Hydrological Modeling from Local to Global Scales

Abstract

There is a need for greater understanding of the seasonal, annual and interannual variability of water and energy cycles at continental-to-global scales, and in doing so, a greater understanding of the role of the terrestrial hydrospherebiosphere in Earth’s climate system. It is well known that land surface processes control local climate through the partitioning of precipitation and incoming radiation into their budget components. What is not well understood are the mean values and variability of the water and energy budget terms over a range of temporal and continental-to-global spatial scales. This chapter presents a multi-scale observational-modeling strategy and its testing for the development and validation of process-based, terrestrial water and energy balance models that can be applied from local point scales to global scales. This strategy includes (i) the development, calibration and validation of process-based hydrologic models using data from small scale land surface experiments; (ii) the use of the developed models to scale up to larger spatial scales on the order of 10⁵ km² , with foci on model parameterizations at regional scales and on testing remote sensing products in the hydrological models; and (iii) the simulation of continental-to-global fields of water and energy flaxes through modeling and remote sensing, and their validation using large scale hydrologic data.