Coastal Inundation High 2FT

These data were created as part of the National Oceanic and Atmospheric Administration Coastal Services Center's efforts to create an online mapping viewer depicting potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise (slr) and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses.Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: http://www.csc.noaa.gov/slr These data depict the potential inundation of coastal areas resulting from a projected 1 to 6 feet rise in sea level above current Mean Higher High Water (MHHW) conditions. The process used to produce the data can be described as a modified bathtub approach that attempts to account for both local/regional tidal variability as well as hydrological connectivity. The process uses two source datasets to derive the final inundation rasters and polygons and accompanying low-lying polygons for each iteration of sea level rise: the Digital Elevation Model (DEM) of the area and a tidal surface model that represents spatial tidal variability. The tidal model is created using the NOAA National Geodetic Survey's VDATUM datum transformation software (http://vdatum.noaa.gov) in conjunction with spatial interpolation/extrapolation methods and represents the MHHW tidal datum in orthometric values (North American Vertical Datum of 1988). The model used to produce these data does not account for erosion, subsidence, or any future changes in an area's hydrodynamics. It is simply a method to derive data in order to visualize the potential scale, not exact location, of inundation from sea level rise.本数据集由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）海岸服务中心（Coastal Services Center）为搭建在线地图查看器而生成，该查看器旨在展示潜在海平面上升及其对美国沿海地区的相关影响。 本查看器的设计初衷是为沿海管理者与科研人员提供海平面上升（Sea Level Rise, SLR）及沿海洪涝影响的初步研判视角，其作为筛查级工具，采用全国统一的数据集与分析方法开展工作。 所提供的数据集与地图可多尺度应用，助力研判不同情景下的发展趋势并排序行动优先级。 可通过以下网址访问本海平面上升与沿海洪涝影响查看器：http://www.csc.noaa.gov/slr 本数据集展示了在当前平均高高潮位（Mean Higher High Water, MHHW）基础上，海平面预计上升1至6英尺时，沿海地区的潜在淹没范围。 本数据集的生成流程可被描述为改进型浴缸法（modified bathtub approach），该方法兼顾局地/区域潮汐变化与水文连通性特征。 该流程依托两类源数据集，针对每一轮海平面上升情景生成最终的淹没栅格（raster）、矢量多边形（polygon）及配套的低洼区域多边形：一是研究区域的数字高程模型（Digital Elevation Model, DEM），二是表征空间潮汐变化的潮汐表面模型。 该潮汐模型借助美国国家海洋和大气管理局国家大地测量局的VDATUM基准转换软件（http://vdatum.noaa.gov），结合空间插值/外推方法构建，以正高数值（1988北美垂直基准面，North American Vertical Datum of 1988）表征平均高高潮位（MHHW）潮汐基准。 本数据集所采用的模型未考虑侵蚀、沉降或区域未来水动力变化，仅用于推演海平面上升引发淹没的潜在规模，而非精确淹没位置，以实现可视化展示。