No abstract

Design of greenways is one of the most important planning tools in the promotion of quality of life of the city residents. Greenways are necessary due to their major role in increase of air quality and positive changes in the climate of the urban environments for keeping the environmental quality of the cities and considerably increasing aesthetic values of these environments. Protection of natural ecological systems, provision of extensive recreational opportunities for people in urban regions and rural districts, provision of economic benefits and protection of cultural values and historical heritage are the advantages of designing and creating greenways inside cities. The present paper which was conducted with descriptive-analytical method tried to explain design dimensions of ecological greenways in three urban physical, environmental and social-economic systems by studying suitable experimental concepts and samples in the world. In this regard, this paper studied five main goals of designing greenways: promotion of local and urban accesses with greenways, aesthetic aspects of urban landscapes, improvement of performance and distribution of activities by creating greenways, increase of efficiency and environmental aspects in the city and revival of social values considering economic sustainability and in this regard design strategies and policies were presented for each one of them based on these goals.

The main objective of this manuscript is to investigate the effects of environmental aesthetics elements of urban designing on formation of the main part of the city (as the fundamental characteristics of the urban form). For this purpose, this comparative article explains the environmental aesthetic elements that are affecting the formation of main structure of the cities during the history of urbanism history (Teotihuacan, Beijing, Athena, Rome, Paris, Washington, Brasilia, and Isfahan) to pave the way for analysis of environmental aesthetics and improvement of contemporary cities' quality. For this purpose, the present study employs analytical-descriptive research methods, and literature, references, and visual documents reviews. The results from this study indicate that environmental aesthetic elements of urban designing are affecting the formation of an urban form in two ways, namely visual-form and cognitive-semantic. Visual-form elements include the quality of landscape and its factors, the quality of urban buildings and their elements, the quality of public spaces and their elements, continuity, enclosure, diversity of forms, the quality of views and vistas, and coordination with the context. Cognitive-conceptual elements include identity, legibility, concept, perceptibility, coherent mental image, customizability, social and cultural environment, and richness of activities.

The rapid and uncontrolled haphazard urbanization is a serious threat to the manmade and natural environment and the socio-economic balance of our time. There is a global concern that urbanization must be oriented in responsible, sustainable, and livable urban forms. High quality of sustainable urban design plays a key role in creating these sustainable living environments. In this regard, learning from culture and history and searching together are vital for new ways of designing. In this paper, the evolution of the settlements with respect to sustainable urban design in past, present, and future is analyzed. The study indicates that we had sustainable urban design in pre-industrial period in an organic way; however, we altered the existing ecosystems by welcoming incompatible technological elements; elements that cause a kind of ill growth similar to cancer. In this relation, a case study of urban environmental design for Darabad River Valley in Tehran as a sustainable urban design project is presented brie y. Finally, it is concluded that we should know that designing is a kind of altering the systems. A comprehensive wise and conscious approach similar to what we have used in Darabad River Valley project is suggested for similar situations.

In this article by reviewing the environmental aesthetics experience, natural townscape, and ecological assessment related concepts, ecological assessment is known as a process that pave the way for achieving a positive (pleasant) experience of natural aesthetics in natural townscape. In fact, it seems that ecological assessment and evaluation of the natural context should be the fundamental part in the process of urban design of large scale projects, which are developed to improve the quality of environment aesthetics experience. Since, ecological assessment of the context contributes to analysis and evaluation of those elements and aspects of the environment that provide human with better concentration to obtain more pleasant aesthetic experience. In this study, by performing ecological study, analysis, and assessment of the natural context of Darabad valley's river, as one of the central urban and natural landscapes in Tehran, approaches and policies that are related to environmental aesthetics in this natural townscape are developed. These approaches and policies highlight better rehabilitation and restoration of the context of valley's river, as a human real and public space; preservation, improvement, and understanding of ecological and biological resources; and increase of visual quality and enrichment of views and vistas in the river's bed. The present analytical-descriptive case study has used several research methods such as literature, references, and visual documents review, and observation and simulation in the context of library and field investigations.