黄土高原半干旱区主要作物生育期土壤水分变化

摘要

Based on the observed soil moisture dada in the farmland of springwheat,winter wheat,benne,oat,potato and bean from 1971 to 2006 in the semi-arid region of Gansu Province,the variation character of soil moisture in the farming land was analyzed by using EOF and wavelet analysis method.Results show that the soil there kept long-term drought,and the soil moisture had 2 and 4 years variation period.The vertical change of soil moisture presented decreasing trend with soil depth increase,and soil moisture dropped down during the period of crop growth,it was smaller in summer than that in other seasons.The vertical variation of soil moisture was correlated with the sort of the crop,different crops consuming soil moisture had the obvious spatio-temporal difference.%利用黄土高原半干旱地区农业气象观测站点春小麦、冬小麦、胡麻、燕麦、马铃薯、扁豆等主要作物农田土壤含水量实测资料,采用EOF、小波等方法分析研究该区域农田土壤水分变化特征。结果表明：长期干旱是这一地区土壤水分的基本状态,土壤水分垂直分布以递减为主,深层湿度小于浅层,夏季小于其它季节,秋季得以恢复;土壤水分垂直分布的差异与不同作物关系密切,作物对土壤水分耗费存在明显时空差异。