衡阳盆地紫色土丘陵坡地土壤水分变化动态研究

2007年对衡阳盆地紫色土丘陵坡地0-50 cm土壤进行研究.结果表明:(1)在同一水平空间位置上,土壤平均含水量总的变化趋势是阴坡>阳坡.而土壤水分变异系数则呈现出相反的变化规律;(2)在同一垂直空间位置上,阴坡与阳坡不同坡位的土壤含水量的变化规律均为:下坡>中坡>上坡.阳坡的土壤水分变异系数的大小顺序是:阳坡上坡>阳坡中坡>阳坡下坡;而阴坡则呈现出相反的变化趋势;(3)土壤含水量的消长与同期的降雨量有关,1-6月为雨季水分补偿期,7-12月属于旱季水分亏缺期;(4)在同一水平空间,不同坡向土壤含水量剖面变化明显.随着土层深度的增加,土壤含水量增加.从土壤水分的变异系数来看,阳坡土壤水分的变异系数随土壤的加深而变大,阴坡土壤水分的变异系数随土壤深度的加深而变小,土壤水分的最稳定层均出现在10-30 cm处.

Study on Dynamic of Water Content on the Sloping-land with Purple Soils in Hengyang Basin

The soil of 0-50 cm on the sloping-land with purple soils in Hengyang Basin was studied in 2007. The results showed that: (1) The water content on the sloping-land with purple soils was higher in north-facing slope than those of the corresponding level places in south-facing slope, but there was a contrary tendency in coefficient of variance in the water content on the sloping-land with purple soils in Hengyang Basin:(2)In the same perpendicular space, the sequence of the water content in sloping-land with purple soils in Hengyang Basin was as follows, the lower-slope>the middle-slope>the upper-slope;The sequence of coefficient of variance in the water content in south-facing slope was as follows:the upperslope>the middle-slope>the lower-slope,and there a contrary tendency in the coefficient of variance in north-facing slope:(3)The water content in sloping-land with purple soils in Hengyang Basin had something to do with the rain in the same period. There was much rain from January to June, but there was little rain from July to December:(4)In the same level space, there was an increasing tendency in the water content with the increasing in the depth in soil, there was an increasing tendency in the coefficient of variance with the increasing in the depth in soil in south-facing slope,and there was a contrary tendency in the coefficient of variance in north-facing slope. In the depth of 10-30 cm, the water content in soil was the stablest.