DIGITAL TERRAIN MODEL VS. CONTOURS HOW TO
DIGITAL TERRAIN MODEL VS. CONTOURS PC

is the hydrography file associated with this quad. 29elu.Z is a UNIX-compressed USGS ASCII file that is 2,443 KB. Select and download 29elu.Z and to the DEMWORK folder. This brings up a page showing the zipped USGS DEM files for this quad.

Use the map's reference grid to locate and click on quad S 29 (Homer), the northwest quad in Cortland County.

Visit the Cornell University's Geospatial Information Repository (CUGIR)to download project data files.

Create a new folder named DEMWORK to hold downloaded data files.

Locating and downloading the sample data set is the first step in this project. On converting and importing DEM files is available from theР”Р„rcView GIS OnLine Discussion Forum at the Esri Web site.

DIGITAL TERRAIN MODEL VS. CONTOURS HOW TO

How to prepare DEM data downloaded from the USGS Web site using a free utility. 'Converting and Using SDTS Digital Elevation Model Data,' describes Another article in this issue of ArcUser magazine, This project uses a DEM file downloaded from a source that provides converted 7.5' DEM coverages Ordering DEM data sets can be obtained at the USGS Web site. Details regarding available coverages and procedures for DEM dataР”Р„t this scale is particularly useful because each data set provides the same large-scale coverage as a Terrain models constructedР”Р‡rom elevation data can be used for a variety of purposes including line-of-sight forecasting, slopeР”Р„nd aspect determination, surface runoff pattern analysis, and drainage basin delineation. USGS 7.5' DEM, a raster data set containing elevation information, has 10 x 10 meter data spacing.Р”Р„fter converting the data, it can be easily imported into ArcView GIS. Visit the Terrain Modeling with ArcView GIS for additional resources for modeling with ArcView GIS. Large model, working with a smaller model while learning these techniques might be a good idea. Even if the computer used for modeling is sufficiently robust to render a 'Making Data More Manageable.' This article explains how to create a custom theme thatР”В¬an speed navigation and improve refresh rates. Steps for reducing the size of the area modeled by clipping the contour line theme are described in the accompanying article, He gives additional instructions on how to produceР”Р„ three-dimensional model by draping and modeling two-dimensional With the contour line theme, a triangulated irregular network (TIN) model can be built.

DIGITAL TERRAIN MODEL VS. CONTOURS PC

Pentium-class PC with 64 MB RAM suggested.Р”В¬ompute an attractive hillshaded map, and create a contour line theme. Using ArcView Spatial Analyst, the author tells how to output a grid theme that can be used to Perform two-dimensional and three-dimensional modeling in ArcView GIS with the ArcView Spatial Analyst and ArcView Editor's Note: This article describes how to use sample 1:24,000-scale 7.5' digital elevation model (DEM) data files to

Digital terrain model vs. contours