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.

RESEARCH ON THE POPULATION CARRYING CAPACITY OF THE LAND RESOURCES IN THE ECONOMIC AREA OF ZHUJIANG DELTA

The authors once made a preliminary research on population carrying capacity of the land in the Economic Area of Zhujiang Delta (EAZD for short) in 1995, and reckoned that the ultimate population in this region will be 23 550 thousand by year of 2000. While the population in being in EAZD was 22.62 million in 1999.This accords with the prefigured result in the rough from the point of view of development. According to the data of plow land resources from the 2000 Statistical Yearbook of EAZD and the study on the population-foodstuff-plow land relationship, this paper calculates the productive potential of plow land and the population carrying capacity of land by year of 2010, and puts forward the countermeasures for improving the population carrying capacity of land in this region.

Assessment of Comprehensive Carrying Capacity of Land Resources Based on Land Functions

Based on relevant research results,from the perspective of land use functions,an evaluation indicator system of carrying capacity of land resources composed of three second-grade indicators( production,living and ecological carrying capacity) including 24 third-grade indicators was established,and the carrying capacity of land resources in ten cities of Shaanxi Province in 2013 was assessed and analyzed by using mean square error analysis method and hierarchical clustering method. The results showed that the three types of carrying capacity in most cities of Shaanxi Province are shown as follows: ecological carrying capacity > living carrying capacity > production carrying capacity,and the differences between various regions in a single type of carrying capacity basically accorded with the actual situation of development in each city; there were obvious differences between various cities in the comprehensive carrying capacity of land resources,which was basically consistent with regional economic and social development.

The Coordination Effect of Marine and Land Resources Carrying Capacity of Coastal Areas in China

The carrying capacity of marine and land resources is one of the indicators to measure the sustainable development level of coastal areas,reflecting the supporting capacity of the ecological environment for human activities and the impact of human activities on the regional environment.This paper establishes an evaluation index system to determine the evaluation value of the carrying capacity of marine and land resources in China’s coastal areas,the evaluation index of marine and land resources supply capacity(economic and social development demand)subsystem,and the degree of coordinated development of the subsystems in 11 coastal areas from 2006 to 2017.The results showed that the average supply and demand capacity of the two subsystems in each region is not high;the average demand level of economic and social development is higher than the supply capacity of marine and land resources;the carrying capacity of marine and land resources is slightly overloaded in most areas;the collaborative development between the supply and demand subsystems is barely coordinated with moderate imbalance;most regions need to move in the direction of green development to ensure the supply capacity of marine and land resources.

Research on Resources and Environmental Carrying Capacity

This paper, in the context of resources and environmental carrying capaci-ty, systematic reviewed resources and environmental carrying capacity in monitoring, evaluation and early warning, and then putted forward the development direction for promoting the sustainable development of China’s social and economic environment.

Quantitative evaluation of Tibet’s resource and environmental carrying capacity

This study identifies the carrying state and value of Tibet’s resource and environmental carrying capacity.A new theoretical framework is proposed for exploring the resource and environmental carrying capacity based on two perspectives of“growth limit”and“stability of Human-Earth relationship system”.On this basis,an ideal growth model that accords with the“short board”effect is established to predict the population limitation.Analytical results show that the holistic state of resource and environmental carrying capacity in Tibet is in jeopardy.From 2010 to 2016,Tibet’s carrying state continued to decline,moreover,the negative forces still overwhelm the positive forces.Although the resource reserves still have room for more population,the environmental capacity and ecological capacity have been overloaded.Meanwhile,the Human-Earth relationship system is in an unstable stage.Three scenarios that respond to different socioeconomic developments are implemented to predict the population limitation of resource and environmental carrying capacity in Tibet;thus,authors argue that Tibet should keep its population size within 4 million around 2025.This research will provide reference for sustainable development and resources and environmental conservation in Tibet.

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.

