Using geomatics techniques to produce a geospatial database system for geological hazards in the Al-Salt area

In the Al-Salt area of Jordan, natural geological hazard events occur frequently because the area northeast of the Dead Sea is recognized as an active seismic zone. Therefore, using the cutting edge technology represented in this study by the geomatics techniques of remote sensing, GPS and GIS were become necessary and sufficient, that because there are many variables a several features to be mapped and store. This study was focused on faults and landslides because these are the dominant events in the study area. Satellite images, geological maps and topographic maps were used to produce GIS layers describing geological hazard elements. The mapped elements included faults, landslides and many other spatial features including lineaments, drainage patterns, road networks, vegetation, contour lines, slopes, aspects and residential areas. Faults, lineaments and landslide maps were extracted from the published geological map of the Al-Salt area (1:50 000 scale). Other features were extracted either from a topographic map or from satellite images of the study area. Digital image-processing techniques were performed on satellite images to enhance the required spatial features (i.e., faults and landslides). Several techniques were applied to the digital images, including false-color composite band ratio analysis, principal-component analysis and high-pass filtering. A Garmin hand-held GPS (model GPSMAP60CSx) was used to track and to map the city's recently constructed main ring road. The hand-held GPS was also used to locate positions of the faults and landslides in the study area. Finally, the produced GIS layers and their attributes were stored in a spatial GIS database using the Arc GIS software package. These layers could be used for retrieving data on the geological hazard elements and for producing a geological hazards map (or any other thematic map) for the Al-Salt area in Jordan.