西秦岭地区气候变化特征与干旱灾害趋势

Characteristics of Climatic Change and Trend of Aridity in West Qinling

根据1961—2011年西秦岭地区12个气象站的逐月气温和降水资料,利用线性回归、反距离加权空间插值(IDW)、Z指数法和Morlet小波变换等方法,分析了近51年来西秦岭地区气候时空变化特征,区域干旱强度与旱涝灾害发展趋势。结果表明:近51年来西秦岭地区气温呈增加趋势,增温倾向率为0.26℃/(10 a),降水量呈减少趋势,减少倾向率为16.04 mm/(10 a),气候暖干化趋势明显。近51年来西秦岭地区年旱涝Z指数呈下降趋势,与降水量呈减少的趋势一致;旱涝灾害主要存在5 a和7 a的变化周期,干旱灾害极度易发,干旱化趋势明显。西秦岭地区对全球气候变化的区域响应特征是旱灾增加。

By using methods of linear regression, inverse distance weighted spatial interpolation,Z index and Morlet wavelet transform, the characteristics of precipitation, drought intensity and the trend of drought were analyzed based on temperature and rainfall data from 1961 to 2011 collected from 12 meteorological sites in west Qinling of China. Results showed as follows： temperature presented an increasing trend over the last 51 years in west Qinling, the temperature tendency rate was 0.26℃ / （ 10 a）, precipitation presented a decreasing trend, the precipitation tend- ency rate was 16.04 mm/（ 10 a） ,climate warming-drying trend was apparent. The trend of Z index showed a down- ward trend, the decreasing trend was consistent with the precipitation;the drought-flood had a 5 years and 7 years periodic oscillation, it was extremely prone to drought, the drought trend was obvious. The characteristics of regional response to global climate change was drought increased in west Qinling.