This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological L...This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.展开更多
A small scale red soil resources information system (RSRIS) with applied mathematical models wasdeveloped and applied in red soil resources (RSR) classification and evaluation, taking Zhejiang Province,a typical distr...A small scale red soil resources information system (RSRIS) with applied mathematical models wasdeveloped and applied in red soil resources (RSR) classification and evaluation, taking Zhejiang Province,a typical distribution area of red soil, as the study area. Computer-aided overlay was conducted to classifyRSR types. The evaluation was carried out by using three methods, i.e., index summation, square root ofindex multiplication and fuzzy comprehensive assessment, with almost identical results. The result of indexsummation could represent the basic qualitative condition of RSR, that of square root of index multiplicationreflected the real condition of RSR qualitative rank, while fuzzy comprehensive assessment could satisfactorilyhandle the relationship between the evaluation factors and the qualitative rank of RSR, and therefore it is afeasible method for RSR evaluation.展开更多
Soil organic carbon is of great importance to terrestrial ecosystems. Studies on the amount and spatial distribution of soil organic carbon stock in various types of soil can help to better understand the role of soil...Soil organic carbon is of great importance to terrestrial ecosystems. Studies on the amount and spatial distribution of soil organic carbon stock in various types of soil can help to better understand the role of soil in the global carbon cycle and provide a scientific basis for the assessment of the magnitude of carbon stored in a given area. Here we present estimates of soil organic carbon stock in soils in the upper reaches of the Yangtze River based on soil types as defined by Chinese Soil Taxonomy and recently compiled into a digital soil database. The results showed that the total soil organic carbon stock of the upper Yangtze River to a depth of 100 cm was 1.452x1013 kg. The highest soil organic carbon stock was found in felty soils (2.419x10TM kg), followed by dark brown soils (1.269x10=kg), and dark feltysoils (L139x10=kg). Chernozems and irrigation silting soils showed the lowest soil organic carbon stock, mainly due to the small total area of such soils. The soil organic carbon density of these major soil types ranged from 5.6 to 26.1 kg m2- The average soil organic carbon density of the upper reaches of the Yangtze River was 16.4 kg m-2, which was higher than that of the national average. Soil organic carbon density indicated a distinct decreasing trend from west to east, which corresponds to the pattern of increasing temperature from cold to subtropical.展开更多
The Qinghai-Tibet Plateau is the word's highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, w...The Qinghai-Tibet Plateau is the word's highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling (ENM) for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method (Maxent), an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve (AUC) values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen's kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables: mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.展开更多
This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics i...This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5 mu m or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER's urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.展开更多
Based on previous evaluating methods, a new method which combines GIS with Fussy Clustering algorithm is proposed and applied in evaluating the engineering geological environment of the research area of XuZHou City in...Based on previous evaluating methods, a new method which combines GIS with Fussy Clustering algorithm is proposed and applied in evaluating the engineering geological environment of the research area of XuZHou City in this paper. By analyzing the characteristics and formation of engineering geological environment,the major problems are discussed, including stability of basement rock, sandy soil liquefaction and cultural stratum.According to effecting factors of these problems, the stability of every engineering geological problem in the worked area is classified into different classes. Then, the Fussy Clustering method is used in assessing all conditions of engineering geological environment. Finally, the evaluation is fulfilled in the whole studied area. The calculating result shows the method is feasible.展开更多
Migratory birds are known to use a number of different orientation cues to determine and maintain the direction of their movements. They are able to use at least three different sources of compass information, includi...Migratory birds are known to use a number of different orientation cues to determine and maintain the direction of their movements. They are able to use at least three different sources of compass information, including solar, stellar and geomagnetic cues. However, little is known about how these cues are calibrated into uniform reference direction information, while the hierarchy of these cues remains controversial. In recent studies, researchers suggest that avian migrants calibrate their geomagnetic compass on sunset cues, whereas others fail to find such patterns and insist on the prevalence of the magnetic compass. We carefully reviewed the existing literature and suggest that the conflicting results reported by different authors are due to genuine variation among species and propose hypotheses to explain this variation.展开更多
In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a ...In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990.展开更多
