Through the field survey, previous researches and interpretation of aerial photos, a landslide information database of Xiaojiang Valley, Yunnan Province was set up based on the remote sensing (RS) and geographic infor...Through the field survey, previous researches and interpretation of aerial photos, a landslide information database of Xiaojiang Valley, Yunnan Province was set up based on the remote sensing (RS) and geographic information system (GIS) technologies. In the paper, a quantitative model for the landslide hazard assessment and zoning was presented, in which the potential energy could be obtained on basis of thorough analysis of the potential sliding volume, distance and direction of the landslide body. Taking landslide potential energy as the index of the hazard severity zonation, the study area was divided into severe, heavy, medium and light hazard zones.展开更多
Landslides are prevalent,regular,and expensive hazards in the Karakoram Highway(KKH)region.The KKH connects Pakistan with China in the present China-Pakistan Economic Corridor(CPEC)context.This region has not only imm...Landslides are prevalent,regular,and expensive hazards in the Karakoram Highway(KKH)region.The KKH connects Pakistan with China in the present China-Pakistan Economic Corridor(CPEC)context.This region has not only immense economic importance but also ecological significance.The purpose of the study was to map the landslide-prone areas along KKH using two different techniquesAnalytical Hierarchy Process(AHP)and Scoops 3 D model.The causative parameters for running AHP include the lithology,presence of thrust,land use land cover,precipitation,and Digital Elevation Model(DEM)derived variables(slope,curvature,aspect,and elevation).The AHP derived final landslide susceptibility map was classified into four zones,i.e.,low,moderate,high,and extremely high.Over 80%of the study area falls under the moderate(43%)and high(40%)landslide susceptible zones.To assess the slope stability of the study area,the Scoops 3 D model was used by integrating with the earthquake loading data.The results of the limit equilibrium analysis categorized the area into four groups(low,moderate,high,and extremely high mass)of slope failure.The areas around Main Mantle Thrust(MMT)including Dubair,Jijal,and Kohistan regions,had high volumes of potential slope failures.The results from AHP and Scoops 3 D techniques were validated with the landslides inventory record of the Geological Survey of Pakistan and Google Earth.The results from both the techniques showed similar output that coincides with the known landslides areas.However,Scoops 3 D provides not only susceptible zones but also the range of volume of the potential slope failures.Further,these techniques could be used in other mountainous areas,which could help in the landslide mitigation measures.展开更多
Background:Wetlands provide diverse ecological services to sustain rich biodiversity,but they are recklessly exploited around the globe.East Kolkata Wetlands(EKW;Ramsar site No.1208,~125 km^(2))was once very rich in f...Background:Wetlands provide diverse ecological services to sustain rich biodiversity,but they are recklessly exploited around the globe.East Kolkata Wetlands(EKW;Ramsar site No.1208,~125 km^(2))was once very rich in faunal diversity that declined over the years due to various anthropogenic pressures.In such scenarios,effective management plans need to contemplate local and landscape level initiatives and prioritize areas for conservation.Studying the foraging guild structure and spatial patterns of relationship between bird and its environment provides important insight of ecological processes of avifauna.Thus,we carried out extensive surveys in 142 point count stations to explore the diversity and foraging guild structure of birds in EKW.We addressed two important questions that how bird diversity varied from the outer periphery of the city towards the wetlands and how bird diversity is influenced by land cover features at local and landscape level in wetland complex.The goal of this study was to prepare a spatial map of avian diversity and to find the conservation priority areas for birds in this internationally recognized wetland complex.Results:We recorded 94 species of birds and the Shannon diversity index values ranged between 1.249 and 3.189.We found that the avian diversity increased with increasing distance from city periphery.Omnivores and insectivores were the dominant foraging guilds,followed by carnivores,granivores,frugivores and piscivores.Generalized Linear Models revealed that bird communities were positively influenced by areas of wetlands,dikes and banks,agricultural field and emergent vegetation,and negatively influenced by built-up area.In the projected spatial map of species diversity,74.15 km^(2)area has high diversity.Finally,we identified 12.82 km^(2) of top 10%conservation priority areas.Conclusions:Low bird diversity near city periphery is related to habitat degradation due to anthropogenic pressure.Dominance of omnivores and insectivores indicates a possible impact of urbanization in E展开更多
