introduction the urban population experienced rapid growth in the recent decades, particularly between 1975 and 2000 when it has reached from 1.5 to more than 2 billion people. by turn of the century; half of the world's populations are concentrated in cities. this would severely affect the quality of life in urban areas. accordingly, cities will be faced with significant challenges in inf...

intra-city natural structures have always had a key role in creating sustainable urban greenspaces. adapting to natural features and relating the intra-city greenspaces to such natural structures as river-valleys, hillsides, lakes and forests, guarantee the endurance, sustainability and longevity of the natural quality of city. this paper looks at intra-city natural structures which have underg...

One of the most important natural factors and critical facilities in Tehran is presence of AlborzSlopes River-Valleys which have been considered as natural tourist places for citizens since a long time ago, especiallyin hot summers and play effective role in creating a balance between manmade and natural spaces. Importance ofthese river-valleys as ecological pathways is enhanced with the increa...

tehran city has been subject of critical environmental challenges during the course of 20th. century namely: massive population growth, broad expansion, reduction in urban open/green spaces, increasing in energy consumption and waste production. releasing industrial wastewater into river valleys have led to considerable changes in structure of city's natural landscape. the natural structur...

rainfall and flow rate are of the most important climatic and hydrologic parameters whose investigation and determination of their behavior are of great importance in water resources management. one of the most suitable methods available for assessment of hydro-climatological conditions in the watershed is trend analysis which is used to examine the changes of a variable during time. current st...