To improve China's residential environment evaluation system and enhance its guiding role, current research results are analyzed and summarized from three aspects including research scales, evaluation methods and app...To improve China's residential environment evaluation system and enhance its guiding role, current research results are analyzed and summarized from three aspects including research scales, evaluation methods and applied technology by means of comparison, induction and empirical application. The guiding role of the current macro-scale evaluation system of urban planning and construction is generally not obvious, whereas the guiding role of medium and micro-scale systems to the improvement of residential environments is improving. There are diversified methods for determining the threshold values and the weights of indices in China's evaluation system. For instance, the analytic hierarchy process(AHP) method is adopted to determine the weights of indices. The advantages and disadvantages of the method are analyzed on the basis of empirical calculation. In the course of comprehensive analyses, a nonlinear model can reflect interactions among indices more than a linear model; the evaluation model under the ARCGIS platform prevails since it combines space and attribute, and it has intuitive results. So far, the methodological system of China's residential environment evaluation has not been established; its subject coverage and research category should be expanded, and its guiding role should be enhanced.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
Shanghai is a coastal metropolitan city with various types of natural wetlands, which account for 23.5% of its total area. According to the definition of wetland in Ramsar Convention on Wetlands, the wetlands of Shang...Shanghai is a coastal metropolitan city with various types of natural wetlands, which account for 23.5% of its total area. According to the definition of wetland in Ramsar Convention on Wetlands, the wetlands of Shanghai were classified into 4 types: coastal, riverine, lacustrine, and reservoir and pond wetlands. In order to examine the roles of wetlands in the life-support system of Shanghai, we calculated the area of each type of the wetlands using GIS technique, and then measured the ecological service values of different ecosystems in Shanghai based on the classification of ecosystem services proposed by COSTANZA et al. (1997). The estimated annual value of ecosystem services in the study area was 7.3×109US$/a for the total area of 1 356 700ha, among which about 97% was provided by the wetlands. Effective conservation and management of wetlands are therefore crucial to Shanghai’s sustainable development. The limitations of the evaluation method for ecosystem service value were also discussed in the present paper.展开更多
This paper uses a spatial statistics method based on the calculation of spatial autocorrelation as a possible approach for modeling and quantifying the distribution of urban land price in Changzhou City, Jiangsu Provi...This paper uses a spatial statistics method based on the calculation of spatial autocorrelation as a possible approach for modeling and quantifying the distribution of urban land price in Changzhou City, Jiangsu Province. GIS and spatial statistics provide a useful way for describing the distribution of urban land price both spatially and temporally, and have proved to be useful for understanding land price distribution pattern better. In this paper, we apply the statistical analysis method to 8379 urban land price samples collected from Changzhou Land Market, and it is turned out that the proposed approach can effectively identify the spatial clusters and local point patterns in dataset and forms a general method for conceptualizing the land price structure. The results show that land price structure in Changzhou City is very complex and that even where there is a high spatial autocorrelation, the land price is still relatively heterogeneous. Furthermore, lands for different uses have different degrees of spatial autocorrelation. Spatial autocorrelation of commercial lands is more intense than that of residential and industrial lands in regional central district. This means that treating land price as integration of homogeneous units can limit analysis of pattern, over-simplifying the structure of land price, but the methods, just as the autocorrelation approaches, are useful tools for quantifying the variables of land price.展开更多
Based on the geographic information system (GIS) technology, ArcInfo software was adopted to collect, process andanalyze spatial data of Guangdong Province for an evaluation of soil resource quality. The overlay analy...Based on the geographic information system (GIS) technology, ArcInfo software was adopted to collect, process andanalyze spatial data of Guangdong Province for an evaluation of soil resource quality. The overlay analysis method wasused in combining evaluation factors of Guangdong soil resource quality to determine the evaluation units. Because ofits favorable convergent speed and its ability to search solutions, the immune algorithm was applied to the soil resourcequality evaluation model. At the same time, the evaluation results of this newly proposed method were compared to twoother methods: sum of index and fuzzy synthetic. The results indicated that the immune algorithm reflected the actualcondition of soil resource quality more exactly.展开更多
