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

Abstract

The development of karst features is a complex and interactive process of many factors with varying influence over time. The following main factors seem to have influenced the occurrence and development of karst features in the Middle Atlas in Morocco: Precipitations after extreme weather events depending on the precipitation pattern modified by orographic effects and exposition of the terrain towards the main rain-bearing clouds are determining surface water input and infiltration as well as the outline of morphologic watersheds and drainage basins. The lithologic conditions such as the outcrops of lower Jurassic limestones, the geomorphologic disposition, the volcanic activity within limestones combined with hydrothermal dissolution processes, and the structural conditions influencing water permeability in fault and fracture zones and, thus, the dissolution intensity, are further factors. Ongoing aseismic vertical and horizontal neotectonic movements due to plate tectonic activities and shallow earthquake activities are causing the development and reactivation of fault zones and as consequence modifying groundwater flow conditions in the karst hydrologic systems. Seismic activity can lead as well to the development of sinkholes and the collapse of caves. The development of a systematic Karst-Geo Information System (GIS) is recommended that should be updated regularly.

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

“…19). Along the concentrically arranged hills surrounding this enclosed topographic depression caves and springs in the Jurassic outcrops are documented [4]. Slope failure directed towards the depression center can be detected on Google Earth images.…”

“…Although a large amount of research has been carried out related to the geologic history and structural and tectonic inventory in Northern Morocco [1]- [3] combined evaluations of different satellite data can contribute to further additional knowledge. After previous evaluations of optical and radar satellite images and digital elevation data from northern Morocco [4] it became obvious, that there are some circular structures visible on the satellite images and on morphometric maps that were neither documented on available geologic maps, nor described in the geologic literature. The reasons for this vary according to the specific situation.…”

Overview of Circular Structures of Various Origins and Sizes in Egypt as a Contribution to Natural Hazard Data Mining Based on Remote Sensing Data and Geoinformation Systems (GIS) Analysis

“…Earthquake data were integrated in order to investigate if there is a relationship between surface-near geologic/tectonic structures and earthquake occurrence. Previous studies have indicated that the position of larger ring structures related to plutons with specific geomechanical properties seems to have an influence on regional earthquake occurrence and effects, such as on the macroseismic intensities [8].…”