Geography Reference
In-Depth Information
4.3.2.3 Analysis of Test Results
The LUCC in the North China Plain, which was characterized by the regional
urbanization, had led to some changes of the near-surface temperature. The annual
average temperature was 14.61 and 14.64 C in the control test and sensitivity test,
respectively. The LUCC in the North China Plain made the regional near-surface
temperature increase by 0.03 C/year. All the months except January and June
were characterized by a temperature increase during 1992-2005. Besides, the
LUCC in the North China Plain also led to an increase of the near-surface tem-
perature in all the seasons, among which the temperature increment was the
highest in the summer and the lowest in the winter, reaching 0.05 and 0.02 C,
respectively. The monthly and seasonal temperature differences in the control test
and the sensitivity test were as shown in Fig. 4.14 .
The spatial patterns of temperature increase are consistent in the spring and the
autumn on the whole, both indicating a significant temperature increase in the
North China Plain (Fig. 4.15 ). The amplitude of the temperature increase is rel-
atively small in the spring (generally around 0.03 C), while it is very large in the
autumn (above 0.04 C on average). The temperature increases most greatly in
the summer, increasing by 0.05 C/year on average, and exceeding 0.1 C in the
Circum-Bohai-Sea Region and reaching 0.2 C in the Beijing-Tianjin-Tangshan
zone. Besides, there are much wider regions with a significant temperature in the
summer than in the other three seasons. Although the temperature increases in the
winter on the whole, it still decreases in most regions, especially in the Yanshan
Moutain, Circum-Bohai-Sea Region, Shandong Peninsula, etc.
The spatial pattern of the seasonal temperature change corresponded to that of
the LUCC on the whole. The temperature generally increased in the regions where
the urban and built-up land increases. The temperature increment was very high in
these regions, and the degree and the range of influence of temperature increase
varied significantly among reasons. Taking the Beijing-Tianjin-Tangshan zone as
an example, the temperature increment was very large and the range of the
influence of temperature rise was very wide in the summer in this region. The
regional temperature increased by 0.06-2.8 C in the summer, and the temperature
change due to expansion of urban and built-up land influenced a wide area around
the Beijing-Tianjin-Tangshan zone. The temperature increment was largely the
same in the spring and the autumn, reaching 0.03-3 C. However, the temperature
rise mainly influenced Beijing and Tianjing in the spring, and Beijing and some
areas in the north part of Hebei Province in the autumn. The temperature rise was
only obvious in the regions where urban and built-up land increased, while in other
regions the temperature generally decreased by 0.01-0.06 C, which might be
caused by the wind velocity, which was generally high enough in north China in
the winter and consequently reduced the tendency of temperature rise resulting
from the increase of urban and built-up land (Arnfield 2003 ; Johnson et al. 1991 ).
The temperature changes most greatly in the urban and built-up land among all
the land use/cover types in the North China Plain (0.1 C/year), followed by the
irrigated cropland and pasture (0.06 C/year). While the temperature increases most
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