Geological resources and environmental carrying capacity evaluation review,theory, and practice in China

Evaluations of resources and environmental carrying capacities (GRECC)are the premise of land space planning and use control.Resource allocations and environmental capacity are the basic conditions that restrict development in a region.In this paper,based on a systematic review of China's geological environment,groundwater resources,mineral resources,other geological resources and the environmental carrying capacity research status,the relationship between the natural resource environmental system and the socio-economic system is studied.Then a "coordination theory of resources and environmental carrying"is proposed.Next,on the basis of an evaluation experiment performed at different scales and for different types of regions,the technical methods for an evaluation of the geological resources and environmental carrying capacity at the regional (inter-provincial)and provincial scales in China are established for the first time.This paper presents a standardized method based on technical ideas, evaluation methods,and index systems for geological resource and environmental carrying capacity evaluation.Finally,an evaluation of the groundwater resource carrying capacity in China is used as an example for the demonstration of the groundwater resource background and use of state evaluation methods.

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.

Carrying capacity of water environment in public tourism resources based on matter-element model

When water environmental carrying capacity of public resource tourist attraction is studied, the two action subjects of tourists and local residents should be discussed, and comprehensive consideration must be given to the influence of these two on water environment. On the basis of water resource carrying capacity and water quality carrying capacity, water environmental carrying capacity index of public resource tourist attraction was constructed, the model for the water environmental carrying capacity of public resource tourist attraction was established on the basis of matter-element model and analytical hierarchy process. By applying this method, water environmental carrying capacity situation of a certain public resource tourist attraction can be gained, moreover, situations about several aspects of water environmental carrying capacity can be evaluated.

Safety Evaluation of Water Environment Carrying Capacity of Five Cities in Ningxia Based on Ecological Footprint of Water Resources

[Objectives]To make safety evaluation of water environment carrying capacity of five cities in Ningxia based on ecological footprint of water resources.[Methods]With the help of the grey relational model,15 indicators were selected from the natural,economic,and social aspects,and the most influential factors in the three fields were selected.Based on the concept of ecological priority,the water resources carrying capacity of the five cities in Ningxia from 2010 to 2019 was calculated with the help of the water resources ecological footprint model.Then,the indicators of the water resources ecological footprint model were coupled with the existing indicators to establish a comprehensive evaluation indicator system.Finally,the changes of the water environment carrying capacity of the five cities in Ningxia were analyzed with the help of the principal component analysis(PCA).[Results]The ecological pressure of water resources and the ecological deficit of water resources in the five cities were relatively large.Specifically,Yinchuan City had the most obvious deficit of water resources but good carrying capacity;Zhongwei City had a large ecological deficit of water resources,poor carrying capacity,and the largest ecological pressure index of water resources;Guyuan City had low water resources ecological deficit,water resources ecological carrying capacity and water resources ecological pressure index.[Conclusions]Through the analysis of the coupling indicator system,it can be seen that the water environment carrying capacity of the five cities is in an upward trend,indicating that the water environment in each region tends to become better.

Analysis of the Concept of Environmental Carrying Capacity

From the concept of carrying capacity proposed in the early 20th century to as an important tool for describing development constraints in the 21st century,many scholars have conducted extensive and detailed research on carrying capacity at different levels,but the carrying capacity system has not yet formed a unified theoretical and methodological system.By summarizing and analyzing the existing literature,based on the viewpoints of Mr.Gao Jixi and Mr.Zeng Weihua,the relationship between different mainstream carrying capacities is analyzed,and finally a system for summarizing the elements of different carrying capacities is provided,which to some extent serves as a reference for scholars who have just come into contact with the concept of carrying capacity.It is thought that:①the research on ecological carrying capacity covers the scope of cities,and the research at the urban level complements the neglected and insufficient areas of ecological research.②The main difference among ecological carrying capacity,urban comprehensive carrying capacity and resource environment carrying capacity lies in the different research scopes.In the mainstream view,environmental carrying capacity and resource carrying capacity are summarized under the framework of different research scopes.Water environment carrying capacity,land resource carrying capacity and other single factor carrying capacity are special in-depth studies of environment and resource carrying capacity.③Ecological carrying capacity at the ecological level includes environmental carrying capacity and resource carrying capacity.At the urban level,urban ecology is equivalent to urban environment to a certain extent,and resources can be classified into urban environmental carrying capacity as an environmental element.

