Rainfall Thresholds for The Initiation of Landslides in Trabzon Province of Turkey

Abstract

Knowing the duration, intensity and amount of precipitation triggering landslides is of great importance for understanding landslide mechanisms and landslide warning systems. Global, regional and local studies carried out by the researchers revealed that the rainfalls triggering landslides occur after a certain threshold value. In Turkey, there is no available data on the threshold value of the rainfall. Trabzon province of Turkey is located in a region with the highest rainfall where the landslides mostly occur. Only in the last 20 years, more than 2000 landslides occurred in the region. The majority of these landslides were triggered by rainfall. In this study, using the log-log based graphic obtained by calculation of the duration and intensity of the rainfall in Trabzon province, the threshold value triggering landslides was found to be I=0.69 D-0.99. Rainfall threshold values obtained also for various criteria (slope angle, lithology, cover type, type of agricultural product, landslide type etc.) may be used as a reference for slope stability analysis studies which would be based on geotechnical data

Keywords

• Rainfall, Rainfall Threshold Triggering Landslide, Slope Stability Analysis

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