Erosion is displacement of solids (Soil, mud, rock and other particles) usually by the agents of currents such as wind, water ice, humans. Two kind of erosions were recognized in this area. Water erosion, and weathering. weathering and erosion are geological processes that act together to shape the surface of earth. The rate of erosion can be estimated by the amount of sediment (Particles and dissolved material) carried by zonouz river varies widely depending upon climate, topography, rock type and human influence. Three principal type of weathering are occurred:

Water erosion in zunoz valley

Streams are the most important sculptors of terrestrial landscapes. The erosion of hills slope comes flowing water as the principal creator of landforms and landscapes. so water plays a major role in modifying the surface hills. The ancient Latin word for river was fluvius from which is derived the term fluvial to denote running water. Thus fluvial processes are the geomorphic processes associated with running water, and fluvial landforms and landscapes are pronounced by streams. The rivers degrade (erode) and aggrade (deposit). Hence, the landscape contains degradational or erosional landforms Created when rock is removed, and aggradational or depositional landforms, resulting from accumulation of sediment. zunoz valley is essentially an erosional landscapes.

photo 1                                                                                   By Dr Asgharpour

History of erosion

Allah sends down the water from the clouds,water courses flow ( with water )according to their measure and torrent bears along the swelling foam"Thunder,verse 17,Quran

Hydrologic cycle: water evaporates from surface of oceans makes clouds, condensation of water in clouds make precipitation on the land and back again to the oceans. This unceasing circulation of water ensures the continuation of fluvial erosion because the water that falls on the elevated landmasses will always flow back toward sea level as it does, so it carries the products of weathering with it.

Rainfall comes in different forms. from the steady, gentle rain to the violent heavy down pour associated with spring thunderstorm, during drizzle, the soil generally is able to absorb all or most of the water because its infiltration capacity (the rate at which it is able to absorb water from the surface) is not exceeded. But when rail falls at higher intensities, it may saturate the soil and exceed the infiltration capacity, resulting in run off many small, temporary streamlets form and with such run off comes erosion.

Large, heavy raindrops dislodge soil particles in a process called splash erosion. If the exposed soil lies on a slope, splash erosion results in down slope transfer of soil. The steeper the slope the faster this degradation proceeds. If the rate of erosion, over a long term, exceeds the rate of soil formation, the slope will lose its soil cover and suffer denudation wherever vegetation cover is dense, erosion is generally slight. But where natural vegetation is removed to make way for agriculture or perhaps decimated by overgrazing, which resulted to accelerated erosion