Development of a Stage-Specific Floodplain Inundation Model at a Large River Basin Scale: Comparison of Methods Based on Best Available Data

River-floodplain connectivity is a critical component in understanding ecological processes in river systems. High resolution LIDAR is increasingly becoming more available giving researcher’s the opportunity to develop tools (e.g., digital elevation models) for large-scale inundation analysis at the river basin scale to support flow-ecology questions such as fish recruitment dynamics and riparian productivity. Stage-discharge relationships used to develop floodplain inundation models can vary depending on data availability and spatial resolution. Here we compare two approaches for modeling floodplain inundation across a 300 km river reach in Texas: 1) calibrated HEC-RAS 1D model and 2) existing USGS stage-discharge data. How these methods can be used for development of instream flow recommendations to support healthy river-floodplain ecosystems will be discussed.