Rainfall Erosivity as An Indicator of Sliding Occurrence Along the Southern Slopes of the Backa Loess Plateau: a Case Study of the Kula Settlement, Vojvodina (North Serbia)

Abstract

The risk of soil erosion and landslides is one of the main environmental concerns in Southeast Europe. Although predictions are uncertain, changes in precipitation due to climate variability are expected in the south eastern parts of the Pannonian Basin in the Vojvodina region, North Serbia. To gain a clearer understanding of the dynamics involved in the main climatological agent of erosion, more insight concerning changes in the amount, concentration and variability of precipitation is needed. The Kula settlement on the southern slopes of the Bačka loess plateau in the Vojvodina region, North Serbia was selected for this study. This settlement is endangered by the landslides along the pronounced loess cliff. Various statistical approaches were used to calculate and analyse trends in total annual precipitation and selected rainfall erosivity indices. Results show that annual rainfall displays a relatively uniform distribution for the investigated area, while precipitation concentration indicates a presence of moderate values for the period 1991-2012. Trend analysis of the supra-seasonal scales for wet and dry seasons only indicates the presence of a trend in the time series for the wet season. Calculated values of the Fournier Indices generally display low aggressiveness for the study area with several extremes based on monthly mean values with a pronounced severe erosivity class. These values strongly correspond with the registered occurrence of the landslides in the settlement area. Proposed geomorphological model was applied in order to describe the nature of the dynamic erosional processes on the steep loess cliffs and landslide morphogenesis related to the sedimentological characteristics of the loess-paleosol sequences and influence of the rainfall aggressiveness. Potential solutions for preventative actions are given in order to introduce and conduct qualitative mitigation strategies.