On the Use of Tri-Stereo Pleiades Images for the Morphometric Measurement of Dolines in the Basaltic Plateau of Azrou (Middle Atlas, Morocco)

Abstract

Hundreds of large and deep collapse dolines dot the surface of the Quaternary basaltic plateau of Azrou, in the Middle Atlas of Morocco. In the absence of detailed topographic maps, the morphometric study of such a large number of features requires the use of remote sensing techniques. We present the processing, extraction, and validation of depth measurements of 89 dolines using tri-stereo Pleiades images acquired in 2018–2019 (the European Space Agency (ESA) © CNES 2018, distributed by Airbus DS). Satellite image-derived DEMs were field-verified using traditional mapping techniques, which showed a very good agreement between field and remote sensing measures. The high resolution of these tri-stereo images allowed to automatically generate accurate morphometric datasets not only regarding the planimetric parameters of the dolines (diameters, contours, orientation of long axes), but also for what concerns their depth and altimetric profiles. Our study demonstrates the potential of using these types of images on rugged morphologies and for the measurement of steep depressions, where traditional remote sensing techniques may be hindered by shadow zones and blind portions. Tri-stereo images might also be suitable for the measurement of deep and steep depressions (skylights and collapses) on Martian and Lunar lava flows, suitable targets for future planetary cave exploration.

Inventory of Ring Structures in N- and W-Morocco based on Satellite Data

“…Smaller circular features such as volcanic features (cinder cones, calderas, maars), and sinkholes in karst environments with diameters ranging from several 10 m up to more than 500 m were mapped as well as far as possible based on remote sensing data. Through the tabular morphology of the northwestern part of the Middle Atlas in Morocco, numerous volcanoes arise together with pyroclastic product layers and lava flows, the majority of which are Strombolian cinder cones, and some correspond to maars relayed by strombolian activity [28], [29]. The volcanic shape spectrum, such as cones, maars, tuff-rings, and cone-maar mixes, generally is associated with a later lava flow discharge that could develop many surfaces and appearances.…”

Contribution of Remote Sensing and GIS to the Inventory and Analysis of Factors influencing on the Development of Karst Features in the Middle Atlas, Morocco

“…13). Thus, an influence of hydrothermal dissolution processes on karst development seems to be obvious such as documented [32], [33] in the Ifrane-Azrou region.…”

Appraisal of Ancient Quarries and WWII Air Raids as Factors of Subsidence in Rome: A Geomatic Approach

“…Considering also the achievements reached in the study of analogous cases in Italy and out of the country, further efforts have been directed toward identifying precursory factors [29][30][31][32]. Geomatics monitoring by space-borne, close-range and ground-based platforms bearing a wide range of sensors has been validated for the evidencing of soil raveling, using, as an example, photogrammetric modeling [33,34], ground-based systems [35], geophysics approaches [17,21,26,[36][37][38][39], or sensor networks [40]. The Differential Interferometric Synthetic Aperture Radar (DInSAR) technique, one of the key methods applied in satellite monitoring in urban areas [41][42][43][44], has also recently been applied to the investigation of sinkholes ( [29,31,32,[45][46][47], and a preliminary approach in [48]).…”