TITLE:
Landslide Susceptibility Estimation Using GIS. Evritania Prefecture: A Case Study in Greece
AUTHORS:
Georgios Ntelis, Stavropoulou Maria, Lekkas Efthymios
KEYWORDS:
Natural Hazards, Landslide Susceptibility, Frequency Ratio
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.7 No.8,
August
26,
2019
ABSTRACT: Nowadays, natural hazards constitute an integral
part in the everyday reality of people’s lives. A landslide event, although
usually occurring at a low frequency (compared to other hazards), may develop
into a major natural disaster involving extensive and adverse effects, both in
the natural and man-made environment. Thus, by making this assumption and
combining it with the human mentality that has the tendency to reassure and
resist extreme physical processes, the underlying danger “in total”, is
multiple of what is expected. Therefore, studying of this phenomenon is so
important in many areas. Because of the climate conditions, geologic and
geomorphologic characteristics of the region, the purpose of this study was the
landslide hazard assessment by using Fuzzy Logic, Frequency Ratio and
Analytical Hierarchy Process method in the Evritania prefecture. At first,
landslides occurring in Evritania prefecture,
were identified using a landslide database from Institute of Geology &
Mineral Exploration of Greece and by primary field studies. The influence landslide factors used in this study were
slope, aspect, elevation, lithology, precipitation, land cover, distance from
faults and distance from rivers, were obtained from different sources and maps.
Using these factors and the identified landslides, the fuzzy membership values
were calculated by frequency ratio. Then, to account for the importance of each
of the parameters in the landslide susceptibility, weights of each factor were
determined based on the Analytical Hierarchy Process method. Finally, fuzzy map
of each factor was multiplied to its weight that obtained using AHP method and
at the end—for computing prediction accuracy—the produced map was verified by
comparing to existing landslide locations. These results indicate that the
three methods Fuzzy Logic, Frequency Ratio and Analytical Hierarchy Process
method are relatively good estimators of landslide susceptibility in the study
area. According to landslide susceptibility area map, about 50% of the occurred
landslide fall into high and very high susceptibility zones and also approximately
21% of them indeed located in the low and very low susceptibility zones.