A study on landscape mosaic structure in urban-rural area in northwest China with RS and GIS -- A case study of Xigu region in Lanzhou city

8/13/2019 A study on landscape mosaic structure in urban-rural area in northwest China with RS and GIS -- A case study of X

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CHINESE GEO GRAPHICAL SCIENCEVolume I 1, Nu mb er 4, pp. 366 - 376, 2001Science Press, Beijin g, China

A S T U D Y O N L A N D S C A P E M O S A I C S T R U C T U R EIN U R B A N R U R A L A R E A I N N O R T H W E S T

O F C H I N A W I T H R S A N D G I SA Case S tudy of Xigu Dis t r ic t in Lanzhou Ci ty

X U J i a n - h u a 1, L U Ya n 1, A I N a n - s h a n 2, Y U E W e n - z e 31. Department of Geography, East China Norm al University, Shangh ai 200062, P. R. China;

2. Environm ental Science and Engineering Scho ol, Sichuan University, Chengd u 610064, P. R. China;

3. Department of Geography, Lanz hou Universi ty, Lanzh ou 730000, P. R. China)

A B S T R A C T At the study area o f Xigu District in Lanzhou City, using RS & GIS as tools we apply Diversity, Dom i-

nance, Fragm entation, Isolation and so on to study the quantitative, fractal and spatial characters of landscapes struc-

tures in the four sub-regions divided by the morp hological features. U sin g he Fractal The ory to establish the fractal struc-

ture mode ls, we analyze the complex ity and stability of various landscap es distribution wi th fractal dimension value.

The spatial distribution characteristics o f landscape mosa ic structure are also expounded . At the end of the paper we dis-

cuss the relevant problems on the main factors which control and effect on the spatial pattern of landscapes as w ell as on

landscape o ptimization and managem ent.K E Y W O R D S landscape mosaic; spatial structure; fractal; Xigu District in Lanzho u City

C LC n u m b e r : P 9 01 ; Q 1 49 D o c u m e n tode: A Art icle ID: 1002-00 63(200 1)04-036 6-11

1 R E G I O N A L B A C K G R O U N D A ND R E S E A R C H

M E T H O D S

1 . 1 R e g i o n a l B a c k g r o u n d

I n L a n z h o u C i t y, X i g u D i s t ri c t , w h i c h c o v e r s a n

a r e a o f 1 0 3 0 1 9 ' 4 8 - 1 0 3 4 1 ' 0 2 E a n d 3 5 3 8 ' 1 6 -

3 6 1 3 ' 5 7 N , i s l o c a te d a t t h e u p p e r H u a n g h e ( Ye l l o w )

R i v e r a n d m i d d l e p a r t o f G a n s u P r o v i n c e . I t i s a n i n -

d u s t r i a l- a g r i c u l t u ra l , u r b a n - r u r a l c o u n t y le v e l a d m i n i s -

t r a ti v e r e g i o n w i t h a n a r e a o f 3 6 2 . 9 8 k m 2.

T h e H u a n g h e R i v e r , w h i c h g o e s t h r o u g h it f r o m

w e s t t o e a s t , d i v i d e s t h e w h o l e d i s t r i c t i n t o t w o p a r t s .

T h e H u a n g s h u i R i v e r , t h e Z h u a n g l a n g R i v e r a n d t h e

X i a n s h u i R i v e r r e s p e c t i v e l y f l o w i n t o t h e H u a n g h e R i v e r

i n t h e w e s t a n d n o r t h o f t h e r e g i o n . T h e w h o l e g e o -

m o r p h o l o g y o f t h e r e g io n i s t h a t n o r t h i s m u c h l o w e r

t h a n s o u t h , b u t b o t h a r e h i g h e r t h a n t h e m i d d l e v a l l e y

( F i g . 1 ) . A c c o r d i n g t o g e o m o r p h o l o g i c a l c h a r a c t e r s ,

t h e w h o l e d i s t r i c t i s d i v i d e d i n t o f o u r s u b - r e g i o n s . 1 )

T h e r i v e r v a l l e y a r e a w i th a n a l t it u d e o f 1 5 2 8 - 1 6 0 0 m

i s l o c a t e d a t t h e 1 s t a n d 2 n d f l u v i a l t e r r a c e s b y t h e

H u a n g h e R i v e r a n d t h e H u a n g s h u i R i v e r. I t h a s a n

a r e a o f 7 3 8 6 h a , a c c o u n t i n g f o r 1 9. 8 % o f t h e w h o l e

Received date: 2001-09-25

Foundation item: Under the auspices of the N ational Natural Science Foundation of China ( No . 401 710 69) .Biography: XU Jian-hua( 1965 - ), m ale, a native of Gansu province, professor. His research interest includes Geo-com putation and

GIS.


