The site of the Gharehpiri dam is located in the Simply Folded Zone of the Zagros Mountain Ranges. The abutments of the dam are located on the solid limestone of the Tertiary Asmari-Jahrom Formation. From the structural point of view the morphological and geotechnical characteristics of the dam have been affected by some joint systems and minor faults. Detailed investigations related to engineering geology, structural geology of the dam site and its geotechnical characteristics show a good result considering joint analysis, layering and quality of rock masses, evaluated by two methods, namely Barton and RMR methods. Manuscript profile

Morphological analysis of topographic features, especially lineaments, has been used in tectonic and structural studies for a long time. These studies are considered to be the basis of tectonic analysis. Detecting and enhancing these features in an area like the western part of the Alborz, which is covered by vegetation, was done by use of SRTM 90 m data. To extract lineaments we used various image processing and enhancement techniques on images and three different approaches including manual, semi-automatic and automatic lineament extraction were adopted. Then the lineament layers, obtained from these methods were overlaid to produce a final lineament map. In this way we were able to detect and enhance lineaments and prepare density and intersection maps using GIS software, which enabled us to provide a good view of the structural geology of the area. Manuscript profile