hide
Free keywords:
-
Abstract:
Over the last two decades, a disproportional increase of urban land area in comparison with the population
growth has been observed in many countries of Europe, and this trend is predicted to continue. The
conversion of vegetated land into urban land leads to a higher proportion of impervious surface area,
to decline and change of vegetation cover, to artificial heat sources, and therefore to changes in climate.
This study focuses on the implications of the expansion of urban land for the European climate at the local
and regional scales. Regional climate simulations with the fifth-generation Pennsylvania State University–
NCAR Mesoscale Model (MM5) coupled to the Town Energy Budget model are used to isolate effects
of urban land expansion on temperature and precipitation. The study suggests that the expansion of current
urban land by 40% would lead to an enlargement of regions affected by thermal stress by a factor of 2,
whereas the intensity of the thermal stress does not change significantly. Precipitation in urban areas
would be reduced by 0.2 mm day21 in summer as a result of disturbances of the water cycle caused by
urban surfaces. The area in which precipitation was altered increased nearly linearly with the urban land
increment