Assessment of Geological Security and Integrated Assessment Geo-environmental Suitability in Worst-hit Areas in Wenchuan Quake

The Wenchuan earthquake in 2008 and geo-hazards triggered by the earthquake caused large injuries and deaths as well as destructive damage for infrastructures like construction, traffic and electricity. It is urgent to select relatively secure areas for townships and cities constructed in high mountainous regions with high magnitude earthquakes. This paper presents the basic thoughts, evaluation indices and evaluation methods of geological security evaluation, water and land resources security demonstration and integrated assessments of geo-environmental suitability for reconstruction in alp and ravine with high magnitude earthquakes, which are applied in the worst-hit areas （12 counties）. The integrated assessment shows that： （1） located in the Longmenshan fault zone, the evaluated area is of poor regional crust stability, in which the unstable and second unstable areas account for 79% of the total; （2） the geo-hazards susceptibility is high in the evaluation area. The spots of geo-hazards triggered by earthquake are mainly distributed along the active fault zone with higher distribution in the moderate and high mountains area, in which the areas of high and moderate susceptibility zoning accounts for 40.1% of the total; （3） geological security is poor in the evaluated area, in which the area of the unsuitable construction occupies 73.1%, whereas in the suitable construction area, the areas of geological security, second security and insecurity zoning account for 8.3 %, 9.3% and 9.3 % of the evaluated area respectively; （4） geo-environmentai suitability is poor in the evaluated area, in which the areas of suitability and basic suitability zoning account for 3.5% and 7.3% of the whole evaluation area.

The theory and method research on the double evaluation of land and space:A survey

By reviewing the theories and methods of resource and environmental carrying capacity evaluation and suitability evaluation of land and space development,it provides theoretical and technical support for rational layout and optimization of land and space development pattern.From the aspects of resource carrying capacity,environmental carrying capacity,the importance of ecological protection,the suitability of agricultural production,and the suitability of urban construction,we sort out domestic and foreign documents.The evaluation of resource carrying capacity has changed from single-factor evaluation to multi-factor comprehensive evaluation.At present,the optimization of land use pattern based on the“three-generation”space is still under exploration,it is not enough to systematize and summarize the thought of optimizing the spatial pattern of the national territory.The theoretical framework,model,method and index of“dual evaluation”of territorial space need to be improved continuously,it also needs the scientific analysis and cognition from the natural direction to the human location direction and the spatial equilibrium state as the new driving force.

Comprehensive evaluation of regional resources and environmental carrying capacity using a PS-DR-DP theoretical model

The concepts of regional resources and environmental carrying capacity are important aspects of both academic inquiry and government policy. Although notable results have been achieved in terms of evaluating both these variables, most researchers have utilized a traditional analytical method that incorporates the "pressure-state-response" model. A new approach is proposed in this study for the comprehensive evaluation of regional resources and environmental carrying capacity; applying a "pressure-support", "destructiveness-resilience", and "degradation-promotion"("PS-DR-DP") hexagon interaction theoretical model, we divided carrying capacity into these three pairs of interactive forces which correspond with resource supporting ability, environmental capacity, and risk-disaster resisting ability, respectively. Negative carrying capacity load in this context was defined to include pressure, destructiveness, and degradation, while support, resilience, and promotion comprised positive attributes. The status of regional carrying capacity was then determined via the ratio between positive and negative contribution values, expressed in terms of changes in both hexagonal shape and area that result from interactive forces. In order to test our "PS-DR-DP" theory-based model, we carried out a further empirical study on Beijing over the period between 2010 and 2015. Analytical results also revealed that the city is now close to attaining a perfect state for both resources and environmental carrying capacity; the latter state in Beijing increased from 1.0143 to 1.1411 between 2010 and 2015, an improved carrying capacity despite the fact that population increased by two million. The average contribution value also reached 0.7025 in 2015, indicating that the city approached an optimal loading threshold at this time but still had space for additional carrying capacity. The findings of our analysis provide theoretical support to enable the city of Beijing to control population levels below 23 million by 2020.

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.

