Management & Engineering Based on TM Images

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Management & Engineering Based on TM Images
Management & Engineering 06 (2012) 1838-5745
Contents lists available at SEI
Management & Engineering
Journal Homepage: www.seiofbluemountain.com
Dynamic Monitoring of Land Use/Cover in the Qufu City
Based on TM Images
Weihua JIA
College of Geography and Tourism, Qufu Normal University, 273165, P.R.China
Qufu city,
Land use/cover,
Dynamic monitoring,
TM images
Qufu city is the hometown of Confucius. It is located in the southwest of Shandong Province.
And its area is 895.93 square kilometers. The annual equal temperature is 13.3 degree and
annual amount of precipitation is 666.3 mm. In this paper, the land use/cover change (LUCC)
in the Qufu City is researched using two sets of Landsat images acquired in 1987 and 2005.
The land use information in the study area is derived with the supervised classification, and
the causes resulting in LUCC are analyzed. The research shows that the areas of urban and
rural building land expand by reducing the area of farmland and the areas of the woodland and
water are sharply increased. The economy development and the city development are the
macroscopically driving forces of the land use/cover change. The sharp population growth and
rapid development of primary industry are the direct reasons that reduce the area of farmland.
While the increasing water area is greatly related to the building of Ni Mountain Reservoir.
1 Introduction
With the research and development of global change, land development and the coming land cover change are considered as
important parts of global environmental change. International Geosphere - Biosphere Programme (IGBP) and International Human
Dimensions Programme (IHDP) jointly proposed “Land Use and Cover Change” (LUCC) research projects in 1955, making land use
changes the frontier and hot issues of the current global change research[4]. In China as the huge population base, relatively limited
farmland resources, and the urgent development of economy and improvement of living standards and other special situation.
Remote sensing image has been widely used in the extraction of land cover information. This article analyzes the basic characteristics
and disciplines of the land use/cover change in Qufu city based on Landsat TM image.
2 Research Area and the Data Sources
2.1 General situation of research area
Corresponding author.
E-mail address: [email protected]
English edition copyright © ST. PLUM-BLOSSOM PRESS PTY LTD
DOI: 10. 5503/J. ME. 2012. 06. 007
Located in the southwest of Shandong Province, Qufu city has the latitude ranging from 35°29'N to 34°49'N and longitude from
116°51'E to 117°13'E. It has warm continental monsoon climate which has four distinct seasons and abundant rainfall with the annual
(1965-1990) average temperature of 13.6℃ and the annual precipitation 666.3mm. 135km south of Jinan, 45km southwest from
Jining, the east next to Sishui and north to Ningyang while the west to Yanzhou and south to Zoucheng, Qufu has an total area of
895.93 square kilometers with the largest vertical north-south distance of 35.8 kilometers and east-west distance of 5km. Meanwhile,
as one of 24 historical cultural cities in China, Qufu is the homeland of Confucius, the famous ancient educator and thinker. Being
famous in the world for its rich underground cultural relics and magnificent buildings on the ground, Qufu is a tourist attraction
aspired by Chinese and foreign visitors [6].
2.2 Data sources
The data sources used in this study include: Landsat TM images of Jining accessed on September 19th, 1987 and May 31st, 2005, the
administrative vector map of Jining, the recent land use map of Qufu and the related statistical yearbooks and social economic
statistic data.
3 Research Method and Data Process
3.1 Land categorized system
First of all, the approximate land use types are defined by the unsupervised classification of the remote sensing images of Qufu in
1987 and 2005. Then, 5 categories come out considering the classification standards in the National “Land Use Survey Technical
Specification” as well as the actual situation of the area. They are residential and industrial land, woodland, farmland, water and
unused land.
3.2 Selection of research method
Currently, measurements of land use/cover change based on satellite remote sensing are mainly post-classification comparison and
object spectrum direct comparison. Due to some factors such as atmospheric conditions, solar altitude angle, soil moisture and
phenology in different times have direct impacts on spectral images, spectrum direct comparison must be strictly spectral
standardized, yet standardization is in immaturity. Post-classification comparison does not require rigorous radiation normalization,
but high classify precision of single scene image. Because the accumulation of classification errors in different times will affect the
ultimate accuracy of the information of land use/cover changes, it is critical to succeed of this method that classification accuracy of
single scene image be improved [1]. Based on the dynamic monitoring experiment in small area, taking the long time span of the
remote sensing data into account, this article apply the post-classification comparison to measure the land use/cover change. It firstly
extracts land use information in 1987 and 2005 using supervised classification, then on this basis it calculates land use transition
matrix and then analyzes land use change. The study proceeds in accordance with the remote sensing image processing, land use
information extraction, analysis of land use change.
