基于SPI指数的惠州市干季干旱趋势分析

本研究依据 1971—2017年 10月到次年 3月惠州市气象观测站降水资料， 运用标准化降水指数(SPI)、 M-K突变检验和小波分析等指标分析了惠州市干季的干旱趋势。结果表明： 1971—2017年， 惠州市干季总降水量在 1971—2004年呈下降趋势， 而 2004—2017年呈显著的增加趋势； 干季干旱情况以正常为主， 而季节性干旱表现为以轻微干旱为主， 中等干旱次之， 并未出现严重干旱以及极端干旱的情况；干季干湿转换表现为突变现象， 1975年为湿润到干旱转变的突变年， 而 2015年为干旱到湿润转变的突变年； 惠州干季干湿震荡主周期为 15~32年和 5~15年， 近 46年 10年左右的时间尺度上存在着 7次干湿交替， 且小波系数大于 0的等值线到 2017年并未完全闭合， 表明未来几年惠州干季仍处于湿润化趋势阶段。

Drought Tendency of the Dry Season in Huizhou: Analysis Based on SPI

Based on the precipitation data from 4 meteorological stations in Huizhou from 1971 to 2017, the drought tendency from October to March was analyzed using standardized precipitation index (SPI), Mann- Kendall method and wavelet analysis. The results indicated that the precipitation tendency declined from 1971 to 2004 and increased from 2004 to 2017. The drought condition in dry season was normal, while it showed slight drought in seasonal drought, then was medium drought, severe and extreme drought were not found. The conversion of dry and wet in dry season was jumping, and 1975 was the jumping year from wet to dry, and 2015 was the jumping year from dry to wet. The main oscillation cycle was 15 to 32 and 5 to 15 years of dry-wet in dry season, there were seven dry-wet alternation of 10 years scale in recent 47 years, and the isoline (with wavelet coefficient＞0) was not entirely closed, indicating that it would still have a wetting trend in a few years in Huizhou dry season.