Carrying Capacity and Coupling Coordination of Water and Land Resources Systems in Arid and Semi-arid Areas: A Case Study of Yulin City, China

Quantitatively assessing the carrying capacity of water and land resources systems in arid and semi-arid areas is crucial for achieving the 2030 Sustainable Development Goals.In this work,taking Yulin City in China as a case study and employing the Criteria Importance Through Intercriteria Correlation(CRITIC)method,a modified model of coupling degree was developed to evaluate the car-rying capacity of water and land resources systems endowment and utilization,as well as their coupling coordination degree from 2013 to 2020.Our findings indicate that the water and land resources of Yulin are diminishing due to declines in agriculture,higher industrial water use,and wetland shrinkage.However,reallocating domestic water for ecological sustainability and reducing sloping farmland can mitigate this trend of decline.Temporally,as the coupling coordination between water and land resources system endowment in Yulin continuously improved,the coupling coordination between water and land resources system utilization first decreased and then in-creased with 2016 as the turning point.Spatially,the carrying capacity of water and land resources systems,the coupling coordination degree between water and land resources system endowment,and the coupling coordination degree between water and land resources system utilization in Yulin exhibited the same pattern of being higher in the six northern counties than in the six southern counties.Improving the water resources endowment is vital for the highly efficient use of water and land resources.

Dynamic Changes of Land Ecological Carrying Capacity Based on the Ecological Footprint——By the Case Study of Chengdu City

Chengdu City is in the period of rapid urbanization and industrialization, and the disturbance derived from human activities on environment is increasing remarkablely in recent 20 years. The pressure on environment, economy and population is also increasing and land use in Chengdu has changed enormously. As struc- ture and function of land ecological system change obviously, sustainable development of land productivity has been an important goal and strategic task from now on, and it is necessary to systematically research land ecological carrying capacity based on ecological footprint. The ecological footprint of Chengdu City in the past ten years was calculated and analyzed from the spatial and temporal aspects according to statistical data from 1998 to 2008, as per ecological footprint method, ecological carrying capacity and the GIS spatial analysis method, and regression analysis method. The ecological footprint and ecological carrying capacity values from 2009 to 2019 in Chengdu City were predicted through calculation results in the past ten years. The results show that the ecological footprint and ecological deficit of land use from 1998 to 2008 increased in Chengdu City. The ecological deficit of land use within the city center was in high levels in the past ten years, and the ecological footprint kept raising, especially in areas, such as Shuangliu, Chongzhou, Qingyang among 9 city areas, 4 counties and 6 districts in Chengdu City. There is fanlike distribution of ecological deficit of land use. Analysis shows that the social and natural ecological system is uneven distribution, which is not in sustainable de- velopment situation. The results of the study show that the economic, social and natural ecological system in Chengdu City is not sustainable, and the ecological foot- print is uneven distribution. The analysis of the dynamic change of land ecological carrying capacity in Chengdu City is very important for city government in the pro- cess of the vigorous development in new Tianfu Xinqu, and redevelopment in the northern part of this city.

Assessment of Land Comprehensive Carrying Capacity in Lin'an City

According to regional characteristics and the actual situation in Lin ’an City, an evaluation index system of land comprehensive carrying capacity composed of three support subsystems （eco-environment, social and economic carrying capaci-ties） containing 22 evaluation indexes was established to evaluate the comprehen-sive carrying capacity of land resource in Lin’an City during 2005-2012. Meanwhile, based on the target data of overal land use plan, the level of land comprehensive carrying capacity was predicted at the end of the plan period （2020） .The results showed that land comprehensive carrying capacity had a significant growth in Lin ’an from 2005 to 2012, and the development trend was basical y sustainable. The sub-systems also had been greatly improved, in which the constant improvement of ec-ological environment carrying capacity made the largest contribution to the constant raising of land comprehensive carrying capacity. The degree of coordination between the systems was poor, in which eco-environment carrying capacity had the maxi-mum growth, far more than the social and economic carrying capacities. According to the land comprehensive carrying capacity in 2020, utilization of land resources in Lin＆#39;an city can achieve sustainable development in general. Final y, proposals of im-proving comprehensive carrying capacity were put forward in terms of the enhance-ment of eco-environment protection, accelerating economic development and policy guidance.