The Progress of Resources and Environment Carrying Capacity: from Single-factor Carrying Capacity Research to Comprehensive Research

As a concept to describe development restrictions,resources and environment carrying capacity（RECC）research has developed over more than 100 years since it was first proposed at the beginning of the 20th century.It is now regarded as a significant factor in evaluating the level of cooperation between regional population,resources,and environment;and it is currently used as an effective and operational tool to guide regional sustainable development.This article first reviews the origin of RECC and its early headway.It then reviews the historical development of RECC from single factors,such as land resources carrying capacity,water resources carrying capacity and environmental carrying capacity（environmental capacity）,to more comprehensive research,such as comprehensive evaluation,emergy analysis,and ecological footprint analysis.In general,it appears that comprehensive research will become increasingly important in RECC research.However,there are several deficiencies in the current state of comprehensive research.Firstly,comprehensive RECC research lacks a common measurement standard,though some scholars have attempted to create one.Secondly,the RECC evaluation of open systems and dynamic studies should be strengthened.Thirdly,more attention should be paid to standardization,digitalization,and systematization to promote the applicability of RECC research to national practical demands.

Land development suitability analysis for transport planning evaluation and optimization in mountainous ecological region

Transportation planning is a critical component for creating an orderly,intensive,and sustainable pattern of land development.By comprehensively considering the potential and suitability of transport construction,a comprehensive method combining resources and environmental carrying capacity(RECC)and land development suitability(LDS)was developed by using techniques of GIS,analytic hierarchy process(AHP)and threedimensional magic cube.Taking Aba prefecture in Sichuan Province of Southwest China as a case study,LDS for transportation was analyzed from three aspects,including overall planning layout,different transport modes,and transportation projects.The results showed that the transport planning scales of most counties in Aba were suitable,and the order of LDS of different transport modes was railway>highway=superhighway>tourism track,which already included 42 new transportation projects.We found that two counties(Maoxian County and Jiuzhaigou County)should improve the ecological protection level of transportation,in which the railway network construction should be encouraged,and some transportation projects with low LDS should be postponed or constructed harmlessly.We suggest the combination of RECC and LDS for transportation could enhance the territorial space optimization and sustainable transport construction.

黑土地保护视角下黑龙江省畜禽养殖环境效应分析

为合理利用畜禽粪污资源,保护黑龙江省黑土地资源,优化农畜业生产布局,实现农牧业绿色发展,本研究基于2011—2020年统计数据及文献资料,测算了黑龙江省畜禽粪污排放情况,并据此分析黑龙江省畜禽粪污资源化利用潜力及畜禽养殖环境承载力。结果表明:从时间动态来看,2011—2020年,黑龙江省畜禽粪尿、粪尿养分、COD排放量均有小幅下降,降幅分别为3.68%、3.24%和5.82%;畜禽粪污的化肥替代潜力虽整体略有下降,但10年来均保持在35%以上,2020年化肥替代潜力已达到41.89%,具有较高的有机肥替代化肥潜力;黑龙江省畜禽粪污的能源潜力略有增长,但对煤炭的替代潜力呈下降趋势且替代作用并不显著,2020年畜禽粪污的沼气潜力为46.74亿m^(3),折合为标准煤仅占标准煤消费量的2.90%,能源潜力有待进一步开发利用;黑龙江省畜禽粪尿、粪尿氮、粪尿磷的耕地负荷均未超载,无养殖环境风险,畜禽养殖环境容量的空间剩余呈上升趋势,剩余约2/3,以氮为基准计算,余量为13006.13万头猪当量,以磷为基准计算,余量为8463.19万头猪当量,具有较大养殖潜力。从空间分布来看,黑龙江省各地区畜禽粪污排放及资源化利用潜力存在明显差异,哈尔滨市、齐齐哈尔市、绥化市、大庆市以及佳木斯市等畜禽养殖集聚区的畜禽粪尿资源丰富,畜禽粪污的替代化肥潜力、能源潜力及畜禽养殖发展潜力较大。

流域国土空间水资源承载力评价及保护方法研究

量化测度水资源承载力并制定相应的水资源保护措施,对于区域国土空间可持续发展极为重要。运用DPSIR框架,评价了梁子湖流域的水资源承载力,并对评价结果进行空间落位。基于评价结果,使用FLUS模型模拟未来发展趋势,划定了区域国土空间功能优势区,并综合评价模拟结果,确定了梁子湖流域的水环境保护格局。从量化测度和情景模拟两个方面构建了一套切实可行的流域国土空间水资源保护规划技术路径,可为区域水资源保护目标导向下国土空间规划与生态保护提供参考。