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A S tudy on Landscape Mosaic Structure in Urban-Rural Area in Northwest of Ch ina With RS and GIS

district, and it is also the center of regional economy,

society and culture. 2) The terrace & gentle slope area,

located at the 4th and 5th terraces of two banks of the

Huang he River, with an area of 4401ha, which ac-

counts for 11 .8 of the whole district, is main ly com-

posed of eight terraces with an altitude of 1607 - 1800m

and a slope of less than 10 , namely D ajia terrace,

Zhangjia terrace, Qingshi terrace, Zhama terrace, Li-

ugou terrace, Fanjia terrace, Zhangjia terrace,

Guangjia terrace, etc. 3) The southern mountainous

area is located above the southern terraces, with an al-

t i tude of 1800 - 2621 .4m and an area of 9588ha, ac-

counting for 25 .6 of the whole distr ict . 4) The

northern mountainous area is located above the northern

terraces of the Hu anghe River, with an alt itude of

16 00 - 2064. 6m and an area of 16 001ha, accounting

for 42 .8 of the whole distr ict.

Fig. 1 The d igital elevation mode l of Xigu District

in Lanzhou City

Xigu District is typically continental and semi-arid

clima te and has obvious vertical climate change. Aver-

age daily temperature difference and annual average

temperature are respectively 13.6~C and 8.5 C , ex-

treme high temperature 39.7~C and extreme lower tem-

perature - 23.4 C. And the change rate of rainfall and

distinct spatial discrepancy are much larger. Annual

rainfall gradually decreases from 500ram in the south-

east mountainous area to

mountainous area.

291mm

367

in the northwest

1.2 Data and Research Method

All the data needed include 1) 1:80 00 aerial re-

mote sens ing image data(1 998) , 2) 1 :50 000 TM im-

age data(2 000) , 3) 1 :1 0 000 re l ief map (1998 ) , 4)

other data including climate, hydrology, vegetation,

soil and so on.

The rese arch m ethod consists of six major steps: 1)

use 1: 50 000TM image to interpret and classify the

landscapes , 2) se le c t 1 :80 00 aer ia l remote sens ing

image and 1 :10 000 relief map to make a survey of land

cov er/ lan d use and landscape patches, 3) digitize im-

ages and relief map data( remote sensing image, relief

map, survey data and so on), 4) integrate data into a

GIS system by image calibration, registration and data

processing for building spatial and attribute databases,

5) apply the quanti tat ive methods to the quanti tat ive

characterist ics of the landscape mosaic structure and

fractal theory to fractal characteristics of the distribution

pattern of various landscapes, 6) with spatial analytical

methods of GIS(D ENES H, 1995), study the main fac-

tors which control and influence the spatial pattern of

landscapes. Various methods and techniques used in

this study are briefly described in Fig. 2.

2 LAND SCAPE MOSAIC AND QUANTITATIVE

CHARACTERISTICS

In a region, various landscape patches integrate

systematically into a landscape mosaic (FORMA Net al .

1986), which shows spatial pattern of landscapes and is

the result of the natural factors and human activities.

Some scholars think that the essence of landscape ecol-

ogy is to study the landscape mosaic structure in that

landscapes are diverse mosaic enti t ies(FORMAN,

1995; XIAO, 1991).

2. 1 Landscape Types and Mosaic Map

By TM interpretation we classify the landscapes

into ten kinds of landscapes, which are respectively


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368 XU J ian -hua LU Yan AI Nan-sha h e t a l.

