东北地区夏季土壤湿度垂直结构的时空分布特征

TEMPORAL AND SPATIAL CHARACTERISTICS OF SUMMER SOIL MOISTURE VERTICAL DISTRIBUTION IN NORTHEAST CHINA

借助于概率密度函数(PDF)拟合和经验正交函数(EOF)展开以及小波分析等方法,本文分析了中国东北地区夏季近十年间(1988-1999年)旬平均土壤湿度(0～50 cm层次)垂直分布结构的时空变化特征。结果表明,从区域分布来看,东北夏季土壤湿度的高值中心主要位于牡丹江流域和松嫩平原南侧,而从土壤水分的垂直分布特征来看,其湿润度绝大多数测站(除个别地区呈多峰态外)基本呈上干下湿,服从Weibull分布的单峰偏态型。各层土壤湿度在6月中旬和8月上旬变化最大,并存在以3 a为主的周期振荡。

Soil moisture of dekad average in summer from 1988 to 1999 was used to study the temporal and spatial characteristics of soil moisture vertical distribution in Northeast China, with PDF fitting, OF and wavelet analysis methods. The results show that the biggest values center of soil moisture in summer is located in the drainage area of Mudan River and the south of Songneng Plain, and that the wetness degree of most stations presented by a pattern of dryness in the above soil and wetness in the low one followed a Weibull distribution,except one or two stations. It also shows that there was biggest variation in the middle dekad in June and in the first dekad in August in each soil moisture layer,and existed a periodic variation of about 3 years.