Virginia Physiographic Regions

This is a polygon coverage of Physiographic Divisions in the conterminous United States cropped to the state boundary of Virginia. It was automated from Fenneman's 1:7,000,000-scale map, "Physical Divisions of the United States," which is based on eight major 1946 divisions, 25 provinces, and 86 sections representing distinctive areas having common topography, rock types and structure, and geologic and geomorphic history.本数据集为裁剪至弗吉尼亚州州界范围的美国本土地貌分区（Physiographic Divisions）多边形覆盖数据。该数据集源自芬纳曼绘制的1:700万比例尺地图《美国自然分区》，此地图基于1946年划定的8个一级分区、25个亚区以及86个小区构建，这些分区单元代表了具备统一地形特征、岩石类型与构造条件，且拥有共同地质与地貌演化历史的特色地理区域。