Assessment of the WRF-Hydro uncoupled hydro-meteorological model on flashy watersheds of the Grande Terre tropical island of New Caledonia (South-West Pacific)

Six watersheds of the main island New Caledonia. In context a projected reduction extreme precipitation events by ~ 20% 2100 combined to large land cover variability, distributed hydrological approach was adopted over The WRF-Hydro model implemented using one-way WRF meteorological forcing, with rainfall being spatially interpolated from rain gauge observations Thiessen polygon and IDEW methods. Dynamically Dimensioned Search algorithm applied for calibration on three contrasted flash-floods. Two-year validation allowed dynamics be studied compared. Good results in terms Nash-Sutcliffe efficiency were reached all (NSE ? 0.6). showed consistent water budget components two flash-floods 90% correlation between simulated observed runoff coefficients basins. Adjusted physical parameters matched known watershed morphological features. Both methods interpolation produced similar NSE but strongly different distributions, soil moisture changes varying up 60% during Spatial patterns flood decomposition led improved understanding behavior revision infiltration properties one them. Overall, proved suitable framework better understand processes efficiently handle prospective modifications Caledonia’s climate regimes.