A GIS-Based Approach for Estimating Land Use

Related Carbon Emissions —A case study in Henan Province

Mei Zhang1,2

, Junzhong Tan1,2

, Xianjin Huang1,2

*, Li Lai3, Xiaowei Chuai

1

1School of Geographic & Oceanographic Sciences, Nanjing University, Nanjing, China

2School of Urban and Resources Sciences, Jinling College of Nanjing University, Nanjing, China

3Jiangsu Information Center, Nanjing, China

*Corresponding author, e-mail: hxj369@nju.edu.cn`

Abstract—Due to the important role land use behaviors play in

carbon emissions, research on land use related carbon emissions

has gradually become an academic focus in recent years.

However, few studies have been done on the comprehensive land

use related carbon emissions at the provincial level, including

both carbon emissions from the natural ecosystems caused by

land cover changes and carbon emissions from anthropogenic

sources carried by different land use types. This paper proposed

a GIS based method for estimating comprehensive land use

related carbon emissions. After that, application of this method

was conducted with relevant data of Henan Province. The results

proved this method to be feasible, and it was found that land use

behaviors on urbanized land were responsible for more than 90%

of the total carbon emissions of Henan Province in 2010.

Keywords-carbon emission; land use; Geographic Information

System (GIS); remote sensing

I. INTRODUCTION

Land use behaviors, including deforestation, wetland drainage, agriculture and animal husbandry production, etc, have become the second largest source of greenhouse gas (GHG) emissions, right behind fossil energy combustion emissions, accounting for a third of total anthropogenic emissions [1]. The national strategies for dealing with GHG, which were included in the national long-term science and technology development plan (2006-2020) issued by the State Council, pointed out that carbon emission reduction through adjusting land use patterns should be the national key scientific and technological areas and priority themes, and there should also be important strategic issues. Therefore, research on land use related carbon emissions has gradually become an academic focus.

In recent years, land use related carbon emissions have been studied by many scholars from different aspects. Li et. Al. (2008), Du et. Al. (2010), and Zhou et. Al. (2012) all studied the effects of different land use patterns on carbon emissions [2-4]. Yang (2010), Qu et. Al. (2011), and Xiao et. Al. (2012) all studied the impact of land use change on carbon emissions [5-7]. Zhao et. Al. (2010), Zhu et. Al. (2010), and You et. Al. (2010) all explored low-carbon land use patterns [8-10]. Other scholars such as Houghton also made contributions to this field [11].

However, few have been done on the comprehensive land use related carbon emissions at provincial level, including both carbon emissions from the natural ecosystems caused by land cover changes and carbon emissions from anthropogenic sources carried by different land use types. Using vegetation carbon data, soil organic carbon data, socio-economic data and land use data of the 1980s, 1995 and 2010 in Henan Province, this paper made a preliminary study of comprehensive land use related carbon emissions.

II. THE PROPOSED METHOD

As mentioned in Section 1, comprehensive land use related carbon emissions should include both that from natural ecosystems and that from anthropogenic sources carried by different land use types, as indicated in Fig. 1.

Vegetation

carbon density

map

Corresponding

land use map

Zonal Statistics

Vegetation

carbon densities

of different land

use types

Soil organic

carbon density

map

Corresponding

land use map

Soil organic

carbon densities

of different land

use types

Zonal Statistics

Land use maps of

reference year and

research year

Land use

transition matrix

Combine

Carbon

emissions of

natural

ecosystems

caused by

land cover

changes

Carbon emissions of

Energy Sector

Carbon emissions of

Industry Sector

Carbon emissions of

Agriculture and

Forestry Sector

Carbon emissions of

Garbage Sector

Carbon

emissions from

anthropogenic

sources carried

by different land

use types

Comprehensive

land use related

carbon

emissions

Building

corresponding

relationship

with land use

types

Figure 1. Calculation flow chart of land use related carbon emissions

Supported by the grant project of China Clean Development Mechanism Fund (No. 1214073).

