It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, ...It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4～16 cm by the year 2030 with the optimum estimated value of 6～14cm. It will be 9～26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47～65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ～24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%～2. 0% in the Huanghe River Delta.展开更多
A new method is proposed for calculating the aircraft equivalent single vulnerable area using Monte-Carlo simulation technique. The method simulates the kill events of single vulnerable components and multiply vulnera...A new method is proposed for calculating the aircraft equivalent single vulnerable area using Monte-Carlo simulation technique. The method simulates the kill events of single vulnerable components and multiply vulnerable components or redundant components to ＇Model of Filling Boxes with Balls＇, in which the area of each box is equal to the component＇s vulnerable area. By randomly and uniformly sampling the threat hit locations, the expected number of hits required to kill an aircraft can be given and the aircraft equivalent singly vulnerable area can be attained. Examples demonstrate the correctness and feasibility of the proposed method. Analysis show that the developed method overcomes two shortcomings of currently used methods. （1） It can calculate the equivalent single vulnerable area of aircraft with several sets of multiply vulnerable components, and （2） When the components of each multiple set have different vulnerable areas, the method also applies.展开更多
Drawing the ecological protection red line is to maintain the integrity and benign operation of the ecosystem within the area,and to ensure that the ecological environment is within the boundary of controllable ecolog...Drawing the ecological protection red line is to maintain the integrity and benign operation of the ecosystem within the area,and to ensure that the ecological environment is within the boundary of controllable ecological security.Taking the ecologically vulnerable areas in western China as the research object and using the game theory and literature analysis,this paper studied the game behavior of ecological protection red line in these areas.In addition,this paper also analyzed the stakeholders such as government,enterprises and the masses in the drawing of the ecological protection red line,and comprehensively analyzed the game strategies between the government and the masses,the government and enterprises,and the central and local governments and enterprises.On the basis of the analysis,it came up with a safeguard mechanism for the coordination of the interests of the ecological protection red line.展开更多
Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of hab...Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of habitat quality. This study investigates habitat quality research in ecologically vulnerable regions of China, drawing data from Web of Science and Scopus. Using CiteSpace software analyzes trends in publication volume, geographic distribution, journal outlets, research disciplines, and keyword co-occurrence. The findings identify two distinct research phases: an initial exploratory stage and a period of steady growth, with the Loess Plateau emerging as a primary focal region. Key journals, such as Ecological Indicators and Acta Ecologica Sinica, dominate the field, reflecting contributions from disciplines including environmental science and ecology. Research hotspots center on trade-offs between habitat quality and ecosystem services, driving factors of change, landscape pattern optimization, and simulation techniques. Future research should prioritize addressing the spatial heterogeneity of vulnerable regions, advancing methodological approaches, and enhancing uncertainty analyses in model parameterization. This study provides a critical foundation for addressing key scientific challenges and guiding future research, with implications for ecological security and sustainable development.展开更多
Aircraft single-hit vulnerability/survivability is usually expressed as the probability of kill or the vulnerable area in case of being given a random threat （e.g. a fragment） hit on the aircraft. In this paper, int...Aircraft single-hit vulnerability/survivability is usually expressed as the probability of kill or the vulnerable area in case of being given a random threat （e.g. a fragment） hit on the aircraft. In this paper, introducing the ＂equivalent target method＂ in lethality field into the aircraft vulnerability assessment, a generic vulnerability calculation model is proposed. In order for a good representation of reality, the model considers the threat change of state-of-motion during the threat penetrating into the components successively. Application shows that the proposed generic model has solved the Pk/h （probability of kill given by a hit on the component） calculation problem in aircraft vulnerability assessment, and is easier to be computerized than other commonly used models.展开更多
