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2012 International Conference on Ecology, Waste Recycling, and Environment

Research on Land Use Structure Optimization in Ecological Degradation

Region

Lianghou Li 1,2,a

1 Henan Academy of Forest, Zhengzhou, China

2 College of forestry, Beijing Forestry University, Beijing, China

a llh2006@yahoo.com.cn

Keywords: Ecological degradation region, Land use, Linear programming, objective function,

constraints, optimized structure.

Abstract. The soil is the basis of the vegetation, the vegetation construction is one of the ways of

utilizing the soil, and the structure of the soil utilization is the key task of the soil utilization

planning. There are such features as including complex factors and being difficult to conduct

quantitative analysis in the soil utilization planning. In this paper, according to the existing soil

resources and the utilizing status, using the multi-objective linear programming method and

selecting proper variables, two objective functions, the maximum economic income and the

minimum loss of waters and soil, are established. The optimized structure of utilizing soils is

determined in the concerned region, and the scientific foundation is provided for the soil utilization.

1. Introduction

Optimize land use structure is the core work of land-use planning. Land is the basis conditions for

building vegetation; building vegetation is one of the ways of land use. As part of land use, land for

building vegetation within a certain region should be optimized structure, find the best land use

structure is the ultimate goal of land use planning. Because land use planning involve many

complex factors, it is difficult to carry out quantitative analysis. With the development of related

disciplines, people began to use a variety of mathematical programming methods to optimize land

use structure. Many mathematical programming methods are applied, linear programming is an

important method which is used frequently.

2. Mathematical method

2.1 Linear programming models

Suppose there are n variables, m constraint type, the objective function of linear programming

model is:

max(min) f ( x)

=

The constraint of linear programming model is:

m n

∑∑ ij

i= 1 j=

1

j

i

n

j = 1

c j

x j

a x ≤(

= , ≥)

b x 1 ,x 2 ,……,x n ≥0

In which, a ij denotes coefficient, bi denotes constants, c j denotes interest coefficient of objective

function, i=1,2,……,m, j=1,2,……,n.

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A classification based on land use, land is divided into 8 categories, each category is for a

variable, respectively denotes cultivated land, garden, woodland, grassland, residential and

industrial land, traffic land, waters, land, unused land, codes are: x 1 ,x 2 ,……,x 8 .

Economic objectives expressed formula as:

Ecological goals expressed formula as:

maxf 1 (x) = c 1 x 1 +c 2 x 2 +……+c 8 x 8

maxf 2 (x) = d 1 x 1 +d 2 x 2 +……+d 8 x 8

Merging normalized above two formulas into a comprehensive expression:

maxf(x)= r 1 x 1 +r 2 x 2 +……+r 8 x 8

If there are multiple targets, these formulas will be combined into an integrated normalized formula.

2.2 The establishment of constraint conditions

Labor resource constraint formula is:

a 11 x 1 +a 12 x 2 +……+a 18 x 8 ≤b 1

Funding constraint formula is:

a 21 x 1 +a 22 x 2 +……+a 28 x 8 ≤b 2

Water constraint formula is:

a 31 x 1 +a 32 x 2 +……+a 38 x 8 ≤b 3

Soil erosion constraint formula is:

a 41 x 1 +a 42 x 2 +……+a 48 x 8 ≤b 4

Environmental pollution constraint formula is:

a 51 x 1 +a 52 x 2 +……+a 58 x 8 ≤b 5

Forest cover constraint formula is:

x 3 ≥ms

Land area constraint formula is:

x 1 +x 2 +……+x 8 =b 7

Planned land use indicators constraint, b 8 ~b 14 denotes the various types of land use data of

higher authorities issued, as the level land use planning constraints.

According to linear programming listed above expression, solving by the simplex method, the

optimal solution of x 1 ~ x 8 can be gotten, they are optimize the structure of the level land use.

3. Results and analysis

3.1 Decision variables

Present situation of agriculture, forestry, animal husbandry, etc., land use in the study area are

showed in table 1.

Table1. Present situation of land use in the study area.

Item Area/hm 2 Proportion/% Sub-item Area /hm 2 Proportion /%

Total 28136.22 100 100

Arable land 13792.02 49.02 49.02

Woodland 2017.40 7.17

Timber forest 60.26 0.22

Shelter forest 1137.36 4.04

Economic forest 819.78 2.91

animal husbandry land 2494.92 8.87 8.87

Barren wasteland 9831.88 34.94 34.94

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The area of composing eco-economic system structure unit is the variables of optimization

process, 28 variables are selected from a number of structural units as decision variables. They are

showed in table 2.

