安庆市近60年降水变化特征分析

为了研究安庆市近60年降水以及四季降水变化特征,并预测短期内安庆市降水趋势,为区内农业生产和防汛抗旱提供科学依据和指导,利用Morlet小波对安庆市近60年降水数据进行分析。结果表明,安庆市降水集中在春、夏2季,年降水量呈微弱递增趋势,经历6次丰枯循环,2010年后将进入新的丰水期。四季降水变化趋势各不相同,春季和秋季呈下降趋势,夏季和冬季呈上升趋势。安庆市近60年间小尺度周期震荡显著,周期性强,年际间降水变化幅度大,降水丰枯交替频繁,易出现洪涝灾害和干旱,但是出现严重干旱的概率较小。春、夏季节时期,安庆地区受季风环流影响,大气环流年际变化频繁,降水变率大,丰枯交替频繁,小尺度周期震荡显著,年际间降水变化幅度大,突变点多,旱涝灾害频发。而秋、冬季节受西风带影响,盛行偏北气流,气流较春夏季节偏干燥,降水变率小,年际间降水变化幅度相对较小,旱涝交替较春夏季节缓慢,小尺度周期震荡不显著。

Change Characteristics of Precipitation Nearly 60 Years in Anqing City

In order to study the precipitation and its characteristics at all seasons of Anqing in nearly 60 years, and predict the precipitation trend of Anqing in short term, to provide scientific basis and guidance for the agricultural production in the area, and guidance for flood control and drought relief. The author used Morlet wavelet to analyze the precipitation data of Anqing city in nearly 60 years. The results showed that： the precipitation concentrated in spring and summer and annual precipitation was increasing slightly. After experiencing 6 cycles, it would enter a new wet season after 2010. The variation trend of precipitation was different in four seasons. It was on a declining curve in spring and autumn, but on the rise in summer and winter. Anqing city＇s smaller scale cycle shocked significantly in nearly 60 years, and it had a strong periodicity. The inter-annual rainfall changed greatly and alternate frequently. Floods and drought were easy to appear, but severe drought was hard to appear. In spring and summer, Anqing was influenced by monsoon circulation. Atmospheric circulation changed frequently and inter-annual precipitation varied greatly. Wet and dry alternated frequently. Small scale cycle shocked significantly. The inter-annual rainfall changed greatly and droughts and floods appeared frequently. While it was affected by the westerlies in autumn and winter, north air flow was prevailed. Air was relatively drier than it in spring and summer. Precipitation varied smaller. The inter-annual rainfall changed smaller relatively too. Drought and flood alternated slower than it did inspring and summer. Small scale cycle shocked not significantly.