Geography Reference
In-Depth Information
where R is the effects of future grassland degradation on climate, refers to average
annual and monthly temperatures and average annual and monthly precipitations,
and C and S are the simulated results of WRF model with future projected land
surface and the land surface in the baseline, respectively.
The effects of grassland degradation on temperature and precipitation for each
period of 2010-2020 and 2040-2050 were simulated. Concretely, the temperature
and precipitation of each period of 2010-2020 and 2040-2050 with basic land sur-
face were modeled first, then those of 2010-2020 and 2040-2050 under the projected
land surface data was simulated. Finally, the effects of future grassland degradation
on climate were measured by the difference between these two series of simulated
results. By doing this, it can also reduce the biases induced by other factors.
7.4.2 Results
7.4.2.1 Effects on the Annual Average Temperature
The simulated results show that there will be a upward trend of annual average
temperature with an increment of 0.1-0.3 C during 2010-2020 (Fig.
7.17
). In
addition, the temperature decreases gradually from west to east, and climbs up
first, then declines progressively from north to south. The annual average tem-
perature changes significantly by 0.3 C in the northwest of Mongolia where
grassland covers most. Only a small area near the sea in the northeast, the tem-
perature falls by approximately 0.1 C. Generally, the annual average temperature
changes obviously in the most significant degraded areas, such as Alli county, Ada
Chad's county, and Altay city. This indicates that the grassland degradation has a
great influence on the local temperature change in Mongolia.
We also use the same method to simulate the effects of grassland degradation
on the average annual temperature from 2040 to 2050. The simulated result shows
that the annual average temperature will increase by 0.1-0.4 C during 2040-2050
(Fig.
7.18
). Compared with the simulated results of 2010-2020, the regions
experienced increase of annual average temperature expanded significantly, and
these regions are mainly distributed in northwestern and central regions of
Mongolia. In this period, the annual average temperature increases by about
0.1 C. Besides, the temperature decreases by almost 0.1 C in some areas of
southwestern and eastern regions of Mongolia.
7.4.2.2 Effects on the Annual Average Precipitation
The degradation of grassland leads to the significant change of the spatial pattern
of the annual average precipitation in Mongolia. The simulated result during
2010-2020 indicates the annual average precipitation will decrease by more than
