This appendix is written to explain steps for converting data to input types that are supported by HEC-FIA.
The geographic information system (GIS) pre-processing that is required for an HEC-FIA study can be handled through any GIS software, including HEC-RAS.
The HEC-RAS software is an integral part of the process for running HEC-FIA. HEC-FIA relies on data from HEC-RAS in the form of Storage Area and Cross Section shapefiles; Terrain grids, Inundation grids, Arrival Time grids, and HEC-DSS output. This Appendix shows the basic steps in HEC-RAS to export data for use by HEC-FIA. For more details about using HEC-RAS, pleased see the HEC-RAS Documentation Space :HEC-RAS Documentation
There are several GIS pre-processing steps that need to be completed before creating a study in HEC-FIA. Depending on the level of detail in the study, not all of the following need to be utilized:
- Preparation of maximum inundation depth grids
- Preparation of duration and arrival time grids
- Creation of maximum inundation area polygon
- Generation of the hazard area boundary
- Preparation of a digital terrain model
- Preparation of arrival time grid for depths two feet and greater
- Preparation of emergency planning zone (formerly defined as impact area in HEC-FIA Version 3.0) polygons
- Preparation of double warning time polygon
- Agricultural grid preparation
Each of these steps is explained in the following sections.