大面积开荒扰动下的三江平原近45年气候变化

黑龙江省三江平原近45年来，经过大规模的开荒，农田已取代原来的沼泽和沼泽化湿地，成为现今三江平原的主要景观类型，其下垫面发生了巨大变化，采用1955－1999年三江平原地区21个气象台站的气温，降水，日照时数和气压4个要素的资料，分析近45年来三江平原的气候变化和发展趋势：用Yamamoto法和Mann-Kendall法对5年滑动平均的区域季节和年时间序列进行突变检测，定量地认述了三江平原地区的气候变化事实，对于各气候要素出现在20世纪60年代，70年代和80年代的突变事实，尤其是20世纪70年代以来的阶梯式的持续变暖事实，认为三江平原区域气候系统内部的变化可能是引起这些突变的直接原因。

Climate Variation in the Sanjiang Plain Disturbed by Large Scale Reclamation during the Last 45 Years

Farmland instead of marsh wetland has become the main landscapein the Sanjiang Plain after large-scale reclamation since 1949. The underlying surface of the Sanjiang Plain has been changed tremendously. Based on the data of monthly mean air temperature, atmospheric pressure, monthly precipitation and sunshine time from 21 meteorological stations in the Sanjiang Plain from 1955 to 1999, the climatic variations and tendencies of the Sanjiang Plain have been analyzed during the last 45 years. The climate jumps have been examined in terms of 5-year moving averaged seasonal and annual series of 4 factors using Yamamoto method and Mann-Kendall method. The annual mean temperature was tending to go up and increased +1.2℃ to +2.3℃ in the Sanjiang Plain during the last 45 years. The warmest center was located in the plain field of the Sanjiang Plain. The departure values of annual mean temperature have been positive since 1988. The liner tendency values of annual precipitation in most part of the Sanjiang Plain were negative during the last 45 years. The decrease center in annual precipitation was located in the plain part of the Sanjiang Plain. The largest decrease amplitude of annual precipitation was 90 mm during the last 45 years. The variation of annual precipitation in the Sanjiang Plain during the last 45 years had gone through two increase periods that occurred from 1955 to 1965 and from 1980 to 1999. Between them there was a decrease period from 1966 to 1979. Climate jumps tested by both Yamamoto method and Mann-Kendall method in the Sanjiang Plain during the last 45 years are as follows. According to the annual mean temperature, an abrupt warming occurred in the mid 1980s, the amplitude of abrupt variation was +0.9℃. The seasonal abrupt warming in spring, autumn and winter all took place in the 1980s, and abrupt warming in summer occurred in the late 1970s. Of variation amplitude of all the seasonal abrupt warming, the largest one was +1.8℃ in winter since 1987. The abrupt change of summer precipitation occurred in the 1980s. The abrupt changes of spring and winter sunshine time took place in the late 1980s and the early 1980s respectively. Based on the facts of climate changes of the Sanjiang Plain, it is held that the abrupt warming of the Sanjiang Plain during the last 45 years probably resulted from the large-scale reclamation of various kinds of wetlands.