Production of flood risk maps: Ayancık Stream Example

Abstract

Natural disasters are events that negatively affect human life and cause material and moral damages. As in the rest of the world, one of the biggest natural disasters after earthquakes in our country is floods. The flood event turns into a disaster in cases caused by human interventions such as the change of the river bed, the increase in the construction on the riversides, and the blocking of the river perpendicular to the flow direction. In this study, risk maps for floods with different return intervals (25, 50, 100 years) were produced with GIS for Ayancık stream in Sinop province. As a result, when the flood risk maps were analyzed, the regions located in the floodplain were considered very risky regions. According to the results obtained, the flood disaster reaches a depth of 7 meters. Ayancık Stream and its surroundings are a very risky area exposed to floods as they have a maximum depth of 3.5 m. In addition, flood risk areas with 50 and 100-year return period floods, increase 3.71 and 12.83 percent, respectively, from 25-year return period flood risk areas. In addition, it was concluded that the majority of the areas affected by the floods in all three turning ranges within the scope of the study area are located in the very risky region, while the extreme risk areas are less than the other risky groups.