Wetted channel and bar features for Hunter Creek, Oregon in 1965

Hunter Creek is an unregulated system that drains 115 square kilometers of southwestern Oregon before flowing into the Pacific Ocean south of the town of Gold Beach, Oregon. In cooperation with the U.S. Army Corps of Engineers, the U.S. Geological Survey completed a reconnaissance-level assessment of channel condition and bed-material transport relevant to the permitting of in-stream gravel extraction in the lower 12.4 kilometers Hunter Creek. To support these analyses, digital channel maps were produced to depict channel and floodplain conditions along the Hunter Creek system from different time periods. GIS layers defining the wetted channel and bar features and channel centerline of Hunter Creek were developed for four time periods: 1940, 1965, 2005, and 2009. For this project, the active channel was defined as area typically inundated during annual high flows, and includes the low-flow channel as well as side channels, islands, and channel-flanking gravel bars. The wetted channel and bar feature datasets were developed by digitizing from aerial photographs. Aerial photographs from 1940 and 1965 were scanned, rectified, and mosaicked for this project (See metadata for each photograph set for more information on the rectification process and resolution of each dataset). Digital orthophotographs from 2005 and 2009 are publicly available.亨特溪（Hunter Creek）是一处无调控水系，流域面积达115平方千米，覆盖俄勒冈州西南部区域，最终在俄勒冈州戈尔德比奇镇以南注入太平洋。为配合美国陆军工程兵团（U.S. Army Corps of Engineers）的相关工作，美国地质调查局（U.S. Geological Survey）针对亨特溪下游12.4千米河段的河道状况与推移质输运特征开展了踏勘级评估，该评估服务于河内砾石开采的许可审批流程。为支撑上述分析工作，项目组生成了数字化河道地图，用以呈现不同历史时期亨特溪水系的河道与漫滩状况。针对1940年、1965年、2005年及2009年四个时间节点，项目组开发了涵盖亨特溪湿河道、沙洲特征以及河道中心线的地理信息系统（Geographic Information System，GIS）图层。本项目将活跃河道定义为年度高水位期间通常会被淹没的区域，包含枯水期河道、支流河道、沙洲以及河道两侧的砾石沙洲。湿河道与沙洲特征数据集通过对航空影像进行数字化提取生成：1940年与1965年的航空影像经扫描、几何纠正与镶嵌后应用于本项目，有关影像纠正流程与各数据集分辨率的更多细节可参见各影像集的元数据；2005年与2009年的数字正射影像（Digital Orthophotograph）为公开可用资源。