根溪小流域崩岗分布特征研究

崩岗集中发育于华南丘陵谷坡及山间地以风化花岗岩残积物为基底的红土地貌,被称为南方地区的"生态溃疡",是该地区最严重的土壤侵蚀类型.降雨、气温等气候因子的极端变化,内部各种节理等软弱结构面的广泛分布,加之过度的植被破坏是崩岗形成、发展的主要的驱动因素.通过对南方红壤侵蚀区(根溪小流域)野外调查,分析坡向、形态、发育阶段和活动状况上的数量及面积状况,在此基础上得出:南坡崩岗的数量和面积要明显多于其他坡位;中期崩岗数量最多,面积最大;从形态来看,条形崩岗数量最多,混合形崩岗数量最少,爪形崩岗面积最大,弧形崩岗面积最小;半稳定型崩岗个数最多,且面积最大,活跃型崩岗个数最少,稳定型崩岗面积最小.

Study on Distributed Characteristics of Slump Gully in Genxi Small Watershed

Intensively developing on hills and gullies as well intermountain lands in southern China,underlying the substrate of weathered granite crust residues,slump gully is distinguished as ecological ulcer and has been becoming the most severe soil erosion type. Extreme changes of climatic factors,such as precipitation,temperature and extensive distributions of internal weak structural planes like various joints together with excessive,long-term vegetation deterioration are the main driving factors of the initiation and development of slump gully. Through field investigating the eroded red soil region of southern China（i. e. Genxi small watershed）and analysing the quantity and area conditions including slope positions,shape styles,develop stage and activity states,on this basic,it can be conduded that the number and area in south slope position is more than others;the number and area of slump gully is largest in middle age;in quantity,the stripe type is more than others while the mixed is least,however,on area the claw-shaped is the greatest of all in area whereas the curved is least;the number and area of the semi-stability of slump gully is larger than others;and the number of the active is smallest;while the area of the stable is smallest.