This paper demonstrates a Geographic Information Systems (GIS) procedure of classifying and mapping forest management category in Baihe Forestry Burea, Jilin Province, China. Within the study area, Baihe Forestry Bu...This paper demonstrates a Geographic Information Systems (GIS) procedure of classifying and mapping forest management category in Baihe Forestry Burea, Jilin Province, China. Within the study area, Baihe Forestry Bureau land was classified into a two-hierarchy system. The top-level class included the non-forest and forest. Over 96% of land area is forest in the study area, which was further divided into key ecological service forest (KES), general ecological service forest (GES), and commodity forest (COM). COM covered 45.0% of the total land area and was the major forest management type in Baihe Forest Bureau. KES and GES accounted for 21.2% and 29.9% of the total land area, respectively. The forest management zones designed with GIS in this study were then compared with the forest management zones established using the hand draw by the local agency. There were obvious differences between the two products. It suggested that the differences had some to do with the data sources, basic unit and mapping procedures. It also suggested that the GIS method was a useful tool in integrating forest inventory data and other data for classifying and mapping forest zones to meet the needs of the classified forest management system.展开更多
The study identified spatial variations in flood vulnerability levels in Port Harcourt metropolis with the use of GIS (geographic information systems). This study considered four factors and these included landuse t...The study identified spatial variations in flood vulnerability levels in Port Harcourt metropolis with the use of GIS (geographic information systems). This study considered four factors and these included landuse types, drainage, residential densities and elevation. The elevation data and drainage data were derived from the topographical map of scale 1:35,000, while the land use types were derived from the imagery of Port Harcourt metropolis downloaded from Google Earth, 2010 version. Both the topographical map and imagery were geo-referenced to geographic coordinates and geographic features were digitized in form of shapefiles using both ArcView GIS 3.3 and ArcGIS 9.2 versions. AHP (analytical hierarchical process) was adopted in this study whereby many flood factors were ranked and overlaid for decision making. The contour data was used to generate the DEM (digital elevation model) through the process called kriging in ArcGIS 9.2. Based on the ranking index, factors considered were reclassified to three levels of vulnerability namely highly vulnerable, moderately vulnerable and lowly vulnerable through ranking method and these reclassified factors were then overlaid using an addition operator. The analysis shows that communities like Eagle Island, Ojimbo, Kidney Island were highly vulnerable to flood while communities like Choba, Ogbogoro, Rumualogu were moderately vulnerable. Communities like Rumuigbo, Rumuodomaya etc. were lowly vulnerable to flood. The highly vulnerable places covered 98.18 km2, moderately vulnerable was 220.46 km2 and lowly vulnerable areas covered 330.77 km2.展开更多
Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposit...Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposite polarity. There is no systematic research on the other thin-bed types. In this article, all of the thin-beds are classified into four types: thin-beds with equal magnitude and opposite polarity, thin-beds with unequal magnitude and opposite polarity, thin-beds with equal magnitude and identical polarity, and thin-beds with unequal magnitude and identical polarity. By analytical study, an equation describing the general relationship between seismic peak frequency and thin-bed thickness was derived which shows there is a Complex implicit non-linear relationship between them and which is difficult to use in practice. In order to solve this problem, we simplify the relationship by Taylor expansion and discuss the precision of the approximation formulae with different orders for the four types of thin-beds. Compared with the traditional amplitude method for thin-bed thickness calculation, the method we present has a higher precision and isn't influenced by the absolute value of top or bottom reflection coefficient, so it is convenient for use in practice.展开更多
Although mathematical models(e.g., De Nitrification and De Composition(DNDC) provide a powerful tool to study regional carbon budget, it is still difficult to obtain accurate simulation results because there exists la...Although mathematical models(e.g., De Nitrification and De Composition(DNDC) provide a powerful tool to study regional carbon budget, it is still difficult to obtain accurate simulation results because there exists large uncertainties in modeling regional carbon budget. Through the investigation on the sensitivity of model output parameters to the input parameters, sensitivity analysis(SA) has been proved to be able to identify the key sources of uncertainties and be helpful to reduce the model uncertainties. However, some input parameters with discrete values(e.g., land use type and soil type) and the regional effect of the sensitive parameters were rarely examined in SA. In this paper, taking the Zoige Plateau as a case area, we combined the one-factor-ata-time(OAT) with Extended Fourier Amplitude Sensitivity Test(EFAST) to conduct a SA of DNDC for simulating the regional carbon budget, including Gross Primary Productivity(GPP), Net Primary Productivity(NPP), Net Ecosystem Productivity(NEP), autotrophic respiration(Ra), soil microbial heterotrophic respiration(Rh) and ecosystem respiration(Re). The result showed that the combination of OAT and EFAST could test the contribution of the input parameters with discrete values to the output parameters. In DNDC model, land use type and soil type had a significant impact on the regional carbon budget of the Zoige Plateau, and daily temperature was also confirmed to be one of the most important parameters for carbon budget. For the other input parameters, with the change of land use type or soil type at regional scale, the sensitive parameters of carbon budget would vary accordingly. The SA results would provide scientific evidence to optimize DNDC model and they suggested that we should pay attention to the spatial/temporal effect of SA and try to use the appropriate data in simulation of the regional carbon budget.展开更多
