香港滑坡区雷达图像上线性弱信息与低序次断裂的关系(英文)

The Relationship between Linear Weak-Information of Radar Image and Subordinate Faults in Landslide Area of Hong Kong

香港新界地区多山多坡 ,地势险要 ,土地利用相对不足。在暴雨季节 ,是滑坡和山泥倾泻的重灾区之一 ,对区内道路、建筑构成威胁。港九地块自晚中生代至早第三纪以来 ,以持续稳定上升为主 ,其活动性明显低於周边相对下沉的中新生代盆地。香港地区北侧边界为深圳断裂 ,南侧为海丰断裂。这两条主干断裂呈北东展布 ,左行剪切。它们导致香港地区的三套断裂系统 :北东向的区域断裂 ;北东东到东西向的断裂系统 ;次级的北西向断裂系统。这三组断裂控制了香港地区的构造地貌 ,在雷达图像上清晰的表现出岩块的破裂程度和断裂配套格局。全区的构造地貌特征明显 ,花岗岩火山岩抗风化能力强弱不均 ,地表不稳定因素大量存在 ,再加上高频率、高强度暴雨袭击 ,以及坡积物不易固积等原因 ,极易导致滑坡和山泥倾泻事件发生 ,造成人员伤亡和遭受经济损失。香港滑坡泥石流主要受地形条件、土体结构与强度、暴雨入渗特征、植被复盖以及人为搅动等因素的控制。由于滑坡泥石流规模小、密度大、频率高 ,因此在研究工作中还广泛地使用遥感方法。在新界地区 ,许多滑坡与微地貌有关。在复盖层较簿或缺失的地方 ,微地貌基本上反映了基岩的微构造。雷达对线性构造的探测有其独到的优势 ,低序次构造规模小但数量多 ,在雷达图像上以线性?

By processing the Airborne L SAR image of the study area, we selected the weak information of SAR image as indicator of subordinate faults, and traced the structural background of landslides in the region. The regional fault in the study area is the NE strike slip fault. Its sinistral movement forming a serial subordinate faults, including R plan, P plan and R′ plan, which are represented as weak information of lineation in radar image and related to the development of micro geography. By selecting and enhancing the weak information, we made the deformation frame of subordinate shear faults. Together with field investigation, we found that the location of P shear plan on the northeastern Jubilee Reservoir can form landslides of gravity unbalanced alluvium, with a background of strong strain deformation belt. The newly formed landslide of boulder falls was located at southeast of Jubilee Reservoir. It has features of structural tension background, and relates to the subordinate faults with pull apart action on the direction of the R shear plan.