A study of geomorphologic factors restricting the expansion of Ardebil city using analytical hierarchy process (AHP)

Cities occupy vast and expansive terrain.  Land is composed of several topographic and geomorphological units. As cities expand and develop, they encounter with topographic and geomorphologic units and issues pertaining to them also increase. Ardebil with its increasing population and urban sprawl is a city that is not an exception to this rule and its expansion has been influenced by the dynamics of the natural environment. In this paper, the hindrances to the expansion of this city, often due to geomorphologic factors, are discussed. To this end, topographic maps of 1:5000 and geological maps of 1:100000 were prepared followed by a field study that yielded images of geomorphologic phenomena in the region.  After matching the maps with the geomorphologic phenomena in the region, these maps were scanned in Arc view GIS, digitalized and theme maps of altitude, slope, slope direction, lithology were prepared.  The values of each of these factors were determined using the AHP, and faults, networks of watersheds, slopes, slope direction, thickness of matrices etc were plotted on lithology maps in GIS environment. Finally, after overlaying the maps, sensitive and susceptible points of the region were identified and zonation maps of unstable and sensitive points were prepared in GIS environment.