承德市近58年气温和降水序列多时间尺度分析

Multi-Time Scale Analysis of Temperature and Precipitation in Recent 58 Years in Chengde City

利用墨西哥帽小波(Mexican Hat)函数对承德市1951—2008年共696个月的气温和降水数据进行多尺度分析,确定序列中存在的主周期,并用Mann—Kendall法进行检验。结果表明:承德市气候总体变化特征为小尺度变化嵌套在较大尺度的复杂背景之中,气温序列数据表现出14a、6a和2a左右变化周期,14a左右为变化主周期。降水序列数据表现出10～12a,4a和1a左右周期,4a左右为变化主周期。气温序列14a主周期反应冷暖交替的情况,21世纪以前在多尺度波动的背景下,气温呈现上升的总趋势。降水序列4a尺度主周期反应干湿交替的情况,表明多雨年份明显减少,且当前降水仍然偏少。

By using Mexican Hat Wavelet to analyze the multi-scale characteristics of the temperature and pre cipitation data for 696 months during 1951--2008 to determine the main cycle in the sequences and test by the Mann-Kendall method, the conclusion has been drawn that the overall climate feature in Chengde was that small scale change was embedded in the large-scale complex background. Temperature sequence data showed the general cycle was 14 a, 6 a and 2 a, and 14 a was the main cycle. Precipitation sequence data revealed the general cycle was the 11 a, 4 a and 1 a, and 4 a was the main cycle. The main cycle 14 a of the temperature sequence showed the state of alternation of cold and warm and the overall trend of temperature rise in the multi-scale background before 21 century. The main cycle 4 a of the precipitation sequence showed the alter- nation of wetness and drought, and the sharp reduction of rainy years and less precipitation.