在甘肃和青海交界地区的1:257Y民和县幅、临夏市幅和定西市幅数字区域地质调查中,以“数字填图系统(RGMAP)”为平台,使用遥感ETM^+数据和地形数据对岩石地层进行了信息挖掘。数据准备主要是遥感和数字地形多源信息的提取和预处理.从数字地形图的等高线数据中提取高程,进而提取汇水网络等水文信息和地形参数。遥感数据经过地形校正、线性增强、色彩拉伸,进行空间分辨率增强,经彩色合成并结合数字高程,实现了对调查区构造-地层区划和部分岩石地层单元的识别。实践证明该项工作是地质填图的重要辅助手段。
The ETM+ and DEM (digital elevation model) data were used to help extracting information of lithostratigraphic units based on the "digital mapping system" in 1:250 000 digital regional geological survey of the Minhe County, Linxia City and Dingxi City sheets in the border region of Gansu and Qinghai. The data preparation mainly involves remote sensing and landform information extraction and preprocessing. DEM data were derived from contours of the digital relief map. Other hydrologic and topographic pa- rameters were derived from DEM, for instance, drainage network. After topographic correction, linear enhancement, color elongation, the rate of spatial resolution of remote sensing data was enhanced. Through color synthesis, combined with DEM, the tectono-strati- graphic divisions and recognition of some lithostratigraphic units in the study area were achieved. Practice proves that this work is an important auxiliary means for geological mapping.