Multi-Sensor Spot Imagery for the Detection of Hydrologically Potential Areas in the Tabular Middle Atlas discontinuous Karstic Reservoir of Morocco

Abstract

In fractured systems such as the liassic reservoir of the Tabular Middle Atlas of Morocco, fracturing plays a significant role in feeding patterns and water flow. Knowledge of the geometry of the fracture network is essential for better use of water resources. The use of remote sensing techniques helped us to obtain the latest information and easily cover all large surfaces of the Tabular Middle Atlas in order to extract the fracture network and to detect the hydrologically potential areas. We used visible and infrared high-resolution sensors for multispectral SPOT2, SPOT4, SPOT5 images, and geometrical high-resolution sensors for panchromatic SPOT5 images. Several techniques for image processing, such as enhancement and sharpness optimization and filtering, have been applied to extract a new fracturing map, which was validated by cross-analysis with various cartographic inventories of the study area and with a field survey. The statistical and two-dimensional spatial analysis of the resulting data, based on the fracture azimuth and length, showed heterogeneous and high clustering of the fracture network which predominated in the northeast–southwest and northwest–southeast directions. A very important cluster has been identified along the axis "Ifrane-Bittit" in north west-south east trend, towards the important springs complex in the region “Ribaa-Bittit” making it possible to identify the favorable zones, likely to contain draining fractures that represent a potential site for deep geophysical prospecting