Evaluation of highways in river environmental geomophologic and design considerations (case study : Andimeshek - Ahvaz Road, Iran)

Andimeshek = Ahvaz road and railway are parts of Khozezstan way also a part of the karoon rivers basin. The area of study located : E 47 54' to E 48 47 and N 32 16' 30" to 3301' 30" (Iran). The arid and semi-arid regions influence to this area. The important characteristics for Karoon water shed are Low and high fluctuation ofprecipitation and in some years it may exceed annual average. Since there is no control over climate element it is very important to know those change to assessment and study method of safety railway. Linear structures (such as highways, railway) have main and common effects on geomorpholclimatic and rivers hydrologic system and on houses and structures establishment in geomorphology unit in the region which were studied (Karoon river basin). This region has relative morphologic stability. Without studying and planning æ this leads to unpleasant results and in turn this results change natural units equation and have effects on people in many ways. On the other hand it has main effects on region economic balance in future and it causes that environmental and safety index will be decreased. So in this paper æ according to the reaction of Karoon and its sub rivers and the effects on environmental elements, it is necessary to study the following activities: at first organizing a systematic and exactstudy to change the effect of different selective plans on structures and the way of using them on environment and finally the selection of structural projects measurements and linear structures so that they have minimum effects on environment. For these purposes æ continuous researches neccessarities for improvement of the rivers and city zone linking with rivers also application of their results in urban and regional levels æ it is necessary to systematic study with comprehensive geographic views which based on different subjective sciences such as geomorphology, climatology, hydrology and so on. To distinguish of geomorphologic features and units æ at first aerial photographs and different geomorphologic units have been showed on topographic maps. These units have been reviewed in field study and finally comprised features and units has been reviewed in field study.