中国华北暖季土壤湿度的变化特征  

Variation Feature of Soil Moisture in Warm Season over North China

作　　者：程善俊 黄建平[1] 季明霞[1] 管晓丹[1] 郭瑞霞[1] 

机构地区：[1]半干旱气候变化教育部重点实验室兰州大学大气科学学院,甘肃兰州730000

出　　处：《干旱气象》2015年第5期723-731,共9页Journal of Arid Meteorology

摘　　要：通过与土壤湿度观测资料比较验证发现,GLDAS同化数据能够较好地反映中国地区暖季土壤湿度的时空分布和变化特征,特别是在华北地区,两者显著相关。在此基础上,为研究中国区域干旱化特征,利用1948~2010年的GLDAS数据分析了中国华北地区暖季土壤湿度的周期信号和长期变化,并初步探讨了气温和降水对土壤湿度的影响。结果表明：1948~2010年华北地区暖季4个不同深度层土壤湿度的变化特征基本一致,主要存在3 a、5~7 a和15 a周期信号,其中以5~7 a周期最为显著;长期变化均呈现减小趋势,且中间2层土壤湿度的减小比表层和最深层更为迅速。不同深度的土壤湿度和降水呈正相关关系,且相关性随土壤深度的增加而逐渐减小,与气温呈负相关关系,且中间2层的相关性大于表层和最深层。The soil moisture data from observation over China were used to test the accuracy of assimilation data from GLDAS,results show that assimilated soil moisture can efficiently describe its spatial and temporal distribution and its variation over China in warm season,especially in North China,where the observation and GLDAS data are correlated significantly. As its efficiency,to study the characteristic of regional drought,GLDAS soil moisture data was used to access the long- term variation feature of soil moisture over North China in warm season in the period of 1948- 2010,and also the impacts of temperature and precipitation on soil moisture were explored. Results show that soil moisture of all the four depth layers decreased similarly in the past 63 years and that of the middle two layers had aggravative decrease. The basic cyclic soil moisture was carried out by wavelet analysis and it concluded that for all the four depth layers,soil moisture had almost the consistent cycle with 3 years,5 to 7 years and 15 years,and the 5 to 7 years cycle was the main cycle. For all the four layers,there was positive correlation between precipitation and soil moisture,but negative correlation between temperature and soil moisture,and the correlation with precipitation was weakened in the deeper soil layer while it was more obvious in the middle two layers with temperature.

关 键 词：土壤湿度 华北 暖季 GLDAS 

分 类 号：P468.023[天文地球—大气科学及气象学]