The environmental impact was illustrated by rockslide and erosion on the Duhok Dam and its reservoir. The evaluation of the geotechnical characteristics of the Gercus Formation was conducted. The research plan was divided into three phases, field, laboratory, and office works. The fieldwork included studying all the geological phenomena of the region related to the environmental impact. The laboratory work focused on studying the geotechnical properties of the various rock samples taken from the Gercus Formation. Rocklab program was used to define the geotechnical properties of a rock mass. The results indicated the weak resistance of the Gercus Formation rocks to weathering and erosion processes, as well as their weak resistance to sliding. These results indicate a kind of risk for this formation on the stability of the dam, as well as its effect on the size of the reservoir storage, due to erosion and deposition of huge amounts of sediments in the dam reservoir.

Six caves were studied in north Iraq, which is the Beeston and Shanidar in Erbil, Garston, Swaratuka, and Ain Ishky in Duhok Governorate, Al-Naqut in Nineveh Governorate. All these caves are located within geological formations of carbonate rocks, limestone, and dolostone. Geotechnical and geometrical measurements were made for these caves, and rocks were sampled from different areas inside and outside the caves. The slake durability of the rocks was measured and thin sections were made, in addition to measuring the percentage of insoluble residues and analyzing the mineral constituents of the collected samples by using X-ray diffraction. By reviewing the geotechnical characteristics and environmental conditions, the Beeston Cave was found to be the oldest of the caves studied because its size is greater than that of the other caves and its rocks have better geotechnical characteristics than the other caves, which means that the time required for it to form is longer. The Al-Naqut Cave was also found to be the newest among these six caves because, in addition to its small size, it has the lowest durability value after the Shanidar Cave and has the lowest value of compressive strength.