ECA - Steep Slope

Displays areas with 40% steep slope or greater in the City of Seattle. A polygon feature class showing areas with an incline of 40% or more (10 feet of vertical rise over a horizontal distance of 25 feet or less) with a height of at least 10 feet. This layer was produced using a combination of 2001 LIDAR contours (Puget Sound LIDAR Consortium) and the 1993 topographic contours from aerial photos. The Steep Slope layer was most recently updated under SDCI Director's Rule 12-2019. The steep slope area map is called “advisory” because the mapping is used by the Seattle Department of Construction and Inspections for initial information and screening. Whether or not a site is eventually treated as an environmentally critical area is based on the actual topography of the ground surface. For more information about the definition of steep slope erosion hazard areas, see Seattle Municipal Code section 25.09.012, Environmentally Critical Areas (ECA) definitions. Updated as needed.本数据集展示西雅图市内坡度达到或超过40%的区域。该数据集为多边形要素类，涵盖坡度不低于40%（即垂直每上升10英尺，水平行进距离不超过25英尺）且高度至少为10英尺的区域。本图层由2001年激光雷达（LIDAR）等高线（普吉特海湾激光雷达联盟）与1993年航空摄影地形等高线融合制作而成。该陡坡图层的最近一次更新遵循西雅图建筑与检查局（Seattle Department of Construction and Inspections，SDCI）发布的《2019年第12号主任指令》。本陡坡区域地图被归类为"参考性"地图，因西雅图建筑与检查局仅将其用于初始信息提供与筛查流程。某地块最终是否被认定为环境关键区域，需以地表实际地形状况为判定依据。如需了解陡坡侵蚀危险区域的详细定义，请参阅《西雅图市政法典》第25.09.012条"环境关键区域（Environmentally Critical Areas, ECA）定义"。本数据集将根据实际需求进行更新。