Landslide hazard mapping is a fundamental tool for disaster management activities in Loess terrains. Aiming at major issues with these landslide hazard assessment methods based on Naive Bayesian classification techniq...Landslide hazard mapping is a fundamental tool for disaster management activities in Loess terrains. Aiming at major issues with these landslide hazard assessment methods based on Naive Bayesian classification technique, which is difficult in quantifying those uncertain triggering factors, the main purpose of this work is to evaluate the predictive power of landslide spatial models based on uncertain Naive Bayesian classification method in Baota district of Yan'an city in Shaanxi province, China. Firstly, thematic maps representing various factors that are related to landslide activity were generated. Secondly, by using field data and GIS techniques, a landslide hazard map was performed. To improve the accuracy of the resulting landslide hazard map, the strategies were designed, which quantified the uncertain triggering factor to design landslide spatial models based on uncertain Naive Bayesian classification method named NBU algorithm. The accuracies of the area under relative operating characteristics curves(AUC) in NBU and Naive Bayesian algorithm are 87.29% and 82.47% respectively. Thus, NBU algorithm can be used efficiently for landslide hazard analysis and might be widely used for the prediction of various spatial events based on uncertain classification technique.展开更多
The paper discusses about anthropogenic pressure classification system on landscape oasises. As a result, based on designed criteria rates a thematic map titled "Anthropogenic pressure and its consequences on landsca...The paper discusses about anthropogenic pressure classification system on landscape oasises. As a result, based on designed criteria rates a thematic map titled "Anthropogenic pressure and its consequences on landscapes oasises of mid and lower part of Zarafshan River Basin" was developed. The thematic map depicts realthionship between ecological conditions and population diseases along various landscape oasises of the Zarafshan river valley.展开更多
A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning Sys...A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning System) and ancillary data were combined by the method which adopts the main idea of classifying images by steps from decision tree method and the hybridized supervised and unsupervised classification. An integration of automatic image interpretation, ancillary materials and expert knowledge was realized. Two subscenes of Landsat 5 Thematic Mapper (TM) images of bands 3, 4 and 5 obtained on December 15, 1992, and January 17, 1999, were used for image processing and spatial data analysis in the study. The overall accuracy of the results of classification reached 90%, which was verified by field check.Results showed that shrimp farm land, urban and traffic land, barren land, bush and agricultural developing area increased in area, mangrove, paddy field, swamp and marsh land, orchard and plantation, and tropical grass land decreased, and the forest land kept almost stable. Ecological analysis on the land use changes showed that more attentions should be paid on the effect of land development on ecological environment in the future land planning and management.展开更多
Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management a...Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about 50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.展开更多
The phytogeographical system for vegetation classification splits the vegetation in first level types: forest and grasslands. The forest type can be recognized in tropical rain forest and seasonal depending on the en...The phytogeographical system for vegetation classification splits the vegetation in first level types: forest and grasslands. The forest type can be recognized in tropical rain forest and seasonal depending on the environmental conditions. This determines the occurrence of deciduous species in big or small quantity. And the grasslands are Savannah in majority. This work proposed probabilistic methods to classify these vegetation types based on priori occurrence of species. The test was carded out with forest inventory data using ten vegetation fragments in farm of Embrapa and Cascata's park in Sete Lagoas city, Minas Gerais, Brazil. The distribution of species with occurrence in different types was adapted to set theory and Bayes theorem. In this way, it is possible to calculate belonging of species on vegetation types. The results were compared with usual classification. The main contribution of probabilistic methods was to increase the information to classify tree and shrub vegetation inventoried. It is especially recommended for transition regions between vegetation types.展开更多
