The following steps will guide you through the process of creating contour lines or polygons based on DEM grid data using the “Raster to Contour” tool in your GIS software. Contour lines or polygons represent elevation information and can be valuable for various spatial analyses and visualization purposes.
Step 1: Launch the Tool
1. Click on GIS Tools tab and navigate to the toolset or menu that includes the “Raster to Contour” option.
2. Click on “Raster to Contour” to launch the tool.
Step 2: Select the DEM
1. In the tool interface window, locate the dropdown menu in front of the “Raster” option.
2. Choose your DEM (Digital Elevation Model) from the available options.
Step 3: Specify Contour Generation Parameters
In the tool interface, you will find several parameters that control the contour generation process. Let’s go through each of them:
a. Output Mode: Select the type of contour output you desire, either as lines or polygons.
b. Base: Specify the reference value relative to which contour intervals will be applied. This value helps define the starting point for the contour lines.
c. Minimum length/area: Set the minimum dimension for the generated features. For polylines, this represents the minimum length, while for polygons, it represents the minimum area.
d. Interval Size: Set the desired elevation interval between the generated contours.
e. Smooth factor: If the “Smooth Factor” option is checked, adjust the smooth factor to control the degree of smoothing. Higher values produce smoother lines or polygons.
Step 4: Specify Output Settings
1. In the tool interface, locate the “Output Folder Path” field.
2. Choose or specify a location where you want to save the generated contour file. Note: If you have previously saved your project, this field may already have a directory path pointing to the saved project.
Step 5: Execute the Tool
Click the “Run” or “Execute” button to initiate the contour generation process.
Step 6: Review and Utilize the Generated Contour Data
Once the tool completes its execution, you will find the generated contour lines or polygons in the specified output folder.