Using soil data of the Second National Field Survey,the soil fertility of wetland ecosystem of Dongting Lake was evaluated by using the technology of GIS and method of fuzzy evaluation.Integrated with the wetland actu...Using soil data of the Second National Field Survey,the soil fertility of wetland ecosystem of Dongting Lake was evaluated by using the technology of GIS and method of fuzzy evaluation.Integrated with the wetland actuality of Dongting Lake and particularity of paddy,seven factors (including soil organic matter,total nitrogen,total phosphorus,total potassium,available phosphorus,available potassium,and pH value),closely related with soil fertility,were chosen to establish the index system of synthetical evaluation.Based on the effect degree of each selected index on soil fertility,a judgment matrix was built,and the weight coefficient was determined by the method of correlation coefficient.Finally,under the support of the spatial analysis module of GIS (Geographic Information System),the spatial distribution properties of soil fertility in wetland ecosystem of Dongting Lake were studied.The results show that the soil fertility of Dongting Lake wetland ecosystem is not very good,and the area of type III and type IV achieves 69.8%.As a result,many countermeasures should be taken to improve the soil fertility.As for the spatial properties,the soil fertility level of central and west Dongting Lake is much higher than that of north and south part.The soil fertility of paddy field surpasses that of red soil,and the contents of soil organic matter and total nitrogen in paddy field are large.展开更多
As an important role in the urban land price system, the basic land price appraisal directs and refleets all kinds of land price in the real estate market. Using geographic information systems (GIS) with algo rithms...As an important role in the urban land price system, the basic land price appraisal directs and refleets all kinds of land price in the real estate market. Using geographic information systems (GIS) with algo rithms and powerful analysis functions to valuate land will improve the rationality and convenience of land valu- ation. The objective of the study on basic land price using the optimal path algorithm is to decrease the man made error, enhance automatization, avoid make inconvenience by roadblock object.展开更多
Camellia sinensis is an important commercial crop in China. Suitability evaluation of tea tree planting, which is an embodiment of agricultural planting based on Geographic Information System(GIS), includes overlay ...Camellia sinensis is an important commercial crop in China. Suitability evaluation of tea tree planting, which is an embodiment of agricultural planting based on Geographic Information System(GIS), includes overlay analysis, hierarchical analysis,artificial intellegence, multivariable linear regression and fuzzy evaluation. Via a series of functions of GIS such as data query, retrieve and management, we can be informed of current situation and problems in tea plant development, find out areas which are appropriate or inappropriate for Camellia sinensis planting and figure out corresponding planting schemes and policies. Science and technology are the basic solution to modernization of Camellia sinensis planting. It is necessary to set up decision information and plantation management systems in agriculture on account of GIS, which are important channels to regionalization of Camellia sinensis planting suitability.展开更多
Secondary xylem characteristics and horizontal variations were described in three xerophytic species, Zygophyllum xanthoxylon, Nitraria tangutorum, Tetraena mongolica of Zygophyllaceae native to western China. All the...Secondary xylem characteristics and horizontal variations were described in three xerophytic species, Zygophyllum xanthoxylon, Nitraria tangutorum, Tetraena mongolica of Zygophyllaceae native to western China. All the species have obvious growth ring boundaries except sometimes discontinuous in T. mongolica and Z xanthoxylum ring to semi-ring-porosity; simple perforation plate; alternate intervessel pitting; non-septate fibres; paratracheal confluent axial parenchyrna; helical thickenings and heterocellular rays. However the vessel arrangement and quantitative features of vessels were different. Vessel elements tend to be shorter and narrower and more frequent in T. mongolica than in other two species that are hardly different could lead to greater conductive safety. The variation of vessel element length and fibre length along radial direction showed irregular tendency. There was significant difference in both fibre length and vessel element length among-tree and within-tree. Furthermore, the relationships between anatomical features and adaptability to desert environments were also discussed.展开更多
