Geomorphologic Classification of Rivers in Mountainous Basins (Case study: Khorramabad River)

Iran Country located in arid and semiarid region in terms of quality and quantity Of water and always faced to the problem of shortage of water resources. Khorramabad river is one of the most important rivers and water resources in the Western part of Iran is located in a mountainous region.The River as one of the vital arteries of the city of Khorramabad for managers and planners is very important. Classification is one of simple and applied methods in transfer of knowledge and management tasks. River management plans and engages to natural processes have the most effects on environmental, social and economic conditions. By considering recent year’s flash floods in Khorramabad city which have damages on human beings and properties, and this fact that the river has an important role in supply of water in the region and west part of the country, it is necessary to
In this study, based on three factors, landscape, pattern river and limitations of river bed of Khorramabad river , we using field observations of the study area, the correction of geometric and mosaic of four sin of satellite images data of Kartosat P5, IRS satellite data by 2.5 resolution of the river basin, we present a classification scheme by a tree stage classification and by using Spss software we have clustering finding and compare it to real states of river by field observations. Classification factors for geomorphic pattern were: landscapes, plan, of river bed and finally limitation of river bed. So landscapes categorized to high mountains, low elevation and plains. In second categorizing we used river pattern as main factor and find tree reaches. Generally, Khorramabad River has 12 segments, include 3 meandering sections, one anastomosing section and 8 straight parts.
according to our classification method the case study river, Khorramabad by a 64 km length, have 32.72 km of straight section, 25.2 km of meandering pattern, and 1.08 km of anastomosing plan. There was not braided river pattern in the study area. By considering bed confinement ( limitation) , we find 9 segments which segments 2,4,5 and 6 were inside the first class, segments 7,8 and 9 in second class, segment 3 and segment 1 in third and fourth class respectively. The main factor of separation of these segments and making classification was the landscape factor. River pattern was the main factor in the 3rd segment of the river.
This classification for rivers can help users and water resources planners and mangers to spend less time and cost for categorizing and managing water resources, but field geomorphic observations and modifying systems results and statistical findings is a main toll that should be used to make a reasonable and reliable classification.