Analysis of Qualitative Units and Bridges, and Geomorphologic Effects of Watershed Hajji Bakhtiar, Ilam Province in Iran

The geology of the watershed has significant formations and stratigraphic units. In general, its formation and stratigraphic units include the Sourgah Formation, the Ilam Formation, the Simareh section of the Gurpi Formation, the Gurpi Formation, the Cheile section of the Pabadeh Formation, the Pabadeh Formation Pabadeh Formations, the Pabadeh Formation, Kalhor Formation Asmari Formation, Asmari Formation, Gachsaran Formation, Old Coniferous Fossils, and eventually flood sediments of the river bed and its marginal zone. Gurpi Formation with an area of 255.87 hectares and Sourgah Formation with the area of 26.5 hectares have respectively the highest and the least area in the basin. Their dominant lithology (Gurpi Formation) consists of gray-blue shale and mildew of marl limestone and Sorgah Formation including shale Pirate dark gray and yellow limestone. Geomorphologically, there have been typically three mountainous, clay and plain mountains in the region that have had almost different types and facies. Its mountainous area with the most regular and irregular slopes (MIOM, MROM, mio, miom, MRom and mro) has had the most expansion in the area with an area of 5311/80 hectares. The irregular facies of this unit have been covered with bulk fores which has low soil and low rock shedding in MIom, and the erosion of dull and permafrost, and oak forest has been covered with the low depth of soil, and its outlook has been prominent (miom) with very low cover of soils. There have been separate and abundant masonry deposits (mio), but the regular facade of the mountainous region has been regular with a range of an oak tree cover, but in a small area, there have been MRom and a regular low mountain range with low oak coverings and mro.  The mountainous area, has been as high as the increased density of its tree cover (mostly oak). So that it would be forested in the upstream of its density. The plain area with a plain slope type and facies in agricultural fields (QA), flood deposits (Qdc), alluvial deposits (Qal) and its expansion in the middle part of the area with the north-west-south-east trend, has had the smallest area. The total breadth has been 1767.6 hectares which has been equivalent to 17.7 percent of the total area.