Re lief map (1:10000)] I A c r ia l re m o t e s eo s in g i m a g e : 8 o o o ] I

[ Interpretat ion [

[ ClassiJ} landscap e types ]

[ Land use/co~ er surve~ [

[ Digit izat ion [

Image cal ibrat ion, registrat ion and ~ector/raster exchange

Overlay I

Spatial s tructure of landscape mos aic }

l'iVl image I 1:50000 ) ]

i

Database management

I Quantilati~ e analy ticalmethod

Quanti tat ive characterist icof l andscape mosa ic

[ Fractal mo del [

IFractal characteristicof l andscape mosa ic

Fig. 2 Rese arch methods and techniques

fa rmland , o rcha rd , wood land , s ca t te r ed wood land ,

bare land, water area , urban area , rura l se t t lemen t and

indus t ri a l a r ea f a r f rom se t t lemen t . The spec i a l m ean ing

of each lan dscap e i s l i s ted in Table 1 .

In order to show and an alyze the spat ia l s t ruc ture of

l andscape mosa ic , we made the l andscape mosa ic map

of Xigu Dis t r ic t in Lanzho u Ci ty f rom the spat ia l and

at t r ibute da tabases of GIS, which i s shown in Fig . 3 .

Table 1 Land scape ypes and remarks

Landscap e types Remarks

FarmlandOrchard

GrasslandWoodland

Scattered woodland

Bare land

Water area

Urban area

Rural set t lementIndustr ial area far from sett lement

Covered by crops and vegetationIncluding apple orchard, peach orchard, pear orchard, apricot orchard, etc.

Wasteland, pastureNatural an d artificial woodlands with canopy of trees larger than 30

Woodland with canopy between 10 -3 0 of area and newly-made woodland with no canopy but viable rateno less than 40 of reasonable t ree numbers

Land without vegetation coverage, includ ing bare loess, rock and gravel

Inclu ding river, c reek, alluvial flat and pond

Including satell i te towns and the buil t-up area in the region planned by City PlanningRural residen tial areaIncluding various factories and plants , which are far from sett lement and not in the urban area

2. 2 The Quan t i ta t ive Cha racter is t ics of Lan dscap e

Mosaic

2 . 2 . 1 G enera l quant i ta t ive character is t ics of landscap emosa ic

we can use d ive r s i ty, dominance and f r agmen ta t ion

to com prehens ive ly quan t ify t he l andscape mosa ic

s t ructure .

1 ) Divers i ty, which i s a ge nera l desc r ip t ion of

a b u n d a n c e a n d b a l a n c e o f l a n d s c a p e s T U R N E Ret a l .1991 ; ZHANGet al . 20 00 ) , i s def ined as fol lows:


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A Study on Landscape Mosa ic S t ruc ture in Urban-Rura l A rea in Nor thwes t o f China Wi th RS and GIS 369

N

w E

Legend

F a r m l a n d ~ B a r e l a n dOrcha rd ] [ Water areaG r a s s l a n d ~ U r b a n a r e a

_---~_._-'i~i~_Woodland ~ Rur al se tt le m en t~ Sc a tt er e d ~ Industrial area far

wood land r~'~'~','~ rom settle men t

Fig . 3 L andscape mosa ic ma p of Xigu Dis t r ic t

H = - EP InP (1)i = 1

In formula (1 ), S is the number of landscape types; Pi

is the area pe rcent of landscape type i in the whole

mosaic; H is diversi ty index, which is much larger, the

more abundant landscapes

2) Dominance is an indictor that shows what extent

one or few landscapes dominate in mosaic structure,

and it is defined as follows:S

n = InS + ~ P lnP (2)i = 1

where D represents dominance, which is much larger,

the more highly mosaic structure is dominated by one or

few lands capes ; S and Pi are as same as those in for-

mula (1) .

3) Fragmentation is used to show the number of

patches in one unit area in the mosaic, and i t is defined

a s follows:S

F = ~.~nja (3)k = 1

In formula ( 3) , S is as same as that in formula ( 1 ) ; nk

is the patche s ' numb er of landscape type k; A is the

whole area of al l types of landscapes; F is fragmenta-

t ion, which is much larger, the more patches are in a

unit area.

We use formulas ( 1 ) , (2) and (3) to calculatediversi ty, dominan ce and fragmentation as the following

in Table 2.

