Changes Detection and identification of erosion risk areas of Aji Chay River between Khaje to Vanyar Print

Changes in the human environment in different periods and in different areas it is reasonable by the satellite images، aerial photographs and maps in certain forms are easily done. This is particularly important when the data becomes more critical in areas such as environment، agriculture; Natural resource management and river engineering are used (Pris and etal، 1997، 23). Therefore، in order to discover and detect changes that occur in different regions of the Earth Can ensure that remote sensing technology and satellite images in a sequence -specific forms used (Atood and al. 2005، 8) And their results in the prediction، risk maps، choosing the right strategies to deal with behaviors sudden، More Accurate and more economical operation than to past and successfully implemented projects and structures of organizations and agencies On the rivers for future use. Thus، the geometry changes، the process of depositing and important morphological changes in the organization of the river، flood control، design of linear structures (roads،…) Hydraulic (bridges، dams، …) settlements and destruction of agricultural lands on the river and its margins are evaluation of morphological changes part of river Ajy Chay between Khaje to Vanyar، north east of Tabriz 46° 23'' 55 «to 46 ° 34'' 55» along the eastern and 38 ° 07'' 1 «to 38° 08'' 40» north latitude Length of approximately 22 km with the aim of identifying risk areas to the lateral erosion investigated. How it works for this research have been carried out، the first report -required information and report about the range of research and library -based methods and field studies were collected. In the second stage، maps and aerial photos have been scanned، georefrenced، mosaic. In the third stage of the coastline extraction the River For a the time period three (years 1956، 1995 and 2008) Land and water border with digitization in eara gis To calculate the amount of surface erosion and sediment riverbank was done for three periods. To calculate the erosion and sediment to the coasts، along the river intervals of 250 meters، divided in three periods and than linear displacement due to sediment and erosion per meter on year for each period was obtained. At this stage the layer requirements such as erosion، land use، lithology، slope، floodingbed، and road digital and descriptive data were applied to each. Then all the layers due to the influence and reception of each factor over time and toward River erosion rate، converted to raster and weighting was ready. In the final stage of the layers and changes coastal The softwares environment Arc GIS 9. 3، Excel were processed and charts، tables and maps were extracted needed to determine the risk areas. Displacement of the river using three different data in software Arc GIS by comparing the coasts the river in both periods 1956-1995 (39 years) and 1995- 2008 (13 years) was carried out. This study intended to measure changes in linear sides through time and identifies areas where it has been the erosion and sedimentation. Results of the linear by specifying Areas of erosion and sediment delivery and to chart the lateral rate the changes as a function of distance along the coasts (every 250 m) were mapped in the software Excel. The results of maps and charts show that in both periods right bank of erosion more than left bank and the second term right down the bank deposit and left the bank deposit has increased. Considering that the second term on the right bank more erosion than deposition but also increase the deposition in left bank the erosion can be seen that this phenomenon is due to the high sensitivity right bank to erosion، less shrub cover، accumulation of sediment erosion in the left bank and the relative resistance to against erosion is on the left bank. Cause an increase in vulnerable areas and right bank of the critical in the second period than in the first period and less vulnerable areas، the critical and very the critical left bank in the second period than in the first period can be understood that it was already too much discharge and erosion on the left bank to slip and fall are also effective but with a little discharge due to the uneven impact of the lower left of the bank and the right bank، mostly in left bank sediments have accumulated. But the right bank due to flow in alluvial deposits still contain high erosion potential. Obviously، the results of this research by other professionals can be effective in preventing disaster. In this study، merely the river Lateral changes over time has been and comment on its applications to professional experts in various fields of environmental and engineering.