Different researchers select different factors and use different methods to assess the regional hazard degrees of debris now. consequenily, even for the same region, tb.. are often different hazard zonation maps, and ...Different researchers select different factors and use different methods to assess the regional hazard degrees of debris now. consequenily, even for the same region, tb.. are often different hazard zonation maps, and there must be some uncertainty in the zonations. Thus the ceriainty analysis of zonation maps becomes obviously important.For debris now hazard, those zonation maps with a certainty analysis could provide most valuable information for land users, hazard managers and policy makers. By comparison of three researchers’ findings in Yunnan Province, this paPer shows that seven to nine iafluential factors are chosen for the zonation maps. spatial density of debris flow ravines,regional average rock-weathering coefficient, yearly precipitation, days of≥50 mm daily rainfall, and proportion of sloping land with slope≥25℃to the total land are the most acceptable factors. Mathemahcal methods of maximum-minimumvalues, upperlower limit values and Fuzzy values are used to quantify the factors. Step-by-step methodoogy is commonly used for the zonation maps. Research results show that mchmum uncedrinty is 66. 6% and minimum uncertainty is 35.7% in debris now hazard maps of zhaotong Prefecture and Yunnan Province. Therefore there is still much work for us to improve the zonation methedology.展开更多
This research shows a noticeable comparison between slide zones produced with the results using the Nilsen method with active tectonic hazard zonation map. A determination landform of geometry or morphometry factors i...This research shows a noticeable comparison between slide zones produced with the results using the Nilsen method with active tectonic hazard zonation map. A determination landform of geometry or morphometry factors is one of the best methods for study and evaluation active tectonics. The first image provided is a Dem maps from GIS software showing topography, geology and tectonic maps participant with field activities. The second image provided shows an active tectonic map also generated by the same above mentioned factors into three classes A, B, C, D and a landslide hazard zonation map which shows five classes: Stable zone, generally stable zone, stable moderately stable zone, moderately stable zone and talented to liquefaction zone. The study and comparison and conformity landslide hazard zonation map with hazard zonations into active tectonic hazard zonation map showed about 79 percent (56,880 hectare) moderately unstable zone and talented for liquefaction zone settled in A zone (very high tectonic activity) and B zone (high tectonic activity) active tectonic map and 21 percent (15,130 hectare) remain unsettled sequential 12 percent (8640 hectare) and 9 percent (6480 hectare) in C (moderate tectonic activity), D (lowest tectonic activity) zone of active tectonic hazard zonation produced from above mentioned factors. This research showed a relationship between slide zones produced in landslide hazard zonations using the Nilsen method to measure active tectonic hazard zonation in the study region.展开更多
基金Supported by the Special Project of Chinese Academy of sciences for Mountain Hazards: Debris Flow and Landslide and Oriented Project of Knowledge Innovation of Chinese Academy of sciences(KZCX2-SW-319)
文摘Through the field survey, previous researches and interpretation of aerial photos, a landslide information database of Xiaojiang Valley, Yunnan Province was set up based on the remote sensing (RS) and geographic information system (GIS) technologies. In the paper, a quantitative model for the landslide hazard assessment and zoning was presented, in which the potential energy could be obtained on basis of thorough analysis of the potential sliding volume, distance and direction of the landslide body. Taking landslide potential energy as the index of the hazard severity zonation, the study area was divided into severe, heavy, medium and light hazard zones.
文摘Landslides are prevalent,regular,and expensive hazards in the Karakoram Highway(KKH)region.The KKH connects Pakistan with China in the present China-Pakistan Economic Corridor(CPEC)context.This region has not only immense economic importance but also ecological significance.The purpose of the study was to map the landslide-prone areas along KKH using two different techniquesAnalytical Hierarchy Process(AHP)and Scoops 3 D model.The causative parameters for running AHP include the lithology,presence of thrust,land use land cover,precipitation,and Digital Elevation Model(DEM)derived variables(slope,curvature,aspect,and elevation).The AHP derived final landslide susceptibility map was classified into four zones,i.e.,low,moderate,high,and extremely high.Over 80%of the study area falls under the moderate(43%)and high(40%)landslide susceptible zones.To assess the slope stability of the study area,the Scoops 3 D model was used by integrating with the earthquake loading data.The results of the limit equilibrium analysis categorized the area into four groups(low,moderate,high,and extremely high mass)of slope failure.The areas around Main Mantle Thrust(MMT)including Dubair,Jijal,and Kohistan regions,had high volumes of potential slope failures.The results from AHP and Scoops 3 D techniques were validated with the landslides inventory record of the Geological Survey of Pakistan and Google Earth.The results from both the techniques showed similar output that coincides with the known landslides areas.However,Scoops 3 D provides not only susceptible zones but also the range of volume of the potential slope failures.Further,these techniques could be used in other mountainous areas,which could help in the landslide mitigation measures.
