This study combines the analytical model to build a landside monitoring decision support system of the Web GIS. The landslide area of Lishan is a case study for the research. The analysis of the risk degree for the la...This study combines the analytical model to build a landside monitoring decision support system of the Web GIS. The landslide area of Lishan is a case study for the research. The analysis of the risk degree for the landslide area in Lishan is based on the three-layer architecture of Fuzzy Analytic Hierarchical Process （FAHP）. There are four fuzzy model structures used in monitoring devices： rainfall, groundwater level, Time Domain Reflectometry （TDR） monitored the subsurface deformation, and Global Positioning System （GPS） monitored ground displacement. These structures are relative to four membership functions that are used to classify four states, including safety, attention, warning, and danger. The risk degree of the landslide area can be obtained through the fuzzy rules by determining management criteria. Calculating the total scores of historical monitoring record of the rainfall, groundwater level, TDR, and GPS through the fuzzy theory can determine the analytical results of risk degrees in Lishan landslide area. In this whole area, management criterion is in the state of attention when the total score is larger than 72, in the state of warning when total score is larger than 95, and in the state of danger when total score is larger than 113. The system provides real-time monitoring data, and prewarning decision support in order to announce and prevent the disaster at the earliest time.展开更多
Agricultural landscapes are essential for the conservation of biodiversity. Nevertheless, a negative trend continues to be observed in many rural areas for the most prominent indicator species group, the farmland bird...Agricultural landscapes are essential for the conservation of biodiversity. Nevertheless, a negative trend continues to be observed in many rural areas for the most prominent indicator species group, the farmland birds. However, clear cause-effect relationships are rarely reported and sometimes difficult to deduce, especially from monitoring data which are based only on the detection of species and counts of the numbers of individuals. Because the identification of habitat preferences is a precondition for farmland bird biodiversity conservation efforts, a monitoring scheme for the simultaneous collection and analysis of bird and land use data was developed and tested. In order to assign the occurrence of bird species to land characteristics at various spatial scales and different land use and crop types, we applied a hierarchical structured sampling design. The spatial scales were ‘agricultural landscape', ‘agricultural landscape types', ‘field crops and other habitats' and ‘vegetation structures'. These scales were integrated with a novel concept, the ‘habitat matrix'(HM). This method was applied to farmland breeding bird abundances on 29 plots, each 1 km2 in size, by the use of the territory mapping method. The same plots were enlarged by a 100 m buffer and the sizes and location of habitats documented. Vegetation height, coverage and density were also recorded for all crop fields in the study area. We propose that this monitoring method facilitates the identification of scale dependent relationships between farmland bird habitat characteristics and bird abundance. This is demonstrated by the farmland bird species Corn Bunting(Emberiza calandra), Skylark(Alauda arvensis), and Whinchat(Saxicola rubetra). The breeding territories of these species reveal large differences within the various spatial scales ‘agricultural landscape', ‘agricultural landscape types' and ‘field crops'. Throughout the breeding season the abundances varied, dependent on the field crop and the development of vegetation structures(height, coverage, and density). HM-analysis led to the identification of specific habitat configurations preferred by individual bird species within the agricultural landscape. These findings indicate that the methodology has the potential to design monitoring schemes for the identification of cause-and-effects of landscape configuration, land use and land use changes on the habitat suitability and abundance of farmland birds.展开更多
This paper proposes a clustered trajectories anonymity scheme （CTA） that enhances the kano nymity scheme to provide the intended level of source location privacy in mobile event monitoring when a global attacker is ...This paper proposes a clustered trajectories anonymity scheme （CTA） that enhances the kano nymity scheme to provide the intended level of source location privacy in mobile event monitoring when a global attacker is assumed. CTA applies isomorphic property of rotation to create traces of the fake sources distributions which are similar to those of the real sources. Thus anonymity of each trajectory and that of the clustered is achieved. In addition, location kdiversity is achieved by dis tributing fake sources around the base station. To reduce the time delay, tree rooted at the base sta tion is constructed to overlap part of the beacon interval of the nodes in the hierarchy. Both the ana lytical analysis and the simulation results prove that proved energy overhead and time delay. our scheme provides perfect anonymity with improved energy overhead and time delay.展开更多
Optimal scale is one of the important issues in ecology and geography.Based on land-use data of the Tarim River Basin in Xinjiang of China in the 1950s,regarding the area of land use types as the parameter in scale se...Optimal scale is one of the important issues in ecology and geography.Based on land-use data of the Tarim River Basin in Xinjiang of China in the 1950s,regarding the area of land use types as the parameter in scale selecting,the histograms of the patches in area are charted.Then,by reinforcing the normalized scale variances(NSV) with 3 landscape indi-ces,the scale characteristics of land use in the Tarim River Basin can be summarized.(1) NSV in the Tarim River up to a maximum at scale of 1:50,000 which is considered appropriate for the Tarim River.(2) Diversity indices of saline land are consistent with NSV's.Diversity indices and NSV of sandy land showed that the appropriate scale is in the same scale domain.There is a significant difference between diversity indices and NSV of forestland and shrub-land.(3) Fractal dimension of sandy land and saline land showed a hierarchical structure at a scale of 1:10,000.Fractal dimension of forestland and shrubland are distributed under the same hierarchical structure in the region.展开更多
文摘This study combines the analytical model to build a landside monitoring decision support system of the Web GIS. The landslide area of Lishan is a case study for the research. The analysis of the risk degree for the landslide area in Lishan is based on the three-layer architecture of Fuzzy Analytic Hierarchical Process （FAHP）. There are four fuzzy model structures used in monitoring devices： rainfall, groundwater level, Time Domain Reflectometry （TDR） monitored the subsurface deformation, and Global Positioning System （GPS） monitored ground displacement. These structures are relative to four membership functions that are used to classify four states, including safety, attention, warning, and danger. The risk degree of the landslide area can be obtained through the fuzzy rules by determining management criteria. Calculating the total scores of historical monitoring record of the rainfall, groundwater level, TDR, and GPS through the fuzzy theory can determine the analytical results of risk degrees in Lishan landslide area. In this whole area, management criterion is in the state of attention when the total score is larger than 72, in the state of warning when total score is larger than 95, and in the state of danger when total score is larger than 113. The system provides real-time monitoring data, and prewarning decision support in order to announce and prevent the disaster at the earliest time.
