Landslides in Entre Ríos 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·巴克纳姆（Robert Bucknam）在下游流域及其毗邻区域完成了滑坡及相关影响的制图工作。绝大多数滑坡通过比例尺为1:40000的航空像片，并借助克恩PG-2（Kern PG-2）摄影测量绘图仪以4倍和8倍放大倍率进行解译与绘制。本次使用的航空像片通过显著地形地标完成比例尺校正与方位匹配，随后被转绘至与比例尺为1:50000或1:25000的地形底图配准的透明聚酯覆盖膜上。在滑坡分布极为稀疏的区域，研究人员以4倍放大倍率通过反光立体镜（mirror stereoscope）扫描航空像片，并通过目视解译将滑坡位置转绘至地形底图。已绘制的滑坡数据通过人工或光学扫描仪完成数字化处理，随后在ArcInfo中完成与数字化地形底图的坐标配准。