Geography Reference
In-Depth Information
Fig. 6.3 Difference in the projected monthly average temperature in summer between the
control test
and
sensitivity test
in the Beijing-Tianjin-Tangshan
Metropolitan
area
during
2030-2040
6.1.2.4 Results of the Numerical Simulation
Figure
6.3
depicted the simulated impact of future urban expansion on average annual
temperature in the study area during 2030-2040. There will be significant warming
effects in the summer, mainly occurring in the downtown and eastern part of Beijing
Metropolitan. Transformation from vegetated land to urban land results in significant
differences of near-surface temperature. As a result, the temperature would increase
obviously in the regions with urban expansion, mainly owning to UHL effect, which is
consistent with the results of previous researches (Wang et al.
2002
).
Surface temperature is determined with surface energy balance equation.
qL
v
ð
w
0
q
0
Þ
sfc
þ
R
n
S
qc
p
C
h
u
ð
T
sfc
T
Þ
¼0
where the first item refers to latent heat flux; the second item refers to net radiation
flux; the third item refers to soil heat flux; and the forth item refers to sensible heat flux.
Part of net radiation flux is absorbed by the earth's surface, which further
influences latent heat flux and sensible heat flux, with the rest transformed into soil
and soil heat flux. The heat transfer in soil complies with the thermal diffusion
equation.
