The Kashafrud River, in the northeast of Iran, flows from west to east and connects to Tejen River at the border of Iran – Turkeministan. It’s Length is about 300km with a drainage surface areas of about 16200 km2 and average slope is about 0.5% (low gradient River).
This River is a Gravel-sand Meandering type and flows in the Mashhad–Quchan depression between the kopet–Dagh and Binalud mountain ranges. The northern boundary of this river system is a kashafrud reverse fault and the southern boundary is along the south Mashhad and south Chenaran reverse fault in paleotethyan geosuture strike zone and its eastern boundary is Harirud fault (sinistral) where the Tejen River is flowing along its strike.
The alluvial deposits of Mashhad plain results from the Kashafrud River activites and seasonal flooding with maximum thickness of about 250 meters.
The rate of sediment supply in the Mashhad plain is depends upon climate changes, relief, catchment slope and lithologic units. Sediment preservation ratio (SEPRA) is related to tectonic depression. Therefore in this area aggradation is domminated, but, near the Aghdarband (eastern boundary), because of rejuvenation, degradation is dominated.
The downstream grain size is varible and doesn’t show any fining along the river bed. This is mainly related to channel slope changes and special geological condition such as tectonic activities. Tributaries ot the kashafrud River are the main factor in the downstream coarsening along the riverbed.
Twelve different lithofacies have been recognized in the kasharud River which are mainly controlled by tectonic activities in the region.
In the study area, tectonic warping may result in either longitudinal or lateral tilting of alluvial river profiles and frequent avulsion maybe formed by flash flooding.