Performance of analytical models predicting upstream-to-downstream water depth ratios in asymmetric open-channel confluences with width discordance

Most analytical models to predict the upstream-to-downstream water depth ratios for asymmetric open-channel confluences only apply when the downstream-to-upstream width ratio is one and assume equal water depth ratios for the lateral branch and the main channel. Both limitations are overcome by the model of Shabayek or the Luo variant thereof. The performance of both versions is assessed against a recently published, large dataset produced by a 3D numerical model for geometries with width discordance. The performance of both model versions is quite similar, with an average (resp. maximum) deviation of the water depth ratios of ±1% (resp. ±3%) against the numerical data.