Table 2. Decision variables and their physical meaning.

Decision

Decision

Physical meaning

variable

variable

Physical meaning

X 1 Irrigated land wheat (corn) area X 15 Ⅴ water conservation forest area

X 2 Irrigated land orchard area X 16 Ⅴ firewood forest area

X 3 Dry land wheat (corn) area X 17 Ⅶ timber forest

X 4 Dry land peanut area X 18

Ⅶ soil and water conservation

forest area

X 5 Dry land millet area X 19 Ⅶ water conservation forest area

X 6 Dry land sweet potato area X 20 Ⅶ firewood forest area

X 7 Dry land beans area X 21 Ⅷ timber forest

X 8 Irrigated land shelterbelts area X 22

Ⅷ soil and water conservation

forest area

X 9 Dry land shelterbelts area X 23 Ⅷ water conservation forest area

X 10

Ⅲsoil and water conservation forest

area

X 24 Ⅷ firewood forest area

X 11 Ⅲwater conservation forest area X 25 Ⅱ economic forest area

X 12 Ⅲ firewood forest area X 26 Ⅳ economic forest area

X 13 Ⅴ timber forest area X 27 Ⅵ economic forest area

X 14

Ⅴ soil and water conservation

forest area

X 28

Ⅰpasture area

Note: Ⅰdenotes sunny, gentle slope and thin soil; Ⅱdenotes sunny, gentle slope and gentle thick soil; Ⅲdenotes sunny,

gentle steep slope and thin soil; Ⅳdenotes sunny, gentle steep slope and gentle thick soil; Ⅴdenotes shady, gentle slope

and thin soil; Ⅵ denotes shady, gentle slope and gentle thick soil; Ⅶ denotes shady, gentle steep slope and thin soil; Ⅷ

denotes shady, gentle steep slope and gentle thick soil.

Planning model parameters are showed in table 3.

3.2 Constraint conditions

Constraint conditions are defined based on surveying and analyzing for Natural resource systems

and systems of social resources of whole study area and referencing the relevant research results [2, 3] .

The constraint of planting wheat (corn) and building shelterbelt forest on the irrigated land:

X 1 +X 8 ≤4037.37

The constraint of building shelterbelt forest on the irrigated land:

X 8 ≥44.01

The constraint of orchard area:

X 2 ≤490.20

The constraint of planting wheat (corn), peanut, millet, beans, and building shelterbelt forest on

the dry land:

X 3 +X 4 +X 5 +X 6 +X 7 +X 9 ≤9754.65

The constraint of building shelterbelt forest on the dry land:

X 9 ≥106.33

The total area of building soil and water conservation forest, water conservation forest, firewood

forest on the stand site Ⅲ is less than the total area of the stand site Ⅲ:

X 10 +X 11 +X 12 ≤5412

The total area of building timber forest, soil and water conservation forest, water conservation

forest, firewood forest on the stand site Ⅴ is less than the total area of the stand site Ⅴ:

X 13 +X 14 +X 15 +X 16 ≤791

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Table 3. Planning model parameters

Land use pattern

yield/ Net income/ RMB The amount of labor/ Erosion modulus

kg/hm 2·a yuan/hm 2·a Man-days/hm 2·a t/km 2·a

Irrigated land wheat (corn) 10500 3150 480 1840

Irrigated land orchard 45000 45000 325 1840

Dry land wheat (corn) 9000 2700 375 7370

Peanut (sesame) 900 900 150 7980

Dry land millet 3750 1500 150 7370

Dry land sweet potato 4500 1350 225 7370

Dry land beans 1350 1350 75 8600

Irrigated land shelterbelts 1 600 3 1840

Dry land shelterbelts 1 450 3 1840

Ⅲsoil and water conservation forest 1 0 21 5420

Ⅲwater conservation forest 1 0 21 5420

Ⅲfirewood forest 2600 2420 57 7590

Ⅴtimber forest 3710 26 5490

Ⅴsoil and water conservation forest 0 26 3430

Ⅴwater conservation forest 0 26 3430

Ⅴfirewood forest 2400 3710 73 4800

Ⅶtimber forest 3070 21 6620

Ⅶsoil and water conservation forest 0 21 4140

Ⅶwater conservation forest 0 21 4140

Ⅶfirewood forest 2000 3070 64 5800

Ⅷtimber forest 3610 26 5800

Ⅷsoil and water conservation forest 0 26 3630

Ⅷwater conservation forest 0 26 3630

Ⅷfirewood forest 2300 3610 92 5080

Ⅱeconomic forest 35390 35390 168 10450

Ⅳeconomic forest 31930 31930 183 11300

Ⅵeconomic forest 30790 30790 169 10740

Ⅰpasture 20000 1070 26 6250

The total area of building timber forest, soil and water conservation forest, water conservation

