Now day GIS based suitable dam site
identification has been adaptable in order to minimize the
requirement of high cost, time, and many specialists. GISbased sensitivity analysis of factors weights reduces the
uncertainty of the final dam site suitability map and
increases confidence by avoiding the errors coming due to
an expert’s opinion suggestion. According to the GIS-based
sensitivity analysis, the cumulative geological fault
suitability class difference was the highest value and
elevation was the lowest value from different weighting. As
the suitability area difference of the geological fault at
different weighting is highest; it is the highest sensitive
factor for dam site selection in the Birr watershed and
elevation was the lowest sensitive factor as the difference of
suitability area is relatively lowest. The geological fault is
given the highest rank or preference and finally, the highest
weight and elevation are given the lowest rank and weight.
It indicates that more of the dam site suitability of the
watershed is depend on the suitability of the geological fault.
The geological fault is the highest weight (31%), foundation
geology (21%), soil texture (11%), slope (8%), erosion rate
(5%), road proximity (4%), river proximity (3%) and the
lowest weight is elevation range (2%). Dominantly the
watershed area is suitable (47.57%) and moderately
suitable (41.81%) for the dam site. GIS is software that is
able to input, manipulate, analyze, and displays the output
of spatial data. Therefore when the factor's weight is
certainly determined the final map of the watershed dam
site suitable map is also certain.
Keywords : GIS, Sensitivity, Weight, Suitable Dam Site.