density has a greater impact on the 2 m temperature than the
low building density, and the 2 m temperature is more af-
fected at daytime than at nighttime.
Conclusions
The temperature and humidity of the main urban area in
Guangzhou were extracted from the land use data in 2000 and
2009 by using the
WRF
model. The temperature and building
density were analyzed using the correlation analysis method.
The result shows that diverse human activities brought about
by urbanization and change of land use type have an important
influence on the heat island effect, thereby mainly showing
increasing temperature and humidity in the study area. The
change of human activities and land use type pose consider-
able influences on the heat island effect. The various building
densities have a significant influence on the heat island effect.
The temperature and humidity in Guangzhou have a time
of volatility and spatial difference. In the past few years,
the change of temperature and humidity slightly fluctu-
ated in January and July and the overall trend is increasing.
The temperature and humidity changes in the Tianhe and
Haizhu districts are apparent, whereas those of the Liwan and
Yuexiu districts are insignificant. In particular, the monthly
mean temperature in the simulated area in January and July
increased by 0.20°C and 0.31°C, respectively. The monthly
average relative humidity was significantly lower than that
in other areas in the main study area. The relative humidity
monthly average decreased by 1.14 percent and 2.1 percent in
January and July, thereby forming a broad range of urban dry
island. In general, the study area presents evident warming,
low humidity, and
UHI
effect.
This study used the buildings within Guangzhou as the
land use type for the heat island effect simulation analysis
to verify the effect of various building densities on the heat
island effect. This study shows that the higher the high build-
ing density, the lower the temperature at daytime and the
higher the temperature at nighttime. The lower the density
Figure 10(a). Effects of various building densities on the average 2 m temperature (T2) at daytime in Guangzhou (a, Base; b,
Case1 and Base; c, Case2 and Base)
Figure 10(b). Effects of various building densities on the average 2 m temperature (T2) at nighttime in Guangzhou (d, Base; e,
Case1 and Base; f, Case2 and Base)
Figure 10(c). Influence of various building densities on the
daily variations of the 2 m temperature (T2) in Guangzhou
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