Abstract: In recent years, geographic information systems (GIS)
and remote sensing using has increased to estimate runoff catchment.
In this research, runoff curve number maps for captive catchment of
Tehran by helping GIS and also remote sensing which based on
factors such as vegetation, lands using, group of soil hydrology and
hydrological conditions were obtained. Runoff curve numbers map
was obtained by combining these maps in ARC GIS and SCS table.
To evaluate the accuracy of the results, the maximum flow rate of
flood which was obtained from curve numbers, was compared with
the measured maximum flood rate at the watershed outlet and
correctness of curve numbers were approved.
Abstract: In this research, a part of Aghche basin in Isfahan
province with an area about 2000 hectars, was chosen to be obtain
curve number coefficient runoff and W indicator in second Cook
method By using aerial photos 1968 and 1995, the satellite data of
the IRS in 2008. Then the process of land use changes in the period
of study and its effect on the changes of curve number (CN), W
indicator and surface runoff coefficient (C) of the basin was
investigated. These results showed that on the track of these land use
changes the weight averages curve number (CN), surface runoff
coefficient (C) and W indicator of the basin were increased to 0.92,
0.02 and 0.78 unit in the first period of study and 1.18, 0.03, 0.99
Unit in the second period of study respectively.