How to map SLC data

Background

SLC version 2.2 introduced a new data structure in which hydrographic information in the HYDRO coverage is fully separated from the SLC coverage. The boundaries of the SLC polygons now extend to arbitrary locations within the water bodies visible on the HYDRO coverage. (For an understanding of why this was done, see the rationale.) As a result, mapping the SLC coverage in isolation will now produce a plot that gives no indication of where shorelines and water bodies are found.

In order to properly represent the SLC data, the HYDRO coverage must be used to mask out areas of the map that are actually water bodies. This procedure is illustrated for ARCVIEW, but is applicable to all GIS systems that can display more than one coverage (layer or theme) at a time.

Instructions

1. Add the SLC coverage as a theme.
2. Join to the PAT any attribute information that is to be mapped (see how to map component table attributes), and display the appropriate information.
3. Add the HYDRO coverage as a layer above the SLC coverage.
4. Display the "TYPE" field of the HYDRO coverage in such a way that:
   • land areas (L) are transparent;
   • ocean areas (O) are shown in an appropriate (opaque) hue;
   • fresh water (W) is shown in an appropriate (opaque) hue.
   You can do so by loading this arcview legend file.

effective version 2.2 Source: Peter Schut
Contact: Head, CanSIS