A Manual Method for Selecting Depression Contour Lines in ArcGIS
This study describes a manual method that can be used to evaluate contour lines and select those that are depression contour lines within ArcGIS platform. The method involves adding extra fields to the attribute table of the contour lines, using a layer symbology or color codes for contour lines that portrays progressive contour values, identifying depression contour based on repetition of colors, and assigning 1 to depression contours and 0 to rest of the contour lines in a specific field of the attribute table.
The objectives of this study were to - 1) find a quick, easy and simple method to select depression contours from a contour map produced from high resolution DEM, and 2) use the closed depressions for sinkhole study. The result from this study showed that this method was fast and easy depending on the contour interval and can be applied to larger areas.