scholarly journals Analysis of Landslide Prone Areas in Tampahan, Toba Samosir Regency, North Sumatra Province

2020 ◽  
Vol 1 (1) ◽  
pp. 25-30
Author(s):  
Winda Lestari Turnip
Keyword(s):  
Land Use ◽  
Digital Elevation Model ◽  
Spatial Data ◽  
Field Data ◽  
Class Interval ◽  
Digital Elevation ◽  
Elevation Model ◽  
North Sumatra ◽  
Toba Caldera

The topography of the Tampahan area which tends to be steep and dominated by tuff lithology can result in a landslide. The intensity of landslides and the resulting losses can be reduced by the analysis of landslide-prone areas in Tampahan. The administration of the area is located in Toba Samosir Regency, North Sumatra Province which is included in the Toba Caldera Region. Analysis of landslide-prone areas is carried out with five parameters namely slope, land use, morphological elevation, lithology, and rainfall. The data processed in this analysis comes from field data, DEMNas (National Digital Elevation Model), and other spatial data. Classification of each parameter and weighting based on literature is away in the analysis of landslide-prone areas of Tampahan. Then do each parameter overlay to get the value of landslide-prone and distinguished based on the calculation of the landslide class interval. The results are divided into five classes that are prone to landslides, namely classes not prone (1-1,8), rather prone (1,8-2,6), quite prone (2,6-3,4), prone (3,4-4,2), and very prone (4,2-5). Based on the analysis that has been done, some areas are very prone to landslides in the southeast while areas that are not prone to landslides are in the southwest of the study area. Therefore, landslide-prone studies are categorized as high landslides with almost 60% coverage of the study area.

scholarly journals Impacts of spatial data resolution on simulated discharge, a case study of Xitiaoxi catchment in South China

2009 ◽  
Vol 21 ◽  
pp. 131-137 ◽  
Author(s):  
G. J. Zhao ◽  
G. Hörmann ◽  
N. Fohrer ◽  
J. F. Gao
Keyword(s):  
Land Use ◽  
Cell Size ◽  
Digital Elevation Model ◽  
South China ◽  
Spatial Data ◽  
Input Data ◽  
Grid Size ◽  
Digital Elevation ◽  
Data Resolution ◽  
Elevation Model

Abstract. In this paper we analyse the effects of different spatial input data resolution on water balance simulation using a simple distributed hydrological model: PCR-XAJ model. A data set consisting of land use and digital elevation model at 25 m resolution of Xitiaoxi catchment in South China is used for investigation. The model was first calibrated and validated at 50 m cell size, thereafter an aggregation of the digital elevation model (DEM) and land use maps at 100 m, 200 m, 300 m, 500 m and 1 km are applied to evaluate the effects of spatial data resolution on simulated discharge. The simulation results at a grid size of 50 m show a good correlation between measured and simulated daily flows at Hengtangcun station with Nash-Suttcliffe efficiency larger than 0.75 for both calibration and validation periods. In contrast, the model performs slightly worse at Fanjiacun station. The increasing grid size affects the characteristics of the slope and land use aggregation and causes important information loss. The aggregation of input data does not lead to significant errors up to a grid of 1 km. Model efficiencies decrease slightly with cell size increasing, and more significantly up to the grid size of 1 km.

scholarly journals Automated Conflation of Digital Elevation Model with Reference Hydrographic Lines

2020 ◽  
Vol 9 (5) ◽  
pp. 334
Author(s):  
Timofey E. Samsonov
Keyword(s):  
Spatial Analysis ◽  
Digital Elevation Model ◽  
Spatial Data ◽  
Drainage Network ◽  
Map Generalization ◽  
Data Types ◽  
Digital Elevation ◽  
Elevation Data ◽  
Elevation Model ◽  
Different Sources

Combining misaligned spatial data from different sources complicates spatial analysis and creation of maps. Conflation is a process that solves the misalignment problem through spatial adjustment or attribute transfer between similar features in two datasets. Even though a combination of digital elevation model (DEM) and vector hydrographic lines is a common practice in spatial analysis and mapping, no method for automated conflation between these spatial data types has been developed so far. The problem of DEM and hydrography misalignment arises not only in map compilation, but also during the production of generalized datasets. There is a lack of automated solutions which can ensure that the drainage network represented in the surface of generalized DEM is spatially adjusted with independently generalized vector hydrography. We propose a new method that performs the conflation of DEM with linear hydrographic data and is embeddable into DEM generalization process. Given a set of reference hydrographic lines, our method automatically recognizes the most similar paths on DEM surface called counterpart streams. The elevation data extracted from DEM is then rubbersheeted locally using the links between counterpart streams and reference lines, and the conflated DEM is reconstructed from the rubbersheeted elevation data. The algorithm developed for extraction of counterpart streams ensures that the resulting set of lines comprises the network similar to the network of ordered reference lines. We also show how our approach can be seamlessly integrated into a TIN-based structural DEM generalization process with spatial adjustment to pre-generalized hydrographic lines as additional requirement. The combination of the GEBCO_2019 DEM and the Natural Earth 10M vector dataset is used to illustrate the effectiveness of DEM conflation both in map compilation and map generalization workflows. Resulting maps are geographically correct and are aesthetically more pleasing in comparison to a straightforward combination of misaligned DEM and hydrographic lines without conflation.