基金Funding from the German Federal Ministry of Food,Agriculture and Consumer Protection(BMELV)
文摘Agricultural landscapes are essential for the conservation of biodiversity. Nevertheless, a negative trend continues to be observed in many rural areas for the most prominent indicator species group, the farmland birds. However, clear cause-effect relationships are rarely reported and sometimes difficult to deduce, especially from monitoring data which are based only on the detection of species and counts of the numbers of individuals. Because the identification of habitat preferences is a precondition for farmland bird biodiversity conservation efforts, a monitoring scheme for the simultaneous collection and analysis of bird and land use data was developed and tested. In order to assign the occurrence of bird species to land characteristics at various spatial scales and different land use and crop types, we applied a hierarchical structured sampling design. The spatial scales were ‘agricultural landscape', ‘agricultural landscape types', ‘field crops and other habitats' and ‘vegetation structures'. These scales were integrated with a novel concept, the ‘habitat matrix'(HM). This method was applied to farmland breeding bird abundances on 29 plots, each 1 km2 in size, by the use of the territory mapping method. The same plots were enlarged by a 100 m buffer and the sizes and location of habitats documented. Vegetation height, coverage and density were also recorded for all crop fields in the study area. We propose that this monitoring method facilitates the identification of scale dependent relationships between farmland bird habitat characteristics and bird abundance. This is demonstrated by the farmland bird species Corn Bunting(Emberiza calandra), Skylark(Alauda arvensis), and Whinchat(Saxicola rubetra). The breeding territories of these species reveal large differences within the various spatial scales ‘agricultural landscape', ‘agricultural landscape types' and ‘field crops'. Throughout the breeding season the abundances varied, dependent on the field crop and the development of vegetation structures(height, coverage, and density). HM-analysis led to the identification of specific habitat configurations preferred by individual bird species within the agricultural landscape. These findings indicate that the methodology has the potential to design monitoring schemes for the identification of cause-and-effects of landscape configuration, land use and land use changes on the habitat suitability and abundance of farmland birds.
基金Supported by the National Natural Science Foundation of China(No.60903157)the Fundamental Research funds for the Central Universities of China(No.ZYGX2011J066)the Sichuan Science and Technology Support Project(No.2013GZ0022)
文摘This paper proposes a clustered trajectories anonymity scheme （CTA） that enhances the kano nymity scheme to provide the intended level of source location privacy in mobile event monitoring when a global attacker is assumed. CTA applies isomorphic property of rotation to create traces of the fake sources distributions which are similar to those of the real sources. Thus anonymity of each trajectory and that of the clustered is achieved. In addition, location kdiversity is achieved by dis tributing fake sources around the base station. To reduce the time delay, tree rooted at the base sta tion is constructed to overlap part of the beacon interval of the nodes in the hierarchy. Both the ana lytical analysis and the simulation results prove that proved energy overhead and time delay. our scheme provides perfect anonymity with improved energy overhead and time delay.
基金National Natural Science Foundation of China,No.40571030No.40730633
文摘Optimal scale is one of the important issues in ecology and geography.Based on land-use data of the Tarim River Basin in Xinjiang of China in the 1950s,regarding the area of land use types as the parameter in scale selecting,the histograms of the patches in area are charted.Then,by reinforcing the normalized scale variances(NSV) with 3 landscape indi-ces,the scale characteristics of land use in the Tarim River Basin can be summarized.(1) NSV in the Tarim River up to a maximum at scale of 1:50,000 which is considered appropriate for the Tarim River.(2) Diversity indices of saline land are consistent with NSV's.Diversity indices and NSV of sandy land showed that the appropriate scale is in the same scale domain.There is a significant difference between diversity indices and NSV of forestland and shrub-land.(3) Fractal dimension of sandy land and saline land showed a hierarchical structure at a scale of 1:10,000.Fractal dimension of forestland and shrubland are distributed under the same hierarchical structure in the region.
