00:00

Understanding Digital Elevation Models in GIS and Remote Sensing

Digital Elevation Models (DEMs) play a crucial role in analyzing topography for various applications in GIS and Remote Sensing. They can be derived from different sources such as point elevation data, contour lines, remotely sensed data, etc. DEMs help in determining terrain characteristics, slope, aspect, watersheds, and drainage networks. Various techniques like LiDAR, photogrammetry, and InSAR are used to generate DEMs which can be further used for hazard analysis and other spatial studies.

plensa
Download Presentation

Understanding Digital Elevation Models in GIS and Remote Sensing

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GIS & REMOTE SENSING Subject: GIS Studio Topic: Topography and GIS 2 Presented by: Pallavi Tiwari

  2. Digital Elevation Models Using elevation data in raster format in a GIS

  3. Basic storage of data Digital representation of topography 340 335 330 340 345 Cell based with a single elevation representing the entire area of the cell 337 332 330 335 340 330 328 320 330 335 328 326 310 320 328 320 318 305 312 315 DEM as matrix of elevations with a uniform cell size

  4. Digital Terrain Model (DTM) is a DEM of the shape of the ground surface. Digital Surface Model (DSM) is a DEM of the shape of the surface, including vegetation, infra-structures etc. Both a DTM and DSM can be a DEM and, moreover, “elevation” would not have to relate to terrain but could relate to some subsurface layer such as groundwater layers, soil layers or the ocean floor.

  5. Different sources of elevation data •Point elevation data •Contour and stream-line data •Space-borne and air-borne remotely sensed elevation data

  6. As topography is one of the major factors in most types of hazard analysis, the generation of a Digital Elevation Model (DEM) plays a major role. Digital Elevation Models (DEMs) can be derived through a variety of techniques, such as digitizing contours from existing topographic maps, topographic levelling, EDM (Electronic Distance Measurement), differential GPS measurements, (digital) photogrammetry, Radar remote sensing (InSAR), and Light Detection and Ranging (LiDAR). Many derivate maps can be produced from DEMs using fairly simple GIS operations. These days a wide range of data sources can be selected for the generation of DEMs. The selection depends on the data availability for a specific area, the price and the application.

  7. Uses of DEMs  Determine characteristics of terrain  Slope, aspect  Watersheds  drainage networks, stream channels

More Related