Flood Routing in Ungauged Catchments Using Muskingum Methods

River stage or flow rates are crucial for hydraulic structure design. Ungauged river reaches necessitate flood routing techniques for estimating stages or flow rates. This study assesses Muskingum-based methods for flow routing in ungauged river reaches, including lateral inflows. Model parameters are calibrated using observed data, with the Muskingum-Cunge method evaluated for ungauged reaches. Three sub-catchments in the Thukela catchment are analyzed, employing digital elevation models and empirical equations. The calibrated Muskingum-Cunge method yields accurate outflow hydrographs, indicating its applicability to ungauged catchments. This study concludes that the Muskingum-Cunge method is effective for flood routing in the Thukela catchment and can be extrapolated to other ungauged rivers in South Africa.