Geography Reference
In-Depth Information
Fig. 5.14 Difference in the annual precipitation (mm) in the winter (a) and summer (b) from
2010 to 2040 in overgrazing areas of Northwest China between the sensitivity test and control test
the surface albedo of croplands and grassland and the higher evapotranspiration of
the croplands. The grassland degradation would mainly lead to the increase of
surface temperature in summer in the overgrazing areas of Northwest China.
5.3.2.4 The Effect of Grassland Degradation on Precipitation
The simulation result indicates that the grassland degradation can cause the decrease of
precipitation in the winter in most parts of the overgrazing areas in Northwest China,
with a decrement from 0 to 12 mm (Fig.
5.14
a). Particularly, the annual precipitation
in the northwest part of Shanxi Province, southern part of Inner Mongolia Autonomous
Region will decline most obviously due to the serious grassland desertification, with a
decrement of about 12 mm. Besides, in the summer, the conversion from grassland to
barren land can result in the obvious decrease of precipitation in northern and central
part of Shanxi Province, northern part of Inner Mongolia and Ningxia Province, with
the decrement ranging from about 4 to 20 mm (Fig.
5.14
b).
The numerical simulation of temperature and precipitation in the next 30 years
shows that the grassland degradation in the overgrazing areas of Northwest China
will make the climate change to show a dry-warm trend according to the results of
the control test and sensitivity test. The results are consistent with theoretical
analysis results that the underlying surface change will lead to regional climate
change (Boucher et al.
2012
), i.e., the vegetation degradation will cause the
increase of surface albedo, and thereby leads to the decrease of precipitation and
increase of temperature.
