SPATIALLY DISTRIBUTED RAINFALL FOR THE FLORIDA WATER MANAGEMENT DISTRICTS

摘要

Representative rainfall information with known accuracy is needed by water management agencies in Florida. The Florida Water Management Districts (Districts) are regional governmental agencies with responsibilities for water quality, flood control, water supply, and environmental restoration. Rain gauge-adjusted radar rainfall is used by the Districts to support water management decision-making. Rainfall data is drawn from both radar and rain gauges because rain gauge networks do not provide information on how much rain falls between the rain gauges, and it is not feasible to maintain a network dense enough to capture the spatial variation of rainfall. Weather radar does capture the spatial pattern and relative intensities of rainfall, but is not reliable at quantifying these intensities without rain gauge adjustment. Rain gauge-adjusted radar rainfall captures the spatial variability of rainfall and adjusts for radar bias, resulting in better characterized basin-wide rainfall amounts. The Districts' rainfall system produces statewide rainfall at high resolution through a combination of rain gauge networks operated by the Districts and radar data collected by the US National Weather Service from the NEXRAD (WSR-88D) radar network. Rainfall estimates are issued at 2x2 km resolution with 15-minute updates, using the data of 531 gauges and eight NEXRAD radars. The system supports the quality control and quality assurance (QA/QC) of the rain gauge and radar data, performing bias correction in real-time and in post-analysis to provide accurate and representative maps of rainfall in GIS format for hydrologic applications.