Remote Sensing and Geographic Information System (GIS) Contribution to the Inventory and Investigation of Dikes in Egypt

Dikes are widespread in Egypt and are partly even the prevailing elements in the landscape besides the youngest sedimentary covers, especially in the southern and eastern part of the country. Although dikes are one of the predominant phenomena in Egypt, a systematic, standardized inventory of dikes in the whole country and a dike data base has not been published so far, although several selected areas have been investigated very detailed such as along the Red Sea and in the Sinai. Remote sensing and Geographic Information System (GIS) offer tools for such an inventory. This inventory is of interest for many purposes such as for the mining industry (many dikes are related to mineral occurrence of economic value), and also for hydrogeologic investigations and land use planning. Surface-near dikes, major fault zones, volcanic and structural features were digitized based on Landsat 8 and 9, Sentinel 2, Sentinel 1 and ALOS PALSAR data. High resolution images of World Imagery files/ESRI and Bing Maps Aerial/Microsoft were included into the evaluations. More than 32,000 dikes were digitized and analysed. The evaluations of satellite images allow a geomorphologic differentiation of types of dikes and the description of their characteristics such as dike swarms or ring dikes as well as of their distribution pattern and orientations. Dike density calculations were carried out in ArcGIS to support the detection of areas with dike concentrations. Earthquake data were included into the investigations as dikes might play a role in the development and effects of earthquake swarms in the area of reservoirs.