好发展；在判别系统态势发展方面，基于普通减法集对势的联系数值由2011年的-0.279变化到2018年的-0.037，再到2019年的-0.218，基于半偏减法集对势的联系数值由2011年的-0.267变化到2018年的-0.035，再到2019年的的-0.207，说明两种方法均适用，但在确定评价等级值方面，评价效果后者更优，相对误差在1 % 以内，这与半偏减法集对势的物理解释意义更为深刻有关. 联系数系统结构中联系数分量间的微观运动结果表明，原联系数中最大分量的值会减小，其他两个分量的变化情况与该分量本身的大小、半偏联系数表示的增量与原联系分量的比例、被迁移的原联系分量的大小有关. 基于半偏联系数和动态减法集对势法可实现联系数的修正更新和差异度系数的动态确定，方法物理解释性强、评价结果准确可靠，为从系统结构成因机理角度准确判别水资源复杂系统所处状态及总体发展趋势提供了新的有效途径.;In order to accurately and objectively evaluate the level of regional water resources carrying capacity (WRCC), from the perspective of WRCC evaluation samples and evaluation level standards, set pair analysis semipartial connection number (SCN) and subtraction set pair potential (SSP) method were applied in this study. A mobility matrix which quantitatively reflects and describes the micro movement between the connection number components (CNCs) in the connection number system structure was constructed, along with a correction method on CNC values. Meanwhile, the difference coefficient was dynamically determined based on SSP and triangular fuzzy number method, and the quantitative evaluation method of regional WRCC was constructed. The application of this method in Huaibei City, Anhui Province showed that WRCC in 2011-2019 was between level 2-3, and the carrying capacity was relatively poor. The overall system situation transited from partial inverse potential to equilibrium potential, and gradually developed for the better. In judging the development of system situation, the connection number value based on SSP changed from -0.279 in 2011 to -0.037 in 2018 and then to -0.218 in 2019, and connection number value based on SSP changed from -0.267 in 2011 to -0.035 in 2018 and then to -0.207 in 2019. Results indicated that both methods were applicable, with the latter one better in determining the evaluation grade value and relative error < 1 %, which was related to the more profound physical interpretation of the semipartial SSP. The micro motion results between the CNCs in the structure of the connection number system showed that the value of the largest component in the original connection coefficient will decrease, and the changes of the other two components are related to the size of the component itself, the proportion of the increment represented by the SCN to the original CNCs, and the size of the migrated original CNCs. Based on the SCN and dynamic SSP method, the correction and updating of connection number and the dynamic determination of difference coefficient can be realized. The method has strong physical interpretation and accurate and reliable evaluation results, which provides a new and effective way to accurately distinguish the state and overall development trend of complex water resources system from the perspective of system structure and genetic mechanism.

A retrospect on the water diversion project from Yangtze River to Lake Taihu during 2002-2021: Practices, achievements and future challenges

过去几十年太湖流域经济社会快速发展，但由于经济增长方式尚未根本转变，流域水循环系统遭到无序干扰和破坏，太湖水污染问题严重，水质型缺水问题突出，流域水安全面临巨大挑战. “引江济太”作为太湖流域水安全保障的关键措施和流域水环境综合治理的重要举措，自2002年启动实施以来，以丰补枯，增加流域水资源供给；以动治静，抑制太湖蓝藻大规模暴发，改善流域区域水环境；科学应对，保障突发水污染事件和重大活动期间供水安全，取得了显著的综合效益，社会各界予以了广泛关注. 本文基于监测数据和大量文献，在综述“引江济太”实践背景、过程和成效的基础上，重点围绕“引江济太”调度模式、水量水质保障、洪旱风险管控、调水事件驱动等进行了研究. 结果表明，“引江济太”通过试验探索回答了流域治理管理的一些关键科学问题，已经成为提升流域水资源和水环境承载能力的重要手段. 面对极端气候变化、流域水循环格局变化、保障长三角一体化高质量发展水安全新需求和挑战，建议“引江济太”实践中，探索多目标统筹协调调度、开展数字孪生太湖调水、促进流域骨干水网建设，实现”引江济太”综合效益最大化.;In the past decades, Taihu Basin has witnessed rapid economic and social development. However, due to the lack of corresponding alternation in the economic growth mode, the water circulation system of Taihu Basin has been disturbed and destroyed, resulted in great threaten in the water security. As a key measure to ensure water security and an important measure to comprehensive water treatment in Taihu Basin, the water diversion project from Yangtze River to Lake Taihu has been launched since 2002. Supplementing drought with increased abundant water resources, suppressing the large-scale outbreak of cyanobacteria in Lake Taihu and improving water environment in the basin, prompt response to water pollution crisis to ensure the safety of water supply, the water diversion project has achieved remarkable comprehensive benefits which attracted extensive attention from social public. Based on monitoring data and published literatures, the paper reviewed the background, process and achievements of water diversion practice focusing on the scheduling mode, water quantity and quality ensure, flood-drought risk management and water diversion event-driven. The results show that water diversion project has resolved some key scientific questions of management through series of practices and exploration, and has become an important means to improve the carrying capacity of water resources and environment. Facing extreme climate and water cycle pattern changes of the basin, new demands and challenges emerged to ensure water security of the integrated high-quality development of Yangtze River Delta. It is suggested that multi-objective coordination scheduling should be explored, water diversion based on digital twin should be carried out, and water network construction should be promoted to maximize the comprehensive benefits of water diversion from Yangtze River to Lake Taihu.