陇中半干旱区月气候对全球气候变化的响应特征

Characteristics of Month Tempereture Over Middile Area in Gansu Province Response for Variation of the Globle Temperature

利用甘肃定西地区67a（1937—2003年）的月降水、气温资料，采用小波分析等统计方法．研究了陇中半干旱区月气候变化特征．结果表明，陇中半干旱区月降水变化率在-5．45～2．58ram／10a之间，1977年以前降水以增加为主，1977-1997年降水减少突出，1998年转为全面上升．夏季（7月）降水在1998年之前一直处于下降趋势．春季（4月）降水趋势与7月相反．6月降水增加具有明显的阶段性，主要在1977年之前和1998年之后，降水周期谱与其对应．各月气温以升高为主，变化率在0．018～0．424℃／10a之间，2月增幅最大，振荡周期复杂，3月存在降温趋势，振荡周期简单．

By investigating distributing of month rainfall and temperature in Dingxi area from 1937 to 2003, applying the wavelet analysis, the results showed that month rainfall increased before 1997 and after 1998, decreased during 1977-1997. However, rainfall in July mainly kept decreasing, in April kept increasing. The rainfall climate shift in 1998 at middle part of Gansu province. The slopes of the rainfall and temperature were difference. The rate of month rainfall was during -5. 45-2.58 ram/10 a, the month temperature was during 0. 018-0. 424 ℃/10 a. The periods of temperature in February and rainfall in June were complexible, the periods of temperature in March and rainfall in July were simple. Also the rainfall and temperature changes had the variation evolvement correspond with 4 years variation period weaken.