The study centers on the necessity,t he workflowand the synthetically in tegrated methods(Principal Compo-nentAnalysis(PCA),AndyticalHierarchy Process(AHP)andFuzzy Comprerhensive Evaluatio n(FCE))ofstrategic environ-m...The study centers on the necessity,t he workflowand the synthetically in tegrated methods(Principal Compo-nentAnalysis(PCA),AndyticalHierarchy Process(AHP)andFuzzy Comprerhensive Evaluatio n(FCE))ofstrategic environ-ment assessment (SEA)on land-use planning.The whole article includes three main parts:firstly,some attribute database,graphic-base and the spatial transform matrix,which reflect the change of regional land-use pattern,can be ob-tained by GIS technique;secondly,a dopting fitting method of trend-sur face analysis will convert environm ent monitoring data from scattered spots to regular control spots,based on which we can p erform regional environment impact assess-ment;finally,Changchun Economic a nd Technological Developmen Zone is chosen as a case study on land-use pla nning.Through those efforts the results ma y be obtained as follows:1)according to transform matrix,the p ossibility of transforma-tion from one land-use to another can be obtained after the planning is carried out;2)environment quality would change as a result of the change of land-use p attern;3)the SEA on land-use plan is an effecti ve tool to make land-use pattern more reasonable.展开更多
The objective of the study was to establish spatial land evaluation for oil palm cultivation using GIS (geographic information system). The study area is situated in the KESEDAR region in the state of Kelantan, Mala...The objective of the study was to establish spatial land evaluation for oil palm cultivation using GIS (geographic information system). The study area is situated in the KESEDAR region in the state of Kelantan, Malaysia. The evaluation of the land in terms of the suitability classes were based on the method of FAO (Food and Agriculture Oganization of the United Nations). Five land qualities are important for determining the physical land suitability for oil palm; these are nutrient availability, oxygen availability, water availability, workability and availability of foothold for roots. Each of the above mentioned land qualities with associated attribute data were digitally encoded in a GIS database to create thermatic layers. Overlay operation on the layer produced resultant polygonal layer each of which is a land unit with characteristics of the land. The results from GIS overlay analyses showed that Bungor, Chat, Chempaka, Alluvium, Musang and Tok Yong series are highly suitable while Kawang series is moderately suitable for oil palm cultivation. The same results were obtained by using parametric-limitation method.展开更多
By integrating the merits of the map overlay method and the geographic information system (GIS), a GIS based map overlay method was developed to analyze comprehensively the environmental vulnerability around railway a...By integrating the merits of the map overlay method and the geographic information system (GIS), a GIS based map overlay method was developed to analyze comprehensively the environmental vulnerability around railway and its impact on the environment, which is adapted for the comprehensive assessment of railway environmental impact and the optimization of railway alignments. The assessment process of the GIS based map overlay method was presented, which includes deciding the system structure and weights of assessment factors, making environmental vulnerability grade maps, and evaluating the alternative alignments comprehensively to obtain the best one. With the GIS functions of spatial analysis, such as overlay analysis and buffer analysis, and functions of handling attribute data, the GIS based map overlay method overcomes the shortcomings of the existing map overlay method and the conclusion is more reasonable. In the end, a detailed case study was illustrated to verify the efficiency of the method.展开更多
Land suitability assessment is a prerequisite phase in land use planning; it guides toward optimal land use by providing information on the opportunities and constraints involved in the use of a given land area. A geo...Land suitability assessment is a prerequisite phase in land use planning; it guides toward optimal land use by providing information on the opportunities and constraints involved in the use of a given land area. A geographic information system-based procedure, known as rural settlement suitability evaluation(RSSE) using an improved technique for order preference by similarity to ideal solution(TOPSIS), was adopted to determine the most suitable area for constructing rural settlements in different geographical locations. Given the distribution and independence of rural settlements, a distinctive evaluation criteria system that differed from that of urban suitability was established by considering the level of rural infrastructure services as well as living and working conditions. The unpredictable mutual interference among evaluation factors has been found in practical works. An improved TOPSIS using Mahalanobis distance was applied to solve the unpredictable correlation among the criteria in a suitability evaluation. Uncertainty and sensitivity analyses obtained via Monte Carlo simulation were performed to examine the robustness of the model. Daye, a resource-based city with rapid economic development, unsatisfied rural development, and geological environmental problems caused by mining, was used as a case study. Results indicate the following findings: 1) The RSSE model using the improved TOPSIS can assess the suitability of rural settlements, and the suitability maps generated using the improved TOPSIS have higher information density than those generated using traditional TOPSIS. The robustness of the model is improved, and the uncertainty is reduced in the suitability results. 