Paleoflood Analysis and Flood Areas Mapping of Saricay (Canakkale) Using Geographical Information Systems (GIS)

Abstract:

Floods are one of the most damaging natural phenomenon among natural hazards. Floods damage to environment and effect socio-economic life of people. In this study defining the old stream bed and flood risk of Saricay passing through the Canakkale settlement area are aimed. The Canakkale Province is situated in the northwest of Turkey.

Geological, geomorphological, sedimentologic and hydrological properties of the region examined while investigating the flood risk of Saricay from past to present. Furthermore, stream deposits were dated using Optically Stimulated Luminescence (OSL) method. Based on the dates it was defined that Saricay bed changed approximately 30 thousand years ago. While the old bed was with NW-SE direction, now it was moved to current bed (with E-W direction) passing through the settlement area. Geological and geomorphological data were showed that Saricay bed had changed as well. Marsh land dominates far from stream bed whereas silty and sandy gravel was observed near of stream bed.

The flood risk map was carried out using GIS techniques. Processes were performed using the Spatial Analysis module of the ArcGIS 10. Five parameters such as geologic units, land use, slope, aspect and elevation were considered affecting the flood risk in this region. Sub-criterias were defined for each main parameter and susceptibility analysis was performed using weighted overlay method. Each criteria was assessed according to their effect. Based on the results, risk map of the study area was carried out. The region was divided into 5 categories from very low risky (1) to very high risky (5).