3.3 Data processing
3.3.1 Image registration
To begin with, change the map projection of TM image of Jining in 2005 into WGS84, then use quadratic polynomials and bilinear
interpolation to do the geometric correction of the images. By means of reselecting 15 ground control points to be tested, the error is
within one pixel and the re-sampling of image output is 30 meters. Then it does matching processing of the TM image in 1987
according to the corrected image in 2005, unifying projection and pixel size. The RMS error is less than one pixel after reselecting
the points, which meets the requirements of further analysis. The image of Qufu city is cut based on the well-geometric correction
image using the administrative vector map of Jining by software ERDAS.
3.3.2 Image enhancement processing
Due to the stability of the satellites, atmospheric conditions, solar altitude angle, soil moisture and phenology, all of which have
direct impacts on spectral images,directly extracting information from the remote sensing images is difficult. Therefore, it is
necessary to do image enhancement processing in order to extract information easily. Take color composite by selecting the best band
combinations for example, the result of color composite of band 5,band 3 and band 1 standing for RGB is better in the test.
3.3.3 Classification of RS image and extraction of land use information
Unsupervised classification is a natural classification depending on the distribution of spectrum characteristics of remote sensing
images. The classification results only distinct different categories, not knowing the certain types of the property, which is achieved
by analyzing the various spectral response curve afterwards. Compared with unsupervised classification, supervised classification has
some advantages, but its results often have mistakes, leading to low classification accuracy. Therefore, measures should be taken
before classification in order to improve the accuracy of supervised classification when extracting land use information. Measures
taken before image classification mainly aimed at training area, because the supervised classification accuracy is closely related to
the choice of training areas [3]. Therefore, classification module should be defined before supervised classification combined with
spectral information of remote sensing images. Initial definition of the classification module may be very different from the actual
situation, which requires redefinition of the module until it is consistent with the actual situation of the land use. Small polygons will
inevitably appear in the supervised classification when using this classification module. The analysis function of GIS such as Clump,
Sieve, and Eliminate in ERDAS can complete the processing of these small polygons. The ultimate result after processing is shown
in Figure 1.
Fig.1 Distribution of land use types in the Qufu region (left: 1987; right: 2005)
3.3.4 Accuracy analysis
With reference to the surface data of the same period, it calculates the classification confusion matrix and kappa coefficients by
selecting randomly a number of samples of the area. Kappa coefficients through accuracy test on the final land use results map are
0.75 (in 1987) and 0.78 (in 2005). This shows that the results of both single scene images are ideal, so it can be further analyzed to
extract dynamic information of land use/cover change.
3.3.5 Analysis of LUCC characteristics
On the basis of information of land-use types in 1987 and 2005, this study obtains the land-use transfer matrix (Table 1) in the study
area during this period, using the method of algebraic operation of the map.
Tab.1 Matrix of the change of land use in the Qufu region during the period from 1987 to 2005 /ha
and industrial
Unused land
As can be seen from Table 1, the land use is mainly on the great increases of structural adjustment, while a great decrease of farmland
during 1987—2005 in Qufu, in which woodland increased 6067.58ha accounts for 22.8% of the total area of woodland in 1987, and
water area which increased 1576.71ha is 119.1% times of waters in 1987, which is directly related to the construction of Ni Mountain
Reservoir. Farmland which decreased 5658.17ha accounts for 17% of the area of farmland in 1987. The decreasing of farmland ca n
not be ignored in the process of local development. Therefore, we should protect the limited farmland resources strengthening the
construction of basic farmland to achieve regional sustainable development. Residential and industrial land which increased
1052.37ha accounts for 11% of the total area in 1987. Combined with the land use in 1987 and 2005 and land-use transfer matrix, it
is easily drawn that the increase of residential and industrial land was mainly achieved through the occupation of a lot of farmland. A
total of 2530.08ha farmland changes into residential and industrial land, representing 46.4% of total conversion of residential and
industrial land. Area of unused land reduces 3038.49ha, showing that unused land is well developed.
