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1.
The Ground Penetrating Radar (GPR) is a newly developing geophysical tool for imaging the sub-surface and is potentially useful in groundwater exploration. We test its usefulness in characterizing a groundwater rich lineament near Gajularamaram in the Hyderabad granite terrain, where groundwater is limited to soil, weathering zone and lineaments. The lineament is 2 km long and 50–100 m wide, and oriented in WNW-ESE direction. It is characterized by many closely spaced sub-vertical fractures and faults, majority of which are parallel to the lineament. On either sides of the lineament, sub-horizontal sheet joints are abundant. The lineament is saturated with groundwater that discharge as springs at some places. About 450 m long, 400–100 MHz GPR data (~5–30 m depth) were acquired along five profiles across the lineament. In the lineament, soil thickness varies from ~0.5 m to 5 m, and is underlain by weathered granite. In the WNW part, a thick weathering zone (~15 m) is present and a 10 m wide vertical anomaly zone (lineament) is also present. The presence of shallow reflectors at 1 m depth in the lineament is attributed to the groundwater surface. The GPR images reveal many sub horizontal to gently dipping reflectors, which are interpreted to be the sheet joints. The GPR data clearly reveal the saturated lineament, from which groundwater may migrate laterally to long distance through the sheet joints. We demonstrate the GPR as a rapid geophysical tool that can be used successfully to explore the nearsurface groundwater.  相似文献   

2.
We use beaver-pond deposits and geomorphic characteristics of small streams to assess long-term effects of beavers and climate change on Holocene fluvial activity in northern Yellowstone National Park. Although beaver damming has been considered a viable mechanism for major aggradation of mountain stream valleys, this has not been previously tested with stratigraphic and geochronologic data. Thirty-nine radiocarbon ages on beaver-pond deposits fall primarily within the last 4000 yr, but gaps in dated beaver occupation from ~ 2200–1800 and 950–750 cal yr BP correspond with severe droughts that likely caused low to ephemeral discharges in smaller streams, as in modern severe drought. Maximum channel gradient for reaches with Holocene beaver-pond deposits decreases with increasing basin area, implying that stream power limits beaver damming and pond sediment preservation. In northern Yellowstone, the patchy distribution and cumulative thickness of mostly < 2 m of beaver-pond deposits indicate that net aggradation forced by beaver damming is small, but beaver-enhanced aggradation in some glacial scour depressions is greater. Although 20th-century beaver loss and dam abandonment caused significant local channel incision, most downcutting along alluvial reaches of the study streams is unrelated to beaver dam abandonment or predates historic beaver extirpation.  相似文献   

3.
The Pirapemas Lineament is a remarkable 200-km-long, NE-SW trending structure in the Barreirinhas Basin, one of the several Brazilian coastal basins. This lineament splits the study area in two sectors of distinctive morphology, drainage patterns, and sedimentary covers. Terrain northward of the lineament presents a smooth topography with sub-parallel to sub-dendritic drainage patterns, whereas a dissected plateau characterized by incised valleys and rectangular drainage pattern occurs southward, suggesting a structural control by joints and faults. Geological field data, crossed with thermal luminescence (TL) and optically stimulated luminescence (OSL) dating, revealed that the surface southward of the lineament consists mostly of Miocene and late Pleistocene sedimentary deposits, represented by the Barreiras Formation and the Post-Barreiras sediments, respectively. In contrast, relatively younger sands mantle most of the northward terrain, as indicated by well-preserved paleodune deposits that grade into active aeolian dunes of the Lençóis Maranhenses National Park. Geomorphological and geological data analysis suggests that the northern sector is under the effect of subsidence, proving that the Pirapemas Lineament is an active agent modeling the landscape in the region. Geophysical data (gravity and seismic) confirm that such a structural feature is the surface expression of an active deep-seated basement fault.  相似文献   

