서울地方 降水量의 永年變化(1770~1968)

Abstract

The purpose of this study is to determine the long term variations in precipitation in order to identify annual and seasonal patterns. On the basis of the patterns derived, an effort is made to estimate cycles of historical flood occurance. An atte-mpt is also made to correlate precipitatin variati-ons with sunspot activity. The basic used is the redord of precipitation observation made in Seoul between 1770 and 1968. Ten-year moving average are derived in order to clarify major average are derived in order to clarify major fluctuation trends. Maximum and minimum precipitation extremes are accounted for by adding or subtracting 1.28 standard devia-tion from the normal distribution. A coefficient of correlation is derived for years of maximum and minimum sunspot activity and fluctuations in precipitation. the analysis show an abrupt decrease in the annual precipitation totals after 1880, with slightly increasing totals after 1990(Figure1). Fluctuations in the seasonal precipitation patterns generally coincide with the annual fluctuations. Spring rain- fall patterns, however, show exceptional variation prior to 1880 but generally tend to coincide with other seasons after 1900.