摘要
基于1960—2011年广东省25个地面气象站点的逐日气象资料,采用6个月尺度的标准化降水指数(SPI)为干旱评价指标,计算了广东省各站点每月的干旱指数,并在此基础上利用Mann—Kendall趋势检验法、旋转经验正交函数法(REOF)、小波分析等方法分析了该地区干湿状况的时间演变趋势和空间分布特征。结果表明:广东省变干趋势的月份主要集中在1—3月,而变湿的月份主要为7—9月,且中部地区变湿趋势的月份数要明显多于东西部。此外,雨季(4—9月)广东东部及沿海大部分地区呈变湿趋势,而冬季全省大部分地区都表现为变干的趋势;根据REOF方法可将广东省干旱分布特征划分为4个典型的空间异常型:南岭型、粤西型、粤东型和雷州半岛型;各空间型对应的旋转主成分(PRC)序列分析结果表明,雨季各空间型都表现为统一的先变湿后变干趋势,而冬季除了雷州半岛型外则都表现为明显的变干趋势。小波分析结果表明各空间型干湿状况普遍存在1.5a、2—3a的显著变化周期。
The monthly dryness/wetness conditions were calculated by applying the Standardized Precipi- tation index (SPI) at the 6 month scale based on the daily precipitation records of 25 meteorological sta- tions in Guangdong Province from 1960 to 2011. The methods including Mann-Kendall trend test, Rota- ted Empirical Orthogonal Function (REOF) and wavelet analysis were employed to detect the spatial and temporal patterns of dryness/wetness conditions over Guangdong Province. The results indicate: decrea- sing trends of SPI are identified mainly in January, February and March, while increasing trends are dominantly concentrated in July, August and September. In the middle part of the study area, the num- ber of months with increasing trends is more than in eastern and western parts. In addition, the easternand coastal regions of Guangdong are characterized by increasing trends (wet tendency) of SPI in the rainy season ( April to September), and the majority portion of Guangdong shows decreasing trends ( dry tendency) of SPI in winter. According to the results of REOF, there are four main anomaly sub modes in Guangdong, i. e. , the Nanling, Leizhou Peninsula, the East and West Guangdong. All corresponding ro- tated principal components (RPC) of REOF indicate a wet-dry tendency in the rainy season, and all of them show a dry tendency in winter except the West Guangdong sub mode. 1.5-year and 2 to 3-year peri- ods ( significant at a = 0. 05 confidence level) can be investigated in all sub modes with the help of wave- let analysis.
出处
《中山大学学报(自然科学版)》
CAS
CSCD
北大核心
2013年第5期153-160,168,共9页
Acta Scientiarum Naturalium Universitatis Sunyatseni
基金
国家林业局公益性行业专项(201104005
201204104)
国家林业局948引进项目(2011-4-76)基金联合资助项目