FEMA - Harvey Flood Depths Grid

This resource describes a dataset of gridded depth at horizontal resolution of 3 meters, published as an Esri ArcGIS geodatabase on November 15, 2017 by FEMA. This dataset is no longer accessible from FEMA, but is now uploaded to this HydroShare resource in the contents list. This product utilized Triangulated Irregular Network (TIN) interpolation, four quality assurance measures (identifying dips, spikes, duplication, and inaccurate/unrealistic measurements). High Water Marks were obtained from the Harris County Flood Control District (HCFCD), US Geological Survey (USGS), and other inspection data. Elevation data comprised a mosaic of 3 meter resampled elevations from 1M & 3M LiDAR, and IFSAR data. One section of the IfSAR data was found to be erroneous, and replaced with a blended 10 meter section.
[This method description was from correspondence January 22, 2018, from Mark English, GeoSpatial Risk Analyst, FEMA Region VIII, Mitigation Division.]

See FEMA's Natural Disasters data site [1] for additional HWM-based depth grids and inundation polygons:
- Harris County Areas of Interest (AOIs) and Inundation Boundaries
- Harris County Depth Grids
- Aransas, Nueces, and San Patricio Coastal Depth Grids and Boundaries

Some of the data available below in the contents list is from the FIMA NHRAP program, which is no longer available from FEMA, as of the summer of 2019.

FEMA notes on these Modeled Preliminary Observations:
o Based on observed Water Levels at stream gauges interpolated along rivers, downsampled to 5m resolution DEM
o Depth grids updated with new observed peak crest as they become available
o Will include High Water Mark information as it becomes available
o Extents validated with remote sensing
o Use for determining damage levels on specific structures

References:
[1] FEMA Harvey data [https://disasters.geoplatform.gov/publicdata/NationalDisasters/2017/HurricaneHarvey/Data/] [link is no longer accessible]

本资源详细描述了一个水平分辨率为3米格网深度数据集，该数据集于2017年11月15日由联邦紧急事务管理署（FEMA）以Esri ArcGIS地理数据库格式发布。该数据集自发布以来已不再通过FEMA提供访问，但现已上传至本HydroShare资源的内容列表中。该产品采用了三角形不规则网络（TIN）插值方法，并实施了四项质量保证措施（识别洼地、尖峰、重复以及不准确或不切实际的测量）。高水位标记数据来源于哈里斯县洪水控制区（HCFCD）、美国地质调查局（USGS）及其他检查数据。高程数据由1米和3米激光雷达（LiDAR）以及合成孔径雷达（IFSAR）数据的3米重采样高程镶嵌而成。发现IFSAR数据中存在错误的部分，已被10米混合数据替代。

[该方法描述摘自2018年1月22日Mark English（FEMA第八区域地理空间风险评估分析师）的通信内容。]

欲获取更多基于高水位标记的深度网格和淹没多边形数据，请参阅FEMA的自然灾害数据网站[1]：
- 哈里斯县感兴趣区域（AOIs）和淹没边界
- 哈里斯县深度网格
- 阿兰萨、纽西斯和圣帕特里西奥沿海深度网格和边界

以下内容列表中的一些数据来自FIMA NHRAP项目，该项目自2019年夏季起不再由FEMA提供。

联邦紧急事务管理署关于这些模拟初步观测的注释：
o 基于河流中观测到的水位在河流测流站处的插值，并下采样至5米分辨率的数字高程模型（DEM）
o 随着新观测到的峰值洪水位的可用性更新深度网格
o 随着可用性的增加，将包括高水位标记信息
o 使用遥感技术验证范围
o 用于确定特定结构的损害程度

参考文献：
[1] FEMA Harvey数据 [https://disasters.geoplatform.gov/publicdata/NationalDisasters/2017/HurricaneHarvey/Data/] [链接已无法访问]