2) Highly suitable land is mainly distributed in the northeast of the study area, and the majority of which is cultivated land, thereby leading to tremendous pressure on the loss of cultivated land. 3) Lastly, 12.54% of the constructive expansion permitted zone and 8.36% of the constructive expansion conditionally permitted zone are situated in an unsuitable area, which indicates that the general planning of Daye lacks the necessary verification of suitability evaluation. Guidance is provided on the development strategy of rural settlement patches to support decision making in general land use planning.展开更多
A detailed landslide susceptibility map was produced in the Youfang catchment using logistic regression method with datasets developed for a geographic information system(GIS).Known as one of the most landslide-prone ...A detailed landslide susceptibility map was produced in the Youfang catchment using logistic regression method with datasets developed for a geographic information system(GIS).Known as one of the most landslide-prone areas in China, the Youfang catchment of Longnan mountain region,which lies in the transitional area among QinghaiTibet Plateau, loess Plateau and Sichuan Basin, was selected as a representative case to evaluate the frequency and distribution of landslides.Statistical relationships for landslide susceptibility assessment were developed using landslide and landslide causative factor databases.Logistic regression(LR)was used to create the landslide susceptibility maps based on a series of available data sources: landslide inventory; distance to drainage systems, faults and roads; slope angle and aspect; topographic elevation and topographical wetness index, and land use.The quality of the landslide susceptibility map produced in this paper was validated and the result can be used fordesigning protective and mitigation measures against landslide hazards.The landslide susceptibility map is expected to provide a fundamental tool for landslide hazards assessment and risk management in the Youfang catchment.展开更多
Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extrac...Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extracted from thousands of bore wells, and used for potable purpose without proper testing and treatment. This paper describes a groundwater quality monitoring strategy and database model developed for Gulbarga city, located in Karnataka, India. Sampling wells are selected one each in 55 wards of the city corporation having easy access for regular sampling. Various attributes of sampling wells including their spatial coordinates, location address and a photograph are registered for ready recognition on site. Water samples are collected and analyzed for various physico-chemical parameters. Spatial coordinates and levels of sampling points are measured on site using a hand held GPS instrument. Gulbarga city map is digitized. A GIS database of the measured spatial and water quality data is developed using ArcGIS Desktop 9.3, and ground water quality maps are prepared which may serve as useful tools for developing policy, and regulatory mechanism for sustainable groundwater use.展开更多
基金The National Key Technology R&D Program during the 11th Five-Year Plan(No.2006BAJ11B04-2)the Soft Science Project of the Ministry of Construction of China(No.2008-R2-25)
文摘To improve China's residential environment evaluation system and enhance its guiding role, current research results are analyzed and summarized from three aspects including research scales, evaluation methods and applied technology by means of comparison, induction and empirical application. The guiding role of the current macro-scale evaluation system of urban planning and construction is generally not obvious, whereas the guiding role of medium and micro-scale systems to the improvement of residential environments is improving. There are diversified methods for determining the threshold values and the weights of indices in China's evaluation system. For instance, the analytic hierarchy process(AHP) method is adopted to determine the weights of indices. The advantages and disadvantages of the method are analyzed on the basis of empirical calculation. In the course of comprehensive analyses, a nonlinear model can reflect interactions among indices more than a linear model; the evaluation model under the ARCGIS platform prevails since it combines space and attribute, and it has intuitive results. So far, the methodological system of China's residential environment evaluation has not been established; its subject coverage and research category should be expanded, and its guiding role should be enhanced.
