Ezatollah  Ghanavati, Ehsan Amir  Yazdadi, 
    Landslide Hazard Zonation by Using AHP (Analytical Hierarchy Process)
Model in GIS (Geographic Information System) Environment
(Case Study: Kordan Watershed),
    Research Journal of Applied Sciences,
    Volume 12,Issue 2,
    2017,
    Pages 161-173,
    ISSN 1815-932x,
    rjasci.2017.161.173,
    (https://makhillpublications.co/view-article.php?doi=rjasci.2017.161.173)
    Abstract: Landslides are one of the critical phenomena that frequently lead to loss of human life and property
as well as causing severe damage to natural resources. Kordan watershed located in the Alborz Province which
including areas that are prone to landslide. The area under investigation is located from 50°45-05°51' East
longitude and 35°55'-36°05' North with expansion of about 488 km2 and elevation ranges from 1320-3900 m. The
purpose of this study is to identify factors in landslides and zonate landslide hazard of Kordan watershed using
AHP (Analytical Hierarchy Process) model in GIS environment. In this study, 4 factors, namely geology,
hydrology, human and geomorphology were identified as important factors that could play an important role
in Landslide watershed. In this study, geological mapping, using topographic maps and satellite images of the
study area and data layers of various factors including lithology, fault, land use, roads, residential areas, slope
aspect, elevation, rainfall, temperature, congestion and drainage system in GIS using ArcGIS Software has been
developed and weight and relative importance of each factor in landslide hazard zonation with Analytical
Hierarchy Process (AHP) were determined. Among the effective factors, sub-criteria of lithology, distance from
the river, distance from fault, landuse and rainfall, respectively with weights 0.314, 0.219, 0.105, 0.086 and 0.054
have been identified as the most important factors in the development of landslide in study area that In total,
form up >75% of the total weight. The role of other factors reduces according to their weights in landslide. The
final cumulative map of study area was categorized into four hazard zones and classified as zone 1-4 (very low
risk, low risk, medium risk and high risk). According to presented model and final zonation map, about
34% (30 km<sup>2</sup>) of Kordan watershed area have the occurrence of high risk and about 29.16% (142.386 km<sup>2</sup>) have
the occurrence of moderate risk. As a result of the zonation performed according to the layers, most sensitive
parts of the landslides are locted in the basin quaternary deposits and the banks of rivers. The landslide hazard
zonation map is useful for landslide hazard prevention, mitigration and improvement to society and proper
palnning for land use and construction in the future.
    Keywords: analytical hierarchy;Kordan;Alborz;Zonation of landslide;process