EFFECTS OF VEGETATION ON RUNOFF IN SMALL RIVER BASINS IN SERBIA

The aim of this paper is to show the real impact of vegetation types on runoff, expressed by a mathematical model. Better understanding of this relationship may significantly contribute to the prevention of extreme natural processes that are more and more frequent in the world in recent years. Particular attention to this problem has been paid after the historic flooding that occurred in Serbia in May 2014, taking away many lives, property and starting up numerous erosive processes. In this work multiple linear regression was used to make an estimation of the mean annual, maximum and minimum river runoff in Serbia for the period of 1998-2009. The sample analyzed consisted of 40 small river basins with natural runoff and the independent variables used were mean annual precipitation, mean annual air temperature, basin altitude, the humidity index, basin area, average basin slope, and vegetation factors separated in 8 categories. It was shown that vegetation has an important role in runoff regulation and that it is justified to classify it particularly into three categories: forests, meadows and agriculture. A total of 33 models were formed with R2 > 0.8 and runoff changes from 0.1% to 1% within 1% changes to vegetation, depending on type.