

Zhang, YQ, Chiew, FHS, Zhang, L, Leuning, R, Cleugh, HA (2008). Estimating catchment evaporation and runoff using MODIS leaf area index and the PenmanMonteith equation. WATER RESOURCES RESEARCH, 44(10), W10420. Abstract This paper shows the feasibility of using steady state water balances of gauged catchments to calibrate a spatially explicit evaporation model and then applying this to estimate mean annual runoff for 120 gauged catchments in the MurrayDarling Basin (MDB) of Australia from 2001 to 2005. We used remotely sensed leaf area indices from the Moderate Resolution Imaging Spectrometer (MODIS) mounted on the polarorbiting Terra satellite with the PenmanMonteith equation, gridded meteorology, and a twoparameter biophysical model for surface conductance (G(s)) to estimate 8day average evaporation at 1km resolution. Parameters for the G(s) model were optimized using steady state water balance estimates (precipitation minus runoff) in the gauged catchments in three precipitation zones of the MDB, and the calibrated evaporation model was then used to estimate evaporation (ERS) and runoff from gauged and ungauged catchments in the MDB. Mean annual calibrated estimates of ERS compared well with water balance estimates, indicated by a rootmeansquare error (RMSE) of 78.6 mm/a and the NashSutcliffe coefficient of efficiency (CE) of 0.68. Reasonable agreement was obtained between the estimated mean annual runoff (RRS) (rainfall minus ERS), and the measured runoff (RMSE = 71.0 mm/a and CE = 0.75). Cross validation showed that estimated ERS and RRS were almost as good as the calibrated ones. Furthermore, RRS has an accuracy similar to that of a sevenparameter conceptual rainfallrunoff model in the gauged catchments. The results show that the evaporation model can be easily applied to estimate steady state evaporation and runoff and that ERS can be used with rainfallrunoff models to improve accuracy of estimated runoff in ungauged catchments. DOI: 10.1029/2007WR006563 ISSN: 00431397 