Evaluation of regional water resources carrying capacity based on binary index method and reduction index method

Based on the regional water resources carrying capacity(WRCC)evaluation principles and evaluation index system in the National Technical Outline of Water Resources Carrying Capacity Monitoring and Early Warning(hereafter referred to as the Technical Outline),this paper elaborates on the collection and sorting of the basic data of water resources conditions,water resources development and utilization status,social and economic development in basins,analysis and examination of integrity,consistency,normativeness,and rationality of the basic data,and the necessity of WRCC evaluation.This paper also describes the technique of evaluating the WRCC in prefecture-level cities and city-level administrative divisions in the District of the Taihu Lake Basin,which is composed of the Taihu Lake Basin and the Southeastern River Basin.The evaluation process combines the binary index evaluation method and reduction index evaluation method.The former,recommended by the Technical Outline,uses the total water use and the amount of exploited groundwater as evaluation indices,showing stronger operability,while the latter is developed by simplifying and optimizing the comprehensive index system with greater systematicness and completeness.The mutual validation and adjustment of the results of the above-mentioned two evaluation methods indicate that the WRCC of the District of the Taihu Lake Basin is overloaded in general because some prefecture-level cities and city-level administrative divisions in the Taihu Lake Basin and the Southeastern River Basin are in a severely overloaded state.In order to explain this conclusion,this paper analyzes the causes of WRCC overloading from the aspects of basin water environment,water resources development and utilization,water resources regulation and control ability,water resources utilization efficiency,and water resources management.

System dynamics model of Suzhou water resources carrying capacity and its application

A model of Suzhou water resources carrying capacity （WRCC） was set up using the method of system dynamics （SD）. In the model, three different water resources utilization programs were adopted： （1） continuity of existing water utilization, （2） water conservation/saving, and （3） water exploitation. The dynamic variation of the Suzhou WRCC was simulated with the supply-decided principle for the time period of 2001 to 2030, and the results were characterized based on socio-economic factors. The corresponding Suzhou WRCC values for several target years were calculated by the model. Based on these results, proper ways to improve the Suzhou WRCC are proposed. The model also produced an optimized plan, which can provide a scientific basis for the sustainable utilization of Suzhou water resources and for the coordinated development of the society, economy, and water resources.

Comprehensive Measurement for Carrying Capacity of Resources and Environment of City Clusters in Central China

Studying the carrying capacity of resources and environment of city clusters in the central China has important practical guidance significance for promoting the healthy, sustainable and stable development of this region. According to their influencing factors and reciprocity mechanism, using system dynamics approaches, this paper built a SD model for measuring the carrying capacity of resources and environment of the city clusters in the central China, and through setting different development models, the comprehensive measurement analysis on the carrying capacity was carried out. The results show that the model of promoting socio-economic development under the protection of resources and environment is the optimal model for promoting the harmony development of resources, environment, society and economy in the city clusters. According to this model, the optimum population scale of the city clusters in 2020 is 42.80×106 persons, and the moderate economic development scale is 22.055×1012 yuan (RMB). In 1996-2020, the carrying capacity of resources and environment in the city clusters took on obvious phase-change characteristics. During the studied period, it is basically at the initial development stage, and will come through the development process from slow development to speedup development.

Empirical Research on Carrying Capacity of Human Settlement System in Dalian City, Liaoning Province, China

Using the theories of population carrying capacity and ecological elasticity in other fields for reference, the connotation of regional human settlement system was defined from the viewpoint of the complex relationship among the factors such as regional population, resources, environment and economic and social development in the context of China′s rapid urbanization. Then the concept and characterization methods of the regional human settlement carrying capacity were proposed by means of population scale. Furthermore, a model of carrying capacity-pressure-state-response(CPSR) on regional human settlement system was established by referencing pressure-state-response(PSR) model, and the Catastrophe Theory was introduced to determine the corresponding standards of multi-criteria programming and evaluation. Taking Dalian City, Liaoning Province, China as an example, an empirical analysis on evaluation of human settlement system from 2000 to 2012 was carried out. The results showed that the carrying capacity of human settlement system in Dalian was fluctuating between 9.6 × 106 to 10 × 106 persons with a quantitative stage of the dynamic regulation. During the research period the load index of human settlement system in Dalian dropped from 0.96 to 0.84 with a lower pressure of human settlement system than the national average level. And the emergency response grades of human settlement system in Dalian were kept in grade Ⅱ(orange warning) or grade Ⅲ(yellow warning). Human settlement system of Dalian was in slight security state as a whole, but the load had a tendency of increase in recent years. The related departments should pay close attention to regional human settlement system and take active measures to improve human settlement by both intensity control and total quantity control. By comparison, analysis and discussion, it was considered that the results were basically accordded with the current situations of human settlement in Dalian, and the evaluation results were more reliable, visualized and easily applied in practice. Therefore, the above-mentioned concepts, characterization and evaluation methods of the regional human settlement system and carrying capacity could provide a new thought and method for quantitative evaluation of human settlement.

