The effect of a three-dimensional replacement of urban thermal environment
activity is discussed on the basis of numerical simulation with a mesoscale
climate model. Given a three-dimensional replacement of urban activity, gr
eater concentration decreased surface air temperatures. Such concentration
is apparently effective for modifying the thermal environment during the da
y-time, while the reduction of energy consumption is more effective during
the night-time. Through sensitivity analysis, it is shown that building wid
th and height variations with associated drag effects modify the environmen
t near the ground. (C) 1999 Elsevier Science Ltd. All rights reserved.