TR-139 : Application of macro-scale atmospheric and land surface process hydrologic modelling system

Abstract

The need of macroscale modelling of hydrological processes for the use in GCMs has attracted considerable attention of the climate modellers as well as the hydrologists in the recent years. This is mainly because the climate models consider a grid size of approx. 104 - 105 km² which is a macroscale for hydrological processes. Our present under-standing of land surface-atmosphere interactions and the processes and fluxes,, Hot define these interactions is limited. In India, no specific work has been carried out in this area.

In order to develop increased understanding of land surface-atmosphere interactions and to highlight the importance of macroscale hydrologic land surface modelling. describes the studies carried out using Biosphere Atmosphere Transfer Scheme (BATS) - a land surface parameterization scheme that considers a grid size of 4. 5 °X7. 5° (1° -110 km) and its modified version that allows the simulation of spatially inhomogeneous conditions in precipitation input. The model has been applied to the soil and vegetation type characteristics of Central India. An attempt has been made to study the sensitivity of energy and moisture balance components to sub grid scale variability in precipitation The result highlight the importance of accounting for the sub grid scale heterogeneity and show the large sensitivity of energy and Moisture balance components to precipitation variability in space. Future research needs in this area have been identified.