4.
Three statistical models—frequency ratio (FR), weights-of-evidence (WofE) and logistic regression (LR)—produced groundwater-spring potential maps for the Birjand Township, southern Khorasan Province, Iran. In total, 304 springs were identified in a field survey and mapped in a geographic information system (GIS), out of which 212 spring locations were randomly selected to be modeled and the remaining 92 were used for the model evaluation. The effective factors—slope angle, slope aspect, elevation, topographic wetness index (TWI), stream power index (SPI), slope length (LS), plan curvature, lithology, land use, and distance to river, road, fault—were derived from the spatial database. Using these effective factors, groundwater spring potential was calculated using the three models, and the results were plotted in ArcGIS. The receiver operating characteristic (ROC) curves were drawn for spring potential maps and the area under the curve (AUC) was computed. The final results indicated that the FR model (AUC?=?79.38 %) performed better than the WofE (AUC?=?75.69 %) and LR (AUC?=?63.71 %) models. Sensitivity and factor analyses concluded that the bivariate statistical index model (i.e. FR) can be used as a simple tool in the assessment of groundwater spring potential when a sufficient number of data are obtained.  相似文献   

5.
The present study deals with the preparation of a landslide susceptibility map of the Balason River basin, Darjeeling Himalaya, using a logistic regression model based on Geographic Information System and Remote Sensing. The landslide inventory map was prepared with a total of 295 landslide locations extracted from various satellite images and intensive field survey. Topographical maps, satellite images, geological, geomorphological, soil, rainfall and seismic data were collected, processed and constructed into a spatial database in a GIS environment. The chosen landslide-conditioning factors were altitude, slope aspect, slope angle, slope curvature, geology, geomorphology, soil, land use/land cover, normalised differential vegetation index, drainage density, lineament number density, distance from lineament, distance to drainage, stream power index, topographic wetted index, rainfall and peak ground acceleration. The produced landslide susceptibility map satisfied the decision rules and ?2 Log likelihood, Cox &; Snell R-Square and Nagelkerke R-Square values proved that all the independent variables were statistically significant. The receiver operating characteristic curve showed that the prediction accuracy of the landslide probability map was 96.10%. The proposed LR method can be used in other hazard/disaster studies and decision-making.  相似文献   

6.
The Asna river basin is located in Hingoli and Nanded districts of Marathwada region of Maharashtra. A geomorphometric analysis is an important method for the investigation and management of natural resources of watershed. The geomorphometric analysis of Asna river basin classifies three sub-basins that have been delineated using GIS and remote sensing through measurements of linear, aerial, and relief aspects. The Asna river basin comprises an area of 1187 km2 with seventh-order drainage pattern. As per Strahler classification, the upper part of the basin shows dendritic to sub-dendritic and the lower part exhibits parallel to sub-parallel drainage pattern. The total numbers of stream segments are 2422 and length of streams is 2187.92 km. The bifurcation value ranges from 1.26 to 5.58 indicating that there are no structural disturbances. The form factor value (0.49) indicates that the shape of the basin is moderately circular. The high values of drainage density, stream frequency, and low infiltration number indicate the high runoff due to impermeable lithology. The slope of the basin varies from 1 to 32.2%, terrain elevation ranges from 333 to 551 m, and overall relief of the basin is 218 m amsl. River sub-basin prioritization has an immense importance in natural resource management, especially in semi-arid regions. The present study is an attempt to prioritize the sub-basins of Asna river based on geomorphometric parameters. The weightage is assigned to different morphometric parameters of sub-basins based on erosion potential. The Asna river sub-basins have been classified into three categories as high, medium, and low on the basis of priorities for soil and water conservation. It is confirmed that sub-basin I is characterized as highly vulnerable to erosion and has high sedimentation load; sub-basin II has low priority, i.e., very low erodibility; and sub-basin III is of moderate type. The morphometric analysis and prioritization methods can be applied to hydrological studies in surface as well as subsurface water, climatic studies, rainwater harvesting, groundwater recharging sites, and watershed management.  相似文献   

7.
Factors influencing nitrate within a low-gradient agricultural stream   总被引:1,自引:1,他引:0  
In low-gradient agricultural streams, the proportion of land use devoted to agriculture, the sinuosity of the stream and the time of year influence the concentration of nitrate in the stream waters. Land use influences the source of nitrate and also the morphology of the stream. Greater agricultural land use weakly correlated (r = 0.67) to higher nitrate concentrations. Streams in agricultural areas have been straightened, which decreases the sinuosity. As a stream meanders and becomes more sinuous, the potential for lateral hyporheic flow increases, which can enhance a stream system’s ability to remove nitrate. Logically, higher sinuous streams should remove more nitrate and likely sulfate as there is a greater potential for lateral hyporheic flows. To test this hypothesis, nitrate and sulfate were monitored. Mass fluxes of nitrate along six stream segments with varying sinuosity values were calculated and statistically analyzed to assess if differences in mass fluxes along the segments existed. Along the segments, there are statistically significant differences in the mass fluxes of nitrate [F(5,174) = 4.777; p = 0.001]. Stream segments with higher sinuosity index values exhibited a loss or lower gain in nitrate and sulfate than lower sinuosity index segments. The data suggest that stream segments with high sinuosity indices provide greater stream distance and increased hyporheic interaction within the streambed. Additionally, the more sinuous segments provide for an increase in lateral hyporheic flow beneath meander lobes. These additional hyporheic flows lead to enhanced denitrification in low-gradient agricultural streams. Seasonal differences were also noted. August through October experienced the lower nitrate concentrations as compared to June and July which exhibited the highest nitrate concentrations.  相似文献   