scholarly journals Extração de Atributos Morfométricos da Serra Mossoró (Mossoró-RN) a Partir do Modelo de Elevação Digital (MDE)

2020 ◽  
Vol 12 (6) ◽  
pp. 2239
Author(s):  
Gutemberg Henrique Dias ◽  
João Paulo Bezerra Rodrigues ◽  
Francisco Sérgio Coelho ◽  
Robson Fernandes Filgueira ◽  
Filipe Silva Peixoto
Keyword(s):  
Digital Elevation Model ◽  
Sedimentary Basin ◽  
Rio Grande ◽  
Field Observations ◽  
Accurate Calculation ◽  
Mapping Software ◽  
Potiguar Basin ◽  
Digital Elevation ◽  
Elevation Model

Por possibilitar o cálculo rápido e preciso de variáveis associadas ao relevo, nas últimas décadas, o aprimoramento do Modelo Digital de Elevação (MDE) tem contribuído bastante para a pesquisa geomorfológica, particularmente em áreas de bacias sedimentares. No setor noroeste da Bacia Potiguar, no município de Mossoró, estado do Rio Grande do Norte, existe uma elevação que se destaca em meio ao relevo plano, conhecida como Serra Mossoró. Apesar da importância da região no que se refere à exploração de água subterrânea, prospecção de petróleo e fruticultura tropical, os trabalhos já produzidos sobre esta forma de relevo são escassos e superficiais. Este trabalho tem como objetivo realizar a extração de atributos morfométricos da Serra Mossoró e de suas adjacências a partir de Modelo de Elevação Digital (MDE), de modo a precisar a classificação deste relevo e correlaciona-lo com a neotectônica regional. Pesquisa bibliográfica, tratamento de imagens orbitais georreferenciadas com software de mapeamento e observações de campo possibilitaram a elaboração dos mapas hipsométrico, de relevo sombreado (hillshade) e clinométrico. A análise dos dados hipsométricos evidencia que a Serra Mossoró está estruturada em patamares e rampas, apresentando altimetria máxima de 268 metros. O mapa de relevo sombreado confirma a ocorrência de lineamentos  nos sentidos NE-SW e NW-SE, bem como, em menor proporção, no E-O, já descritos em outros trabalhos. Juntos, os mapas hipsométrico e de relevo sombreado definem a estrutura da Serra Mossoró como um inselberg de natureza sedimentar, resultante da erosão diferencial nas rochas da Bacia Potiguar.  Extraction of Morphometric Attributes from Serra Mossoró (Mossoró-RN) From the Digital Elevation Model (MDE) A B S T R A C TFor enabliling a rapid and accurate calculation of the variables associated to relief, in the last decades the enhancement of the Digital Elevation Model (DEM) has contributed greatly to geomorphological research, particularly in sedimentary basin areas. In the northwestern section of the Potiguar Basin, in the municipality of Mossoró, state of Rio Grande do Norte, there is an elevation that stands out in the middle of the flat relief known as Serra Mossoró. Despite the importance of the region in the exploration of groundwater, oil prospecting and tropical fruiticulture, the works already produced on this landform are scarce and superficial. From the analysis of morphometric attributes, this work aims to produce the DEM of Serra Mossoró and its surroundings, in order to clarify the classification of this relief and correlate it with the regional neotectonics. Bibliographical research, treatment of georeferenced orbital images with mapping software and field observations enabled the elaboration of the hypsometric, hillshade and clinometrical. The analysis of hypsometric data shows that Serra Mossoró is structured in steps and ramps, with a maximum altimetry of 268 meters. The hillshade map confirm the occurrence of lineaments in the NE-SW and NW-SE directions, as well as, to a lesser extent, in the E-O direction, already described in other works. Together, the hypsometric and hillshade maps define the Serra Mossoró structure as a sedimentary inselberg resulting from differential erosion in the rocks of the Potiguar Basin. Key words: Serra Mossoró, geologic-geomorphologic mapping, morphometric attributes, Digital Elevation Model

Estimation of solar radiation from digital elevation model in area of rough topography

