地形ㆍ氣候變數와 洪水量의 關係에 關한 硏究

Abstract

The purpose of this study is to show the internal patterns of topographic characteristics and climatic factors which affect flood runoff and to construct the statistical model for predicting mean annual flood in Han, Nakdong and Geum River Basin, by means of principle component analysis and multiple regression analysis. The analyzed variables are (1) Drainage Area, (2) Basin Shape, (3) Main Channel Slope, (3) Average Land Slop, (5) Drainage Density, (6) Length of Main Stream, (7) Magnitude of First Order Stram, (8) Precipitation Intensity, and (9) Mean Annual Flood. The variables of topographic characteriatics were measured from 1 : 50,000 topographic maps and checked on 1 : 37, 500 airphotos. The data

of runoff were gathered at 20 observation posts in 3 Basins over a period of 27 years(1952~1979). And data on rainfall were expressed in unit area per unit time (mm/sec) for 24-hour duration over a period of 27 years. The results of this study are as follows. (1) The variables are classified into three dimensions. The first three principle components account for 83.4% and the first component, 48. 4 % of total variance. The variables which are significantly correlated with the first component are; drainage area, basin shape, main channel slope, length of main stream, magnitude Of first order stream, and mean annual flood. The first component is thought to represent a size dimension in conformity with Horton's law of stream numbers and stream lengths.