There are three well known types of wire lines for transmitting electrical energy or information. The first type is ordinary two wires line (below A-Line). The second type is so-called single-wire line, where ground...There are three well known types of wire lines for transmitting electrical energy or information. The first type is ordinary two wires line (below A-Line). The second type is so-called single-wire line, where ground plays the role instead of second wire. Polyphase systems belong to the third type, three phase system is the most popular among them. The purpose of this article is another attempt to build a one-wired (without ground) system--the transmission of electrical energy. In this paper an original idea of building such a system is justified, the results of simulations and laboratory modeling are presented. It is shown that the proposed method can reduce the cost of electric transmission lines, the losses in them and significantly reduce interferences.展开更多
The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession...The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession of rangelands, has been subject to disorders for the variety of reasons since many years ago. Floods, hungry animals and desertification are the consequences of such disorders. Therefore, the rangeland managers have suggested the multiple usages of rangelands based on their existing talent and efficiency which is called "rangeland suitability". In this research, based on bio-diversity potentials of the region, the recognition and functions of plants of Alborz Mountain rangelands have been considered as rangeland management tools. The sampling has been carried out in work units (combination of traditional systems in plant types) randomly-systematically by setting ten 50 m transects and putting down a metal bar. In this way, the relative frequency of medicinal and nectarous rangeland plants in work units has been evaluated. Planning for multiple usage of rangelands were performed based on two criteria of suitability of medicinal and nectarous plants, 1991 Food and Agriculture Organization (FAO) method, and using Geographical Information Systems (GIS) with the scale of 1:50,000. The best-growing habitat of the plants was selected based on the modeling. By proving the existence of environmental gradient, one can recommend the above methods to study the environmental factors as complementary to incarnation models theories.展开更多
基金supported by Chinese Academy of Sciences"100 people’project and the Open Research Station of Changbai Mountain Forest Ecosystem
文摘This paper depicted the physiographic landscape features and natural vegetation situation of study area (the eastern Jilin Province), and expatiates the definition, basic characters and its development of Ecological Land Classification (ELC). Based on the combination of relief map, satellite photography for study area and vegetation inventory data of 480 sample sites, a 5-class and a 15-class ecological land type map was concluded according to 4 important factors including slope, aspect, vegetation and elevation. Ecological Classification System (ECS) is a method to identify, characterize, and map ecosystems. The Ecological Land Type (ELT) was examined and applied initially in eastern Jilin Province.
文摘A small scale red soil resources information system (RSRIS) with applied mathematical models wasdeveloped and applied in red soil resources (RSR) classification and evaluation, taking Zhejiang Province,a typical distribution area of red soil, as the study area. Computer-aided overlay was conducted to classifyRSR types. The evaluation was carried out by using three methods, i.e., index summation, square root ofindex multiplication and fuzzy comprehensive assessment, with almost identical results. The result of indexsummation could represent the basic qualitative condition of RSR, that of square root of index multiplicationreflected the real condition of RSR qualitative rank, while fuzzy comprehensive assessment could satisfactorilyhandle the relationship between the evaluation factors and the qualitative rank of RSR, and therefore it is afeasible method for RSR evaluation.
基金funded by Special Program of Strategic Science and Technology of Chinese Academy of Sciences (Grant No. XDA05050506)State Key and Basic Research Development Planning (Grant No. 2012CB417101)+1 种基金Project of Natural Science Foundation of China (Grant No. 40901134)West Light Foundation of Chinese Academy of Sciences
文摘Soil organic carbon is of great importance to terrestrial ecosystems. Studies on the amount and spatial distribution of soil organic carbon stock in various types of soil can help to better understand the role of soil in the global carbon cycle and provide a scientific basis for the assessment of the magnitude of carbon stored in a given area. Here we present estimates of soil organic carbon stock in soils in the upper reaches of the Yangtze River based on soil types as defined by Chinese Soil Taxonomy and recently compiled into a digital soil database. The results showed that the total soil organic carbon stock of the upper Yangtze River to a depth of 100 cm was 1.452x1013 kg. The highest soil organic carbon stock was found in felty soils (2.419x10TM kg), followed by dark brown soils (1.269x10=kg), and dark feltysoils (L139x10=kg). Chernozems and irrigation silting soils showed the lowest soil organic carbon stock, mainly due to the small total area of such soils. The soil organic carbon density of these major soil types ranged from 5.6 to 26.1 kg m2- The average soil organic carbon density of the upper reaches of the Yangtze River was 16.4 kg m-2, which was higher than that of the national average. Soil organic carbon density indicated a distinct decreasing trend from west to east, which corresponds to the pattern of increasing temperature from cold to subtropical.
