GCPO Inundation Frequency Mosaic

In large river ecosystems, the timing, extent, duration and frequency of floodplain inundation greatly affect the quality of fish and wildlife habitat and the supply of important ecosystem goods and services. Seasonal high flows provide connectivity from the river to the floodplain, and seasonal inundation of the floodplain governs ecosystem structure and function. River regulation and other forms of hydrologic alteration have altered the connectivity of many rivers with their adjacent floodplain – impacting the function of wetlands on the floodplain and in turn, impacting the mainstem river function. Conservation and management of remaining floodplain resources can be improved through a better understanding of the spatial extent and frequency of inundation at scales that are relevant to the species and/or ecological processes of interest. Spatial data products describing dynamic aspects floodplain inundation are, however, not widely available. This study used Landsat imagery to generate multiple observations of inundation extent under varying hydrologic conditions to estimate inundation frequency. Inundation extent was estimated for 50 Landsat scenes and 1334 total images within the Gulf Coastal Plains and Ozarks Landscape Conservation Cooperative (GCPO LCC), a conservation science partnership working in a 730 000-km 2 region in the south central USA. These data were composited into a landscape mosaic to depict relative inundation frequency over the entire GCPO LCC. An analytical methodology is presented in the related publication for linking the observed inundation extent and frequency with long-term gage measurements so that the outcomes may be useful in defining meaningful critical thresholds for a variety of floodplain dependent organisms as well as important ecological processes

The GCPO Inundation Frequency (IF) mosaic is a cartographic product is intended to provide a landscape scale comparison of floodplain inundation frequency. For a more detailed analysis, please refer to the IF data for an individual Landsat scene (path/row), and the excel file listing the dates of imagery used to construct IF for that scene (Available at https://www.sciencebase.gov/catalog/item/5617e3c3e4b0cdb063e3fc35). Methodology and potential application details are in: Allen, Y. 2015. Landscape Scale Assessment of Floodplain Inundation Frequency Using Landsat Imagery. River Research and Applications:n/a–n/a.