This article, firstly, categorizes aircraft＇s presented area in a particular hit aspect into non-vulnerable region, non-overlapping vulnerable region and overlapping vulnerable region. Then, the aircraft＇s unique ex...This article, firstly, categorizes aircraft＇s presented area in a particular hit aspect into non-vulnerable region, non-overlapping vulnerable region and overlapping vulnerable region. Then, the aircraft＇s unique existing states are divided into kill states, intermediate states and no kill states. The parameters pertinent to aircraft＇s existing states in the above-mentioned regions are analyzed by using the shot line scanning method. Finally, the method provides two kinds of shot line geometric descriptive data： （1） component＇s vulnerable area and presented area in each region, which can be used to calculate the component＇s single-hit vulnerability and （2） aircraft＇s unique existing states and the areas corresponding to each state, which can be used to calculate the aircraft＇s single-hit and multi-hit vulnerability. Examples show that the proposed method can provide the parameters of the aircraft＇s or its component＇s area under threat being hit through tracing the shot line path thereby enabling the vulnerability calculated results to conform with reality to larger extent. In addition, the method solves the generality problem in dealing with overlapping components.展开更多
We built a classification tree （CT） model to estimate climatic factors controlling the cold temperate coniferous forest （CTCF） distributions in Yunnan province and to predict its potential habitats under the curre...We built a classification tree （CT） model to estimate climatic factors controlling the cold temperate coniferous forest （CTCF） distributions in Yunnan province and to predict its potential habitats under the current and future climates, using seven climate change scenarios, projected over the years of 2070-2099. The accurate CT model on CTCFs showed that minimum temperature of coldest month （TMW） was the overwhelmingly potent factor among the six climate variables. The areas of TMW〈-4.05 were suitable habitats of CTCF, and the areas of -1.35 〈 TMW were non-habitats, where temperate conifer and broad-leaved mixed forests （TCBLFs） were distribute in lower elevation, bordering on the CTCF. Dominant species of Abies, Picea, and Larix in the CTCFs, are more tolerant to winter coldness than Tsuga and broad-leaved trees including deciduous broad-leaved Acer and Betula, evergreen broad- leaved Cyclobalanopsis and Lithocarpus in TCBLFs. Winter coldness may actually limit the cool-side distributions of TCBLFs in the areas between -1.35℃ and -4.05℃, and the warm-side distributions of CTCFs may be controlled by competition to the species of TCBLFs. Under future climate scenarios, the vulnerable area, where current potential （suitable ＋ marginal） habitats （80,749 km^2） shift to non-habitats, was predicted to decrease to 55.91% （45,053 km^2） of the current area. Inferring from the current vegetation distribution pattern, TCBLFs will replace declining CTCFs. Vulnerable areas predicted by models are important in determining priority of ecosystem conservation.展开更多
The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,t...The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,to evaluate the effects of voltage sag caused by short circuits,it is necessary to determine the areas of vulnerability(AOVs).In this paper,a new method is proposed for the AOV determination that is applicable to large-scale networks.The false position method(FPM)is proposed for the precise calculation of the critical points of the system lines.Furthermore,a new method is proposed for the voltage sag monitor(VSM)placement to detect the fault locations.A systematic placement scheme is used to provide the highest fault location detection(FLD)index at buses and lines for various short-circuit fault types.To assess the efficiency of the proposed methods for AOV determination and VSM placement,simulations are conducted in IEEE standard systems.The results demonstrate the accuracy of the proposed method for AOV determination.In addition,through VSM placement,the fault locations at buses and lines are detected.展开更多
Vulnerability assessment is essential for understanding and launching effective flood risk reduction strategies.This study aimed to examine the vulnerability of flood-prone rural communities in southern Punjab,Pakista...Vulnerability assessment is essential for understanding and launching effective flood risk reduction strategies.This study aimed to examine the vulnerability of flood-prone rural communities in southern Punjab,Pakistan to external shocks.The concept of vulnerability encompasses a range of dimensions,including physical,social,institutional,environmental,economic,and attitudinal.Using a composite index method,indices were developed for each dimension and combined to create a multidimensional measure of vulnerability.A sample of 365 communities was selected using the Yamane sampling technique,and data were collected through a questionnaire containing 65 indicators across all dimensions.Descriptive statistics and ANOVA tests were used to analyze the data.The results show that communities near the Chenab River had higher attitudinal and institutional vulnerability compared to other communities.High attitudinal vulnerabilities were as sociated with poorly perceived flood risks and low preparedness measures,whereas institutional vulnerabilities were driven by conventional flood protection strategies,lack of institutional trust,and lack of flood risk awareness.This research provides insights into the various components of vulnerability in flood-prone rural communities in Pakistan and demonstrates a useful methodology that can be applied to other disasters at different spatial scales.展开更多
