Can Remote Sensing Data Improve Short-term Rainfall-runoff Simulation?

Remote sensing (RS) data are widely used for surface vegetation dynamic analysis, energy balance budget and evaporation estimation. However, RS-based evaporation (E{RS}) estimates are seldom used together with conceptual rainfall-runoff (RR) models to estimate catchment runoff. This paper investigates whether simple uses of E{RS} in a lumped conceptual daily RR model, SIMHYD, can improve daily runoff estimates. The study was conducted in 120 gauged catchments in Murray-Darling Basin (MDB) for the period of 2001 to 2005. Firstly, a spatially explicit daily E{RS} model was used to estimate 1 km x 1 km gridded E{RS} by using Terra Moderate Resolution Imaging Spectrometer (MODIS), leaf area index and gridded surface meteorological data over the MDB. The gridded E{RS} was then aggregated to obtain catchment E{RS}. Various modifications of the SIMHYD model to use the catchment E{RS} directly were investigated. The paper demonstrates the potential for using E{RS} with rainfall-runoff models, but the modelling results here did not show significant improvements in the daily runoff estimates. However, it is also possible that other considerations of the use of E{RS} with rainfall-runoff models, or the use of E{RS} with a distributed hydrological model or a lumped model with a distribution function could lead to better results.