Table 2 shows that diversi ty ranks in the four

sub-regions as r iver va lley area(2 . 037 5)> te r race

Table 2 Landscap e d ivers i ty index , dominan ce and f ragmenta t ion in sub- reg ions

Area River valley area Terrace & gentle slope area Southern mountainous area Norhtern mountainous area The whole district

Diversity (H ) 2.0 35 7 1. 8544 1. 3080 1. 2395 1. 827

Dom inanc e(D) 0. 2669 0. 4482 0. 9987 1. 1584 0. 658

Fragm entation (F) 27. 4772 51. 4398 9. 4733 8. 3118 12. 147(pa tehes /km2)


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37

gen t le s lope a rea (1 . 8544) > sou the rn moun ta inous a r ea

(1 . 3080 )> no r the rn moun ta inous a r ea (1 . 2395 ) , bu t

the re is an adve r se r ank in t e rms o f dominance , name lynor the rn moun ta inous a r ea (1 . 1584)> sou the rn moun-

t a inous a r ea (0 .9987)> t e r r ace & gen t l e s lope a rea

( 0 . 4 4 8 2 ) > r iv e r v a l l e y a r e a ( 0 . 2 6 6 9 ) . O b v io u s ly i n

the r iver va l ley area var ious landscapes are d is t r ibuted

equab ly wi thout d is t inc t dom inant landscap e types . But

in t he sou the rn moun ta inous a r ea and no r the rn moun-

t a inous a r ea t hey a re d i s t ri bu ted ex t r eme ly uneven ly and

there are obvious dom inant landscap es . In the nor thern

moun ta inous a r ea , t he dom inan t l andscape i s g ra s s land ,

which comprises of 85 .9 6 of the whole area . In the

sou the rn moun ta inous a r ea , t he dominan t landseapes a r e

g ra s s land and f a rmland , wh ich r e spec t ive ly accoun t fo r

60 .93 and 28 .51 o f t he who le a r ea . And d ive r si ty

and dominance in the ter race & gent le s lope area are

between those in the r iver va l ley area and those in the

sou th and no r the rn moun ta inous a r eas.

Fragmenta t ion represents what extent the land-

scapes are cut by var ious corr idors(cre eks , roads and

etc . ) . The larger f ragmenta t ion , the more s t rongly

landsca pes are cut by corr idors . Obviously the f rag-

men ta t ion o f t e r r a ee & gen t le s lope a rea is t he l a rges t

X U J i a n - h u a L U Ya h A I N a n - s h a h e t a l.

and the pa t ches w i th an a rea o f l km 2 a re a s many a s

above 51. 4398, and the f ragmenta t ion of the r iver va l-

l ey a r ea is much l a rge r, 27 .4 772 pa t ches w i th an a reaof lk m 2. But in the south and n or thern mo unta inous

area the f ragmen ta t ions are smal l , respect ive ly 9 . 4733

and 8 . 3118 patches wi th an are a of lk m 2.

2. 2. 2 Landscap e isolation

Isola t ion shows tha t the d is t r ibut ion of d i fferent

patche s tha t be long to the sam e type of landsc ape in the

landsca pe mosaic . I t i s def ined as the fo l lows(X IAO,

1991) :

1 ni~/AA_~k (4)

where A is the i so la tion of landscap e typek nk and A

are a s s ame a s t hose in fo rm ula ( 3 ) , Ak i s t he a r ea o f

landscape type k .

For the same type landscape , i so la t ion shows tha t

what extent the landscape i s cut and iso la ted by o ther

landsca pes or corr idors . That i s , the larger the i so la t ion

is , the more d ispersedly the patches d is t r ibute .

As for the four sub-regions in th is region, we apply

form ula(4 ) to figure out the i so la tion of var ious land-

scapes l i s ted in Table 3 .

Table 3 shows tha t farmland is most densely d is -

Table 3 Isolation of various landscapes in sub-regions

Area Famland Orchard Grassland Woodland Scattered Bare land Water area Urban area Rural Industrial area farwoodland settlement from settlement

River 6. 1682 12. 3953 7. 942 51. 2730 36. 5440 11. 0947 3. 8840 O. 2244 13. 1183 5. 91 80

valley area

Terrace gentle 6. 2548 8. 4266 7. 1522 44. 1453 23. 9741 29. 2099 - 10. 4207 12. 4217 17. 1712slope area

Southern mountainous 9. 5215 28. 8777 3. 8371 9. 9431 14. 4415 38. 7253 - 21. 0350 -area