The application of de-icing salts to improve winter road safety,although necessary in cold climates,may adversely affect groundwater resources and degrade aquatic life in urban streams,if over-prescribed,and cause an ...The application of de-icing salts to improve winter road safety,although necessary in cold climates,may adversely affect groundwater resources and degrade aquatic life in urban streams,if over-prescribed,and cause an increase in crash rates,if under-prescribed.The main objective of this research is to develop algorithms for precision salt application rate(SAR)using advanced machine learning methods to achieve the desired road safety with less adverse environmental effects.This study highlights the importance of accurate realtime monitoring of pavement surface temperature and meteorological variables(i.e.,storm duration,hourly precipitation rate,and air temperature)as key factors in prescribing salt application rates during winter storm events.A new SAR model was trained/tested using a decade of historic salt application rates from a range of winter storm events on three different road classes.The application of this model can help road authorities to achieve greater road safety and reduce adverse environmental impacts,especially in the identified and mapped salt vulnerable areas.展开更多
文摘It can be seen from the calculation that the vulnerable area along China's coast in which the elevation is less than 5 m, is 143 900 km2, accounting for about 11. 3% of the total area of the 11 coastal provinces, municipalities and autonomous regions. These areas are threatened to varying extent by sea level rise. According to prediction, the relative sea level rise (including global sea level rise caused by climate change and local relative as level rise caused by vertical crust movement and ground subsidence) along China's coast will be 4～16 cm by the year 2030 with the optimum estimated value of 6～14cm. It will be 9～26 cm by the year 2050 with the optimum estimated value of 12-23 cm. And it will be 31-74 cm by the year 2100 with the optimum estimated value of 47～65 cm. The calcuation result shows that the percentage of the cost for up-grading (heightening and consolidating) sea dykes/walls in adaptation strategy in the losses of submerged areas varies from area to area: 6. 9% in the Zhujiang (Pearl) River Deta, 1. 3% ～24. 6% in the Changjiang (Yangtze) River Delta, and 0. 9%～2. 0% in the Huanghe River Delta.
基金National Natural Science Foundation of China (10372082) Aeronautical Science Foundation of China(02B53008) and Doctorate Foun-dation of Northwestern Polytechnical University(CX200301)
文摘A new method is proposed for calculating the aircraft equivalent single vulnerable area using Monte-Carlo simulation technique. The method simulates the kill events of single vulnerable components and multiply vulnerable components or redundant components to ＇Model of Filling Boxes with Balls＇, in which the area of each box is equal to the component＇s vulnerable area. By randomly and uniformly sampling the threat hit locations, the expected number of hits required to kill an aircraft can be given and the aircraft equivalent singly vulnerable area can be attained. Examples demonstrate the correctness and feasibility of the proposed method. Analysis show that the developed method overcomes two shortcomings of currently used methods. （1） It can calculate the equivalent single vulnerable area of aircraft with several sets of multiply vulnerable components, and （2） When the components of each multiple set have different vulnerable areas, the method also applies.
基金Sponsored by Social Science Foundation Project of Hunan Province(16YBX008)Major Program of Hunan Provincial Social Science Evaluation Committee(XSP18YBC143)
文摘Drawing the ecological protection red line is to maintain the integrity and benign operation of the ecosystem within the area,and to ensure that the ecological environment is within the boundary of controllable ecological security.Taking the ecologically vulnerable areas in western China as the research object and using the game theory and literature analysis,this paper studied the game behavior of ecological protection red line in these areas.In addition,this paper also analyzed the stakeholders such as government,enterprises and the masses in the drawing of the ecological protection red line,and comprehensively analyzed the game strategies between the government and the masses,the government and enterprises,and the central and local governments and enterprises.On the basis of the analysis,it came up with a safeguard mechanism for the coordination of the interests of the ecological protection red line.
