ANATOMY OF A CENOTE WITH USE OF DRON

Abstract

Background: Detailed geomorphological analysis of the karst depressions in Yucatán has received little attention because the measurement of morphometric parameters taken in the field involves a lot of work, time and costs. A pioneering exercise is presented that arose with two questions. What would be the characteristics of the relief that can be observed and / or measured in a cenote through images acquired with a drone? Would they be features similar to those seen with Google Earth images? Objective: To identify the units of the relief and morphometry of a cenote using images from two different platforms. Methodology: An open cenote located in the municipality of Chapab, Yucatán, was studied. A flight was carried out with a drone obtaining 259 images in 14 minutes, with which an orthomosaic, a digital elevation model and a point cloud were generated. We proceeded to the analysis of the data of the visible range (RGB), work with filters in ArcMap; the same spatial analysis procedure was performed with an image from Google Earth. Results: Nine units of the relief were identified in detail (permanent lake, intermittent lake, an area subject to flooding, beach, mouth, flooded slope, upper slope, scarp and lake coast); the differences between inputs are mainly in the morphometric parameters and in the values of the elevations. Implications: Drones facilitate imaging that allows detailed characterization of karst depressions to represent attributes that cannot be expressed on small scales. Conclusion: The anatomy of the Polol cenote technically corresponds to a sinkhole that houses a karst lake; nine relief units were identified that reveal limnological processes generating a karst-lacustrine environment that leads to the geomorphological enrichment of this region.