DYNAMIC CHANGE OF LAND USE STRUCTURE IN HAIKOU BY REMOTE SENSING AND GIS *

Transcription

1 DYNMIC CHNGE OF LND USE STRUCTURE IN HIKOU BY REMOTE SENSING ND GIS * Tan Guangjn 1 Lu Jyuan 2 Zhang Zengxang 1 1.Renewable Resource and Ecologcal Envronment Department.Insttute of Remote Sensng pplcaton, Chnese cademy of Scences. 2. Insttute of Geographcacl Scences and Natural Resources Research,CS. Datun Road, Chaoyang Dstrct, Bejng,.R. Chna. ost Code: ost Box:9718. Tel: E-mal address:tanguangjn@sna.com. KEY WORDS: Hakou; converson matrx;fractal dmenson;drvng forces;remote sensng BSTRCT: By nterpretatng TM magery n 1986,1996 and 2000, the land use structure change n Hakou cty was gotten.the cultvated land? water? unused land and forest was converted nto the urban? rural settlement and constructon land.the land use source and destnaton was analyzed by converson matrx.the natural landscape such as forest and water was dsturbed by the human actvtes and the fractal dmenson decreased.the fractal dmenson of the cultvated land decreased wth the acreage decreasng.the urban land concentrated wth the extenson and the decrease of the patches.the rural settlement and constructon dspersed and ts complexty ncreased.the general trend n Hakou cty was the deepenng and the urban? rural setttlement land encroached the natural land. Urbanzaton s perhaps one of the most mportant human actvtes that creats enormous mpacts on the envronment at the local, regonal and global scales(turner et al.,1990). The urbanzaton process s the urban sprawl and the converson of the rural area nto ctes. In Chna owng to the lmt of the regstered permanent resdence and the employment opportuntes, the mmgraton from the rural resdence to the ctes s fewer than that of the developed countres. Wth the buldng of the provnce and the mplementaton of the favorable polces n 1988, a great amount of captal from abroad and other provnces was nvested n Hakou. The real estates development stmulated the urban sprawl as the captal and poltcal?economc?cultural and transportaton center of Hanan provnce. The paper studed the land use structure change durng the rapd urbanzaton process. 1 STUDY RE Hakou s located n lattude 19 57'04?~ 20 05'11? north and longtude '18?~ '05? east. It s n the north of Hanan sland and border to the Qongzhou strat. The clmate s tropcal monsoon wth the annual precptaton of 1639 mm and average temperature 23.8 C. The man morphology of the terran s step and hgh n south, low n north(hsbc,1998). s the captal and the poltcal? economc? cultural and transportaton center of Hanan provnce, the buldng-up area sprawled up wth the rapd economc development after the mplementaton of the reformaton and open polcy n Its GN(Gross natonal product) was Yuan n 1986 and Yuan n 1996 and the growth rate was 20% per year. Durng ths perod the populaton ncreased from to whose growth rate was 4.8 % per year. The rural populaton ncreased from to and the growth rate was 0.72% per year far lower than 5.99%, that of the urban populaton. t the same tme the urbanzaton level ncreased from 72.59% to 83.03%(HSBC,1996,1998).Therefore the rapd extenson of the bult-up area nduced the land use structure change. * Foundaton roject:innovaton project of Chnese academy of scences(kzcx1-y-02)? Innovaton project of nsttute of remote sensng applcaton,cs (CX000009).