Northern mountaino us 13. 3231 21. 7048 1.44 31 - - 1. 3171 - 22. 8955 -area

t r ibuted in the r iver va l ley area and ter race & gent le

s lope area , more densely in the southern mo unta ins ,

but in the nor thern mounta inous area i t i s d is t r ibuted

more d ispersedly. Orcha rd most ly i s com pact ly d is -

t r ibuted in the ter race & gent le s lope area , more com-

pact ly in the r iver va l ley area , however i t i s d is tr ibuted

more d ispersedly in the south and nor thern mounta inous

areas . Grass land is more sparse ly d is t ributed in the

ter race & gent le s lope area , more densely in the

southern moun ta inous area , but i t i s d is tr ibuted most

dense ly in t he no r the rn moun ta inous a r ea . W ood land

( inc lud ing wood land and sca t t e r ed wood land) ha rd ly

exis ts in the nor thern mounta inous area and is sparse ly

dis t r ibuted in the r iver va l ley area and level & gent le

s lope area , but most densely d is t r ibuted in the southern

mou nta inous area . Bare land is most dens ely d is t r ibuted


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A S t u d y o n L a n d s c a p e M o s a i c S t r u c tu r e i n U r b a n - R u r a l A r e a i n N o r th w e s t o f C h i n a W i t h R S a n d G I S

i n t he no r the rn moun ta inous a r ea , more dense ly in the

r iver va l ley area , but more sparse ly in the ter race

gent le s lope area , most sparse ly in the southern moun-ta inous area . Urban area i s mainly located a t the r iver

val ley area a nd level gent le s lope area , more dens ely a t

the r iver va l ley area , but more sparse ly a t the ter race

gent le s lope area . Rura l se t t lem ent is d is t r ibuted in a l l

the four sub-regions , most densely in the ter race

gent le s lope area , more densely in the r iver va l ley area

and m ore spa r se ly i n the sou the rn moun ta inous a r ea , bu t

most sparse ly in the nor thern moun ta inous area . Indus-

t r ia l a rea far f rom se t t lements i s mainly d is t r ibuted in

the r iver va l ley area and ter race gent le s lope area ,more dens ely in the r iver va l ley area , but more sparse ly

in the ter race gent le s lope area . Al l the water area i s

d is t r ibuted in the r iver va l ley area .

3 T H E F R A C TA L C H A R A C T E R I S T I C S O F L AN D -

SCAPE MOSAIC

Resea rch f ind ings show tha t l andscape mosa ic i s

the most typica l ly f rac ta l ent i ty in na ture(B AI, 2000;

XU e t h l . , 2000 ) , and va rious l andscapes can be

quan t i f i ed by the f rac t a l t heo ry. MA ND ELB ROT (1982)

s tudied the s t ruc tures of f rac ta l ent i t ies and pu t for th a

model :

E S ( r ) ] ~ - [ V ( r ) ] f f ( 5 )

where S ( r ) i s su r f ace a r ea , V( r ) i s vo lume , r i s

me asurem ent sca le , D is f rac ta l d imen sion. DONG

Lian-ke used formula (5) to bui ld the f rac ta l s t ruc ture

model which i s for n d imensions Eucl id space as the

3 7 1

be low fo rmula (DON G, 1991) :

IS (r ) ]~-T, =kr /oo ,[ V r )]-~ (6)

Tak ing n = 2 , we get the f rac ta l s t ruc ture m odel in

2 -d imens ion Euc l id space :[P (r ) ]1/o, =kr ~ , -o , ) /o , [a r )~1/2 (7)

where P r ) i s c i rcumference; A r ) is area; k is

constant ; D1 is f rac ta l d im ension in 2-dim ension Euc l id

space .

As for a landscap e patch , a re i t s a rea and c i r-

cumfe rence su i t ab le fo r t he fo rmu la (7 )? Tha t is , ha s

landscape shape the f rac ta l character is t ic? Rela ted re-

sea rch showed tha t any type l andscape has t he f r ac t a l

cha rac t e r i s t i c s (BAI , 2000 ; XUe t a l . , 2 0 0 0 ) .

Taking the formula(7) logar i thmic t ransformat ion,

we ob ta in :

l n [ A ( r ) ] = D ~ l n [ P ( r ) ] + C ( 8 )

I t i s obvious tha t as long as we es tabl ish the regress ive

mode l l i ke fo rmula (8 ) w i th t he a r ea and c i r cumfe rence

o f t he pa t ch , we can ge t r eg re s s ive coe ff i c ien t 2 /D 1 and

D1. , where Dt represents the com plexi ty and s tabi l i ty of

lands cape type . The larger D~, the more com pl ica ted

the landsc ape type i s . W hen D~ is equa l to 1 .50, the

lands cape type i s in the s ta te of probabi l i ty s imi lar to

Brown movement , which i s in the most uns table s ta te .

