论文部分内容阅读
相关函数分析表明,生长季当年4～7月上旬的降水总量对内蒙古锡林浩特白音敖包地区的红皮云杉(Picea Koraiensis)宽度的形成具有显著的制约作用,在此基础上,设计转换方程,对这一地区过去160余年以来4～7月上旬的降水总量进行模拟重建,重建序列的解释方差达到49.3％(调整自由度后为45.7％,N=31,r=0.702,F=13.608,p<0.0001).重建序列表现出3个降水较多时期:1869～1875,1886～1921和1943～1968年;4个降水较少时期:1851～1868,1876～1885,1922～1943和1969～1999年.降水较多的1886～1921和1943～1968年以及降水较少的1922～1943年时期与祁连山地区的湿期和干期几乎同时出现,而1922～1943年的干期和1943～1968年的湿期,与我国西北、华北和长江流域20世纪20年代的升温少雨和40年代以后的降温多雨非常吻合.计算表明,重建序列与旱涝等级序列显著相关(r=-0.234,p<0.007,N1=143).子波分析表明,1838～1920年期间,白音敖包地区4～7月上旬的降水主要存在22年的周期,1920～1952年主要表现为11年的周期.1953年之后,周期成分比较复杂,未检测到信度达95％的周期成分.1920年代该地区4～7月上旬降水由多向少出现快速转变,1950年代以后降水持续减少.20世纪90年代后期,降水增加的趋势十分明显.
Correlation analysis showed that the total amount of precipitation from April to July in the growing season was significantly restricted by the formation of Picea Koraiensis width in Baiyin-Aobao area, Xilinhot, Inner Mongolia. On the basis of this, , The total precipitation in the region from April to early July over the past 160 years was simulated and reconstructed. The explained variance of reconstructed sequence reached 49.3% (45.7% after adjusting for degrees of freedom, N = 31, r = 0.702, F = 13.608 , p <0.0001). The reconstructed sequences showed three periods with more precipitation: 1869 ~ 1875, 1886 ~ 1921 and 1943 ~ 1968; four periods with less precipitation: 1851 ~ 1868, 1876 ~ 1885, 1922 ~ 1943 and 1969 ~ 1999. In 1886 ~ 1921 and 1943 ~ 1968 with more precipitation and in the period of 1922 ~ 1943 with less rainfall, the wet period and dry period of Qilian Mountain almost coincided with each other in 1918 ~ 1943 and 1943 ~ The wet period in 1968 is in good agreement with the warming and rain in the 1920s in the northwestern, northern and Yangtze basins of our country and the cooling and rainy days after the 40s. The results show that the reconstructed sequence is significantly correlated with the sequence of drought and flood (r = -0.234, p <0.007, N1 = 143). Wavelet analysis shows that from 1838 to 1920, Precipitation in Baiyao-Aobao area from April to early July mainly existed in 22-year period and from 1920 to 1952 mainly in 11-year period.After 1953, the periodic components were rather complicated, and the periodic components whose reliability was 95% were not detected In the 1920s, the precipitation changed rapidly from many directions to less in the early April to early July, and the precipitation decreased continuously after the 1950s.In the late 1990s, the trend of increasing precipitation was obvious.