Water Environment Carrying Capacity of New Zhengdong District in Zhengzhou City

Taking sections of the Dongfeng Canal, the Xionger River and the Wei River in New Zhengdong District for example, this paper applied water environment capacity to analyze the carrying capacity of surface water environment in the east development zone of the city. The analysis shows that carrying capacity of surface water environment in the study area is not good, carrying capacity of 3 studied waters for TP, BOD_5 and COD is approaching to the limit. New Zhengdong District, in terms of industrial structure, should promote the projects with less water consumption, less or no discharge of wastewater, and also should enhance the sewage treatment, improve recycling rate of the reclaimed water, and reduce the negative impact of sewage and pollutant discharge on environment.

Evaluation of carrying capacity of city clusters in China with the example of the Blue Economic Zone of Shandong Peninsula

The conflict between city development and urban carrying capacity is getting ever prominent.In order to study and predict the restriction factors and prominent problems in the development of the Shandong Peninsula Blue Economic Zone as well as promote the transfer of economic development pattern in this region,this study starts from four single factor carrying capacity indicators of water,earth,transportation and environment in the city and its comprehensive carrying capacity indicator,evaluates and analyzes its carrying capacity and then papooses policy suggestions for improving its carrying capacity.

Performance Evaluation of Urban Comprehensive Carrying Capacity of Harbin, Heilongjiang Province in China

Urban comprehensive carrying capacity is an important guarantee and external representation of regional sustainable development. Based on urban comprehensive carrying capacity, this paper constructed a performance evaluation index system of urban comprehensive carrying capacity, and used entropy method, urban comprehensive carrying capacity measurement model and urban sustainable development model to measure spatial and temporal comprehensive carrying capacity of Harbin City in Heilongjiang Province from 2012 to 2017. The results show that: 1) index weight analysis suggested the regional development mode in Harbin still followed an epitaxial development mode, which pursued the expansion of scale and the growth of total amount of regional development, neglecting the effective utilization of resources and the improvement of structural benefits. 2) In the pressure system, the index of resource support has dropped sharply. The index of environmental capacity and social progress has risen circuitously, while the degree of agglomeration and the value of transportation facilities have risen steadily;in the pressure system, the index of population development and economic growth tended to fluctuate, while energy consumption and environmental pollution showed a more synchronous change in characteristics, and the livable demand remained at a high level. 3) The carrying capacity index of resources and environment in Harbin has been declining, and the acquired carrying capacity index fluctuated. The long-term regional development model has severely impaired the carrying capacity of resources and environment. 4) The comprehensive carrying capacity of Harbin has clear spatial differentiation characteristics. Finally, the paper proposes that location conditions, economic development level, government regulation, and science and technology are the main factors influencing the spatial differentiation of urban comprehensive carrying capacity.

Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County, Shaanxi Province, China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle(UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.

The Population Carrying Capacity of Water Resources in Yulin City

Assessing the water resource carrying capacity is beneficial for measuring the scale of industry and population agglomeration,and also avoiding the contradiction between increasing people and decreasing available water resource,due to the expansion of industry and city size.Based on the prediction model of optimum population development size,by using hydrological data,also with the demographic data from 1956 to 2010,this article analyzes and predicts the urban moderate scale under the limit of the water resource in the future of Yulin City by GIS. The main conclusions are as follows. There is growing tendency of water resources overloading. According to the result of model simulation,by2015,the overload rate of population size will be 1. 04. By 2020,the overload rate of population size will grow up to 1. 08. The oversized population mainly comes from cities and towns. The overload rate for cities and towns in 2015 and 2020 is 1. 89 and 1. 73,respectively. With the expansion of cities and industries,suburban areas could have a great potential for carrying population,because lots of suburban people may move to cities and towns according to prediction. In view of the above-mentioned facts,the population size should be controlled in a reasonable range.