文摘Research on habitat quality in ecologically vulnerable areas has gained attention due to mountain urbanization and climate change. However, the absence of comprehensive reviews limits a systematic understanding of habitat quality. This study investigates habitat quality research in ecologically vulnerable regions of China, drawing data from Web of Science and Scopus. Using CiteSpace software analyzes trends in publication volume, geographic distribution, journal outlets, research disciplines, and keyword co-occurrence. The findings identify two distinct research phases: an initial exploratory stage and a period of steady growth, with the Loess Plateau emerging as a primary focal region. Key journals, such as Ecological Indicators and Acta Ecologica Sinica, dominate the field, reflecting contributions from disciplines including environmental science and ecology. Research hotspots center on trade-offs between habitat quality and ecosystem services, driving factors of change, landscape pattern optimization, and simulation techniques. Future research should prioritize addressing the spatial heterogeneity of vulnerable regions, advancing methodological approaches, and enhancing uncertainty analyses in model parameterization. This study provides a critical foundation for addressing key scientific challenges and guiding future research, with implications for ecological security and sustainable development.
基金National Natural Science Foundation of China (10372082) Aeronautical Science Foundation of China (02B53008) and Doctorate Foundation of Northwestern Polytechnical University (CX200301)
文摘Aircraft single-hit vulnerability/survivability is usually expressed as the probability of kill or the vulnerable area in case of being given a random threat （e.g. a fragment） hit on the aircraft. In this paper, introducing the ＂equivalent target method＂ in lethality field into the aircraft vulnerability assessment, a generic vulnerability calculation model is proposed. In order for a good representation of reality, the model considers the threat change of state-of-motion during the threat penetrating into the components successively. Application shows that the proposed generic model has solved the Pk/h （probability of kill given by a hit on the component） calculation problem in aircraft vulnerability assessment, and is easier to be computerized than other commonly used models.
基金Foundation items： Ph.D. Programs Foundation of Ministry of Education of China （200806991002） Natural Science Foundation of Shaanxi Province （SJ08A 11）+1 种基金 NPU Foundation for Fundamental Research （NPU-FFR JC200804） NPU Young Teacher Foundation （W016208）
文摘This article, firstly, categorizes aircraft＇s presented area in a particular hit aspect into non-vulnerable region, non-overlapping vulnerable region and overlapping vulnerable region. Then, the aircraft＇s unique existing states are divided into kill states, intermediate states and no kill states. The parameters pertinent to aircraft＇s existing states in the above-mentioned regions are analyzed by using the shot line scanning method. Finally, the method provides two kinds of shot line geometric descriptive data： （1） component＇s vulnerable area and presented area in each region, which can be used to calculate the component＇s single-hit vulnerability and （2） aircraft＇s unique existing states and the areas corresponding to each state, which can be used to calculate the aircraft＇s single-hit and multi-hit vulnerability. Examples show that the proposed method can provide the parameters of the aircraft＇s or its component＇s area under threat being hit through tracing the shot line path thereby enabling the vulnerability calculated results to conform with reality to larger extent. In addition, the method solves the generality problem in dealing with overlapping components.
