Flood Event Mapping

Flood Event Mapping 

Price Geographic Consulting is able to provide accurate mapping of peak flood events, low water, or levels on a given date. The usual data set includes custom georeferenced aerial imagery of a river reach, bay, estuary, or any other body of water, and a corresponding polygon that depicts the water surface at the time the imagery was taken.

A detailed flight plan is prepared that creates camera target locations, and flight line routing.

Careful flight planning is performed to minimize flight time, assure complete coverage of the study area. A detailed flight plan is prepared that creates camera target locations, and flight line routing for use by GPS aircraft navigation and shutter trigger timing. By timing the flight to collect aerial imagery to coincide as closely as possible with the peak flood (or any other criteria) Price Geographic Consulting is able to record the actual ground coverage of the water body at the specified time. PGC will work with your team to keep abreast of stream gauging data, estimated time of maximum flooding, along with the weather conditions (visibility) & aircraft availabilty, to schedule the date and time of the flight.
After the flight and collection of overlapping high resolution aerial imagery, PGC imports the imagery into a GIS mapping system and georeferences the imagery to a specified cartographic projection to create a base layer showing visual water coverage.After georeferencing the imagery, a GIS mapping specialist, digitizes the water surface limit creating a polygon that maps the extent of water coverage at the time of the flight. This results in a useful data layer for Emergency response personnel, hydrologists, fisheries & aquatic scientists, civil engineers, soil scientists and community planners.

Peak Flood Polygon overlayed on georeferenced source imagery, with resulting channel scouring shown in green.

This process can also be incremented over time to create a record of the change of river banks, stream channels, riparian vegetation, stream bed conditions and a host of other visually observable conditions.