Tuesday, 11 February 2003: 2:45 PM
Satellite observations of river and wetland hydrologic processes
Emerging satellite technologies offer new ways to observe and model dynamic hydrologic and related geomorphic and biological processes in riverine and flood plain environments. Satellite methods have the potential to produce global observations of river stage, and/or inundation extent, from which discharge may be estimated via various means. Such global observations would have important implications for global water cycle research. However,the type of observations that could be made from spaceborne platforms differ fundamentally in many ways from those produced by in situ methods - e.g., the traditional transformation to discharge of stage observations via rating curves. These differences offer both challenges and opportunities. For instance, a number of important science questions regarding hydrologic processes across rivers and wetlands remain unanswered primarily due to the inability of in-channel gauging stations to characterize spatially varying flow conditions and storage. A key example is the lack of in-situ measurements of water levels across a majority of the world's flood plains and wetlands. Lacking these observations, questions remain regarding the changes in wetland storage, the global magnitude of biogeochemical fluxes from wetlands, sediment transport between channels and floodplains, flooding hazards, and the role of these processes in the global hydrologic cycle. As part of our NASA working group, we have identified and will present a number of potential satellite based methods of measuring riverine and wetland processes that are useful toward an understanding of hydrologic, climatic, geomorphic or biogeochemical processes.