Two computational inputs are required to distribute a population throughout a study area. One of these required inputs, structure inventory, is described in Hydraulics Event Computation. A critical element of the structure inventory is the occupancy type-naming scheme, which is addressed in the next section. The additional required input is population information from the HAZUS database, which is contained in the HzbndrygrbsB.mdb database.

Occupancy Type Schema

Population information is imported into HEC-FIA in the form of totals of people at the census block level, subcategorized to represent industrial, commercial, and residential groups (occupancy types). These categories need to be aggregated based on times of day, but also need to be disaggregated to represent the count in each structure. To perform the aggregation or disaggregation, the population in each structure is prorated using the average number of households by occupancy type. This proration is based on the description of the 36 standard HAZUS MH occupancy types, which is currently not editable by the user. Definitions for these occupancy types can be found in Table 3.1 of the HAZUS-MH Flood Technical Manual (Appendix A, Section A.1). The table below is provided to give the user insight to the weights applied by occupancy type.

HAZUS Population Data

Population information is imported into HEC-FIA from the HzDemographicsB table in the HAZUS database.

Number of Households per HAZUS MH Occupancy Type