Carbon emissions from the natural ecosystems caused by land cover changes can be calculated as indicated in Fig. 1. With vegetation carbon density map and the land use map of corresponding year, vegetation carbon densities of different land use types can be calculated using Zonal Statistics function of ArcGISMap. Similar methods can be used to calculate soil organic carbon densities of different land use types. Based on that, the difference between comprehensive carbon densities (the sum of vegetation carbon and soil organic carbon densities) of the former land use type and the later land use type in land cover change can be calculated. It should be noted that the carbon density stabilizing cycle must be considered, which is widely accepted as 20 years. Therefore, to get the annual value, the results should be divided by the carbon density stabilizing cycle. On the other hand, land use transition matrix can be calculated with land use maps in reference year and research year using Combine command in Raster Calculator of ArcGIS software. So, annual carbon emission from each land use conversion category can be calculated by multiplying the land use change area and the annual comprehensive carbon density change value.

Carbon emissions from anthropogenic sources carried by different land use types can be calculated as follows. First, carbon emission from each item in Energy Sector can be calculated using related socio-economic data and carbon emission factors. Then, carbon emissions of Industry Sector, Agriculture and Forestry Sector and Garbage Sector can be calculated the same way. After that, corresponding relationships can be built between items of the four sectors and land use types, and carbon emissions from anthropogenic sources carried by different land use types can be estimated using the corresponding relationships.

By combining both parts, comprehensive land use related carbon emissions can be estimated.

III. APPLICATION

A. Study Area

The study area of this paper is Henan Province, as indicated in Fig. 2, which is located in the center of China and by the middle and lower reaches of the Yellow River. Henan is one of the cradles of Chinese civilization and the Chinese nation. She is China's major economic province, whose total GDP ranked fifth in 2011.

Figure 2. Location of study area in China

B. Data Preparation

The land use maps of Henan Province in the 1980s, 1995 and 2010 were extracted using ArcGIS software with the administrative zoning map of Henan Province from the national land use maps supplied by the Institute of Remote Sensing Applications, Chinese Academy of Sciences. The vegetation carbon density map was formed with the vegetation type map of Henan and carbon densities of different vegetation types collected by Lai [1]. The vegetation type map of Henan was extracted from the national vegetation type map compiled in the 1980s by Hou [12]. The soil organic carbon density map of Henan Province was formed with the soil type map of Henan and soil organic carbon data provided by the National Soil Survey Office. The soil type map of Henan was extracted from the national soil type map published in 1995 by the National Soil Survey office. The distribution maps of vegetation carbon and soil organic carbon densities are shown in Fig. 3 and Fig. 4.

Figure 3. Vegetation carbon densities of Henan Province (t/ha)

The social-economic of Henan Province in 2010 was collected yearbooks such as the China Energy Statistical Yearbook and the China Statistical Yearbook. The carbon

emission factors were generated by Lai by studying factors provide by IPCC and relevant researches [1].

C. Applications of the Proposed Method

Using procedures mentioned in Section 2, vegetation carbon densities of different land use types were calculated

Figure 4. Soil organic carbon densities of Henan Province (t/ha)

using the land use map of Henan in the 1980s and the vegetation carbon density map, and soil organic carbon densities of different land use types were calculated using the land use map of Henan in 1995 and the soil organic carbon density map. After that, with the land use maps of Henan Province in the 1980s and 2010, annual carbon emissions of natural ecosystems caused by land cover changes from 1980 to 2010 were calculated, and the results are shown in Table 1. Because there was not sufficient data on water area, this land use type was not studied. It was found that the greatest carbon emission occurred during the transfer from cultivated land to urbanized land, which was 453.90 Gg·a-1 (1 Gg·a-1 means 109g per year).

TABLE I. ANNUAL CARBON EMISSIONS OF NATURAL ECOSYSTEMS

CAUSED BY LAND COVER CHANGES FROM 1980 TO 2010

To

From

Annual Carbon Emissions (Gg·a-1)

CLa WL

b GL

c UrL

d UnL

e

CL -158.63 47.79 453.90 0.32

WL 72.22 35.26 10.07 0

GL -89.09 -290.64 1.03 0

UrL -327.62 -15.07 -0.11 0.04

UnL -9.20 -4.13 -0.08 -0.11

a. CL stands for cultivated land; b. WL stands for woodland; c. GL stands for grassland.

d. UrL stands for urbanized land; e. UnL stands for unused Land.