8.
The relationship between major structural lineaments and locations of ore deposits in Iran has been investigated using geospatial data. In the course of lineament extraction, satellite images, aeromagnetic data, digital elevation model (DEM) and structural maps were processed and the lineaments and large-scale faults were identified. The extracted lineaments, based on subjective assessment, from each dataset were imported into GIS software and the “lineament map of Iran” was prepared by data integration. The analysis for selecting significant lineament was mainly based on fault correlated lineament and lineament with field map fractures, which was sets as benchmarks for compiling a final output map. Four major regional lineament trends of N–S, E–W, NW–SE and NE–SW were identified in the data of all images, which are corresponded to the structural zones and the major fault systems of Iran. The mineral deposits (active and abandoned) and mineral indications database compiled are based on the published maps, papers, reports and the ore deposits data files of Geological Survey of Iran. Integrating the output of these two datasets by GIS software resulted in the “Combined Map of Lineaments and Gold, Copper, Lead, Zinc and Iron Deposits of Iran”. The number and distance of ore deposits toward the lineaments were processed by the counting and cumulative methods in the GIS software's. Approximately, over 90% of the ore deposits of Iran are located in the central part of the lineaments (15 km on each side) which are concordant with a definition of large lineament. About 50% of these mineral deposits are closer than 5 km to the lineaments. There are significant correlations between lineament density and intersections with ore deposits occurrences. The observed associations at this scale are informative in establishing exploration strategy and decreasing exploration risks for detailed work on ore deposit scale.  相似文献   

9.
The Cairngorm Mountain area of Scotland is a classic example of a landscape of selective linear glacial erosion, with sharp contrasts in the intensity of glacial erosion between the deeply incised troughs and valleys and the undulating high plateau. This article examines the Quaternary development of Glen Avon, a 200 m deep glacial trough set within the high plateau of the mountains. Evidence concerning the aggregate basal thermal regimes of the topographically controlled ice streams that formerly developed in this area is reconstructed from the geomorphological record, including bedforms indicative of wet-based, sliding ice and of dry-based ice frozen to its bed. This mapping indicates that basal sliding was not confined exclusively to the troughs but extended towards valley heads and on to parts of the plateau adjacent to troughs. The extent of basal sliding appears to have been greatest beneath pre-Late Devensian ice sheets. Basal ice temperatures are modelled under steady-state conditions for the last ice sheet at c. 18 ka BP. Basal thermal regimes are predicted using a reconstruction of the preglacial relief and for the current topography of the area. Convergent flow of ice through the preglacial valley system appears to have been sufficient to induce basal melting and therefore to initiate valley deepening. This effect is enhanced when the model is run across the present topography. Comparison of results of the geomorphological mapping and the modelling reveals significant differences between the actual and predicted extent of basal sliding outside the main ice stream. The overall conclusion is that many ice streams in mountainous terrain are inherited from the locations of preglacial valleys, which serve to accelerate ice flow and promote frictional heating beneath ice sheets.  相似文献   

10.
The purpose of this study is to produce a landslide susceptibility map for the lower Mae Chaem watershed, northern Thailand using a Geographic Information System (GIS) and remotely sensed images. For this purpose, past landslide locations were identified from satellite images and aerial photographs accompanied by the field surveys to create a landslide inventory map. Ten landslide-inducing factors were used in the susceptibility analysis: elevation, slope angle, slope aspect, lithology, distance from lineament, distance from drainage, precipitation, soil texture, land use/land cover (LULC), and NDVI. The first eight factors were prepared from their associated database while LULC and NDVI maps were generated from Landsat-5 TM images. Landslide susceptibility was analyzed and mapped using the frequency ratio (FR) model that determines the level of correlation between locations of past landslides and the chosen factors and describes it in terms of frequency ratio index. Finally, the output map was validated using the area under the curve (AUC) method where the success rate of 80.06% and the prediction rate of 84.82% were achieved. The obtained map can be used to reduce landslide hazard and assist with proper planning of LULC in the future.  相似文献   

