AN ANALYSIS ON TOPOGRAPHICAL FACTORS AND DETERIORATION OF BEECH TREES AT 
MT. HINOKIBORAMARU, TANZAWA, USING GIS 
Yujiro HIRANO* and Ryosuke SHIBASAKI 
Institute of Industrial Science, University of Tokyo 
7-22-1 Roppongi, Minato-ku, Japan, 106-8558 
*E-mail: hirano@skl.iis.u-tokyo.ac.jp 
Commission VII 
KEY WORDS: Tanzawa, beech trees, deterioration, topography, geographic information system 
ABSTRACT: 
The purpose of this study is to investigate the deterioration of beech (Fagus crenata) forests in the Tanzawa 
mountains, and to examine the relation with topographical factors by utilizing geographical information 
technology. 
Firstly, geometric distortion of an aerial photograph due to mountain topography is corrected using Digital 
Elevation Model (DEM). Secondly, degrees and spatial extent of the deterioration are investigated using aerial 
photographs. Also, in order to check the reliability of the interpretation results and field survey is carried out. 
A distribution map of the forest deterioration made up in this way is represented as a bird's eye view image using 
Geographic Information System (GIS), allowing for visualization of the relationship between the distribution of 
deterioration and topography. The influence of topographical factors, such as elevations, slope gradient, and slope 
aspects, are also identified quantitatively. 
1. INTRODUCTION 
In recent years, the deterioration of forests in various 
districts in Japan has been reported(Tanimoto et al., 
1996; Hasegawa, 1989). There is pressing need to 
investigate the actual situations and the causes for the 
purpose of proper maintenance and management of 
forests. Although the deterioration of beech(Fagus 
The area, around the top of Mt. Hinokiboramaru in the 
western part of the Tanzawa mountains, has been 
selected(Fig-2), because the most serious deterioration 
is observed in the Tanzawa mountains. The selected 
area extends from 35° 27° 00” to 35° 29' 06" N and 
from 139° 04’ 48” to 139° 07' 12" E. This area 
includes the top of Mt. Hinokiboramaru and a part of 
its mountain trail. 
  
crenata) forest in the Tanzawa mountains has also 
been reported, it is said that the investigation still 
  
  
remains at the stage of grasping actual conditions. In Examination of ; RR of 
particular, geographical research, such as the aerial photograph's degrees o : 
distortion deterioration using 
investigations of spatial distribution of forest 
deterioration and analysis on the relation with 
topographical factors, have not yet been conducted, Y 
though several "non-geographical" studies have been Y 
correction method aerial photographs 
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
reported from forestry and ecological viewpoints. Geometric correction of aerial 
photographs 
On the other hand, the recent advances in geographical Ÿ 
information technologies such as Geographical 
Information System (GIS), Global Positioning System Calculation of Verification of 
(GPS), and the development of Digital Elevation Model slope gradient and interpretation of 
(DEM), enables much more efficient work, quantitative aspect by DEM aerial photographs 
assessment and visualization of the results. by Ground Survey 
This paper aims to investigate the geographical Y Y 
situation of deterioration at ( Hinokiboramaru Mt. Analysis on dhe Generation of 
Tanzawa Japan, and to examine the relations with ; "m ; 
; iti zi topographical factors bird's eye view 
topographical conditions by utilizing geographical rt i 
and deterioration images 
information technology. Fig-1 depicts the flow of this 
  
  
  
  
study. | Fig-1 The flowchart of the analysis 
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998 713