OBSERVING THE TERRESTRIAL WATER CYCLE FROM SPACE: ERA OF BIG DATA TO SOLVE GLOBAL WATER PROBLEMS (Invited Presentation)

Land surface hydrology is a collection of complex processes. Precipitation is partitioned into infiltration

and runoff depending on antecedent soil moisture conditions, the properties of the soil, the slope of the

land surface and the atmospheric demand for evapotranspiration. The spatial variability both the land

surface properties (soil and vegetation) as well as the meteorological inputs (precipitation and radiation)

play an important role in hydrology. Land surface hydrology is heterogeneous in space and time - making

observation and modeling activities very difficult. Satellite remote sensing has a broad spatial view of the

land surface and is able to provide data for use in hydrology such as soil moisture, surface temperature and vegetation density. Satellite sensors include - microwave observations for soil moisture and precipitation; visible/near infrared for vegetation and evapotranspiration, gravity for groundwater/total water and thermal observations for surface temperature.

I will present a few examples on use of data sets from satellite remote sensing and standard off-line

hydrological model outputs. Firstly, I will present study of hydrological extremes for global river basins.

Secondly, I will present a new technique that we have developed for downscaling satellite soil moisture

to a higher spatial resolution.