Abstract:
A method for delineating watersheds by computer using digital
elevation model (OEM) data is presented. The five steps in this
process are detailed and examples are shown. The algorithm was tested
using a manually created OEM for a small area in Northern
California. Three basins were delineated using the delineation
algorithm and compared to the same basins delineated by manual map
interpretation. The computer basins correlated closely to the
manually delineated ones with correlation factors of around 75%.
A second test of the algorithm was made to determine the effects
of OEM resolution on the correlation factors. Four DEMs with cell
sizes ranging from 333 feet to 1000 feet on the ground were used. As
the OEM resolution became finer the correlation factor declined. The
correlation factors ranged from 73% to 92%.
The significance of these results and areas for further research
are discussed.
