GIS based natural disaster mapping: A case study

Sebinkarahisar Township which has been selected as study area is located between Black Sea and Central Anatolian Regions. Not only geological characters but also social life in the township had been affected by these two regions. History of the settlements goes back to early Hittite period. Even it was a province in the first years of Turkish Republic, today it is a township belongs to Giresun province. Landslide is one of the most effective natural disasters in the region. Due to wrong decisions of local authorities caused lots of damage, during the last two decades. Firmly some part of the city, which has the highest landslide risk, is prohibited for new settlement, and some studies (still at beginning level) had been carried out. In this study, morphology, geology, land cover, slope inclination, elevation of the region is investigated. 1:25000 standard topographic and 1:25000 standard geological maps are scanned and referenced geographically by using Topol software. Contours, settlements, roads, meadows, and forests are digitised from the geo-referenced topographic map and different geological formations are digitised from the geo-referenced geological map. These layers are saved as blocks. By extrapolating method, the third dimensions of these blocks are reedited from the contours using QuickSurf module of AutoCad software. These blocks are added to ArcView software and digital elevation model is produced. Also the reasons of the occurred landslides are investigated and they are added to ArcView software. Finally the region classified by the amount of their potential landslide risks and risk map is produced. The aim of this study is; producing a landslide risk map and giving some precautions before the planning of the settlement.