Figure 1
From: Detecting desertification in the ancient oases of southern Morocco
(a) Long profile of a typical khettera. (b) Satellite image shows khettera shafts and outlet: KH9 1217-100011-F023c, 12th May 1982. (c) Satellite image of the same feature: Google Earth Pro map data: 2023 CNES/Airbus, Maxar Technologies https://www.google.com/intl/en_uk/earth/versions/#earth-pro. Image prepared using ArcGIS ArcMap 10.6.1 https://www.esri.com/en-us/home and GIMP 2.10.34 https://www.gimp.org/.