基金supported by the Natural Science Foundation of China (Grant No. 41171330)National High Technology Research and Development Program of China (863 Program)(Grant No. 2013AA12A302)the Special Foundation for Free Exploration of State Laboratory of Remote Sensing Science (Grant No.Y1Y00245KZ)
文摘The Qinghai-Tibet Plateau is the word's highest and largest plateau. Due to increasing demands for environment exploration and tourism, a large transitional area is required for altitude adaptation. Hehuang valley, which locates in the transition zone between the Loess Plateau and the Qinghai-Tibet Plateau, has convenient transportation and relatively low elevation. Our question is whether the geographic conditions here are appropriate for adapted stay before going into the Qinghai-Tibet Plateau. Therefore, in this study, we examined the potential use of ecological niche modeling (ENM) for mapping current and potential distribution patterns of human settlements. We chose the Maximum Entropy Method (Maxent), an ENM which integrates climate, remote sensing and geographical data, to model distributions and assess land suitability for transition areas. After preprocessing and selection, the correlation between variables and spatial auto- correlation input data were removed and 106 occurrence points and 9 environmental layers were determined as the model inputs. The threshold- independent model performance was reasonable according to lO times model running, with the area under the curve (AUC) values being 0.917± 0.01, and 0.923±0.002 for test data. Cohen's kappa coefficient of model performance was 0.848. Results showed that 82.22% of the study extent was not suitable for human settlement. Of the remaining areas, highly suitable areas aceounted for 1.19%, moderately for 5.3% and marginally for 11.28%. These suitable areas totaled 418.79 km2, and 86.25% of the sample data was identified in the different gradient of suitable area.The decisive environmental factors were slope and two climate variables: mean diurnal temperature range and temperature seasonality. Our model showed a good performance in mapping and assessing human settlements. This study provides the first predicted potential habitat distribution map for human settlement in Ledu County, which could also help in land use management.
文摘This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5 mu m or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER's urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.
文摘Based on previous evaluating methods, a new method which combines GIS with Fussy Clustering algorithm is proposed and applied in evaluating the engineering geological environment of the research area of XuZHou City in this paper. By analyzing the characteristics and formation of engineering geological environment,the major problems are discussed, including stability of basement rock, sandy soil liquefaction and cultural stratum.According to effecting factors of these problems, the stability of every engineering geological problem in the worked area is classified into different classes. Then, the Fussy Clustering method is used in assessing all conditions of engineering geological environment. Finally, the evaluation is fulfilled in the whole studied area. The calculating result shows the method is feasible.
基金supported by grant 12-04-00296-a from the Russian Foundation for Basic ResearchX.L. was supported by grant 60905060 from the National Natural Science Foundation of China+3 种基金grant BS2010DX025 from the Scientific Research Foundation for Excellent Middle-Aged and Youth Scientists of Shandong Province of Chinagrant 2011B11114 from the Fundamental Research Funds for Central UniversitiesThe writing of this review was inspired by the Bilateral Sino-Russian symposium ‘Animal Magnetic Navigation’ supported by grant 11-04-91216-NSFC-z from the Russian Foundation for Basic Researchgrant 61010164 from the National Natural Science Foundation of China
文摘Migratory birds are known to use a number of different orientation cues to determine and maintain the direction of their movements. They are able to use at least three different sources of compass information, including solar, stellar and geomagnetic cues. However, little is known about how these cues are calibrated into uniform reference direction information, while the hierarchy of these cues remains controversial. In recent studies, researchers suggest that avian migrants calibrate their geomagnetic compass on sunset cues, whereas others fail to find such patterns and insist on the prevalence of the magnetic compass. We carefully reviewed the existing literature and suggest that the conflicting results reported by different authors are due to genuine variation among species and propose hypotheses to explain this variation.
