ABSTRACT
Remote sensing measurements of hydrologic variables and processes represent one of the most challenging research problems in Earth system sciences. Hydrologic processes in the nexus of energy and water cycles include precipitation, runoff, infiltration and soil water contents, evapotranspiration (ET), and groundwater movement. Remote sensing estimates provide water budget information of the temporal and spatial distribution of water fluxes, often difficult to capture by conventional ground-based sparse sensor network with point-measurement instruments. Many hydrological processes can be observed from satellite- to ground-based remote sensing technologies individually. However, integrated approach to measure all relevant hydrological processes at the same time to completely address the changing hydrological states during the cycling of water remains a scientific challenge. Scale linkage of water fluxes integrating hydrological processes observed from small scale to regional and to continental scale has been contemporary challenges for decades.
