The microclimates of a suburban Colorado (USA) landscape and implications for planning and design

The microclimates of a suburban Colorado residential landscape were studied to examine the effect of design decisions on temperature, wind speed, and relative humidity. On a hot day typical of summer, vegetated landscape elements were several degrees cooler throughout the day than non-vegetated surfaces. Across the development, dry, native grass landscapes were warmer than irrigated greenbelts and irrigated residential lawns. These data demonstrate the importance of evapotranspiration as a cooling agent in the dry, semi-arid Colorado environment. Extended meteorological measurements throughout the summer suggested housing density created microclimatic differences in the development. Heat generated by built landscape elements was readily vented from a porous neighborhood but not in a denser neighborhood. This study demonstrates that in the semi-arid Colorado environment, the choice of planting material, the design of irrigated greenbelts within a community, and the density of housing all have important consequences in creating thermally-pleasing environments. (C) 2000 Elsevier Science B.V.