松嫩平原干旱变化特征及其对气候变化的响应

Drought Variation in Songnen Plain and Its Response to Climate Change

利用松嫩平原36个气象站点1961-2013年气象数据,选用相对湿润度指数作为干旱指标,探讨年尺度和季节尺度干旱的时空分布特征,并分析其与气候要素间的关系。结果表明:(1)从年尺度来看,1961-2013年松嫩平原年平均相对湿润度指数呈极显著递减(P<0.01)趋势,说明干旱逐年加重,且中旱级别以上干旱的发生范围逐年扩大;(2)春季和秋季相对湿润度指数呈极显著递减趋势(P<0.01),干旱加重的速度秋季大于春季,干旱范围存在扩大的趋势,近30a冬季相对湿润度指数呈显著递增趋势,存在干旱减缓和发生范围缩小的变化趋势。各季相对湿润度指数均呈现从西南向东北递增的变化趋势,西南部是重旱区域和高发生频率的重叠区;(3)相对湿润度与气温、太阳辐射呈负相关,与相对湿度、风速、降水量呈正相关。年尺度的相对湿润度与降水量、风速和气温呈极显著相关,各季相对湿润度与降水量、太阳辐射和相对湿度也表现出较强的相关性。

Based on observed data from 36 meteorological stations from 1961 to 2013, taking relative moisture index as a drought index, the temporal and spatial distribution of drought was analyzed by using Kriging method. The results showed that the annual index decreased significantly（P〈0.01） from 1961 to 2013, drought severity was steadily increased, and the drought grades also showed an increasing trend. The index decreased significantly in spring and autumn（P〈0.01）, and more obviously in autumn. While the index in winter increased significantly, but the range was narrowed. The index in all seasons increased from southwest to northeast, with the southwest region as high risk region. There was negative correlation between the index and temperature, solar radiation, respectively, and positive correlation between the index and relative humidity, wind speed and precipitation, respectively.