Impact of urban constructions weight on instability, case study district 1 of region 2 municipalty of Tehran

Geomorphological developed subjects concerning urban studies during past half century are different. Analysis of landsides vulnerability in the hillside of mountains، and the study of changes of surface drainage channels and their relations to urban developments، are some of these issues. This paper which is besed upon analytical mothod and its main tool is GIS software، tries to investigate the effect of urban constructions weight as effective factor on the accurance of slide movements and surface unatabilities creation in distric 1 of region 2 of Tehran municipality. First، coordinates and hight of 100 unstable points were collected. Weights of buildings materials were used to calculate total weights of buildings in study area. By overlaying the map of unstable points and weight distribution in five catagories (from very light to havey)، it is concluded that 53 % of unstable points are in areas were havey and new buildings are situated and remaing 47 % are within light weight building areas. Furthermore، most of the obsereved points were in wor-out urban texture.