11.
Environmental isotopes including \({\updelta }^{18}\)O, \({\updelta }^{2}\)H and \(^{3}\)H of precipitation, streams and springs were determined in the mountainous Bringi catchment of Kashmir Himalaya, dominated by carbonate lithology. The isotopic signature of winter precipitation is reflected in stream and spring water in late spring and is, therefore, representative of snow melting. The spring waters in September bear the enriched isotopic signatures of summer rainfall. The strong correlation (\(r^{2} = 0.97\)) between the isotopic composition of streams and springs indicates the streams and springs either share similar catchments or the springs are recharged by the streams. Chloride mass balance and isotopic mass balance studies suggest that the surface recharge component averages 337.35 m\(^{3}\)/s, which is about 75% of total stream discharge during the high flow period. Similarly, the contribution of surface water to groundwater recharge during the low flow period averages 7.5 m\(^{3}\)/s, which is about 18.6% of total stream flow. Furthermore, the mean residence time of the springs calculated from the tritium decay equation is very short (<1 year). The residence time is longer for Kongamnag and short for Achabalnag, which is further supported by dye testing.  相似文献   

12.
The NE-oriented Dasht-e-Arjan graben is located 65 km west of Shiraz and has resulted from the active Kare-e-Bas fault segmentations. This extensional graben bounded by two fault system east-Arjan and west-Arjan to the Shahneshin and Salamati anticline. In these study using Landsat 7 ETM images with resolution 2.5 m and directional filtering in the four azimuths and semi-automatic technique for linear structure in the study area. Using the obtained data from extracted lineaments, the rose diagrams of the main strike lineaments are well confirm with field measurements of faults with N56° ± 4°E direction. The structural lineaments of the study area show that the Dasht-e-Arjan area is underlain by the limestone, sandstone, and marl. LANDSAT imagery of the area has been analyzed and interpreted in order to determine the lineament and groundwater quality across the area. The fracture is structurally controlled and mostly influences both the groundwater and surface water pollution and flow directions in the Dasht-e-Arjan. Using visual interpretation, determining the lineaments on the satellite image is very difficult and subjective, and it requires an experienced interpreter. In this study, the lineament analysis is undertaken to examine the orientation of the lineament, the relationship between lineaments and tectonic features and groundwater quality. Lineament density maps show that the lineament density is high around areas. Areas having high lineament density represent areas with relatively high groundwater pollution. Field observations agreed with the results from the analysis of the imagery.  相似文献   

13.
The drainage basin of the Kalyani river, a tributary of Gomati river has been mapped and delineated using Survey of India toposheets (1:50,000 scale) and remote sensing satellite data. The digitization, slope map preparation and statistical calculations have been carried out with the help of geographical information system (Arc GIS 10). Kalyani a fifth order river exhibits meandering behavior having 2.45 sinuosity index (SI). The Kalyani river basin has about 1235 km2area with NW-SE sloping trend. The total number of first, second, third, and fourth order streams are 373, 71, 12 and 2 respectively, showing dominance of first order streams in the basin. The mean bifurcation ratio (Rb) of the entire basin is 4.8, which indicates that the drainage is not much influenced by geological structures and exhibits dendritic drainage pattern. Relief ratio (Rr) indicates low to medium surface run-off, and low stream power for erosion. The analysis of river bank height ‘r’ (escarpment) and longitudinal profile of the river closely reveals neotectonic activity at some locations in the basin. To prepare a comprehensive watershed development and management plan, it is important to understand the topography and drainage characteristics of the region.  相似文献   

