Using GIS & RS in Mass Movements Hazard Zonation - A case study in Germichay Watershed, Ardebil, Iran
PHD student of Watershed Management, Natural Resources Faculty, Tehran University, Karaj, Iran
Email : Yashar_esmi@yahoo.com
Full Professor of Natural Resources Faculty, Tehran University, Karaj, Iran
As a final goal, the investigation and studying of landslides is to find ways to reduce their damages. This objective is possible via different ways such as landslides hazard zonation for determining the hazardous areas and providing recipes and regulations for appropriate uses of these areas or for keep away from they. Also it can be earned by studying a one landslide and presenting ways to control it.
In the course of 1980 decade, using of GIS for supplying the slope instability map was accelerated as the result of developing commercial GIS systems such as Idrisi, Arc / Info, ArcView, Ilwis, Spans, Intergraph and increasing the abilities of PC-based platforms. In this decade, many of studies about GIS were to zonate the landslides hazard qualitatively. The application of GIS in mass movements hazard zonation is to providing the maps with high speed and accuracy. Some of the maps are DEM, slope, aspect, altitude, lineament factors, precipitation, lithology etc. Also the application of RS is very appropriate in providing the land use map. Therefore the using of GIS & RS must always be as a recipe of a natural resources expert and to use it as an instrument.
Nagarajan et al (1998) in part of western ghat in India used temporal remote sensing and GIS techniques to zonate the landslide hazard and said that their works were too successful in comparing with previous manual methods.
Hassanzadeh (2000) has been used the Multiple Regression method and GIS technique for landslides hazard zonation with using four factors lithology, slope angle, precipitation and land use, and has been assessed the results very successful .
Germichay watershed was selected for this study that runs from 48? 1? to 48? 10? eastern longitude and from 38? 54? to 39? 12? northern latitude. This watershed is a part of Ardebil province, Iran, and reaches from north and south to Azerbayjan republic, from east reaches to Arazchay watershed and from west reaches to Sarighamishchay watershed. This watershed contains Germi City that lies in it center. Its area is about 180 km2 that 55% of it is mountainous and 45% of it is the plain areas.