Factor Analysis for Forestation in First-Class Rivers of Chugoku District

Abstract

In recent years, the forestation in rivers is one of the biggest pr oblems for river administrator. In this study, th e f actor analysis o n t he forestation about t he w illow a nd ba mboo communities in r ivers is conducted f or t he l ong-term a nd appropriate ma nagement. The twelve f irst-class rivers i n Ch ugoku District are divided into small drainage basins, where a rate of trees and seven parameters: distance from a weir, to tal n itrogen, to tal phosphorus, ma ximum discharge d ivided by ordinary di scharge, d istance between levees divided by average water s urface width, slope of t he river bed and be d deformation are allocated. The correlation a nalysis and t he cluster a nalysis between t he rate o f t he t rees an d t hese parameters were performed to f ind the c ontributing f actor o f t he f orestation i n rivers. These factor analyses indicate that the deformation of riverbed is a main f actor for the river for estation about t he willow.