14.
The Himalayan foothill region is traversed by the Main Boundary Thrust, the Himalayan Frontal Thrust and the Piedmont Fault which make the entire densely populated foothill region vulnerable to seismic damages. Tectonic morphometric studies of selected active tectonic indices in conjunction with analysis of multispectral satellite imagery of the foothill terrain from North of Chandigarh to West of Dehradun have revealed the presence of two major active faults. The Jainti Devi Fault, in the vicinity of Chandigarh, has offset nearly all the drainage channels by about 780 m while the Trilokpur Fault, in the vicinity of Nahan, has offset the streams and rivulets by about 1500 m. The values of ratio of valley floor width to valley height, the stream length gradient index, stream sinuosity index and mountain front sinuosity index have been computed and these reaffirm the active tectonic setup of the foothill terrain. The digital terrain model and field investigations reveal the presence of offset streams, sag ponds, linear valleys, shutter ridges and pressure ridges along the fault trace. Trenching carried out in the region has revealed the presence of numerous seismites.  相似文献   

15.
The aim of this study is to produce landslide susceptibility mapping by probabilistic likelihood ratio (PLR) and spatial multi-criteria evaluation (SMCE) models based on geographic information system (GIS) in the north of Tehran metropolitan, Iran. The landslide locations in the study area were identified by interpretation of aerial photographs, satellite images, and field surveys. In order to generate the necessary factors for the SMCE approach, remote sensing and GIS integrated techniques were applied in the study area. Conditioning factors such as slope degree, slope aspect, altitude, plan curvature, profile curvature, surface area ratio, topographic position index, topographic wetness index, stream power index, slope length, lithology, land use, normalized difference vegetation index, distance from faults, distance from rivers, distance from roads, and drainage density are used for landslide susceptibility mapping. Of 528 landslide locations, 70 % were used in landslide susceptibility mapping, and the remaining 30 % were used for validation of the maps. Using the above conditioning factors, landslide susceptibility was calculated using SMCE and PLR models, and the results were plotted in ILWIS-GIS. Finally, the two landslide susceptibility maps were validated using receiver operating characteristic curves and seed cell area index methods. The validation results showed that area under the curve for SMCE and PLR models is 76.16 and 80.98 %, respectively. The results obtained in this study also showed that the probabilistic likelihood ratio model performed slightly better than the spatial multi-criteria evaluation. These landslide susceptibility maps can be used for preliminary land use planning and hazard mitigation purpose.  相似文献   

16.
The amount of pollution from non-point sources flowing in the streams of the Wujiang River watershed in Guizhou Province, SW China, is estimated by a GIS-based method using rainfall, surface runoff and land use data. A grid of cells, 100 m in size, is laid over the landscape. For each cell, mean annual surface runoff is estimated from rainfall and percent land use, and expected pollutant concentration is estimated from land use. The product of surface runoff and concentration gives expected pollutant loading from that cell. These loadings are accumulated going downstream to give expected annual pollutant loadings in streams and rivers. By dividing these accumulated loadings by the similarly accumulated mean annual surface runoff, the expected pollutant concentration from non-point sources is determined for each location in a stream or river. Observed pollutant concentrations in the watershed are averaged at each sample point and compared to the expected concentrations at the same locations determined from the grid cell model. In general, annual non-point source nutrient loadings in the Wujiang River watershed are seen to be predominantly from the agricultural and meadow areas.  相似文献   

17.
Primary sedimentary structures and sedimentary textures of the Pleistocene fluvial sediments of the Columbia Formation were investigated both in the outcrops and in the subsurface. Three hundred and thirty-one subsurface samples, taken from forty holes, and fifty-six outcrop samples were analysed in the laboratory and the results were statistically treated. Unknown sedimentary structures were recognized in the subsurface by correlating some textural parameters (mean grain size, skewness, and kurtosis) of the drilling (subsurface) samples with those of the outcrop samples where the sedimentary structures were known. The utilization of both the sedimentary structures and the textures made it possible to recognize major morphologic elements of a Pleistocene stream system (channels, channel bars, floodbasins, and channel-fills) in the subsurface and to reconstruct, in a general way, the events that occurred during the existence of the stream system. It seems that in the initial stages of the Columbia deposition, the streams were confined to the valleys in the underlying surface made up of the Palaeocene-Eocene glauconitic greensands. After the valleys were filled with the Pleistocene sediments, the streams were able to shift their channels freely throughout the study area; at least two new tributary streams were added to the system and a major flood occurred during that time. Although the technique of the recognition of primary sedimentary structures in the subsurface employed in this study has shown useful in the interpretation of the fluvial sedimentary bodies, it needs further testing before it can be accepted as a new geologic tool.  相似文献   

