基于标准化降水指数(SPI)的宝鸡地区干旱趋势变化及周期研究

Studyon the drought trend and period of Baoji area on the basis of standardized precipitation index

目的研究基于标准化降水指数(SPI)的宝鸡干旱变化、突变以及周期等特点。方法利用宝鸡地区3个标准站1961-2016年的逐月降水数据,选用SPI作为干旱监测指标,辅以小波分析、滑动T检验、Yamamoto检验等方法进行分析。结果 1961-2016年宝鸡地区SPI在波动中呈下降趋势,变化倾向率为0.095/10a。夏季最为湿润,春季和秋季有下降倾向,倾向率分别为-0.06/10a和-0.062/10a,冬季最干旱。1961-2016年宝鸡地区干旱变化存在多个震荡周期,其中15a为第一主周期,6a为第二主周期。宝鸡地区干旱突变年份主要为20世纪70年代末到80年代初以及2000年左右。结论宝鸡地区1961-2016年气候变化呈现干旱倾向,春、秋两季的干旱气候主导了地区干旱趋势,且未来几年仍有干旱趋势。

Purposes-To study the characteristics of the change, mutation and cycle of the drought in Baoji area on the-basis of the standardized precipitation index （SPI）. Methods-With the SPI se- lected as the drought monitoring index, the monthly precipitation data of 3 standard stations from 1961 to 2016 in the Baoji area was analyzed with wavelet analysis, sliding T test and Yamamoto test. Results-The SPI fluctuation of the Baoji area was on the decline in the period from 1961 to 2016, and the change tendency was 0. 095/10a. In summer Baoji area tends to become more humid. In spring and autumn Baoji area is inclined to be more arid and the tendency rate is 0.06/10a and 0. 062/10a respec- tively. In winter Baoji area has the most severe aridification tendency. From 1961 to 2016, Baoji area had multiple oscillation cycles, of which 15a is the first main cycle, and 6a the second main cycle. Drought in the Baoji area mainly happened from the late 1970s to the early 1980s and around the year 2000. Conclusions-The climate change in Baoji area from 1961 to 2016 showed drought tendency.The arid climate in spring and autumn led to the drought trend in the area, and the area will continue drought in the next few years.