城市降水多尺度长程演变特征分析

针对当前降水研究尺度与精细化程度难以满足城市雨洪预报预警、排涝规划与应急管理需求,提出城市降水多尺度长程演变特征分析方法与框架,为城市洪泛区的科学管理提供导向。以哈尔滨主城区为研究基点,选用线性拟合、Mann-Kendall检验以及Morlet小波分析方法对其降水进行多尺度分析。结果表明:近53年来,哈尔滨主城区除秋季降水有不明显的减少趋势外,春、夏以及冬季降水均呈与年降水相同的增多趋势,夏季降水约占全年降水的66.07%,大雨以上降水日数整体趋势缓增,但强度逐渐减弱;年降水变化出现突变点的时间为1964、1966、1980和2011年。春季降水在2007年发生突变,夏季降水在1981和2003年发生突变,秋冬两季降水突变年份分别为1973、1997年和1971、1991年;年降水变化的主次周期分别为35和20年,大雨以上降水日数的周期与其保持一致。春季降水变化存在36年的主周期和14年的次周期。夏、秋和冬季降水时序变化呈现20和36年的周期性,但主次周期存在一定差异。

Analysis on the long-term multi-scale evolution characteristics of urban precipitation

In view of the fact that the scale and refinement of current precipitation research are difficult to meet the needs of urban stormwater forecasting,drainage planning and emergency management,methods and framework for analysis of the long-term multi-scale evolution characteristics of urban precipitation are proposed to provide guidance for the scientific management of urban floodplain.Harbin is taken as the research area.The linear fitting,Mann-kendall test and Morlet wavelet analysis methods are adopted to analyze the precipitation evolution characteristics of Harbin main urban area.The results show that:In the past 53 years,the autumn precipitation in Harbin has decreased,and the precipitation in spring,summer and winter display the same trend as annual precipitation.The precipitation in summer accounts for 66.07% of the annual precipitation.The number of rainy days above the heavy rain increases slowly,but the intensity is gradually weakened;The annual precipitation mutation periods are the years of 1964,1966,1980 and 2011.The spring precipitation mutation is on 2007,and the summer precipitation mutation periods are on years of 1981 and 2003.The abrupt changes in precipitation in autumn and winter are on 1973,1997 and 1971,1991;The primary and sub-cycle of annual precipitation change are 35 and 20,and the same as the days above heavy rain,spring precipitation changes show a 36-year main cycle and a 14-year sub-cycle.There are 20-year and 36-year cyclical changes of precipitation in summer,autumn,and winter.However,there is a difference between the main cycle and the sub-cycle.