Abstract:

o find out the rule of soil water resources under different vegetations，six typical vegetations including coniferous and broadleaved mixed forest，coniferous forest，the chestnut plantation，shrub forest，wasteland and sloping farming land were chose in Zhaigou district of Ningshan county at Water Catchment Region of Central Route for SouthtoNorth Water Diversion Project.Physical characteristics and organic content in soil water were measured by sample plot investigation and experiment analytical method.It is found that soil physical and chemical characteristics such as soil density，porosity and organic matter under forests are all better than wasteland and sloping farming land.Soil water content under coniferous and broadleaved mixed forest is the highest and its water retention is much better than other vegetations.On the vertical section，soil water content and soil water retention reduced following with the increase of soil depth，but it decreased quickly under forests and its surface layer water content is evidently higher than the surface layer of wasteland and sloping farming land.Judging from water conservation，it is concluded that coniferous and broadleaved mixed forest is the best，followed by coniferous forest，and then by the chestnut plantation，shrub forest，wasteland and sloping farming.

Key words: SouthtoNorth Water Diversion Project, south slope of Qinling Mountains, vegetation types, soil moisture characteristic