Athens lies 5 miles (8 km) from the Bay of Phaleron, an inlet of the Aegean (Aigaíon) Sea where Piraeus (Piraiévs), the port of Athens, is situated, in a mountain-girt arid basin divided north-south by a line of hills.
Drainage density is calculated as the total length of all the streams and rivers in a basin divided by the total area of the drainage basin.
The West Bokaro coalfield is broadly divided into two sub-basins: the Northern Sub-basin and the Southern Sub-basin, divided by the Archean highland around Mandu.
Under the Colorado River Compact of 1922, the Upper and Lower Basins divided the river with the Upper Basin assuring the Lower of an average of 7.5 million acre-feet (maf) of water per year delivered to Lees Ferry Arizona, the dividing point between the two.
The Colorado River Compact of 1922 apportioned an equal portion of the river's flow to the Upper Basin (the U.S. states of Colorado, New Mexico, Utah, Wyoming and northern Arizona) and the Lower Basin (Arizona, California and Nevada), with the individual "basins" divided by an imaginary line at Lee's Ferry.
Model has capability to delineate the DEM into watershed or basin and divided into sub-basin.
Ankaratra is a major watershed divide separating three main river basins.
According to the maximum depths of basins, we divide them into shallow basins (<2,000 m), middle basins (2,000 4,500 m), deep basins (4,500 6,000 m), and ultra-deep basins (>6,000 m).
The technique applied generally during these studies is to create a Digital Elevation Model (DEM) of the studied area and make an output model subject to the ArcMap Hydrologic Modelling Extension (ESRI) application, and so to yield a map outlining basin water divide lines (Fig. 4).
The sea's basin is divided into four physiographic areas.