2 2 STUDY METHOD 2.1 Data Source The spatal resoluton of TM magery was m and three perods n ? and were adopted and the weather was cloud-free. The magery of 1996 was geo-rectfed based on 1:100,000 DEM and nterpretated usng the software MGE. The land use change map was gotten by nterpretng TM of 1986 and 2000 grounded on the vector map of If the land use was not changed, the label was same;f changed, the label was altered. For example, t was labeled as f the cultvated land was converted nto cty. RC/INFO was appled to process the land use map. The land use type was dvded nto cultvated? forest? grass? water? urban? rural? constructon and unused accordng to the natonal standard. 2.2 Study Method In order to study the land use structure change n the urban area, the land use converson matrx was used to analyze the source and destnaton of the land. seres of the ndcators were chosen. (1) Basc statstc ndcators was the total area of the land type ; type ; n was the number of the patches. was the percentage of the land (2) Fragmentaton ndex a was the mean area of the land type. The fragmentaton was the fragmented degree of the landscape. The bgger a was, the more fragmented the land type was. The equaton was as follows: a = (1) n (3) Fractal Dmenson The fractal geometry was appled wdely n the landscape structure analyss(. eralta, Mather,2000). The fractal dmenson D descrbed the fractal relatonshp between the permeter and the area of the landscape.e. the complexty of the landscape. If the boundary of the landscape was rough, the fractal dmenson would be near 2;f smooth, t would be 1. Therefore t was between 1 and 2. The fractal dmenson of all landscape was calculated by the regresson analyss. The bgger the fractal dmenson was, the more complex the patch was; the smaller, the less complex the patch was. It appeared n the ecologcal studes and was defned as follows: = 0.5D (2) Where D was the fractal dmenson. was the permeter of the patches and was the area of the patches of land n the study area. Turned nto the log as follows: ln() = ln(c) D ln() + e (3) (4) Dversty ndex The dversty was the abundance and the complexty of the land components(chen Ldng,1996,2001,Su Danel Z,2001). The dversty was expressed by the Shnnon equaton as follows: H n = = 1 log ( ) (4) Where H was the landscape dversty ndex; the land type. The hgherh was, the dversty of the landscape was. 3 RESULT ND NLYSIS s the percentage of the landscape ; n s the number of 3.1 The land use change The concluson could be drawn that the land use change n Hakou cty was rapd from Table 1. From 1986 to 1996

3 the cultvated land? water and unused land decreased whle the urban? rural settlement and the constructon ste ncreased. From 1996 to 2000 the cultvated and constructon land ncreased whle the forest decreased. The unused land was encroached completely. Durng the perod of 1986~2000 the cultvated land decreased by 37.87% and annual decrease rate was 3.34%. The forest lessened by 8%. The water decreased by 84% and annual decrease rate was 12.4%. The bult -up area ncreased by 211% and the growth rate was 8.43% per year. The rural area ncreased by 94.76% and the growth rate was 4.87% per year. The constructon ncreased by 51.95% and the growth rate was 3% per year. Table 1 The land use structure change n Hakou n 1986, 1996, 2000 /hm 2, % Land Type ~ ~ ~2000 Cultvated Forest Grass Water Urban Rural Constructon Unused Total The Land Use Converson Matrx The converson matrx was gotten to study the land use source and destnaton. The data n column was the land of year and the lne was that n +1 year n Table 2. From 1986 to 1996 the cultvated land was converted manly nto the urban and constructon land. The unused land and forest were converted nto the constructon and rural settlement and cultvated land. Some of the foreshore near the sea was flled and turned nto the urban land. The constructon was manly turned nto the urban land. The unused land was turned nto the forest and cultvated land. Durng the past 15 years the urban land was derved from the cultvated land and the foreshore near the sea; the rural settlements were derved from the forest and constructon land came from the forest and the cultvated land. Table 2 The land-use converson matrx from 1986~2000 n Hakou /hm 2 Year Land type Cultvated Forest Urban Rural Constructon Unused Cultvated Forest Water ~1996 Urban Contructon 59.5 Unused Sea Forest ~2000 Water Unused

