利用灾后苏门答腊岛DMC32米多光谱遥感图像,经过几何精校正、主要地名标注、波段B2(R)、B1(G)、B3(B)组合和直方图正态增强处理制作了影像图,图像总体纹理信息较弱,但对海啸受灾区有突出作用。为了突出不同区域植被的色差和纹理信息,对影像图进行比值增强组合处理实验,比值增强处理后的图像对空间纹理有增强效果。依据DMC增强图像显示的纹理影像特征,通过人机交互方式对图像中有较明显规律的线状和环状纹理信息进行提取和制图,作为进一步分析该地区构造活动及与之相关地质灾害的基础依据。通过对图像的纹理信息综合分析,发现该地区存在着大量的线形纹理信息和一些环形和火山机构影像信息,这些影像特征可能与该地区的一些地质活动有关,如新构造运动、活动断裂和火山活动中心、火山机构等。结合已知的地质、遥感三维立体图像和早期的TM图像资料,根据遥感图像上显示的特殊的地形和水系、线性纹理分布特征和典型地质体与断裂构造的遥感解译标志,对部分线性影像和环状影像的地质意义进行了解译,认为北西断裂为岛内的主干断裂,其次是与其相垂直配套的北东向断裂。初步分析了可能控制或诱发该地区地质灾害的断裂分布特征,推断出三处泥石流、崩塌、滑坡等地质灾易发区和两处火山活动可能区域。所推断的地质灾害易发区具备了泥石流、崩塌、滑坡等灾害形成、流通、堆积等先决条件,如果植被遭到破坏,一旦遇到强降雨影响,极有可能诱发上述地质灾害。火山活动区均处于北东向断裂带与北西向断裂带的交汇部位,根据地质构造和遥感影像特征分析推断,区内地震及火山活动有可能受板块活动地震影响而再次激活,形成新的地质灾害。以上遥感地质信息,在进一步经过相关资料和实地调查证实后,对岛内灾后重建及减灾、抗灾等活动具有积极指导意义。

In this paper, tsunami hazard monitoring system with Small Satellite applied on geological hazard is introduced. The DMC 32-meter multi-spectral remote sensing image acquired on 7 January 2005 for hazard areas in Sumatra Island, Indonesia was processed with image geometric correction, place name annotation, band combination with B2(R), B1(G), B3(B) and histogram enhancement. The produced image shows that although the overall texture, which show collectively information is weak due to dense vegetation, it is useful to tsunami hazard areas. In order to enhance tone difference of the different plant cover areas and textural information at the different regions, the data processing experiment based on ratio transform and combination has been done to enhance the image texture character, this is in effect benefit to enhance spatial texture information. Based on the DMC enhanced image map, by man-computer interactive interpretative way, the obvious disciplinary linear and ring texture information are extracted and then mapped, regarding it as basic information for further analysis to this area structure activity and geological hazard caused by active tecfonics. By means of synthetic analysis for image texture information, a lot of linear information and some ring information, as well as some image sign of volcanic apparatus are found in this area. These image characteristics are possibly related local geological activities, such as neo-tectonic, active fault, and volcanic active center and volcanic apparatus etc. Considering the known geologic information, the DMC 3-D image and the early TM images, and focusing on the special relief feature and drainage, the character of linear feature distribution shown on remote sensing image and remote sensing explanation signs for typical geologic body and fault structure, a part of linear and ring image features are explained in term of geological content. The north to west strike fault is considered as dominant fault, ranking second is the north-east strike fault which is the matched uprightness to former one. The fault distribution character with potential controlling or inducing geological hazard in this area is initially analyzed, furthermore, three regions of easily broken geological hazard of mud-rock flow, collapse and landslide and two potential burst districts of volcanic activity are predicted. These deduced target places have the precondition and condition of the form,pass and accumulation for mud-rock flow, collapse and landslide, and if the plant cover are suffered from being destroyed and heavy rain, then it is possible to produce those geologic disasters. The volcanic activity areas are almost located into the junction parts along north-east fault zone with north-west fault zone. Considering the geological structure and remote sensing image character, the earthquake and volcanic activity could be activated and revived after undergone plate movement, and possibly form next new geological hazard. Generally speaking, the above mentioned remote sensing geologic information which ought to further be investigated and confirmed from related materials and practice, will benefit for reducing disaster, and fighting natural disaster on the island. For fundament establishment reconstruction after this great earthquake and tsunami hazard, this has an important significance.