The more c loser D~ is to 1 .5 , the more uns table the

l a n d s ca p e t y p e i s ( P E A R C E , 1 9 92 ; Z H A Oe t a l . ,

1995 ) . Acco rding to the s teps me nt ioned above, we

es tabl ish the f rac ta l s t ruc ture m odels of var ious land-

scapes and ge t t he i r d imen s ions (Tab le 4 ) .

1) Acco rding to com plexi ty (D1 ) , var ious land-

Ta b l e 4 T h e f r a c t a l m o d e l s a n d d i m e n s i o n s o f d i ff e r e n t ty p e s o f l a n d s c a p e

L a n d s c a p e t y p e F r a c t a l m o d e l r e g r e s s i o n e q u a t i o n ) F r a c t a l d i m e n s i o n D ~ ) S a m p l e n u m b e r n ) C o r r e l a t io n R 2 )

Fa rm l an d In A ,

Orcha r d I n A ,

Gra s s l an d In A

Wo o d l a n d I n A

Sca t t e r ed In A

wood l an d In A

B a r e l a n d l n A ,

Wa t e r a r e a l n A ,

U r b a n a r e a l n A ,

R u r a l S e t t le m e n t l n A ,

Indu s t r i a l a r e a f a r f r om se t t l emen t I n A ,

r ) = 1 . 6 2 4 7 1 n P r ) - 1 . 1 6 6 8 1 . 2 3 1 0 1 2 3 1 0 . 9 3 5 2

r ) = 1 . 5 6 6 1 n P r ) - 0 . 7 4 3 1 1 . 2 7 7 1 7 0 7 0 . 9 5 3 5

r ) = 1 . 7 2 6 4 1 n P r ) - 2 . 1 3 3 9 1 . 1 5 8 5 1 0 4 1 0 . 9 2 6 7

r ) = 1 . 5 1 n P r ) - 0 . 3 9 2 8 1 . 3 3 3 3 1 6 9 0 . 9 2 9 3

r ) = 1 . 5 7 3 1 1 r i P r ) - 0 . 8 1 6 4 1 . 2 7 1 4 1 1 9 0 . 9 1 1 5

r ) = 1 . 5 9 0 2 1 n P r ) - 1 . 0 4 5 5 1 . 2 5 7 7 2 1 2 0 . 9 3 0 4

r ) = 1 . 4 9 1 n P r ) - 0 . 7 5 3 9 1 . 3 4 2 3 1 6 0 0 . 9 2 4 4

r ) = 1 . 8 1 0 2 1 n P r ) - 2 . 9 3 5 1 1 . 1 0 4 9 5 4 0 . 9 1 5 9

r ) = 1 . 6 0 9 9 1 n P r ) - 1 . 0 0 11 1 . 2 4 2 3 4 0 0 0 . 9 5 8 9

r ) = 1 . 6 2 4 7 1 n P r ) - 1 . 1 6 6 8 1 . 0 7 9 3 2 8 3 0 . 9 3 5 5

r ) = 1 . 8 5 3 1 1 n P r ) - 2 . 3 1 3 3


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372

scapes a r e r anked a s fo ll ows: w a te r a r ea (1 . 34 23 )>

w o o d la n d ( 1 . 3 3 3 3 ) > o r c h a rd ( 1 . 2 7 7 1 ) > s c a tt e r e d

w o o d la n d ( 1 . 2 7 1 4 ) > b a r e l a n d ( 1 . 2 5 7 7 ) > r u r als e t t l emen t ( 1 . 242 3 ) > f a rmland ( 1 .2 31 0) > g ra s s l and

(1 . 158 5)> u rban a r ea (1 . 104 9 )> indus t r i a l a r ea f a r

f r om s e t tl e m e n t ( 1 . 0 7 9 3 ) , b u t i f t h e y a r e r a n k e d i n t h e

terms of s tab i l i ty, the con clus ion i s jus t adverse .

2 ) Wa te r a r ea i s t he mos t uns t ab l e l andscape be -

cause Xigu Dis t r ic t i s loca ted in the t rans i t ional region

of three na tura l reg ions , and i t i s very com pl ica ted as a

r e su l t o f e f f ect s o f uns t ab l e r a in f al l and su r f ace wa te r

suppl ies .

