1990--2010年神农架林区气候变化特征分析

利用1990-2010年神农架林区国家气象站点的气象数据资料，对林区近21年的平均气温、最高气温、最低气温、雨日数、大雨日数、降水量、干旱指数进行分析．结果表明，近21年神农架林区的平均气温呈上升趋势，以春季最为显著；最高气温趋势与平均气温趋势基本一致，全年、春季、夏季及冬季均呈上升趋势，而秋季最高气温有所下降；最低气温亦呈上升趋势，其中冬季最低气温倾向率低于全年水平，春季、夏季和秋季最低气温倾向率高于全年水平；雨日数及大雨日数均呈增加趋势；降水量全年倾向率为正，春夏2季亦为正，秋冬2季则为负；干旱指数各年均〉1，且有变大的趋势．

The characteristics of climate change in Shennongjia Forest Area from 1990 to 2010

According to the meteorological data of Shennongjia Meteorological Station from 1990 to 2010, we analyzed the change of average temperature, highest temperature, lowest temperature, rainy days, heavy rainy days, precipitation and drought index in Shennongjia Forest Area. The results showed that, in the past 21 years, the average temperature of Shennongjia Forest Area has been increasing, especially in spring. The highest temperature showed the same trend to the average temperature, with the annual, spring, summer and winter temperature increasing, except for autumn that decreased. The lowest temperature also trended upwards. The rate o~ increase for spring, summer and autumn were higher than the annual rate, but that of winter was lower than the annual rate. The rainy days and heavy rainy days also increased during the past 21 years. The annual, spring and summer precipitation showed an increasing trend, whereas the autumn and winter precipitation decreased. The drought index in the past 21 years was above one, and showed an upward trend.