摘要
利用1981-2002年黄河中游地区(32°～42°N,100°～116°E)土壤湿度资料,分析该地区土壤湿度的水平和垂直分布特征、年际和年代变化。结果表明:黄河中游地区土壤湿度水平分布大致呈中部干,西南和东南湿的分布趋势;该地区的中南部土壤湿度垂直分布具有独特性,随季节而变,初春至5月底土壤湿度迅速下降,表层下降最快,且达到最干的时间比50～100cm层早3旬,垂直分布表现为上干下湿;雨季开始表层土壤湿度迅速上升,垂直分布反转为上湿下干。黄河中游地区土壤湿度变化总体呈下降趋势,1981-1996年存在5～6年的变化周期;中南部1991年前后发生突变,1991年以前土壤较湿,年际变幅大,之后较干,年际变幅小。中南部是土壤湿度变化差异最明显的区域。
In this paper,the data of soil moisture content in the middle reaches of the Yellow River during the period of 1981-2002 were analyzed to find the horizontal and vertical distribution laws. Characteristics of interannual and inter-decadal change of soil moisture content were also analyzed. The results reveal that,horizontally,soil moisture content was approximately higher in the central part than that in the southwestern and southeastern parts of the study area. Vertical distribution of soil moisture content changed seasonally. Soil moisture content was sharply decreased from early spring to May,especially in topsoil,the time when soil became the driest was earlier for 3 ten-day periods than that in soil layer of 50-100 cm,and the upper soil layer was drier than the lower one. Moisture content in topsoil was sharply increased in rainy season,and it was higher than that in lower layer. Holistically,soil moisture content was in a decrease trend,and there was a 5-6-year periodic change in the study area during the period of 1981-1996. There was an abrupt change of soil moisture content around 1991 in the central-southern part. Soil moisture content and its interannual change extent were high before 1991,and then soil became drier and the interannual change extent was lower. The change of soil moisture content was the most remarkable in the central-southern part of the study area.
出处
《干旱区研究》
CSCD
北大核心
2011年第1期85-91,共7页
Arid Zone Research
基金
国家自然科学基金(40775047)资助
关键词
土壤湿度
水平分布
垂直分布
陆面过程
黄河中游
soil moisture content
horizontal distribution
vertical distribution
land surface
middle of the Yellow River