文摘Background:Wetlands provide diverse ecological services to sustain rich biodiversity,but they are recklessly exploited around the globe.East Kolkata Wetlands(EKW;Ramsar site No.1208,~125 km^(2))was once very rich in faunal diversity that declined over the years due to various anthropogenic pressures.In such scenarios,effective management plans need to contemplate local and landscape level initiatives and prioritize areas for conservation.Studying the foraging guild structure and spatial patterns of relationship between bird and its environment provides important insight of ecological processes of avifauna.Thus,we carried out extensive surveys in 142 point count stations to explore the diversity and foraging guild structure of birds in EKW.We addressed two important questions that how bird diversity varied from the outer periphery of the city towards the wetlands and how bird diversity is influenced by land cover features at local and landscape level in wetland complex.The goal of this study was to prepare a spatial map of avian diversity and to find the conservation priority areas for birds in this internationally recognized wetland complex.Results:We recorded 94 species of birds and the Shannon diversity index values ranged between 1.249 and 3.189.We found that the avian diversity increased with increasing distance from city periphery.Omnivores and insectivores were the dominant foraging guilds,followed by carnivores,granivores,frugivores and piscivores.Generalized Linear Models revealed that bird communities were positively influenced by areas of wetlands,dikes and banks,agricultural field and emergent vegetation,and negatively influenced by built-up area.In the projected spatial map of species diversity,74.15 km^(2)area has high diversity.Finally,we identified 12.82 km^(2) of top 10%conservation priority areas.Conclusions:Low bird diversity near city periphery is related to habitat degradation due to anthropogenic pressure.Dominance of omnivores and insectivores indicates a possible impact of urbanization in E
文摘Different researchers select different factors and use different methods to assess the regional hazard degrees of debris now. consequenily, even for the same region, tb.. are often different hazard zonation maps, and there must be some uncertainty in the zonations. Thus the ceriainty analysis of zonation maps becomes obviously important.For debris now hazard, those zonation maps with a certainty analysis could provide most valuable information for land users, hazard managers and policy makers. By comparison of three researchers’ findings in Yunnan Province, this paPer shows that seven to nine iafluential factors are chosen for the zonation maps. spatial density of debris flow ravines,regional average rock-weathering coefficient, yearly precipitation, days of≥50 mm daily rainfall, and proportion of sloping land with slope≥25℃to the total land are the most acceptable factors. Mathemahcal methods of maximum-minimumvalues, upperlower limit values and Fuzzy values are used to quantify the factors. Step-by-step methodoogy is commonly used for the zonation maps. Research results show that mchmum uncedrinty is 66. 6% and minimum uncertainty is 35.7% in debris now hazard maps of zhaotong Prefecture and Yunnan Province. Therefore there is still much work for us to improve the zonation methedology.
文摘This research shows a noticeable comparison between slide zones produced with the results using the Nilsen method with active tectonic hazard zonation map. A determination landform of geometry or morphometry factors is one of the best methods for study and evaluation active tectonics. The first image provided is a Dem maps from GIS software showing topography, geology and tectonic maps participant with field activities. The second image provided shows an active tectonic map also generated by the same above mentioned factors into three classes A, B, C, D and a landslide hazard zonation map which shows five classes: Stable zone, generally stable zone, stable moderately stable zone, moderately stable zone and talented to liquefaction zone. The study and comparison and conformity landslide hazard zonation map with hazard zonations into active tectonic hazard zonation map showed about 79 percent (56,880 hectare) moderately unstable zone and talented for liquefaction zone settled in A zone (very high tectonic activity) and B zone (high tectonic activity) active tectonic map and 21 percent (15,130 hectare) remain unsettled sequential 12 percent (8640 hectare) and 9 percent (6480 hectare) in C (moderate tectonic activity), D (lowest tectonic activity) zone of active tectonic hazard zonation produced from above mentioned factors. This research showed a relationship between slide zones produced in landslide hazard zonations using the Nilsen method to measure active tectonic hazard zonation in the study region.
