The bearing capacity of land construction refers to the carrying capacity
of land resources. It is analyzed by considering
the elevation, slope and water system in the study area,
so as to analyze the land area suitable for human habitation in the study area.
Land construction capacity includes the following 8 indicators: water area,
grassland area, cultivated area, forest area, construction land area,
desert area, elevation, slope.
The land carrying capacity is usually reflected by
the index of land pressure. The land pressure index is a percentage
that is calculated by taking into account the existing land use conditions,
topographic conditions, and water conditions in the study area.
(1)Consider the impact of land use on land resource pressure index.
(2)Consider the effect of slope on land resource pressure index.
The gradient grading standard is set to four levels:
0 ° to 8 °, 8 ° to 15 °, 15 ° to 25 °, and greater than 25 °.
The first level of slope of the land for urban construction;
the second level of slope of the land to take a certain design
can also be converted into suitable for urban construction of the land;
the third level of slope for the less suitable for industrial
and urban construction land. The fourth level of slope of the land
for the distribution of debris flow area, the state provides it
for the ecological area of returning farmland to forests.
(3) Consider the influence of water conditions on land resource pressure index.
Construction land should be selected in the area away from the river bank 70-100 meters
away from the reservoir catchment area 1500-2000 meters outside the area;
industrial and urban construction land should be selected in the distance
of 1000 meters away from the lake area.
(4) The land resource pressure index refers to the ratio of the existing
development intensity and the upper limit of development intensity.
The existing development intensity refers to the ratio of the existing construction land area
to the total area of the area. The existing construction land includes urban construction land,
independent industrial and mining, rural residential area, transportation,
water conservancy and other construction land. The upper limit of
development intensity is the ratio of the upper bound of the land area
to the total area of the area. The upper limit of the construction land area
is based on the comprehensive consideration of the existing land use situation,
topography and water and other factors, based on the sustainable use of land as
the target to determine the area can be used as construction land area ceiling.
The upper limit of the construction land area is suitable
for the construction land area minus the basic farmland area.
Suitable for construction land area is equal to the slope and altitude are suitable for
living area minus the waters, forest grassland, desert Gobi area.
The area of the basic farmland is equal to the area of cultivated land
within the appropriate construction land area multiplied by α, α is in the range of [0.80,1].