Land Potential Productivity and Population Carrying Capacity of Yan'an City

The productivity attenuation method is adopted to calculate land potential productivity of counties of Yan'an City and calculate population carrying capacity at current productivity level. Result shows that high photosynthetic potential productivity area and high light and temperature potential productivity area are mainly situated in the north,while high climatic potential area and high land potential productivity area are mainly concentrated in the south. From solar radiation,moisture and landform,the attenuation amplitude of land potential productivity in northern counties ( districts) is greater than that in southern counties ( districts) . In the whole city,the population carrying capacity of 9 counties reaches well-off living level,and 1 district still does not reach the level of adequate food and clothing. These results can provide reference for land resource use,agricultural production distribution and population growth control.

Quantitative Assessment of Climate Carrying Capacity for Cities: A Case Study of Shanghai City

The concept of climate carrying capacity has been proposed recently for climate risk management. Based on identification of the concept of climate carrying capacity and analysis of the relationship among its influencing factors, this study established a comprehensive assessment indicator system of climate carrying capacity from aspects of the climate situation, the level of climate usage, and the development potential of cities. Taking Shanghai City as a case study, we developed a quantitative assessment model of climate carrying capacity. The climate carrying capacity and its influencing factors were analyzed and discussed in relation to the period 2004–2013. The results were as follows.（1） Current climate natural capacity indicator showed that the climatic situation of Shanghai City was inferior to its base climatic value and it had been in a state of fluctuation.（2） The climate stress and urban coordinated development capacity indicators increased steadily, but the growth rate of the urban coordinated development indicator was less than the growth rate of urban climate stress.（3） The climate carrying capacity was far lower than the benchmark value and it had been in a state of fluctuation mainly due to the effect of current climate situation.（4） According to a principal component analysis, seven factors of urban population density, per capita GDP, energy consumption per unit GDP, total industrial output value, investment in environment protection, spending on science and technology, and green area per capita were main influential factor of climate carrying capacity. It was proved that the proposed system for assessment of climate carrying capacity of a city was feasible. It can be used to describe the spatiotemporal changes of cities, and identify problems of regional climate carrying capacity associated with their development and function. This assessment system can provide a reference for the construction of an early warning system of climate carrying capacity for cities.

Resources development and tourism environmental carrying capacity of ecotourism industry in Pingdingshan City, China

Background:Pingdingshan City has unique and rich ecotourism landscape.To realize the sustainable development of ecotourism industry in Pingdingshan and simultaneously achieve economic development and environmental protection in the development of ecotourism resources,literature analysis and field investigation methods were used to deeply explore the advantages and problems of Pingdingshan in the process of resources development in this study.Then,the indicator system of environmental carrying capacity of Pingdingshan was established and environmental carrying capacity was calculated to understand the local tourism environmental carrying capacity.Results:The development of ecotourism resources in Pingdingshan has advantages of natural conditions,convenient transportation,and sound infrastructure,but there were also problems,such as insufficient resources protection and unscientific management system.After calculation,it was found that the environmental carrying capacity of ecotourism in Pingdingshan was overloaded.Conclusion:This study reveals the development of the tourism industry in Pingdingshan and provides a basis for the future development of Pingdingshan tourism resources,which is beneficial to the sustainable development of the local ecotourism industry.

Research on the impact of mega-projects on carrying capacity of cities taking the first-line project of the West-East gas pipeline as an example

With the acceleration of China's urbanization,the functions and benefits of mega-projects are required higher.With the deepening of"the Silk Road Economic Belt and the 21st-Century Maritime Silk Road",the quantitative evaluation of multinational investment projects will help strengthen cross-border communication among gov-ernment,society and enterprises,which provide a basis for mutual trust.This study empirically analyzes and evaluates the impact of mega-projects on carrying capacity of cities,by using the DID method based on the panel data of 15 cities in China from 2000 to 2013.The results show that the construction and operation of the first-line project of the West-East gas pipeline has a significant positive impact on the improvement of carrying capacity of cities along the line.However,the degree of impact on three di-mensions is slightly different.The impact on the social carrying capacity is the greatest,then the ecological and economic carrying capacity.Therefore,the decisions of do-mestic mega-projects should be unified with urban planning to promote the sustain-able development of China's economy and social.The investment of mega-projects abroad should also be coordinated with the carrying capacity of host cities,in order to enhance the competitiveness and creativity of Chinese multinational mega-projects investment.

