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...

The effects of five towns on river water pollution were examined along the Łyna River (southern watershed of the Baltic Sea, northern Poland). The relationships among the spatially derived indicators of urbanization, environmental variables, and physico-chemical and microbiological data (heterotrophic plate count at 22 and 37 °C, and fecal coli) obtained from longitudinal river profiling have b...

1. The world’s population is increasingly urban, and streams and rivers, as the low lying points of the landscape, are especially sensitive to and profoundly impacted by the changes associated with urbanization and suburbanization of catchments. 2. River restoration is an increasingly popular management strategy for improving the physical and ecological conditions of degraded urban streams. In ...

The aim of this study was to evaluate the amount and quality of water in the Magdalena-Eslava river system and to propose alternatives for sustainable water use. The system is the last urban river in the vicinity of Mexico City that supplies surface water to the urban area. Historical flow data were analyzed (1973-2010), along with the physicochemical and bacteriological attributes, documenting...

Megalopolis is a group of densely populated metropolitan areas that combine to form an urban complex. Since China introduced the economic reforms in late 1970s, the Chinese urban system has experienced unprecedented growth. The process of urbanisation prevailed in the 1980s, and the process of predominantly large city growth appeared to continue through 1990s and 2000s. In this study, the magni...

Megalopolis is a group of densely populated metropolitan areas that combine to form an urban complex. Since China introduced the economic reforms in late 1970s, the Chinese urban system has experienced unprecedented growth. The process of urbanisation prevailed in the 1980s, and the process of predominantly large city growth appeared to continue through 1990s and 2000s. In this study, the magni...

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...

The safety of river-crossing tunnels is an important aspect of urban road traffic systems. Previous studies concerning traffic safety mainly focused on urban roads. Given the absence of a number of variables, such as speed and real-time traffic volume, in traffic accident databases, the traffic safety of urban river-crossing tunnels has rarely been studied. This study used the microscopic traff...

The issues of loss of quality of life and functional disruption of the river valleys are very important. In the present settlement system, the river valleys should not be places for reproducing poverty. To link the environmental values with urban development, the research is to answer the following question: How can the results of the integrated development of urban valleys be achieved via urba...

This study is a first attempt to investigate the impact of urban contamination on metal tolerance of heterotrophic river biofilms using a short-term test based on β-glucosidase activity. Tolerance levels to Cu, Cd, Zn, Ni and Pb were evaluated for biofilms collected at three sites along an urban gradient in the Seine river (France). Metallic pollution increased along the river, but concentratio...