forest, firewood forest on the stand site Ⅶ is less than the total area of the stand site Ⅶ:

X 17 +X 18 +X 19 +X 20 ≤5034

The total area of building timber forest, soil and water conservation forest, water conservation

forest, firewood forest on the stand site Ⅷ is less than the total area of the stand site Ⅷ:

X 21 +X 22 +X 23 +X 24 ≤611

The area of building economic forest on the stand site Ⅱ is less than the total area of the stand

site Ⅱ:

X 25 ≤432

The area of building economic forest on the stand site Ⅳ is less than the total area of the stand

site Ⅳ:

X 26 ≤545

The area of building economic forest on the stand site Ⅵ is less than the total area of the stand

site Ⅵ:

X 27 ≤235

83

The area of planting pasture on the stand site Ⅰ is less than the total area of the stand site Ⅰ:

X 28 ≤794

The total area of every measure use land is less than the total area of the whole study area:

X 1 + X 2 +X 3 +X 4 +X 5 +X 6 +X 7 +X 8 +X 9 +X 10 +X 11 +X 12 +X 13 +X 14 +X 15 +X 16 +X 17 +X 18

+X 19 +X 20 +X 21 +X 22 +X 23 +X 24 +X 25 +X 26 +X 27 +X 28 ≤28136.22

Food constraint:

1050X 1 +900X 3 +375X 5 +450X 6 +135X 7 ≥102500000

Edible oil constraint:

900X 4 ≥2050000

Fuel wood constraint:

2600X 12 +2400X 16 +2000X 20 +2300X 24 ≥10250000

Labor constraint:

480X 1 + 325X 2 +375X 3 +150X 4 +150X 5 +225X 6 +75X 7 +3X 8 +3X 9 +21X 10 +21X 11 +57X 12

+26X 13 +26X 14 +26X 15 +73X 16 +21X 17 +21X 18 +21X 19 +64X 20 +26X 21 +26X 22 +26X 23 +

92X 24 +168X 25 +183X 26 +169X 27 ≤21360000

Forestry labor constraint:

3X 8 +3X 9 +21X 10 +21X 11 +57X 12 +26X 13 +26X 14 +26X 15 +73X 16 +21X 17 +21X 18 +21X 19 +

64X 20 +26X 21 +26X 22 +26X 23 +92X 24 +168X 25 +183X 26 +169X 27 ≤6408000

The constraint of the largest mountain forestation area:

X 10 +X 11 +X 12 +X 13 +X 14 +X 15 +X 16 +X 17 +X 18 +X 19 +X 20 +X 21 +X 22 +X 23 +X 24 +X 25 +

X 26 +X 27 ≤13060

The constraint of shelterbelts area:

X 8 +X 9 ≤1379.2

The constraint of mountain forest coverage:

X 10 +X 11 +X 12 +X 13 +X 14 +X 15 +X 16 +X 17 +X 18 +X 19 +X 20 +X 21 +X 22 +X 23 +X 24 +X 25 +

X 26 +X 27 ≥4156.2

The constraint of fruit demand:

45000X 2 +35390X 25 +31930X 26 +30790X 27 ≥2050000

The constraint of water conservation forest area:

X 11 +X 15 +X 19 +X 23 ≥636

3.3 Objective functions

Maximum net income is selected as the objective functions of economics indicators [4] , the formula

is:

Max f 1 (x) =3150X 1 +45000X 2 +2700X 3 +900X 4 +1500X 5 +1350X 6 +1350X 7 +600X 8 +450X 9

+ 2420X 12 + 3710X 13 + 3710X 16 + 3070X 17 + 3070X 20 + 3610X 21 + 3610X 24 + 35390X 25 +

31930X 26 +30790X 27 +1070X 28

Minimum amount of soil erosion is selected as the objective functions of ecological indicators [4] ,

the formula is:

