Extreme July precipitation and its consequences on Crna Trava municipality, Serbia

ABSTRACT: Even though climate variability, geology, and human activity are main triggers of landslides, based on earlier research, precipitation is considered the most important natural factor responsible for soil erosion in the landslide context. In this study landslide activation has been correlated with precipitation in least developed municipality of Crna Trava located in South-east Serbia. The purpose of this study is analyzing the precipitation in thirteen surrounding settlements: Vranje, Leskovac, Babušnica, Bela Palanka, Pirot, Dimitrovgrad, Kalna, Kriva Feja, Vladičin Han, Vučje, Vlasotince, Grdelica, Brestovac and finding its correlation to landslide occurrences. Precipitation for seven decades (period 1946-2017) has been interpolated by IDW method in the software ArcMap 10.5 and correlated to Crna Trava slope map. Potential locations of landslides were determined and compared to the recent landslides which occurred in July in 2018, in Bankovci village. Potential years for landslide activation were compared to calculated values of The Precipitation Concentration Index (PCI), The Modified Fournier Index (MFI), and Lang Aridity Index (AILang). The case study was done based on fieldwork which happened in a period from 20 to 26 of July 2018 in the village of Bankovci. On the 25 of July landslides were activated because of the extreme weather conditions, which affected wider region in Central and South-east Serbia: 100 liters of rain fell during the three-hour period. Habitants were interviewed about their memories on extreme floods and landslides in Crna Trava municipality, and the years they mentioned are in well agreement with our results of the extreme precipitation events.