The "Total Effective Drainage Areas of the AAFC Watersheds Project – 2013” dataset is a geospatial data layer containing polygon features representing the areas within the “total gross drainage areas” of each hydrometric gauging station of the Agriculture and Agri-Food Canada (AAFC) Watersheds Project that would contribute to average runoff.
A ‘total gross drainage area’ is the maximum area that could contribute runoff for a single gauging station – the ‘total effective drainage areas’ are those parts of that ‘total gross drainage area’ that would contribute surface runoff to an average runoff. For each “total gross drainage area” there can be only one “total effective drainage areas”.
These polygons may overlap with those from other gauging stations’ “total gross drainage area”, as upstream land surfaces form part of multiple downstream gauging stations’ “total gross drainage areas”.