Landslides in La Tinta quadrangle, Guatemala

This cover contains the outlines of landslides formed during Hurricane Mitch in October - November 1998. Jeffrey Coe and Robert Bucknam mapped the landslides and related effects in and adjacent to downstream drainages. Most landslides were mapped using 1:40,000-scale aerial photographs and a Kern PG-2 photogrammetric plotter at 4X and 8X magnifications. The photographs were scaled and oriented to the topographic base map using prominent topographic landmarks and plotted on a transparent polyester overlay registered to the topographic base maps at scales of 1:50,000 or 1:25,000. In areas where landslides were very sparse, the aerial photographs were scanned with a mirror stereoscope at 4X magnification, and landslide locations were transferred to base maps by inspection. The mapped landslides were digitized manually or by an optical scanner, and the data were then digitally registered to a digital version of the base map in ArcInfo.

本数据集涵盖了1998年10月至11月米奇飓风（Hurricane Mitch）引发的滑坡轮廓。杰弗里·科（Jeffrey Coe）与罗伯特·巴克纳（Robert Bucknam）对下游流域及其周边区域内的滑坡及相关影响开展了测绘工作。大部分滑坡通过1:40000比例尺航空照片，以及采用4倍、8倍放大倍率的克恩PG-2（Kern PG-2）型摄影测量绘图仪完成测绘。本次作业以显著地形地标为参照，将航空照片进行比例尺校正与方位匹配以适配地形底图，随后将解译结果绘制在透明聚酯薄膜覆盖图上，该覆盖图与1:50000或1:25000比例尺的地形底图完成配准。在滑坡分布极为稀疏的区域，研究人员以4倍放大倍率的立体镜扫描航空照片，通过目视解译将滑坡位置转绘至底图之上。已测绘的滑坡矢量数据通过手动数字化或光学扫描仪完成数字化处理，随后在ArcInfo软件中将数字化数据与数字版地形底图进行数字配准。