comparison between models with different precision

Before Ramses, there was only a small number of topographic surveys of the paving with the characteristics of precision and spatial distribution required to generate a three-dimensional model discretized to 2 cm in elevation.
The case of the island of San Lorenzo (a surface of 7.300 square metres) clearly illustrates the difference in results between the previously available data and the new data: two models were generated, both discretized to 2 cm, based on the two available data bases, and the results were compared.
The first chart highlights the differences in the assessment of the flooded areas as a function of the altitude interval. The surface at a level between 1.02 m and 1.04 m, for example, is estimated at 5.6% on the model generated from the existing data and about 1.5% on the new model.
More important considerations are to be made based on the second chart which, for the same area, shows the percentage of flooded surface in relation to tide levels, measured on the two models both discretized to 2 cm. The chart shows how the model obtained from the existing data overestimates the area of flooded paving by more than 10% for tide levels below 1.14 m, and underestimates it for higher tide levels.