Min f 2 (x) =1840X 1 +1840X 2 + 7370X 3 + 7980X 4 + 7370X 5 + 7370X 6 + 8600X 7 +1840X 8 +

1840X 9 +5420X 10 +5420X 11 +7590X 12 +5490X 13 +3430X 14 +3430X 15 +4800X 16 +6620X 17 +

4140X 18 +4140X 19 +5800X 20 +5800X 21 +3630X 22 +3630X 23 +5080X 24 +10450X 25 +11300X 26

+10740X 27 +6250X 28

Taking the objective function of economic indicators and the objective function of ecological

indicators as the same weights, based on the above objective function and constraints, using the

DPS software [4] solution to obtained the optimal solution of 2012 as follows:

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X 1 =3993.36 ; X 2 =490.2 ; X 3 =6729.97 ; X 4 =0 ; X 5 =0 ; X 6 =0 ; X 7 =0 ; X 8 =44.01 ;

X 9 =106.33;X 10 =0;X 11 =281.82;X 12 =0;X 13 =0;X 14 =0;X 15 =0;X 16 =791;X 17 =0;X 18 =0;

X 19 =354.18;X 20 =4679.82;X 21 =0;X 22 =0;X 23 =0;X 24 =611;X 25 =432;X 26 =545;X 27 =235;

X 28 =0 ;f 1 =112316607.28;f 2 =108360464.72

Based on the optimal solution, optimize the structure of land use in the study area is showed in

table 4.

Land type

Total

Table 4. Optimize the structure of land use in the study area

Agricultural land Forestry land Pastoral land

Area/hm 2 Proportion/% Area /hm 2 Proportion /% Area /hm 2 Proportion /%

Irrigated land 4527.57 3993.36 14.19 534.21 1.90 0 0

Dry land 9754.65 6729.97 23.92 3024.68 10.75 0 0

Mountain land 13854.00 0 0 13854.00 49.24 0 0

4. Conclusion and discussion

Comparing Table 1 and Table 4 can be seen, ratio for Agriculture, forestry, animal husbandry land

should be adjusted form 7.54:1.10:1.36 to 3.81:6.19:0. The proportion of forest land increased by

4.63 times, the proportion of agricultural land decreased by 49.47%, animal husbandry slope should

be adjusted to zero. The entire region should be adjusted form dominate by agricultural land to

dominate by forestry land. This is consistent with the regional ecological environment is fragile,

need to increase the forest to improve the environmental requirements. Animal husbandry slope be

adjusted to zero, this shows that ecological environment in the mountain areas is fragile not suitable

for the development of animal husbandry. The proportion of forest land types in the structure of

forest land, timber forest land shall be 3.00% to zero; Shelter forest should be adjusted form 56.45%

to 9.18%; Economic forest should be adjusted form 40.55% to 19.86%; Firewood forest should be

adjusted form zero to 70.96%. These show that timber forest is not suitable for development in the

region, and for planting a certain percentage of economic forest. Firewood holds the largest

proportion for it has both a high income, but also has good soil and water conservation effect, and

also the need for the life of the masses.

According to land use present situation and Optimization results, irrigated land and dry land

should be created shelterbelts 44.01 hm2 and 106.33 hm2 respectively; existing irrigated orchards

should be kept. All of area of site type Ⅱ, Ⅳ, Ⅵ are planted economic forest. All of the area of site

type Ⅴ, Ⅷ and 92.96% site type Ⅶ should be planted firewood forest. 5.21% site type Ⅲ and

7.04% site type Ⅶ should be planted water conservation forest. All of the area of site typeⅠand

94.79% site type Ⅲ should be kept the current status, after the new need to be used.

References

[1] Hao Zhang, Liting Zhang, Shaohang Song, etc., Creation of mathematical model of synthesis

coordination in land using and planning, Journal of Zhejiang University of Technology, vol. 28,

no.3, pp. 267-271, 2000.

[2] Huaipu Li, Small Watershed Management Theory and Methods, China Water Power Press,

Beijing, 1989.

[3] Forestry Research Institute of Chinese Academy of Forestry, Evaluation of Suitable Tree in

Taihang Mountains, China Forestry Publishing House, Beijing, 1993.

[4] Qiyi Tang and Mingguang Feng, DPS Data Processing System, Science Press, Beijing: 2007.

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