基金supported by the National High Technology Research and Developmemt Program of China (No2007AA12Z162)the Program for New Century Excellent Talents in University, Ministry of Education (NoNCET-06-0476)the Jiangsu Provincial 333 Engineering for High Level Talents(No.BK2006505)
文摘In order to analyze changes in human settlement in Xuzhou city during the past 20 years, changes in land cover and vegetation were investigated based on multi-temporal remote sensing Landsat TM images. We developed a hierarchical classifier system that uses different feature inputs for specific classes and conducted a classification post-processing approach to improve its accuracy. From our statistical analysis of changes in urban land cover from 1987 to 2007, we conclude that built-up land areas have obviously increased, while farmland has seen in a continuous loss due to urban growth and human activities. A NDVI difference approach was used to extract information on changes in vegetation. A false change information elimination approach was developed based on prior knowledge and statistical analysis. The areas of vegetation cover have been in continuous decline over the past 20 years, although some measures have been adopted to protect and maintain urban vegetation. Given the stability of underground coal exploitation since 1990s, urban growth has become the major driving force in vegetation loss, which is different from the vegetation change driven by coal exploitation mainly before 1990.
基金Foundation project: This research was jointly supported by the National Natural Science Foundation of China (70373044&30470302), China's Ministry of Science and Technology (04EFN216600328), and Northeast Rejuvenation Program of the Chinese Academy of Sciences.
文摘This paper demonstrates a Geographic Information Systems (GIS) procedure of classifying and mapping forest management category in Baihe Forestry Burea, Jilin Province, China. Within the study area, Baihe Forestry Bureau land was classified into a two-hierarchy system. The top-level class included the non-forest and forest. Over 96% of land area is forest in the study area, which was further divided into key ecological service forest (KES), general ecological service forest (GES), and commodity forest (COM). COM covered 45.0% of the total land area and was the major forest management type in Baihe Forest Bureau. KES and GES accounted for 21.2% and 29.9% of the total land area, respectively. The forest management zones designed with GIS in this study were then compared with the forest management zones established using the hand draw by the local agency. There were obvious differences between the two products. It suggested that the differences had some to do with the data sources, basic unit and mapping procedures. It also suggested that the GIS method was a useful tool in integrating forest inventory data and other data for classifying and mapping forest zones to meet the needs of the classified forest management system.
文摘The study identified spatial variations in flood vulnerability levels in Port Harcourt metropolis with the use of GIS (geographic information systems). This study considered four factors and these included landuse types, drainage, residential densities and elevation. The elevation data and drainage data were derived from the topographical map of scale 1:35,000, while the land use types were derived from the imagery of Port Harcourt metropolis downloaded from Google Earth, 2010 version. Both the topographical map and imagery were geo-referenced to geographic coordinates and geographic features were digitized in form of shapefiles using both ArcView GIS 3.3 and ArcGIS 9.2 versions. AHP (analytical hierarchical process) was adopted in this study whereby many flood factors were ranked and overlaid for decision making. The contour data was used to generate the DEM (digital elevation model) through the process called kriging in ArcGIS 9.2. Based on the ranking index, factors considered were reclassified to three levels of vulnerability namely highly vulnerable, moderately vulnerable and lowly vulnerable through ranking method and these reclassified factors were then overlaid using an addition operator. The analysis shows that communities like Eagle Island, Ojimbo, Kidney Island were highly vulnerable to flood while communities like Choba, Ogbogoro, Rumualogu were moderately vulnerable. Communities like Rumuigbo, Rumuodomaya etc. were lowly vulnerable to flood. The highly vulnerable places covered 98.18 km2, moderately vulnerable was 220.46 km2 and lowly vulnerable areas covered 330.77 km2.
基金supported by National Key S&T Special Projects of Marine Carbonate 2008ZX05000-004CNPC Projects 2008E-0610-10
文摘Quantitative thickness estimation below tuning thickness is a great challenge in seismic exploration. Most studies focus on the thin-beds whose top and bottom reflection coefficients are of equal magnitude and opposite polarity. There is no systematic research on the other thin-bed types. In this article, all of the thin-beds are classified into four types: thin-beds with equal magnitude and opposite polarity, thin-beds with unequal magnitude and opposite polarity, thin-beds with equal magnitude and identical polarity, and thin-beds with unequal magnitude and identical polarity. By analytical study, an equation describing the general relationship between seismic peak frequency and thin-bed thickness was derived which shows there is a Complex implicit non-linear relationship between them and which is difficult to use in practice. In order to solve this problem, we simplify the relationship by Taylor expansion and discuss the precision of the approximation formulae with different orders for the four types of thin-beds. Compared with the traditional amplitude method for thin-bed thickness calculation, the method we present has a higher precision and isn't influenced by the absolute value of top or bottom reflection coefficient, so it is convenient for use in practice.
