Statistical analysis of lateral migration of the Rio Grande, New Mexico

The lateral migration rates of alluvial rivers are affected by changes in water and sediment regimes. The Rio Grande downstream from Cochiti Dam exhibits spatial and temporal variability in lateral movement rates documented since 1918. A tremendous database exists that documents planform, bed material size, channel geometry, and water and sediment regimes. A statistical analysis reveals that migration rates primarily decreased with decreasing flow energy (R2 > 0.50, p < 0.0001). The addition of a second parameter describing total channel width increased the explained variance to > 60%. The findings show that lateral movement increases with increasing flow energy and with degree of braiding.