BASIN INSERTION IN HYDROLOGIC RISK

Basin's identification features within the program can be done from Numeric Input or Graphic Input menus.

The Numerical Input can be activated from the Input data menu. At the first level of this window must be filled in the coordinates that define the basin's extension (X, Y, Z), its external vertices and the main reach's vertices.

At the second level secondary reaches' vertices are entered (ramifications that meet in the main reach).

At the third level are defined the transversal section coordinates and at the last level of input the eventual sub-basins coordinates (alimentation areas for the main reaches) are specified.

Graphic Input gives the possibility to determine the basin with the help of the mouse.

This type of input is based on a raster base (mapping scanning) that is inserted into the program.

For both the cases (numerical or graphic input) the program converts the declared data into a Digital Terrain Model (DEM, Digital Elevation Model) of triangular network. Every point is connected to the other by Deluney's triangular elements method.

It is clear that the net generated this way depends on the triangles' dimensions and therefore on the number of point filled in by the user.