Assessing tidal flat deposition potential using spatial analysis: A case study on the northern coast of Vietnam

The evolution of tidal flats is influenced by various forcing factors resulting from interactions among terrestrial, oceanic, and atmospheric environments. This study employs spatial analysis models to assess the potential for deposition of tidal flats along the northern coast of Vietnam. A series of 14 forcing factor maps, categorized into four groups sediment sources, oceanographic factors, coastal properties, and tidal flat properties, is derived. These forcing factors are analyzed using both heuristic and empirical approaches, and their relevance to deposition during the period 1989–2014 is evaluated using the Relative Operating Characteristic (ROC) method. The analysis quantifies the relative discriminatory influence of each factor on historical deposition. Subsequently, the Multi Criteria Evaluation (MCE) method is applied to integrate critical factors with varying weights, generating 9 scenarios of deposition potential. Scenario 5, produced using a weight series linearly proportional to the relative discriminatory influence of the forcing factors and showing the best fit to historical deposition, is selected to generate the potential map of future tidal flat deposition. This map achieves an accuracy of 77.6%, indicating high deposition potential around the Red River mouth and low potential along rocky coastal tidal flats. The study represents a significant advancement in applying complex spatial analysis methods to predict the potential for future changes of tidal flats within diverse coastal environments at a large scale.