2016 ◽  
Vol 13 (5) ◽  
pp. 453-460 ◽  
Author(s):  
Lurwan Mahmoud Sabo ◽  
Norman Mariun ◽  
Hashim Hizam ◽  
Mohd Amran Mohd Radzi ◽  
Azmi Zakaria
Keyword(s):  
Solar Radiation ◽  
Digital Elevation Model ◽  
Spatial Data ◽  
Energy Planning ◽  
Solar Photovoltaic ◽  
Content Type ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Impact ◽  
Topographic Parameters

Purpose The purpose of this study is to evaluate the reliability of the technique for estimating solar radiation in areas of rough topography and to detect the source of error and means for improvement. Design/methodology/approach Spatial data of the study area in the form of digital elevation model (DEM) coupled with geographic information system (GIS) were used to estimate the monthly solar radiation at locations with rough topography. The generated data were compared with measured data collected from all the selected locations using NASA data. Findings The results show that the variation in topographic parameters has a strong influence on the amount of solar radiation received by two close locations. However, the method performed well for solar radiation estimated in the areas of rough topography. Research limitations/implications The proposed approach overestimates the monthly solar radiation as compared with NASA data due to the impact of topographic parameters accounted for by the model which are not accounted by conventional methods of measurements. This approach can be improved by incorporating the reflected component of radiation in the model used to estimate the solar radiation implemented in the GIS. Originality/value The approach of using GIS with DEM to estimate solar radiation enables to identify the spatial variability in solar radiation between two closest locations due to the influence of topographic parameters, and this will assist in proper energy planning and decision making for optimal areas of solar photovoltaic installation.

scholarly journals The impact of digital elevation model and land use spatial information on Hydrologic Simulation Program-FORTRAN – predicted stream flow and sediment uncertainty

2013 ◽  
Vol 16 (5) ◽  
pp. 989-1003 ◽  
Author(s):  
Huiliang Wang ◽  
Xuyong Li ◽  
Wenzan Li ◽  
Xinzhong Du
Keyword(s):  
Land Use ◽  
Digital Elevation Model ◽  
Spatial Resolution ◽  
Simulation Program ◽  
Hydrologic Simulation ◽  
Hspf Model ◽  
Sediment Loads ◽  
Digital Elevation ◽  
Elevation Model ◽  
The Impact

The Hydrologic Simulation Program-FORTRAN (HSPF) model is widely used to develop management strategies for water resources. The spatial resolution of the input data used to parameterize the HSPF model may lead to uncertainty in model outputs. In this study, we evaluated the impact of the spatial resolution of the digital elevation model (DEM) and land use data on uncertainty in HSPF-predicted flow and sediment. The resolution of DEMs can affect stream length, watershed area, and average slope, while the resolution of land use data can influence the distribution of land use information. Results showed that DEMs and land use maps with finer resolutions generated higher flow volumes and sediment loads. There was a non-linear relationship between changes in resolution of the DEM and land use data and changes in the uncertainty of predicted flow and sediment loads. Relative error was used to describe model uncertainty and the probability density function was used to estimate these uncertainties. The best-fit distributions of uncertainty in modeled flow and sediment related to DEM and land use data resolution were the generalized Pareto distribution and the Johnson SB distribution, respectively. The results of this study provide useful information for better understanding and estimating uncertainties in the HSPF model.

scholarly journals GIS-Based Study To Develop Landslide Susceptibility Zonation Map Of District Mandi, Himachal Pradesh

2021 ◽  
Author(s):  
Sachin Verma ◽  
Vidya Sagar Khanduri
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Digital Elevation Model ◽  
Landslide Susceptibility ◽  
Drainage Density ◽  
Land Use Land Cover ◽  
Landslide Susceptibility Zonation ◽  
Zonation Map ◽  
Digital Elevation ◽  
Elevation Model

Abstract Rising Incidents of landslide at district Mandi is issue of concern in Himachal Pradesh. Every year many people losses their life and property in these landslide event. This study is conducted with aim to preparation of landslide susceptibility zonation map of district Mandi using method of frequency ratio. Causative factor of landslide involved in preparation of Landslide susceptibility zonation map is Lithology, Slope, Drainage density, Aspect and Land use land cover. Slope, Drainage density, Aspect map are extracted through digital elevation model. Source of Digital elevation model used here is based on SRTM data whereas lithology map is based on data of geological survey of India. Land use land cover map is extracted by images of Landsat 8 satellite. Total of 52 existing landslides are used to model final map. LSZ map show 40.42% area is falling under medium susceptibility class, 34.5 % under low and 25.07% is under high susceptibility class which cover tehsils Mandi, Chachyot, Thunag and some part of Padhar, Aut and Bali Chowki. Further to validate these result areas under curve (AUC) method is use which give prediction rate of 76.06%.

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