بررسي عوامي موثر در تحول ژئومورفولوژي مخروط افكنه ها مطالعه موردي: مخروط افنكنه جاجرود

Assessment of Effective Factors on Evolution of Alluvial Fans Case Study: Jajroud Alluvial Fan

This study intends to assess the evolution of characteristic of Jajroud alluvial fan that spreading on Varamin plain. Alluvial fans are one of the most dynamic landforms in arid regions. There are some different and opposite opinions on formation of alluvial fans and their evolution that submitted by scientific papers and reports. The object of this research is explanation of characteristics of Jajroud alluvial fan and assessment of effective factors on its formation and evolution. In this study we use satellite image of IRS (2002), aerial photos, 1:25000 and 1:250000 digital topographic maps and 1:250000 and 1:100000 geological maps as basic materials. Also we used digital image processing and map producing softwares. For the image processing PCI and Ilwis softwareʹs and for preparing of maps, Arc\GIS, Freehand and Microstation softwareʹs were used. In spite of this, in many cases with field check and observation of some natural and artificial profiles on the surface of alluvial fan we collect some valuable and supplementary information for controlling and supply accurate evidences. For this reason with taking of photos and tracing of graphic logs we collect some information about the fan. At the end, we used some tectonic activity indexes for explain the effect of tectonic activity on Jajroud alluvial fan. The result of this study shows that evolution of Jajroud alluvial fan affected by tectonic activities and climatic change and the base level change in long time and human activity in short time.