Wpływ rumoszu drzewnego na granulometrię osadów korytowych

Abstract

The aim of paper is to investigate the impact of woody debris deposited on the river bed on the granulometry of the bed material. The analysis included upstream and downstream sides of the investigated woody debris. The investigations comprised determination of the geometric dimensions of the analyzed wood deposits, determination of the granulometric composition of the bed material in the area of deposition of woody debris, determination of the range of influence of the investigated woody debris on the bed material and determination of the relationship between the geometric dimensions of the woody debris and the extent of their impact on the bed material. The granulometric analysis was conducted using the conventional sieving method. The extent of the influence of woody debris was determined on the basis of the Nash’s-Sutcliffe’s efficiency coefficient. The dependence of the extent of wood influence and the dimensions of the investigated woody debris was determined on the basis of the Spearman’s correlation coefficient. It was found that the woody debris deposited on the bed of the Raba river affects the granulometry of the bed material on both the upstream and downstream sides. The study also showed that the extent of the impact on the grain-size composition of the bed material on the downstream sides of the woody debris is determined to a large extent by the height of the deposited woody debris.