Abstract
This paper is to derive the probable rainfall depths and the probable rainfall intensity formulas for Inchon Metropolitan district. The annual maximum rainfall data from 10 min. to 6 hours have been collected from the Inchon weather station. Eleven types of probability distribution are considered to estimate probable rainfall depths for 12 different storm durations at the Inchon Metropolitan district. Three tests including Chi-square, Kolmogorov-Smimov and Cramer Von Mises with the graphical analysis are adopted to select the best probability distribution. The probable rainfall intensity formulas are then determined by the least squares method using the trial and error approach. Five types of Talbot type, Sherman type, Japanese type, Unified type I, and Unified type II are considered to determine the best type for the Inchon rainfall intensity. The root mean squared errors are computed to compare the accuracy from the derived formulas. It has been suggested that the probable rainfall intensities having Unified type I for the short term duration should be the most reliable formulas by considering the root mean squared errors and the difference between computed probable rainfall depth and estimated probable rainfall depth.
본 논문은 인천지방에서의 확률강우량과 확률강우강도식을 유도하기 위하여 인천기상대에서 관측된 자료로부터 강우 지속기간 10분 ~ 6시간까지의 연최대강우량을 선정하였다. 12개 강우지속기간별 확률강우량을 추정하기 위하여 11개 확률분포형을 적용하였으며 Chi-square 검정방법, Kolmogorov-Smirnov 검정방법, Cramer Von Mises 검정방법으로 적합도 검정과 함께 도시적 해석법으로 가정 적합한 분포형을 결정하였다. 확률강우도식은 최소자승법을 사용하여 Talbot 형, Sherman 형, Japanese 형의 3가지로 분석하고, 최소자승법과 함께 시산법을 사용하여 통합형I과 통합형II의 형태로 결정하였다. 표준제곱근오차와 계산된 강우강도와 추정된 강우강도와의 차이를 분석하여 단기 강우 지속기간에 관한 통합형I의 확률강우강도식을 인천지방 강우강도공식으로 제안하였다.