Effect of destruction factors Bistoon inscription (Kermanshah - province)

The engraved remains on stony parapets of cultural heritage of this country show rich civilization of Iran that protection and reparation of them is a duty of scientific teams with cooperation of related specialist. Geomorphology، geology and geophysics are including of this science. Bistoon inscription is located on long wall (famous broken part) of broken zagros on rough part which is called same name. Broken part، fissure، and thick lime of previous region (Paleoclime) pave way for destruction of engrave figure، which leads to solving process and to make solving holes. This study has been done with the following tools: GPS، topography maps and satellite images. In order to obtain a good quality data and radar images as well as maximum penetration of radar waves، GPR has been used three times on summer 1387 (dry season) with 500 MHz shielded antenna on five profiles from which three of them are parallel to the longitudinal part of the inscription while two of them are perpendicular to the first ones. The Ramac GPR system of a Swedish company، Mala has been used for data acquisition. GPR is a geophysics method which uses electromagnetic high frequency waves (at MHZ range) to get a precise image from underground anomalies which are situated at shallow depths. The principles of data processing and data acquisition are very similar to reflection seismic. The propagation velocity of radar waves depends on electric conductivity and magnetic permeability of the medium while reflection and refraction of radar waves depend on the contrast between dielectric constants of the mediums at both sides of the contact between them. As conductivity increases، the depth of investigation decreases which is an obstacle for radar application for high depth investigation. Therefore a good environmental condition from point view of conductivity and a proper central frequency must be provided for radar work. The dry season for the former one and 500 MHZ for the latter one were the best for the field work. The common offset method has been used for radar data acquisition. The radar grams are processed with REFLEX 2W software. The radar images after filtering such noise reduction، diffraction removal and gain show a hole at 3 m depth that is a path for rain water passage and karstification of the surrounding area. This defect is on those profiles which intersects the anomaly and is on the right side of the profiles (north end). The GPR results confirm the other findings which are based on other methods than geophysics such as geomorphology، geology field observations and archeology prospect ion. This study shows that there are effects of fissure، broken parts، solved hole and karset process at the right side of the inscription in three meters depth. Regarding to destructive agents، it is better to save، and to repair the inscription by appropriate ways.