From the mutual transformation of different land use patterns, farmland mainly changes into woodland and urban construction land,
with the conversion area of 10841.9ha and 2530.08ha respectively. Farmland and woodland transform mutually in spatial land use,
about 7341.84ha of woodland being developed into farmland and 10841.9ha farmland being converted to woodland. Unused land is
developed primarily for the cultivated farmland and woodland, 2640.42ha and 3951.54ha respectively. Part of the waters is the
occupied with the residential and industrial land and woodland. The main ways of increase of farmland in this period are developing
the unused land and occupying a large number of woodland. Increase of woodland is mainly returning farmland to forest as well as
developing unused land. Residential and industrial land enlarges its area mainly through occupation of a large number of farmland
and woodland. Besides 4541.31ha land changes into unused land, showing a certain degree of degradation.
4 Analysis of Driving Forces
4.1 Economy development and urbanization
Since the reform and opening-up, China has taken economic construction as the center of the basic economic policy, making great
changes on economic development strategies and economic system. With the rapid development of China's economy, prospects for
national economic development are good. Especially the development of township enterprises becomes the main pillar of economic
development, which promotes the increase of residential and industrial land by occupying large amount of farmland. There is
2530.08ha farmland in total converting to residential and industrial land. Qufu is a small city, where the contradiction between urban
expansion and farmland protection is not very prominent but has been increasing. Therefore, in future urban development requires
rational planning of urban spatial distribution to avoid occupation of farmland and develop unused land actively.
4.2 Population and economy development
As the population growth increases the need of living area, large farmland surrounding the city is converted into urban construction
land, leading the decrease of farmland area, which is represented obviously in the land use map of 1987 and 2005. Population growth
demands for more farmland, which is lost due to urban expansion. Then more farmland is forced to be obtained by deforestation and
in other ways, but deforestation can cause soil erosion and a series of environmental problems. Therefore, we should control the
population, strengthen the protection of basic farmland, carry out afforestation and soil conservation, protect the local environment
and take the path of sustainable development.
4.3 Government policy and social activities
Land use/land cover change is a result of common impact of natural and human factors. In a very long period of time, changes of
natural conditions such as changes of temperature, precipitation, and biological species and quantities will impact land use/land cover
greatly, which is not obvious in a short period of time because changes of natural conditions isn’t significant. Thus, socio-economic
activities become the main factors affecting land use/land cover change [5]. It is especially true for such a small city as Qufu that the
land use policy and some major socio-economic activities will affect land use changes. The implement of reasonable urban planning
and soil conservation policy will mollify the contradictions of economic development and farmland protection, making the land use
legal and orderly. The construction of some projects will also affect the distribution of land, for the doubled area of water in 2005
compared with it was in 1987 is directly related to the construction of Ni Mountain Reservoir. Therefore, this area should be
strengthened in the research of land use.
5 Conclusion and Discussion
(1) Land use/cover change during the 18 years in Qufu shows that urban land extended by occupying a total area of 2530.08ha
farmland which accounts for 11% of the total farmland in 1987. A substantial increase in woodland mainly comes from the
occupation of farmland while the rest comes from unused land. The increase in the area of water itself is not large, but accounts for
119.1% of the water in 1987, primarily because of the construction of Ni Mountain Reservoir. Changes are very significant in
non-urban land use structure, especially between the farmland and woodland, with 10842.9ha farmland converting into woodland,
while 7341.84ha woodland into farmland.
(2) Spatial pattern of land use: urban land concentrates in urban area of Qufu city either in 1987 or 2005, although little increase
appears in other regions. Woodland as well as unused land mainly concentrates in the mountain areas in northern and southeastern.
Farmland mainly concentrates in the flat plains area with good irrigation conditions, where Si River, Yihe River and other rivers flow
(3) The land use/cover change in Qufu results from combined effect of different levels of driving forces. Human activity changes the
overall pattern of land use, while policy guidance is the macro factor affecting land use change. Population growth and development
of primary industry are the direct driving forces of the decreases of the farmland, and traffic conditions determine directly the scale
and direction of urban development.
Land use change is a very complicated process which is influenced by a lot of natural and socio-economic factors interacting with
each other. As the temporal-spatial scale changes, conversion and succession between the driving factors and background may arise.
Therefore, the research of the land-use change and its driving forces is a complex and difficult task, with the occurrence mechanism
of land use change to be further explored.
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