Prediction of kordan river geometric changes in the meandering Range

Predictions of total and even partial changes in rivers patterns are as the most essential issues related to rivers geomorphology. In this regarding, a lot of researches have been done by geomorphologists. This research has explored Kordan River aqueduct morphology changes in bights areas of Afkaneh cone surface. Kordan river is the one which has been affected by various factors and has changed a lot so that this changes has impressed on components an human activity around the river and on side erosion and channel. The research method is on analytical and time comparison method by which direct and indirect observations, maps and images are used, to the drainage characteristics in the two study periods. In this research topographic maps at 1:25000 scale and photogrammetry at 1:55000 and 1:40000 scale of studied region was used. Beside these, to exploit sack changes some software application such as Arc GIS , Excel and SPSS were applied. Research results show that river side changes in 37 to 165m are varied in river different parts that in average, river has gotten eroded 31583.4 m2 in 44 years that annual erosion amount has been 718.8 m2. It can be predicted for further 20 years that probably right side of the river will get eroded 14415 m2 in average. In 1999, developed and non-developed bights were added to river area, and high developed bights have been reduced from river than 1955. According to Leopold and Wolman index, bend coefficient more than 1.5 has bight pattern, therefore in studied bight parts of Kordan river 90% of bows has had evolved bight pattern in 1955 and this amount has arrived to 81% in 1999. Regarding to calculation, it can be concluded that bights had been increased from 1955 to 1999 but their sharpness were decreased.