Controls on the morphology of braided rivers and braid bars: An empirical characterization of numerical models

Braided rivers exhibit highly variable morphologies, morphodynamic behaviours and resulting depositional records. To evaluate relationships between characteristics of braided-river channel belts river depth, water discharge streambed gradient, 39 numerical modelling experiments were conducted with the software Delft3D to simulate evolution under a broad range boundary conditions. Data from model outputs integrated observations 63 natural braided differing respect depth gradient. The modelled each underwent similar evolutions, yet culminated in markedly different final dependent on riverbed evolutionary stages of: (i) formation transverse unit bars limited relief an initially featureless bed; (ii) development around some cases dissecting bars; (iii) relatively simpler compound (iv) amalgamation these into more complex bars. Quantitative relating channel-belt morphology organization are established, following results noted: bar elongation (length-to-width ratio) is correlated positively gradient; height area discharge, negatively main predictor mean braid-bar area; degree braiding primarily associated width-to-depth ratio Results arising this research improve our understanding controls architectures fluvial belts; they provide novel empirical characterization that can be applied for predicting morphology, modern systems formative ancient preserved successions.