Geography Reference
In-Depth Information
4.2.2 Results and Discussion
4.2.2.1 Cultivated Land Change Under Different Scenarios
The simulation results indicate that the land use change in Northeast China during
2010-2030 is mainly characterized by the conversion from cultivated land into
forests or urban and built-up land under the three scenarios; the total cultivated
land area will show a decreasing trend (Fig.
4.6
). The land use change will follow
the historical trend under the BAU scenario; the cultivated land will mainly change
into urban and built-up land and forests, the newly increased area of which will
reach approximately 3,782 and 1,471 km
2
by 2030, respectively. Besides, a few
water bodies will convert into cultivated land under the BAU scenario. By com-
parison, there will be more cultivated land converted into urban and built-up land
under the REG scenario and forests under the CES scenario, the newly increased
area of which reach 1,889 and 3,798 km
2
, respectively. In addition, the cultivated
land change will show significant spatial heterogeneity under the three scenarios.
The conversion from cultivated land into forests mainly appears in the southern
part of Heilingjiang Province, southern and middle part of Jilin Province, and
southern and eastern part of Liaoning Province. While the conversion from cul-
tivated land into urban and built-up land will mainly appear in the southern and
eastern part of Liaoning Province, middle part of Jilin Province, and eastern part of
Helongjiang Province. What is more, compared to the BAU scenario, more cul-
tivated land change will convert into urban and built-up land in the regions around
cities under the REG scenario. More cultivated land will change in forests in the
regions far from cities under the CES scenario, especially in some important water
conservation area such as Three River Plain and Changbai Mountains.
The land use change in Northeast China is greatly influenced by the socio-
economic activities, with the conversion from cultivated land into forests and
urban and built-up mainly driven by the governmental policies, socioeconomic
development, and urbanization. For example, a series of major ecological con-
struction projects have been implemented, e.g., Three-North Forest Shelterbelt
Program and Green for Grain Project, all of which greatly promoted the expansion
of the forests in Northeast China. For example, a lot of mixed dryland/irrigated
cropland has converted into grassland or mixed forests in the eastern part of Inner
Mongolia Autonomous Region, middle, and eastern parts of Heilongjiang Province
and Jilin Province; the vegetation degradation in Northeast China has been under
control to some degree. Besides, the urban land expansion has led to the occu-
pation of cultivated land around the cities. The simulation results also suggest that
more cultivated land around the metropolis and small cities will be occupied since
the socioeconomic development leads to more demand for land resources. In
summary, under the influence of urbanization and governmental policies, the
spatial heterogeneity of cultivated land reclamation and occupation will lead to
more significant spatial heterogeneity of cultivated land, which will exert signif-
icant impacts on the regional climate.