基于系统动力学模型的郑州市水资源承载力动态模拟

水资源问题制约着缺水城市的可持续发展,近年来郑州市社会经济高速发展,其水资源有限的现状与用水需求快速增长之间的矛盾愈加凸显。为科学研究郑州市水资源承载力远期发展情况,根据郑州市经济社会现状的水资源供需和发展状况,采用多系统综合的系统动力学方法(System Dynamics,SD),结合水资源、生态、经济社会、水利工程四个子系统,构建郑州市水资源承载力研究的SD模型。将2010-2019年的历史数据与SD方法的模拟数据进行比较,平均误差均小于10%,具有较高的可信度,可用来预测郑州市未来的水资源承载力发展情况。在此基础上,通过设定现状延续、控污节流、开源控污和开源节流4种不同方案,对2020-2030年水资源承载力系数进行动态模拟预测。结果表明:2030年4种方案下的水资源承载力系数分别为1.24、1.18、1.00、0.89,现状延续和控污节流方案下的郑州市水资源承载力随着时间的推移呈现严重超载状态,无法承载郑州市经济社会的快速发展;开源控污方案在预测期内的水资源承载力超载状态会对经济社会发展产生较大阻力。故开源节流方案为最佳方案,水资源承载力系数小于1,在研究期内未出现超载状态,可有利缓解郑州市的缺水状况,促进经济社会的发展。结合4种方案的优点,提出有利于郑州市水资源可持续发展的建议与对策。

哈尔滨市水资源环境承载能力评价

哈尔滨市是全国主要缺水城市之一.为了合理使用水资源,维持水资源的可持续发展状况,维护社会经济,进行哈尔滨市水资源环境承载能力评价研究显得十分必要.本研究分析了水资源环境承载力主要影响因素,采用隶属度函数确定各单项指标隶属度,结合Delphi法得出评判结果矩阵,并采用数据离散化,提高了此评价方法的表达能力.根据水资源环境承载力评价结果,分析了哈尔滨市水资源环境承载力变化趋势,为以后相关研究提供了依据.

北京高质量发展与城市综合承载力耦合协同研究

为探究北京高质量发展与城市综合承载力的协同关系问题,本文结合北京高质量发展和城市综合承载力构建了复合评价指标体系,并运用耦合协调度模型定量测度2005—2020年两个系统综合水平以及耦合协调关系。研究表明:北京高质量发展指数和城市综合承载力指数总体呈现增长态势,但目前还处于中低水平;北京高质量发展系统和城市综合承载力系统的耦合协调度从中度失调耦合升级为初级协调耦合,呈现稳定上升态势,但距离优质协调耦合还有一定的提升空间。因此,北京要科学配置资源要素,不断提高城市综合承载力,深入推进京津冀区域协同发展,实现北京经济社会高质量发展。

生态水文系统支撑城市韧性安全建设的若干思考

近40年城市生态水文学应用研究的重要进展,特别是区域水循环要素的优化调控,有效地支撑了韧性安全城市建设。在城市生态水文系统理念的指导下,北美、欧洲和中国相继出现了低影响开发、水框架指令、海绵城市与气候适应型城市建设。全球变化和人为活动相互作用产生了复杂的城市生态水文过程,自然水循环模式已转变为“自然-社会”相互作用的二元水循环模式。面对全球变化,韧性安全城市的建设更加关注对气候变化的减缓和适应,特别是对极端天气气候事件的适应能力。我国长期持续大规模的城市开发建设,强烈影响和改变着区域水循环关键要素,城市地下空间开发利用和地面沉降面临着极端天气气候情境下的灾害风险。因此,地学基础条件及其韧性构成了城市韧性安全底座的基础。基于二元水循环关键要素调控设计的减缓和适应对策,在新一轮气候适应型城市建设中发挥了重要作用。“气候变化—区域二元水循环—水平衡调控—灾害风险”“遥感大数据—台站网小数据—传递函数—云孪生”,可作为一种地球大数据支撑韧性城市建设与可持续发展的技术框架和方法组合。上海作为长江流域的龙头和海陆交互敏感区域,城市韧性安全还面临着海平面上升的考验。在气候变化情景下区域二元水循环关键要素调控,可作为地学服务上海地下空间安全及城市韧性安全的一个策略。