This paper suggests a cause of low density in urban development or urban sprawl that has not been given much attention in the literature. There have been a number of arguments put forward for market failures that may account for urban sprawl, including incomplete pricing of infrstructure, environmental externalities, and unpriced congestion. The problem analyzed here is that urban growth create...

â  â â â â â  â  â  abstract: â  there is a significant relationship between economic growth and the degree of urban concentration, as measured by primacy or the share of the largest city in an urban system. in accordance to urban economic theories, there is an inverse-u shape relationship between urban concentration –urban primacy- and economic growth. that is, as economy grows, urban concen...

10 We examined the impact of the urban environment on the spatial and temporal activity of brood parasitic Brown-headed Cowbirds (Molothrus ater) in Boulder County, CO, USA. We found that cowbirds used the urban areas for foraging and roosting and traveled into the 3240 ha wildland preserve of ponderosa pine in the mornings to parasitize songbird hosts. Cowbird abundance decreased with distance...

Cities are growing and encountering many changes over time due to population growth and migration. Identification and detection of these changes play important roles in urban management and sustainable development. Urban growth models are divided into two main categories: first cellular models which are further divided into experimental, dynamic, and integrated models and second vector models. ...

Conventional two dimensional(2D) maps and DTMs are insufficient to represent geographic information in urban space comprising high-rise buildings and underground structures. There is a pressing need for a model of three dimensional(3D) representation of urban space, that is, a Digital Urban Space Model(DUSM). However, existing solid modelling techniques cannot be directly applied to the 3D repr...

the logistic regression (lr) method, as an empirical estimation method, was used to model urban growth in gorgan city between the years 1987-2001. three groups of variables including social-economic, land use and biophysical variables were used. similarity among variables is probable. to remove the correlated variables, covariance was calculated and distance to administrative, sporting centers ...

Boundary-layer wind tunnel provides a unique platform to reproduce urban, suburban and rural atmospheric boundary layer (ABL) by using roughness devices such as vortex generators, floor roughness, barrier walls, and slots in the extended test-section floor in the contraction cone. Each passive device impacts wind properties in a certain way. In this study, influence of various passive devices o...

fast and unplanned city growth, has effects such as isolation of village societies, threatening urbancores and centers and small and weak societies, destruction of open spaces and open and natural regions. smart growthoffers a sustainable way for urban developing with appropriate use of available sources, increase of urban services,developing neighborhoods with different uses, making public tra...

Knowledge of the mesoscale wind systems is very important to understand the dispersion of pollutants, thermal regulation and human comfort in the city. Wind field modifications brought about by the growth of the city of Lisbon and the possible urban environmental impacts are presented. In the last years the city of Lisbon has been growing towards the northern districts and the city center loose...

BACKGROUND Planners have relied on the urban development boundary (UDB)/urban growth boundary (UGB) and central business district (CBD) to encourage contiguous urban development and conserve infrastructure. However, no studies have specifically examined the relationship between proximity to the UDB/UGB and CBD and walking behavior. PURPOSE To examine the relationship between UDB and CBD dista...