4 3.3 The Landscape Characterstcs of the Land Use Change In table 3 the total area of the forest decreased and the number of the patches ncreased, so the mean area of the forest decreased. The number and mean area of the grass patches kept stable. The total area of water decreased and the number of the patches ncreased, so the mean area of the patches decreased. The urban land concentrated wth the conglomeraton of urban patches wth the decrease of the number. The rural settlement area doubled and the mean area of the patches ncreased. The total area of the constructon ncreased and the number ncreased, so the mean area of the constructon ncreased. Therefore the urban? rural settlment and constructon land extended and became bgger. The forest? cultvated land and water were turned nto the urban? constructon land and rural settlement. That D of forest decreased reflected the decrease of the forest complexty. Durng the past years a great amount of the forest land was transted nto the cultvated? urban? rural and constructon land. t the same tme some forest land was bult up by the unused land and the man-made forest boundary was more smooth. Therefor the complexty decreased. D of the cultvated land decreased because some cultvated land was turned nto urban and constructon land. great amount of the forest was transted nto the cultvated land and the complexty decreased. The total area of the water decreased and ts complexty decreased. The fractal dmenson of the urban land decreased wth the agglometraton the patches. But that of the rural settlement and the constructon land ncreased because ther boundares were rougher. The dversty ndex of the landscape was calculated by equaton (4).Durng the perod of 1986~1996, H decreased from to because the unused land was converted nto other land type.durng the perod of 1996~2000, H ncreased to because the extenson of the urban land. Table 3 The landscape characterstcs of the land use change n Hakou cty Year Land type n a D n a D Cultvated Forest Grass Water Urban Rural Constructon Unused THE DRIVING FORCES OF LND USE CHNGE The spatal and temporal change of the land use was dependent of the economc? technologcal? socal and the poltcal factors and appeared as the landscape change.

5 Extenson of the urban land was the man drvng forces of the land use change. Wth the buldng-up of Hanan provnce and the mplementaton of more favorable polces n 1988, the real estates hgh-rsed and a great amount of the admnstraton unts were bult. The nvestment was up-and-down. The annual growth rate of the real estate n 1991~1998 was 156.8%? 168%? 49.7%? -72.8%? 126.2%? -59.6%? -51.6% and 67.9%. The annual growth rate of the constructon area of the commercal real estates was 39.6%? 87.8%? 20.7%? 12%? -18.9%? -26.5%? -13.2%? -8.6%. The weght of the real estate nvestment even took up 50% n 1992 [2]. The urban land ncreased by 192% durng the perod of 1986~2000 and the annual growth rate was 7.95%. The urban growth took up 84.7% of the total land use ncrement and the rapd urban expanson was the man factors. The ncrement of the constructon and rural settlement was the second factor. The ncrement of the constructon took up 9.7% of the total ncrement owng to the constructon of the nternatonal arport. The rural settlement area doubled although the rural populaton ncreased slowly and the average resdental area ncreased from 30 m 2 to 55 m 2 per capta. The ncreasng rural land derved manly from the forest land and threated the ecologcal envronment. The land use had the deepenng trend. The forest and cultvated land was turned nto the constructon and urban land. t the same tme the unused land was turned nto the forest. The forest was converted nto the cultvated land. Wth the rapd urbanzaton and the mmgrants from the outsde, the urban land would ncrease and a great amount of the forest and cultvated land was converted nto the urban land. The bare land was exhausted at present. The ntensve land use should be encouraged to mprove the economc beneft because the blndness of the real estate development had used up a great amount of the cultvated land. References Turner II B.L.,Clark W.C., Kates R.W.,et al,1990.the earth as transformed by human acton:global and regonal changes n the boshpere over the past 300 years[m].cambrdge,cambrdge unversty press wth clark unversty, pp.713. HSBC(Hanan Statstcal Bureau,Chna).Hanan Statstcal nnals 1986~1998[M]. Hakou:Hakou Statstcal ublshng Houses,1986~ eralta, Mather, 2000, n analyss of deforestaton patterns n the extractve reserves of cre, mazona from satellte magery: a landscape ecologcal approach[j]. Internatonal Journal of Remote Sensng, 21(13),pp.2565~2566. Su Danel Z,Zeng Hu, 2001, Modelng the dynamcs of landscape structure n sa s emergng desakota regon [J].Landscape and urban plannng, 53,pp.37~52. Chen Ldng,Fu Boje, 1996, The mpact of human actvtes on the landscape structure n Yellow Rver Delta[J],cta ecologca snca, 1996, 16( 4),pp.337~344. Chen Ldng,2001,Study on land use change n a small typcal catchment n loess hlly area[j],scenta geographca snca, 21(1),pp.47.