A free cellular model of dune dynamics: Application to El Fangar spit dune system (Ebro Delta, Spain)

Currently, dune field surveying is employed to assess dune net volume changes and their accretion and erosion patterns. In dune fields with complex sediment sources and sink interactions such as El Fangar Spit (Ebro Delta, Spain), it is difficult to establish the sediment input and output with only net volume changes estimated by dune field surveying. This work presents a free dune dynamic cellular model that incorporates algorithms that introduce wind data into the erosion and transport processes. The model can be applied to dune systems with variable wind regime. A calibration methodology based on the morphological reproduction of the observed dune field evolution is proposed. The model and the calibration methodology is applied to a region of El Fangar dune system surveyed with DGPS on 15th and 18th April 2012. The difference between the final measured dune state and the best morphological reproduction obtained with the model is employed to estimate the sediment flux. This operation yields an output sand flux of 98.8 m3 and an input of 292.6 m3. This algorithm could have a great impact on the study of complex dune systems where the dunes act as sinks and sources of beach sediments and in the characterization of the beach-dune interactions.