全球气候变化背景下贵州草海湿地极端降水特征

Extreme Precipitation Characteristics of Caohai Wetland in Guizhou under the Background of Global Climate Change

利用逐日降水量资料,选取8个降水指数,采用趋势分析、相关性分析等方法,对2000—2016年贵州草海湿地极端降水特征进行分析。结果表明:21世纪以来,草海湿地降水量总体呈上升趋势。雨季、旱季降水量占年降水量比例的均值分别为87.3%和12.7%。四季降水量占年降水量比例的区间,春季为8.5%—29.8%,夏季为8.7%—65.1%,秋季为0.9%—38.7%,冬季为0.9%—4.9%。暴雨日数最大值为5 d,暴雨日降水量接近400 mm,两者变化均呈显著上升趋势;连续有雨日数和连续有雨日数≥10 d发生次数的均值分别为14 d和2次;连续无雨日数和连续无雨日数≥10 d的发生次数均值分别为15 d和3次。日最大降水量、暴雨日降水量和连续有雨日降水量三类极端降水指数均值分别为67.0、109.3和115.0 mm,占年降水量比例的均值为7.9%、11.7%和13.3%,比例区间分别为5.4%—13.3%、0—30.4%和7.2%—23.6%。

Based on daily rainfall data, eight corresponding precipitation indices were selected, and the characteristics of extreme precipitation in Caohai wetland, Guizhou during 2000 - 2016 were analyzed using trend analysis and correlation analysis. The results showed that since the 21st century, the rainfall in Caohai wetland had been increasing. Rainfall in the rainy season and dry season accounted for 87.3% and 12.7% of the annual precipitation ratio, respectively. The precipitation ratio of each sea son to the whole year was 8.5% - 29.8% in spring, 8.7% - 65.1% in summer, 0.9% - 38.7% in autumn and 0.9%- 4.9%in winter, respectively. The maximum of rainstorm days was 5 d, with the rainfall close to 400 ram, both of the rainstorm day and rainfall showed a significant upward trend. The continuous rainy days （CRD） and the frequency of CRD larger than 10 days were 14 d and 2 times, respectively. The continuous non rainy days （CND） and the frequency of CND larger than 10 days were 15 d and 3 times, respectively. The average values for the three extreme precipitation indices of the largest daily rainfall, rain storm rainfall and CRD rainfall were 67.0 mm, 109.3 mm and 115.0 mm, accounting for 7.9% , 11.7% and 13.3% of annual precipitation, respectively, and the proportional intervals were 5.4% - 13.3%, 0 - 30.4% and 7. 2% - 23.6%, respectively.