![]() ![]() For more information on using the data in Google Earth™, please see Using the National Flood Hazard Layer Web Map Service (WMS) in Google Earth™. To do so, you will need GIS or mapping software that can read data in shapefile format.įEMA also offers a download of a KMZ (keyhole markup file zipped) file, which overlays the data in Google Earth™. This data can be used in most GIS applications to perform spatial analyses and for integration into custom maps and reports. Using the “Search All Products” on the MSC, you can download the NFHL data for a County or State in a GIS file format. You can also use the address search on the FEMA Flood Map Service Center (MSC) to view the NFHL data or download a FIRMette. For more information on available services, go to the NFHL GIS Services User Guide. Technical GIS users can also utilize a series of dedicated GIS web services that allow the NFHL database to be incorporated into websites and GIS applications. In the NFHL Viewer, you can use the address search or map navigation to locate an area of interest and the NFHL Print Tool to download and print a full Flood Insurance Rate Map (FIRM) or FIRMette (a smaller, printable version of a FIRM) where modernized data exists. Set the following for the tool options.Or you you may view, download, and print current local digital effective flood hazard data in an ArcGIS map. ![]() ![]() If your lidar data is recorded in feet, a value of 0.3048 will rescale the values to meters, but it is generally recommended to build all raster surfaces in the coordinates of the source data to facilitate QC, and then their height values can be rescaled in the later Elevation workflow. Any other value will rescale the z-values of your output DTM. Under Z Factor, you should typically enter 1.For Cell Size, enter the resolution for the DTM tiles as determined in the QC step.something like GDALTranslate -of GTIFF C:\full\path\to\hdr.adf C:\full\path\to\your\output.tif will convert to a geotiff if ArcGIS refuses to open it. Unique tile numbers will be appended to the base name for each DTM tile, stored in TIFF format. You can convert the adf file with GDALTranslate if you're missing all the components, use the path to the hdr.adf as your input. Under Output Base Name, you can enter a common base name for all tiles, such as ProjectName_DTM_.Under Output Destination, enter the folder to store the DTM tiles.Under LAS Values to Export, choose Elevation.(Do not reference the LAS dataset from the Catalog pane or the filter for ground points will not be applied.) For Input LAS Dataset, drag the LAS dataset layer from the table of contents into the GP tool.In this case, use the same settings noted below, ignoring the steps related to defining output tiles. Note that if your LAS data comprises approximately 20 GB or less, you may choose to use the LAS Dataset to Raster geoprocessing tool within ArcGIS and create a single output raster. ![]() For large data collections, it is recommended to use the LAS Dataset To Tiled Rasters geoprocessing tool, which can be downloaded from 3D Samples. This workflow is based on creating rasters in multiple tiles to accommodate very large data collections. This workflow begins with the LAS dataset used to perform QC on the lidar files. Workflow for DTM and DSM derived from points This is the workflow recommended by Esri to ensure the most efficient use of disk space and the greatest scalability for organizations that may have large or numerous lidar collections.Īdditionally, some organizations prefer to have pre-built raster datasets that can be copied or downloaded, ensuring that all users access a single, authoritative version of the elevation data.
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