鄂东南花岗岩区节理对崩岗发育的影响

崩岗是鄂东南花岗岩地区普遍存在的土壤侵蚀现象,给农业生态与经济发展带来了严重影响。研究以鄂东南通城县杨垄小流域崩岗为研究对象,使用RTK测量数据,ArcGIS生成DEM图像,测定坡面坡向及主沟、支沟的发展方向,运用罗盘测量节理产状,描述节理的区域性特征,探讨了节理对崩岗发育的影响。结果表明:杨垄小流域节理产状具有方向性和区域性,多为NE45°—90°和NW280°—310°;崩岗主沟发展方向主要受坡面坡向的影响,多位于北东向;崩岗支沟的发育在一定程度上受节理走向的影响,多分布于NE45°—90°和NW280°—320°;节理倾角大,节理面陡可加快崩岗的侵蚀与发育;节理可加快地下水的下渗,有利于风化壳的形成,加速崩岗侵蚀。研究结果可为探究崩岗地貌系统侵蚀机理及其治理方法研究提供依据。

Impact of Joints of Rock on the Development of Collapse Hills in Southeast of Hubei Province

Collapse hill is a universal phenomenon of soil erosion in granite area in southeast of Hubei Province,which has serious impacts on agricultural ecology and economic development.The research selected the collapse hills in Yanglong watershed as the site,measurement of slope aspect,the DEM images which were made by ArcGIS on the basis of RTK data were explored to measure the development direction of main gully and tributaries,the compass was used to describe joint attitude and its regionality,and discuss the impact of joints of rock on the development of collapse hills.The results demonstrated that the joint attitude in Yanglong watershed is regional and directional,almost all are in the direction of NE45°-90° and NW280°-310°;slope aspect influences the development direction of main gully,for they intensively distribute in North East;joint strike has the impact on the tributaries of collapse hills,almost all are in the direction of NE45°-90° and NW280°-320°;for steep joint inclination,faster erosion and growth of collapse hills are mainly governed by it;joint could make groundwater infiltrate faster,which is beneficial to form weathering crusts so as to accelerate the collapse erosion.The research results could provide the basis for erosion mechanism and the methods of prevention of collapse hills.