基金supported by the Environment Research and Technology Development Fund (S-14) of the Ministry of the EnvironmentJapan and JSPS KAKENHI Grant Numbers 15H02833
文摘We built a classification tree （CT） model to estimate climatic factors controlling the cold temperate coniferous forest （CTCF） distributions in Yunnan province and to predict its potential habitats under the current and future climates, using seven climate change scenarios, projected over the years of 2070-2099. The accurate CT model on CTCFs showed that minimum temperature of coldest month （TMW） was the overwhelmingly potent factor among the six climate variables. The areas of TMW〈-4.05 were suitable habitats of CTCF, and the areas of -1.35 〈 TMW were non-habitats, where temperate conifer and broad-leaved mixed forests （TCBLFs） were distribute in lower elevation, bordering on the CTCF. Dominant species of Abies, Picea, and Larix in the CTCFs, are more tolerant to winter coldness than Tsuga and broad-leaved trees including deciduous broad-leaved Acer and Betula, evergreen broad- leaved Cyclobalanopsis and Lithocarpus in TCBLFs. Winter coldness may actually limit the cool-side distributions of TCBLFs in the areas between -1.35℃ and -4.05℃, and the warm-side distributions of CTCFs may be controlled by competition to the species of TCBLFs. Under future climate scenarios, the vulnerable area, where current potential （suitable ＋ marginal） habitats （80,749 km^2） shift to non-habitats, was predicted to decrease to 55.91% （45,053 km^2） of the current area. Inferring from the current vegetation distribution pattern, TCBLFs will replace declining CTCFs. Vulnerable areas predicted by models are important in determining priority of ecosystem conservation.
文摘The increase in the number of sensitive loads in power systems has made power quality,particularly voltage sag,a prominent problem due to its effects on consumers from both the utility and customer perspectives.Thus,to evaluate the effects of voltage sag caused by short circuits,it is necessary to determine the areas of vulnerability(AOVs).In this paper,a new method is proposed for the AOV determination that is applicable to large-scale networks.The false position method(FPM)is proposed for the precise calculation of the critical points of the system lines.Furthermore,a new method is proposed for the voltage sag monitor(VSM)placement to detect the fault locations.A systematic placement scheme is used to provide the highest fault location detection(FLD)index at buses and lines for various short-circuit fault types.To assess the efficiency of the proposed methods for AOV determination and VSM placement,simulations are conducted in IEEE standard systems.The results demonstrate the accuracy of the proposed method for AOV determination.In addition,through VSM placement,the fault locations at buses and lines are detected.
文摘Vulnerability assessment is essential for understanding and launching effective flood risk reduction strategies.This study aimed to examine the vulnerability of flood-prone rural communities in southern Punjab,Pakistan to external shocks.The concept of vulnerability encompasses a range of dimensions,including physical,social,institutional,environmental,economic,and attitudinal.Using a composite index method,indices were developed for each dimension and combined to create a multidimensional measure of vulnerability.A sample of 365 communities was selected using the Yamane sampling technique,and data were collected through a questionnaire containing 65 indicators across all dimensions.Descriptive statistics and ANOVA tests were used to analyze the data.The results show that communities near the Chenab River had higher attitudinal and institutional vulnerability compared to other communities.High attitudinal vulnerabilities were as sociated with poorly perceived flood risks and low preparedness measures,whereas institutional vulnerabilities were driven by conventional flood protection strategies,lack of institutional trust,and lack of flood risk awareness.This research provides insights into the various components of vulnerability in flood-prone rural communities in Pakistan and demonstrates a useful methodology that can be applied to other disasters at different spatial scales.
基金funded by the Ministry of Transportation of Ontario,and the Natural Sciences and Engineering Research Council of Canada,alliance grant#401643。
文摘The application of de-icing salts to improve winter road safety,although necessary in cold climates,may adversely affect groundwater resources and degrade aquatic life in urban streams,if over-prescribed,and cause an increase in crash rates,if under-prescribed.The main objective of this research is to develop algorithms for precision salt application rate(SAR)using advanced machine learning methods to achieve the desired road safety with less adverse environmental effects.This study highlights the importance of accurate realtime monitoring of pavement surface temperature and meteorological variables(i.e.,storm duration,hourly precipitation rate,and air temperature)as key factors in prescribing salt application rates during winter storm events.A new SAR model was trained/tested using a decade of historic salt application rates from a range of winter storm events on three different road classes.The application of this model can help road authorities to achieve greater road safety and reduce adverse environmental impacts,especially in the identified and mapped salt vulnerable areas.
