International river basins are characterized by their wide extent where mapping earth
surface features and drawing contours by topographic team become–somehow- impossible
because the cost and efforts consumed to execute it become very high and may
exceed
reasonable limits. Here it becomes necessary to use digital elevation models (DEM)
inferred by specialized scientific organizations using remote sensing.
There are several DEMs available on the internet and downloadable for free. The
primary factor in defining the models efficiency in building hydrological models not the
least cost but the maximum reliable results and better resolution that adequate to the
capabilities of the PCs.
In this study, three DEMs were used to derive and build hydrological models for the
Euphrates-Tigris basin using Geographic information system techniques. The resulted
boundaries of Euphrates-Tigris basin were compared with three boundaries implemented
by international research organizations (UNEP, ESCWA, and FAO). As a conclusion of
this comparison, the SRTM—3arc DEM was the most efficient model among used models.
In addition, this study indicated the necessity to reevaluate Basin’s boundaries and correct
the spatial distribution of proportion for basin area between the riparian countries.