基金financial support from National Natural Science Foundation of China(Grants No.41271433,41571373,41301385)the International Cooperation Key Project of CAS(Grant No.GJHZ201320)+3 种基金the International Cooperation Partner Program of Innovative Team,CAS(Grant No.KZZD-EW-TZ-06)STS-Network Plan,CAS(KFJ-EW-STS-020-02)the Strategic Leader Science and Technology project(XDA05050105)“Hundred Talents”Project of Chinese Academy of Sciences
文摘Although mathematical models(e.g., De Nitrification and De Composition(DNDC) provide a powerful tool to study regional carbon budget, it is still difficult to obtain accurate simulation results because there exists large uncertainties in modeling regional carbon budget. Through the investigation on the sensitivity of model output parameters to the input parameters, sensitivity analysis(SA) has been proved to be able to identify the key sources of uncertainties and be helpful to reduce the model uncertainties. However, some input parameters with discrete values(e.g., land use type and soil type) and the regional effect of the sensitive parameters were rarely examined in SA. In this paper, taking the Zoige Plateau as a case area, we combined the one-factor-ata-time(OAT) with Extended Fourier Amplitude Sensitivity Test(EFAST) to conduct a SA of DNDC for simulating the regional carbon budget, including Gross Primary Productivity(GPP), Net Primary Productivity(NPP), Net Ecosystem Productivity(NEP), autotrophic respiration(Ra), soil microbial heterotrophic respiration(Rh) and ecosystem respiration(Re). The result showed that the combination of OAT and EFAST could test the contribution of the input parameters with discrete values to the output parameters. In DNDC model, land use type and soil type had a significant impact on the regional carbon budget of the Zoige Plateau, and daily temperature was also confirmed to be one of the most important parameters for carbon budget. For the other input parameters, with the change of land use type or soil type at regional scale, the sensitive parameters of carbon budget would vary accordingly. The SA results would provide scientific evidence to optimize DNDC model and they suggested that we should pay attention to the spatial/temporal effect of SA and try to use the appropriate data in simulation of the regional carbon budget.
基金Projects(41362015,51164012) supported by the National Natural Science Foundation of ChinaProject(2012AA061901) supported by the National High-tech Research and Development Program of China
文摘Landslide hazard mapping is a fundamental tool for disaster management activities in Loess terrains. Aiming at major issues with these landslide hazard assessment methods based on Naive Bayesian classification technique, which is difficult in quantifying those uncertain triggering factors, the main purpose of this work is to evaluate the predictive power of landslide spatial models based on uncertain Naive Bayesian classification method in Baota district of Yan'an city in Shaanxi province, China. Firstly, thematic maps representing various factors that are related to landslide activity were generated. Secondly, by using field data and GIS techniques, a landslide hazard map was performed. To improve the accuracy of the resulting landslide hazard map, the strategies were designed, which quantified the uncertain triggering factor to design landslide spatial models based on uncertain Naive Bayesian classification method named NBU algorithm. The accuracies of the area under relative operating characteristics curves(AUC) in NBU and Naive Bayesian algorithm are 87.29% and 82.47% respectively. Thus, NBU algorithm can be used efficiently for landslide hazard analysis and might be widely used for the prediction of various spatial events based on uncertain classification technique.
文摘The paper discusses about anthropogenic pressure classification system on landscape oasises. As a result, based on designed criteria rates a thematic map titled "Anthropogenic pressure and its consequences on landscapes oasises of mid and lower part of Zarafshan River Basin" was developed. The thematic map depicts realthionship between ecological conditions and population diseases along various landscape oasises of the Zarafshan river valley.
基金Project supported by the Tingthanathikul Foundation of Thailand, the Provincial Natural Science Foun- dation of Jiangxi (No. 0230025) the Open Research Foundation of Hubei Provincial Key Labaratory of Waterlogged Disaster and Wetland Agriculture (No. H
文摘A comprehensive method of image classification was developed for monitoring land use dynamics in Chanthaburi Province of Tailand. RS (Remote Sensing), GIS (Geographical Information System), GPS (Global Positioning System) and ancillary data were combined by the method which adopts the main idea of classifying images by steps from decision tree method and the hybridized supervised and unsupervised classification. An integration of automatic image interpretation, ancillary materials and expert knowledge was realized. Two subscenes of Landsat 5 Thematic Mapper (TM) images of bands 3, 4 and 5 obtained on December 15, 1992, and January 17, 1999, were used for image processing and spatial data analysis in the study. The overall accuracy of the results of classification reached 90%, which was verified by field check.Results showed that shrimp farm land, urban and traffic land, barren land, bush and agricultural developing area increased in area, mangrove, paddy field, swamp and marsh land, orchard and plantation, and tropical grass land decreased, and the forest land kept almost stable. Ecological analysis on the land use changes showed that more attentions should be paid on the effect of land development on ecological environment in the future land planning and management.