18.
El Bahariya Oasis is a part of the great groundwater reservoir of the Western Desert of Egypt. The different stratigraphic units, the water-bearing zones, aquifer potentiality conditions, and the favorable locations for drilling new wells were evaluated by carrying out 24 Schlumberger vertical electrical soundings (VESs), along with the data of some wells drilled in the near vicinity of the measuring sites. The results of the interpreted field data revealed the presence of ten distinctive subsurface geoelectric layers; a thin surface, dry loose sand and gravel, sandy clay and shale interclations, saturated coarse sand layer, shale and clay, and saturated fine sandstone and saturated coarse sandstone. The aquifer is a multilayer aquifer with different thicknesses represented by the fourth, sixth, eighth, and tenth geoelectric layers. Results also revealed that the thicknesses of the water-bearing horizons increase towards the east direction, consequently the aquifer potentiality increases. Therefore, the best production well locations are in that direction. Depth to water starts from 40 m at VES no. 14 and increases gradually toward the east to reach 66 m at VES no. 5. Hydrogeochemical analysis of two groundwater samples taken from Ein El Ezza and well no. 2 showed that groundwater in the study area is suitable for agricultural purposes but not for human consumption due to the high iron content. Recommendations concerning site selection for drilling new productive groundwater wells are given.  相似文献   

19.
库车前陆褶皱-冲断带盐构造差异变形和分段性特征探讨   总被引:11,自引:6,他引:11  
通过野外地质调查、GIS分析、三维可视化分析、盐相关构造变形样式的探讨、平衡剖面分析以及缩短量和缩短率的估算,表明库车前陆褶皱—冲断带盐构造具有明显的差异变形和分段性特征。差异变形主要表现为纵向上不同层次变形的差异性以及平面上构造变形的分带性与分段性。段与段的分界一般为走滑断层,在野外可见大量断层三角面、擦痕、阶步、错断的山脊和河谷等现象,地貌GIS分析可以揭示一些构造分段的细节特征,三维可视化反映了隐伏的残留盐枕的分段性。不同的段具有迥然不同的构造变形样式,平衡剖面分析可以估算出不同段落缩短量和缩短率的明显差异。盐构造差异变形和分段性的形成一方面受控于天山造山带的分段性活动过程,还和盐岩层本身的沉积学特征及盐体展布格局有关,同时还明显受到基底构造的控制,与基底古隆起、基底断裂及古构造断坡的发育密切相关。  相似文献   

20.
The purpose of the current study is to produce landslide susceptibility maps using different data mining models. Four modeling techniques, namely random forest (RF), boosted regression tree (BRT), classification and regression tree (CART), and general linear (GLM) are used, and their results are compared for landslides susceptibility mapping at the Wadi Tayyah Basin, Asir Region, Saudi Arabia. Landslide locations were identified and mapped from the interpretation of different data types, including high-resolution satellite images, topographic maps, historical records, and extensive field surveys. In total, 125 landslide locations were mapped using ArcGIS 10.2, and the locations were divided into two groups; training (70 %) and validating (25 %), respectively. Eleven layers of landslide-conditioning factors were prepared, including slope aspect, altitude, distance from faults, lithology, plan curvature, profile curvature, rainfall, distance from streams, distance from roads, slope angle, and land use. The relationships between the landslide-conditioning factors and the landslide inventory map were calculated using the mentioned 32 models (RF, BRT, CART, and generalized additive (GAM)). The models’ results were compared with landslide locations, which were not used during the models’ training. The receiver operating characteristics (ROC), including the area under the curve (AUC), was used to assess the accuracy of the models. The success (training data) and prediction (validation data) rate curves were calculated. The results showed that the AUC for success rates are 0.783 (78.3 %), 0.958 (95.8 %), 0.816 (81.6 %), and 0.821 (82.1 %) for RF, BRT, CART, and GLM models, respectively. The prediction rates are 0.812 (81.2 %), 0.856 (85.6 %), 0.862 (86.2 %), and 0.769 (76.9 %) for RF, BRT, CART, and GLM models, respectively. Subsequently, landslide susceptibility maps were divided into four classes, including low, moderate, high, and very high susceptibility. The results revealed that the RF, BRT, CART, and GLM models produced reasonable accuracy in landslide susceptibility mapping. The outcome maps would be useful for general planned development activities in the future, such as choosing new urban areas and infrastructural activities, as well as for environmental protection.  相似文献   

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