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Under the auspices of the National Natural Science Foundation of China (No .40471087),thegrantprojectofSci-ence and Technology Commission ofShanghaiMunicipality(No .042012059)and Young Scientis'stGrantProjectofFudan U ni-versity(2004-2005)
文摘Shanghai is a coastal metropolitan city with various types of natural wetlands, which account for 23.5% of its total area. According to the definition of wetland in Ramsar Convention on Wetlands, the wetlands of Shanghai were classified into 4 types: coastal, riverine, lacustrine, and reservoir and pond wetlands. In order to examine the roles of wetlands in the life-support system of Shanghai, we calculated the area of each type of the wetlands using GIS technique, and then measured the ecological service values of different ecosystems in Shanghai based on the classification of ecosystem services proposed by COSTANZA et al. (1997). The estimated annual value of ecosystem services in the study area was 7.3×109US$/a for the total area of 1 356 700ha, among which about 97% was provided by the wetlands. Effective conservation and management of wetlands are therefore crucial to Shanghai’s sustainable development. The limitations of the evaluation method for ecosystem service value were also discussed in the present paper.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371091), Land Monitoring Project ofthe Ministry of Land and Resources of P. R. China (No. 2005-6.1-6)
文摘This paper uses a spatial statistics method based on the calculation of spatial autocorrelation as a possible approach for modeling and quantifying the distribution of urban land price in Changzhou City, Jiangsu Province. GIS and spatial statistics provide a useful way for describing the distribution of urban land price both spatially and temporally, and have proved to be useful for understanding land price distribution pattern better. In this paper, we apply the statistical analysis method to 8379 urban land price samples collected from Changzhou Land Market, and it is turned out that the proposed approach can effectively identify the spatial clusters and local point patterns in dataset and forms a general method for conceptualizing the land price structure. The results show that land price structure in Changzhou City is very complex and that even where there is a high spatial autocorrelation, the land price is still relatively heterogeneous. Furthermore, lands for different uses have different degrees of spatial autocorrelation. Spatial autocorrelation of commercial lands is more intense than that of residential and industrial lands in regional central district. This means that treating land price as integration of homogeneous units can limit analysis of pattern, over-simplifying the structure of land price, but the methods, just as the autocorrelation approaches, are useful tools for quantifying the variables of land price.
基金the Guangdong Provincial Natural Science Foundation, China (Nos. 980150 and 04300504), the De-partment of Science and Technology of Guangdong Province (No. 2004B20701006), the Bureau of Science and Technologyof Guangzhou City (No. 2004Z2-E0171), and the Bureau of Science and Technology of Zhuhai City (No. PA200320054).
文摘Based on the geographic information system (GIS) technology, ArcInfo software was adopted to collect, process andanalyze spatial data of Guangdong Province for an evaluation of soil resource quality. The overlay analysis method wasused in combining evaluation factors of Guangdong soil resource quality to determine the evaluation units. Because ofits favorable convergent speed and its ability to search solutions, the immune algorithm was applied to the soil resourcequality evaluation model. At the same time, the evaluation results of this newly proposed method were compared to twoother methods: sum of index and fuzzy synthetic. The results indicated that the immune algorithm reflected the actualcondition of soil resource quality more exactly.
基金Projects(40971170,51039001) supported by the National Natural Science Foundation of ChinaProject(2007AA10Z222) supported by the National High Technology Research and Development Program of China
文摘Using soil data of the Second National Field Survey,the soil fertility of wetland ecosystem of Dongting Lake was evaluated by using the technology of GIS and method of fuzzy evaluation.Integrated with the wetland actuality of Dongting Lake and particularity of paddy,seven factors (including soil organic matter,total nitrogen,total phosphorus,total potassium,available phosphorus,available potassium,and pH value),closely related with soil fertility,were chosen to establish the index system of synthetical evaluation.Based on the effect degree of each selected index on soil fertility,a judgment matrix was built,and the weight coefficient was determined by the method of correlation coefficient.Finally,under the support of the spatial analysis module of GIS (Geographic Information System),the spatial distribution properties of soil fertility in wetland ecosystem of Dongting Lake were studied.The results show that the soil fertility of Dongting Lake wetland ecosystem is not very good,and the area of type III and type IV achieves 69.8%.As a result,many countermeasures should be taken to improve the soil fertility.As for the spatial properties,the soil fertility level of central and west Dongting Lake is much higher than that of north and south part.The soil fertility of paddy field surpasses that of red soil,and the contents of soil organic matter and total nitrogen in paddy field are large.
文摘As an important role in the urban land price system, the basic land price appraisal directs and refleets all kinds of land price in the real estate market. Using geographic information systems (GIS) with algo rithms and powerful analysis functions to valuate land will improve the rationality and convenience of land valu- ation. The objective of the study on basic land price using the optimal path algorithm is to decrease the man made error, enhance automatization, avoid make inconvenience by roadblock object.
