Radar and Remote Sensing
Impacts of urbanization on local hydrometeorological variables —A case study in Beijing
Institue of Hydrology and Water Resources
23 April 2012, 1:30 PM
National Weather Center, Room 1350
120 David L. Boren Blvd.
University of Oklahoma
The state-of-the-art numerical weather simulation system-Weather Research and Forecasting (WRF) is employed to quantity the contribution of urbanization to the observed change of local hydrometeorological variables, and the impacts of urbanization on regional potential evapotranspiration, over the Greater Beijing metropolitan area which is a typical example of urbanization now happening in China.
The urbanized area of Beijing is classified into industrial/ commercial area, high intensity residential area and low intensity residential area based on the impervious data extracted from Landsat TM data, then the single layer urban canopy model of Beijing is established and coupled to the WRF modeling framework. The model performance is checked with observed air temperature, wind velocity and rainfall.
Simulation results show that urbanization (here means the conversion of cropland to urban) will cause about 0.29 m/s decline of the local 10m wind velocity, 0.71℃ increase of the 2 m air temperature, 7.64 J/(m2·s) increase of net radiation and 0.04 kPa decrease of 2 m vapor pressure. As a combined effect, the regional potential evapotranspiration will be increased by about 22 mm/yr. The contribution of urbanization to the observed change of local hydrometeorological variables over the Greater Beijing metropolitan area is then estimated.