Impact Geomorphologic Landforms on directs Urban expand physics

One of the interesting issues for geomorphologists is their participation in determining suitable land for urban development according to geomorphologic principles and data in the future. Urban Geomorphology can contribute to the management and development of urban area in two major ways. Firstly, it can help in evaluation of resource potential and suitability of land under consideration for urban development. Secondly, it can monitor geomorphological process-response system following urban development and help in the prediction of changes that might arise from future urban growth. It can be said this study is aimed to evaluate resource potential and suitability of land for urban development. In fact, geomorphological forms such as mountains, plains, rivers, beaches, and etc. have important role in Physical development of cities, so that they can control rate of urban expansion. Research method To perform the study following data is used: A) Documentary data including maps showing development of the DARAB over time, topographic (1:50000) and geological (1:100000) maps. B) Remote sensing data including Landsat ETM + satellite image in 2001, and aerial photograph in 1335. C) Field data gathered from direct observations and survey. Method of research is based on survey and analysis. At first, type, origin and transformation of topographical forms of Darab city and its surroundings was determined. Then, by Using satellite image and aerial photograph, geomorphological units was specified. Each of these layers was analyzed in geographic information system and ultimately suitable alternatives for physical development were classified by considering geomorphologic hazards, urban development priority and economic issues. Physical expansion of Darab prominently is function of urban and rural population growth and economic growth. Besides, phenomenon of land reform, drought, and change in farming pattern has been very effective. Selecting a suitable location for urban development in the first stage requires a comprehensive study. Research about natural environment and related processes is fundamental stage to decide and plan where city is developed. Environmental aspect of urban physical development has as far as important situation which physical development of Darab to the south and southwest, without regarding natural environment, made serious problem for urban management encountered flood in 1982. Although Darab is surrounded by alluvial Fans, but these forms have different conditions in terms of their area, slope, and size of sediment grain, casual morphology and agricultural potential. Field studies show that these differences often result of new tectonic process, climate change and changes in characteristics of rivers and their sediment load. Results show that Although Darab is surrounded by alluvial Fans, but these forms have different conditions in terms of their area, slope, and size of sediment grain, casual morphology and agricultural potential. Generally, overflow of groundwater along bed of waterway on alluvial fans, unstable construction of fans to seismic waves, surface creep, massive slip and land subsidence are geomorphologic constraints Darab encountered. By examining and recognising geomorphological landform importance, suitable alteratives for future physical development of Darab are listed respectively: 1. South eastern region (having suitable slope for groundwater and sewage disposal, absence of active Foothills processes, and feasibility of flood control). 2. West and Southwest region (the least natural hazards, suitable slope). 3. Northwest region (this region is propone to massive movements and has inappropriate slope for future development). 4. South region (which characterized with fertile agricultural land, groundwater and sewage disposal problem, and flood plain issue).