英语翻译The thresholds considered in this study are totalnine ca

英语翻译
The thresholds considered in this study are total
nine cases; the mean,the meanG0.25stdv (stdv:
standard deviation),the meanG0.5stdv,the meanG
0.75stdv,and the meanG1.0stdv.As the thresholds
are represented by the use of the mean and standard
deviation,we may better compare the data collected
before and after the long dry period.Also,we may
overcome the difference in their means of the old
Chukwooki and modern flip-bucket precipitation
measurements.The observed number of occurrences,
and the observed return and duration characteristics
below (or above) these thresholds are summarized in
Tables 2 and 3,respectively.
The decision of proper thresholds was done by
evaluating the occurrence characteristics of dry years.
For a given threshold the number of dry yearsrecorded until time t from the beginning was counted,
and,by dividing it by the total number of dry years for
the whole period,we could estimate the relative
frequency at time t.Then,the Kolmogorov-Smirnov
test was applied to decide if Eq.(1) is valid or not
(Clark and Disney,1985).The results are summarized
in Table 4.
As can be seen from Table 4,the proper threshold
to confirm the independent occurrence of dry years
may be the level of meanG0.75stdv.However,as the
level of meanG0.5stdv was rejected from the
Kolmogorov-Smirnov test by a narrow margin for
the 5% significance level (but accepted for the 1%
significance level),the maximum threshold would be
around the level of meanG0.5stdv.Further analysis in
this study is based on the thresholds of meanG
0.5stdv,meanG0.75stdv,and meanG1.0stdv.

在上一章节中,我们确定了临界值,在这个临界值之下,干旱年的发生是独立的.在这一章节中我们将为mean-0.5stdv,mean-0.75stdv, and mean-1.0stdv（专业名词,不会翻译）用泊松方法从干旱年的返回特征和持续特征开始入手.在这里加上的一个内容就是,代表了在t年里,持续t年干旱年的几率的方程式,是在tC1年独立于干旱年的发生的.那就是说,方程式代表了多于t年持续干旱年的发生几率.由于这里的可能性取决于一个参数I,因此确定一个合适的临界值的重要性就不用过分强调了.这个参数I可以通过分离总年数中的干旱年数来估算.由于首尔的年降水量数据,这个被估算的参数与几个临界值做了比较（见表11）.并且,用表11中的参数观察和估算的持续干旱年的可能性在表12中比较.