The urban boundary layer (UBL), in comparison with ‘rural’ homogeneous PBLs, is characterised by greatly enhanced mixing, resulting from both the large surface roughness and increased surface heating, and by horizontal inhomogeneity of the mixing height (MH) and other meteorological fields due to variations in surface roughness and heating from rural to central city areas. So, it is reasonable ...

• Most of the urban poor in developing countries spend their lives in insecure, poorly paid jobs • They participate in economic growth, and adjust to economic change, through urban labour markets • Pro-poor urbanisation requires labour intensive growth, supported by labour protection, flexible land use regulation and investments in basic services U rbanisation is taking place on a massive scale...

• Most of the urban poor in developing countries spend their lives in insecure, poorly paid jobs • They participate in economic growth, and adjust to economic change, through urban labour markets • Pro-poor urbanisation requires labour intensive growth, supported by labour protection, flexible land use regulation and investments in basic services U rbanisation is taking place on a massive scale...

The conversion of Earth's land surface to urban uses is one of the most irreversible human impacts on the global biosphere. It drives the loss of farmland, affects local climate, fragments habitats, and threatens biodiversity. Here we present a meta-analysis of 326 studies that have used remotely sensed images to map urban land conversion. We report a worldwide observed increase in urban land a...

The urban environment characterized by various stresses poses challenges to trees. In particular, water deficits and high temperatures can cause immense drought stress to urban trees, resulting in reduced growth and die-off. Drought-tolerant species are expected to be resilient to these conditions and are therefore advantageous over other, more susceptible species. However, the drought toleranc...

[1] Since the middle of the last century, global surface air temperature exhibits an increasing trend, with nocturnal temperatures increasing at a much higher rate. Proposed causative mechanisms include the radiative impact of atmospheric aerosols on the nocturnal boundary layer (NBL) where the temperature response is amplified due to shallow depth and its sensitivity to potential destabilizati...

the urban squatter settlements is an urban phenomenon which is formed and developed by uncontrolled and irregular urbanization growth in the world and in iran as well and also by migration from the villages towards the cities. urban squatter settlements, as an unbalancing factor in the urban physical equilibrium, is a sign of irregular growth in the cities and the regions and many of the urbani...