Existing databases were revised, updated, and imported into the ArcGIS software to provide separate
layers on the maps created for study area. The most important GIS layers include roads, waterways,
boundaries and names of community centres, rainfall, river sampling points, chemical data recorded, etc.
- icularly useful in
relating population density and human activities to water quality. As for any contemporary GIS system,
individual layers can be selected and merged arbitrarily for processing and display. From the default
resolution (provincial-level map), users can zoom in areas of interest, show all or only selected layers,
including topography that is useful in hydrological queries, townships, roads, rivers and streams, lakes
and reservoirs, and property ownership maps.