贵州喀斯特峰丛山体土壤水分布特征及其影响因素

CHARACTERISTICS OF SOIL MOISTURE DISTRIBUTION AND ITS INFLUENCE FACTOR IN THE KARST CLUSTER-PEACH MOUNTAIN

喀斯特峰丛山体土壤水是喀斯特地区水文及生态环境的重要影响因素。研究喀斯特峰丛山体土壤水分布及其规律对贵州喀斯特地区控制水土流失、防治石漠化、恢复生态环境具有重要的理论和实际意义。选取贵州普定县岩溶区内典型的喀斯特峰丛山体,利用时域反射(TDR)测定山体不同位置在不同植被覆盖、地形、土壤特征及岩石分布下的土壤含水率,分析喀斯特峰丛山体土壤水的空间分布规律及其影响因素。结果表明:各种土地利用类型的山体土壤含水率总体由山体上部向下逐渐减小,土壤含水率随埋深加大显著增加,随坡度的增加而减小。总体上植被覆盖地带土壤含水率高于裸露土壤,相同条件下,林地、低矮灌丛、草地对土壤持水性的影响依次减小。岩石上覆土层较厚时,土壤含水率较高;土层浅薄时,土壤含水率偏低。

Soil moisture content in the karst cluster-peach mountains is a key factor controlling the hydrology and environment of the area. The study of soil moisture distribution and regularity plays an important role for soil and water loss prevention,rocky desertification control and environment recovery in theory and practice. In this study,the soil moisture contents in typical karst cluster-peach mountains in Puding County,Guizhou Province,were measured by time domain reflectometry in many locations with different vegetation covers,landform,soil characteristics,land surface slopes and rock distributions. Their influencing factors were revealed on the basis of the observation data. The results show that soil moisture content has a significant increase tendency from the mountain higher to lower portion for any different land-uses in the mountains. Soil moisture content increases significantly in the deeper soil layers but decreases in the areas with sharper slope surface. Soil moisture content under vegetation canopy is greater than that in the bare sites,and this influence becomes weak when the land surface vegetation changes from forest to shrub and grass. Soil moisture content in the soil layers above the rock is higher with the thick soil layer and lower with the thin soil layer.