基金Application of Information Technology in Testing for Formulated Fertilization~~
文摘Camellia sinensis is an important commercial crop in China. Suitability evaluation of tea tree planting, which is an embodiment of agricultural planting based on Geographic Information System(GIS), includes overlay analysis, hierarchical analysis,artificial intellegence, multivariable linear regression and fuzzy evaluation. Via a series of functions of GIS such as data query, retrieve and management, we can be informed of current situation and problems in tea plant development, find out areas which are appropriate or inappropriate for Camellia sinensis planting and figure out corresponding planting schemes and policies. Science and technology are the basic solution to modernization of Camellia sinensis planting. It is necessary to set up decision information and plantation management systems in agriculture on account of GIS, which are important channels to regionalization of Camellia sinensis planting suitability.
文摘Secondary xylem characteristics and horizontal variations were described in three xerophytic species, Zygophyllum xanthoxylon, Nitraria tangutorum, Tetraena mongolica of Zygophyllaceae native to western China. All the species have obvious growth ring boundaries except sometimes discontinuous in T. mongolica and Z xanthoxylum ring to semi-ring-porosity; simple perforation plate; alternate intervessel pitting; non-septate fibres; paratracheal confluent axial parenchyrna; helical thickenings and heterocellular rays. However the vessel arrangement and quantitative features of vessels were different. Vessel elements tend to be shorter and narrower and more frequent in T. mongolica than in other two species that are hardly different could lead to greater conductive safety. The variation of vessel element length and fibre length along radial direction showed irregular tendency. There was significant difference in both fibre length and vessel element length among-tree and within-tree. Furthermore, the relationships between anatomical features and adaptability to desert environments were also discussed.
文摘The study centers on the necessity,t he workflowand the synthetically in tegrated methods(Principal Compo-nentAnalysis(PCA),AndyticalHierarchy Process(AHP)andFuzzy Comprerhensive Evaluatio n(FCE))ofstrategic environ-ment assessment (SEA)on land-use planning.The whole article includes three main parts:firstly,some attribute database,graphic-base and the spatial transform matrix,which reflect the change of regional land-use pattern,can be ob-tained by GIS technique;secondly,a dopting fitting method of trend-sur face analysis will convert environm ent monitoring data from scattered spots to regular control spots,based on which we can p erform regional environment impact assess-ment;finally,Changchun Economic a nd Technological Developmen Zone is chosen as a case study on land-use pla nning.Through those efforts the results ma y be obtained as follows:1)according to transform matrix,the p ossibility of transforma-tion from one land-use to another can be obtained after the planning is carried out;2)environment quality would change as a result of the change of land-use p attern;3)the SEA on land-use plan is an effecti ve tool to make land-use pattern more reasonable.
文摘The objective of the study was to establish spatial land evaluation for oil palm cultivation using GIS (geographic information system). The study area is situated in the KESEDAR region in the state of Kelantan, Malaysia. The evaluation of the land in terms of the suitability classes were based on the method of FAO (Food and Agriculture Oganization of the United Nations). Five land qualities are important for determining the physical land suitability for oil palm; these are nutrient availability, oxygen availability, water availability, workability and availability of foothold for roots. Each of the above mentioned land qualities with associated attribute data were digitally encoded in a GIS database to create thermatic layers. Overlay operation on the layer produced resultant polygonal layer each of which is a land unit with characteristics of the land. The results from GIS overlay analyses showed that Bungor, Chat, Chempaka, Alluvium, Musang and Tok Yong series are highly suitable while Kawang series is moderately suitable for oil palm cultivation. The same results were obtained by using parametric-limitation method.
文摘By integrating the merits of the map overlay method and the geographic information system (GIS), a GIS based map overlay method was developed to analyze comprehensively the environmental vulnerability around railway and its impact on the environment, which is adapted for the comprehensive assessment of railway environmental impact and the optimization of railway alignments. The assessment process of the GIS based map overlay method was presented, which includes deciding the system structure and weights of assessment factors, making environmental vulnerability grade maps, and evaluating the alternative alignments comprehensively to obtain the best one. With the GIS functions of spatial analysis, such as overlay analysis and buffer analysis, and functions of handling attribute data, the GIS based map overlay method overcomes the shortcomings of the existing map overlay method and the conclusion is more reasonable. In the end, a detailed case study was illustrated to verify the efficiency of the method.
