基于MK检验的南四湖西平原洼区近58年旱涝特征分析

Drought and Flood Characteristics Analysis in Recent 58 Years in the Western Plain Depression of Nansihu Lake Based on Mann-Kendall Test

文中以南四湖西平原洼区周边地区的3个气象站点近58年逐月降水实测资料为基础,利用算术平均值构建流域年平均降水量的时间序列,并对区域年际平均降水量进行线性回归分析,分析了降水的分布特征和旱涝灾害的趋势。结果表明:1)1961-2018年平原地区年平均降水量为722.0 mm,年平均降水量以6.48 mm/10年的速度递减;2)研究区年平均降水量的UFk和UBk曲线有4个交点,振荡严重。变化最明显的是1966年,洼区年平均降水量从1966年开始明显减少;3)兖州,徐州,菏泽三个站的年降水量均在1966年出现明显变化,三个地区年平均降水量从1966年开始显著下降。说明1966年的突变具有全局性,此后较长的一段时期内洼区都处于枯水期。

Based on the measured data of monthly precipitation over the past 58 years in three meteorological stations in the area around the western plains depression of Nansihu Lake,this paper used the arithmetic mean to construct time series of annual average precipitation in the basin.Linear regression analysis was accomplished on the regional interannual average rainfall.the distribution characteristics of precipitation and the trend of droughts and floods were analyzed.ne results show that:1)the average annual precipitation in the plain area is 722.0 lnnl from 1961 to 201 8.and the annum average precipitation is decreasing at 6.48 mm/lO years;2)the UFk and UBk curves of the annual average precipitation in the study area have 4 intersection points.the oscillation is serious.The most obvious change Was that in 1966,the annual average precipitation in the depression area decreased significantly from 1966;3)the annual precipitation of the three stations in Yanzhou.Xuzhou and Heze showed significant changes in 1 966.The annum average precipitation in the three regions has dropped significantly since 1966.It shows that the mutation in 1966 is overall,and in the longer period of time,the depression area is in the dry season.