Background
The major issues facing ecosystem restoration and management in south Florida are centered on the availability and distribution of clean, fresh water. Surface water flow modeling studies are an important aspect of the scientific information needs of the ecosystem restoration initiative. Hydrologic models provide much needed predictive capabilities for evaluating options for management of parks, refuges, and lands planned for acquisition, as well as for understanding the impacts of land management practices in surrounding areas. Models must account for the expansive and extremely low relief terrain of south Florida, where surface waters of the natural system are transported by sheet flow from Lake Okeechobee through the Everglades to Florida Bay and the Gulf of Mexico. To model sheet flows, highly accurate elevation data that define the surface topography are required as the most critical input parameter to the Natural Systems Model and other hydrologic models. These data are necessary for calculating water surface slope, depth, velocity, and direction of flow. Hydrologists have stated vertical accuracy requirements of between 3 and 15 centimeters. These accuracy requirements are so stringent, because of the extremely flat terrain, that any standard or other currently available data products would not suffice for this modeling application.
