SPOT shallow water bathymetry of a moderately turbid tidal inlet based on field measurements

摘要: The determination of shallow water depth in high-energy tidal inlets is essential to model and forecast the navigation channel position or short-term topographic evolution beaches. Colour satellite imagery provides, at low cost, complete maps areas that are difficult map by traditional hydrographic means due their size rough underwater morphology. In order calibrate SPOT images derive bathymetric maps, a simple method applied waters moderately turbid inlet has been carried out. Its development based on set field measurements, including reflectance bottom sediment, vertically averaged diffuse attenuation coefficient, concentrations inorganic particles suspension, chlorophyll pheopigments dissolved organic carbon (DOC). From these data, it appears, first, directly linked depth, second, varies slowly with turbidity this area for total suspended matter (SM) lower than 9 mg l−1. extinction light characterized inlet. relationship obtained slightly different from observed clear waters. models established clearest do not calculate accurately. contrary, code adapted Case II type, calibrated situ allows us retrieve down 6 m SM ranging 0.2 This five mouth Arcachon lagoon. accuracy derived assessed measurements. mean difference between measured depths computed about 20%. adequate assess morphodynamics quantitatively, which necessary middle-term mathematical modeling 3D evolution.