River Remote Sensing: A Mid-Revolution Report
Abstract
Many parts of river science are in the midst of full-scale revolution, much of which has been brought about by remote sensing. The revolution broadly speaking has encompassed a transition from a data-poor to a data-rich science, a transition from one aimed at generating general average trends to one that is profoundly place-based, and a transition from a science practiced by a relatively narrowly-focused community to one shared by a large, diverse set of practitioners worldwide. Two methodological perspectives dominate river remote sensing today. There is a top-down perspective, where governments and international organizations have developed advanced spaceborne and airborne systems with the intention of providing homogenous synoptic monitoring of rivers over large areas. This perspective has included measurements of river forms and processes and water quality measures, but it has been driven chiefly by the goal of mapping river. By necessity, the top-down perspective takes a somewhat liberal philosophy in relation to merging observation and theory in order to generate river variable estimates. In contrast, the explosion of cheap optical cameras has provided the fuel for a bottom-up perspective in river science. While less centrally-organized, its concerns have to this point been much broader than those of the top-down perspective. In addition to discharge and volumes, the bottom-up perspective has included such disparate topics as floodplain insurance and risk mapping, habitat monitoring, ecohydraulics, water quality characterization, hyporheic exchange, thermal refugia and effluent measurement, geomorphic variables, turbulent exchange and many others. The bottom-up perspective tends to take a more conservative approach to combining theory with observation to produce river variable estimates. The area with the most future promise may be the transition from data-rich observations to information-rich observations. Automated techniques for extracting river process information from observations are both a hot topic and are also woefully inadequate for many river concerns. River remote sensing now encompasses nine orders of magnitude in terms of spatial scale, and finding efficient means of connecting these scales and their processes is a central area of importance in the future of hydrology.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H43N2268F
- Keywords:
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- 1855 Remote sensing;
- HYDROLOGY