With the method of
Detrended Canonical Correspondence Analysis(Dcca),we studied the relationship between the types of spatial
and temporal variation of soil moisture content and the environmental factors at the scale of catchment.Results indicated that in a wetter year(1998),the profile distribution of soil moisture content shows three types:decreasing type,waving type and increasing type contributed to the influencing of land use and topography.Under the influencing of precipitation and topography.soil moisture content changes seasonally in forms of three peak type,synchro four peak type and lagged four peak type.It is concluded that soil water is utilized effectively on sites of both the decreasing type and waving type;from a wetter year to drier year,the profile type of soil moisture content changes from decreasing type to waving type and from waving type to increasing type.The soil layer (0～5cm)and the season(summer),which soil moisture content being spatially stable across overall landscape in the wetter year,are important for predicting the average soil moisture content in the whole catchment.