基金Under the auspices of Major Basic Reseach Development Program of China (973 Program) (No. 2006CB403201)
文摘Karst rocky desertification is a geo-ecological problem in Southwest China. The rocky desertification risk zone delineation could be used as a guide for the regional and hierarchical rocky desertification management and prevention. We chose the middle and lower reaches of the Houzhai underground basin on the karst plateau in Puding County, Guizhou Province, China as the study area and selected land use type, elevation, slope, aspect, lithology and settlement buffer as the main driving factors of the rocky desertification. The potential risk of rocky desertification was quantifed with the factor-weights union method and statistical analysis method. Five grades of rocky desertification risk were delineated based on Geographic Information System. The extremely low, low, moderate, high and extremely high rocky desertification risk zones accounted for 5.01%, 44.17%, 33.92%, 15.59% and 1.30%, respectively. As a whole, the rocky desertification risk level was moderate because the area of low and moderate rocky desertification risk zones occupied 78.09% of the study area. However, more than half of the area (about 50.81%) was predicted to have moderate rocky desertification risk and above, indicating that the study area was subject to rocky desertification. Rocky desertification risk was higher in the southeast and lower in the northwest of the study area. Distinct differences in the distribution of rocky desertification risk zones corresponding to different factors have been found.
文摘The phytogeographical system for vegetation classification splits the vegetation in first level types: forest and grasslands. The forest type can be recognized in tropical rain forest and seasonal depending on the environmental conditions. This determines the occurrence of deciduous species in big or small quantity. And the grasslands are Savannah in majority. This work proposed probabilistic methods to classify these vegetation types based on priori occurrence of species. The test was carded out with forest inventory data using ten vegetation fragments in farm of Embrapa and Cascata's park in Sete Lagoas city, Minas Gerais, Brazil. The distribution of species with occurrence in different types was adapted to set theory and Bayes theorem. In this way, it is possible to calculate belonging of species on vegetation types. The results were compared with usual classification. The main contribution of probabilistic methods was to increase the information to classify tree and shrub vegetation inventoried. It is especially recommended for transition regions between vegetation types.
文摘There are three well known types of wire lines for transmitting electrical energy or information. The first type is ordinary two wires line (below A-Line). The second type is so-called single-wire line, where ground plays the role instead of second wire. Polyphase systems belong to the third type, three phase system is the most popular among them. The purpose of this article is another attempt to build a one-wired (without ground) system--the transmission of electrical energy. In this paper an original idea of building such a system is justified, the results of simulations and laboratory modeling are presented. It is shown that the proposed method can reduce the cost of electric transmission lines, the losses in them and significantly reduce interferences.
文摘The most precious ecological function of rangelands is the conservation of soil and water as well as supplying forage for domestic and wild animals. Such an ecological bio habitat, or in the other words the profession of rangelands, has been subject to disorders for the variety of reasons since many years ago. Floods, hungry animals and desertification are the consequences of such disorders. Therefore, the rangeland managers have suggested the multiple usages of rangelands based on their existing talent and efficiency which is called "rangeland suitability". In this research, based on bio-diversity potentials of the region, the recognition and functions of plants of Alborz Mountain rangelands have been considered as rangeland management tools. The sampling has been carried out in work units (combination of traditional systems in plant types) randomly-systematically by setting ten 50 m transects and putting down a metal bar. In this way, the relative frequency of medicinal and nectarous rangeland plants in work units has been evaluated. Planning for multiple usage of rangelands were performed based on two criteria of suitability of medicinal and nectarous plants, 1991 Food and Agriculture Organization (FAO) method, and using Geographical Information Systems (GIS) with the scale of 1:50,000. The best-growing habitat of the plants was selected based on the modeling. By proving the existence of environmental gradient, one can recommend the above methods to study the environmental factors as complementary to incarnation models theories.