基金Under the auspices of National Natural Science Foundation of China(No.41371429,41401196)
文摘Land suitability assessment is a prerequisite phase in land use planning; it guides toward optimal land use by providing information on the opportunities and constraints involved in the use of a given land area. A geographic information system-based procedure, known as rural settlement suitability evaluation(RSSE) using an improved technique for order preference by similarity to ideal solution(TOPSIS), was adopted to determine the most suitable area for constructing rural settlements in different geographical locations. Given the distribution and independence of rural settlements, a distinctive evaluation criteria system that differed from that of urban suitability was established by considering the level of rural infrastructure services as well as living and working conditions. The unpredictable mutual interference among evaluation factors has been found in practical works. An improved TOPSIS using Mahalanobis distance was applied to solve the unpredictable correlation among the criteria in a suitability evaluation. Uncertainty and sensitivity analyses obtained via Monte Carlo simulation were performed to examine the robustness of the model. Daye, a resource-based city with rapid economic development, unsatisfied rural development, and geological environmental problems caused by mining, was used as a case study. Results indicate the following findings: 1) The RSSE model using the improved TOPSIS can assess the suitability of rural settlements, and the suitability maps generated using the improved TOPSIS have higher information density than those generated using traditional TOPSIS. The robustness of the model is improved, and the uncertainty is reduced in the suitability results. 2) Highly suitable land is mainly distributed in the northeast of the study area, and the majority of which is cultivated land, thereby leading to tremendous pressure on the loss of cultivated land. 3) Lastly, 12.54% of the constructive expansion permitted zone and 8.36% of the constructive expansion conditionally permitted zone are situated in an unsuitable area, which indicates that the general planning of Daye lacks the necessary verification of suitability evaluation. Guidance is provided on the development strategy of rural settlement patches to support decision making in general land use planning.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(164320H101)the Opening Fund of State Key Laboratory of Geohazard Prevention and Geoenvironment Protection of Chengdu University of Technology,China(SKLGP2012K012)+4 种基金the Opening Fund of Key Laboratory for Geo-hazards in Loess area(GLA2014005)the National Natural Science Foundation of China(No.40801212 and No.41201424)the 973 National Basic Research Program(Nos.2013CB733203,2013CB733204)the 863 National High-Tech Rand D Program(No.2012AA121302)the FP6 project"Mountain Risks"of the European Commission(No.MRTNCT-2006-035798)
文摘A detailed landslide susceptibility map was produced in the Youfang catchment using logistic regression method with datasets developed for a geographic information system(GIS).Known as one of the most landslide-prone areas in China, the Youfang catchment of Longnan mountain region,which lies in the transitional area among QinghaiTibet Plateau, loess Plateau and Sichuan Basin, was selected as a representative case to evaluate the frequency and distribution of landslides.Statistical relationships for landslide susceptibility assessment were developed using landslide and landslide causative factor databases.Logistic regression(LR)was used to create the landslide susceptibility maps based on a series of available data sources: landslide inventory; distance to drainage systems, faults and roads; slope angle and aspect; topographic elevation and topographical wetness index, and land use.The quality of the landslide susceptibility map produced in this paper was validated and the result can be used fordesigning protective and mitigation measures against landslide hazards.The landslide susceptibility map is expected to provide a fundamental tool for landslide hazards assessment and risk management in the Youfang catchment.
文摘Groundwater is an essential source of drinking water for many Indian urban habitats. Large numbers of people consume ground water instead of municipal tap water due to contamination of tap water. Groundwater is extracted from thousands of bore wells, and used for potable purpose without proper testing and treatment. This paper describes a groundwater quality monitoring strategy and database model developed for Gulbarga city, located in Karnataka, India. Sampling wells are selected one each in 55 wards of the city corporation having easy access for regular sampling. Various attributes of sampling wells including their spatial coordinates, location address and a photograph are registered for ready recognition on site. Water samples are collected and analyzed for various physico-chemical parameters. Spatial coordinates and levels of sampling points are measured on site using a hand held GPS instrument. Gulbarga city map is digitized. A GIS database of the measured spatial and water quality data is developed using ArcGIS Desktop 9.3, and ground water quality maps are prepared which may serve as useful tools for developing policy, and regulatory mechanism for sustainable groundwater use.