SUMMARYWe examined, through comparison among the full-coupling (FC), operator-splitting (OS), and predictorcorrector (PC) techniques, the e ectiveness of using the PC technique to solve depth-averaged reactive transport equations in the shallow water domain. Our investigation has led to three major conclusions. Firstly, both the OS and PC techniques can e ciently solve reactive transport equations because the advection-di usion transport equations are solved outside the non-linear iteration loop and the reaction equations are solved node by node. However, these two techniques may risk sacriÿcing computational accuracy. Secondly, the OS or PC technique incorporated with the Lagrangian-Eulerian (LE) approach can handle boundary sources more precisely than alternatively with the conventional Eulerian (CE) approach. Thirdly, with the LE approach incorporated, the numerical results from the three techniques agreed highly with one another except when di usion became signiÿcant. In this case, the PC technique's result still matched well with the FC technique's result, but di erences between the OS and FC techniques' results arose as di usion increased. Based on this study, we recommend to apply as a ÿrst step the PC technique to solving reactive transport equations with respect to both computational e ciency and accuracy.