After that, Carbon emissions from anthropogenic sources carried by different land use types were calculated using related socio-economic data of Henan in 2010 and carbon emission factors. According to the results, the amount of carbon emissions from Energy Sector, Industry Sector, Agriculture and Forestry Sector and Garbage Sector in 2010 were 134.88Tg, 1.59Tg, 0.02Tg and 0.01Tg, respectively (1Tg =10

12g).

Next, the annual carbon emissions of natural ecosystems caused by land cover changes were summed up by the “To”

land use types. On the other hand, corresponding relationships were built between anthropogenic sources and land use types. Finally, comprehensive land use related carbon emissions were estimated, and the results are shown in Table 2.

TABLE II. COMPREHENSIVE LAND USE RELATED CARBON EMISSIONS OF

HENAN PROVINCE IN 2010

Annual Carbon Emissions (Gg·a-1)

CLa WL

b GL

c UrL

d UnL

e

4647.35 -468.47 100.79 131944.77 0.36

a. CL stands for cultivated land; b. WL stands for woodland; c. GL stands for grassland.

d. UrL stands for urbanized land; e. UnL stands for unused Land.

It is clear that urbanized land made the greatest contribution to carbon emission, followed by cultivated land, while woodland exhibits carbon sink functions.

IV. CONCLUSIONS

In this paper, we proposed a GIS-based approach for estimating comprehensive land use related carbon emissions. After that, using the land use maps of Henan Province in the 1980s, 1995 and 2010, the distribution maps of vegetation carbon and soil organic carbon densities, social-economic data and carbon emission factors, the comprehensive land use related carbon emissions of Henan Province in 2010 was estimated. The proposed method proved to be feasible. According to the results, the total carbon emission of Henan Province in 2010 was 136.22Tg, among which urbanized land was responsible for 96.86% of the total amount. However, the approach has several deficiencies and should be improved in the future. For example, this approach mainly focuses on land cover changes when estimating carbon emissions from natural ecosystems, but there are situations when land use type remains the same while land use pattern changes. For another example, variations of vegetation carbon and soil organic carbon densities were not taken into consideration. Such aspects should be improved in the future researches.

REFERENCES

[1] L. Lai, “Carbon emission effect of land use in China,” Ph.D. dissertation, Nanjing: Nanjing University, 2009.

[2] Y. Li, X.J. Huang, F. Zhen, “Effects of land use patterns on carbon emission in Jiangsu Province,” Transactions of the CSAE, vol. 24 (supp.2), 2008, pp. 102-107.

[3] G.Y. Du, “Research on Influences of Construction Land on Carbon Emission,” China Land Science, vol. 24(5), 2010, pp. 32-36.

[4] T.T. Zhou, C.M. Mao, “Research on the Relation between Land Use and Carbon Emissions in China,” Journal of Anhui Agri. Sci., vol. 40(2), 2012, pp. 1175-1177, 1242.

[5] Q.Y. Yang, “Land use changes and the carbon cycling,” China Land Science, vol. 24(10), 2010, pp. 7-12.

[6] F.T. Qu, N. Lu, S.Y. Feng, “Effects of Land Use Change on Carbon Emissions,” China Population, Resources and Environment, vol. 21(10), 2011, pp.76-83.

[7] H.Y. Xiao, X.Z. Yuan, B. Li, W.T. Yan, “The effects of land use changes on carbon emission C: take Chongqing as an example,” Journal of Chongqing Normal University (Natural Science), vol. 29(1), 2012, pp.38-42.

[8] R.Q. Zhao, Y. Liu, S.L. Hao, M.L. Ding, “Research on the low-carbon land use pattern, ” Research of Soil and Water Conservation, vol. 17(5), 2010, pp.190-193.

[9] D.L. Zhu, R.R. Lin, “Research on the low-carbon economy and the changing of land use pattern,” China Land Science, vol. 24(10), 2010, pp. 3-6.

[10] H.Y. You, C.F Wu, “Carbon Emission Efficiency and Low Carbon Optim ization of Land Use: Based on the Perspective of Energy Consumption,” Journal of Natural Resources, vol. 25(11), 2010, pp. 1875- 1886.

[11] R.A. Houghton, “Tropical deforestation and atmospheric carbon dioxide,” Climate Change, vol. 19, 1991, pp.99-118.

[12] X.Y. Hou, “Vegetation Atlas of China,” Beijing: China Map Press, 1982.