3 ) Tha t t he d imens ion o f wood land l andscape i s

app rox ima te to tha t o f wa te r landscape shows tha t t hey

are s imi lar in the co mp lexi ty and s tabi l i ty as wel l as d is -

t r i bu t ion pa t t e rn . The r ea son i s t ha t t he r e a r e no

l a rge - sca l e wood -p l an t ed cond i t i ons and even sma l l-

s ca l e wood land i s a l so based on t he wa te r supp l i e s .

4 ) The co mplex i ty o f s ca t t e r ed wood land i s le s s

than tha t of woo dland and i t s s tab i l i ty i s very weak,

because s ca t t e r ed wood land i s ma in ly a r ti f i ci a l , and due

to t he d i f f i cu l ty and ha rd cond i t i ons o f p l an t i ng t r ee s i n

the region .

5 ) The com plex i ty o f f a rmland i s h ighe r t han t ha t

of grass land, but has a wea ker s tabi l i ty. This can be

exp la ined t ha t a l t hough the d i s t ri bu t ion pa t t e rn o f a rt i -

f i c i a l f a rmland i s more compl i ca t ed t han t ha t o f na tu ra l

grass land, i t s s tab i l i ty i s wea ker than grass land ' s s ta -

bil i ty.

6 ) The com plex i ty o f ru r a l s e t t l emen t i s h ighe r t han

those o f u rban a r ea and i ndus t r i al a r ea f a r f rom se t t l e -

men t , but lower in s tabi l ity. Thu s i t i s prove d tha t rura l

s e t t l emen t i s l a ck i n p l ann ing and t he re ex i s t s e r i ous

i r r a t iona l app rova l s and cons t ruc t i on .

4 A N A LY S I S O N S PAT I A L S T R U C T U R E O F L A N D -

SCAPE MOSAIC

4. 1 Slope Analys is

The d i s t r ibu t ion c ha rac t e r i s t ic s o f l andscapes a t

d i fferent s lopes in X igu D is t r ic t of Lanzho u Ci ty are

shown in F ig. 4 . Above 80 o f wa te r a r ea , u rban a r ea

and indus t r i a l a r ea f a r f rom se t t l emen t and above 30

XU J ian-hua , LU } an , A1 Nan- shan e t a l .

of f a rmland , o r cha rd , s ca t t e r ed wood land and ru ra l

se t t lemen t a re d is t r ibuted in the ar ea wi th a s lope of 0 -

2 Among those l andscapes , wa te r a r ea i s ma in ly t heHuang he R ive r and t he r e s t a r e d i r ec t re su l t s o f human

act iv i t ies . The n i t i s indica ted tha t the area , which i s the

mos t su it ab l e fo r human p roduc t ion and l i v ing , i s mos t

in t ens ive ly a f f ec ted by human ac t iv i t y. Seven ty pe rcen t o f

g ra s sl and , wood land and ba re l and a s we l l a s 30 o f

farmlan d are d is t r ibu ted in the area wi th a s lope of 25 -

90 I t shows tha t landscape s affec ted less in tense ly by

hum an ac t iv i t ies a re jus t in the area wi th s teeper s lope , so

the conc lus ion can be m ade t ha t t he s t ruc tu re o f l and u se

is not ra t ional in the region . In the area wi th a s lope of

2 -6 , o r cha rd , r u r a l se t t lemen t , wa t e r a r ea and s ca t-

te red woodland cove r a la rger a rea . In the area wi th a

s lope of 6 - 15 , o rchard , rura l se t t lement and sca t te re d

wood land are d is t r ibutd widely. In the area wi th a s lope

of 15 - 25 there i s mainly farmland .

r i .

~ o o 8

M

I~1 25 90

k~l 15 24 o

m l 6 _ 1 5 o

F:I 2 6

~ I I 1 - 1 0 _ 2 o

Fig. 4 Constitution of landscapes at different slopes

in X igu District

F rom Tab le 5 , we can s ee t ha t mos t o f l andscapes

are d is t r ibutd in the area wi th a la rger s lope , and

pa t ches w i th a s l ope o f above 25 accoun t fo r 50 . 9 o f

a l l t he pa t ches . The num ber o f pa t ches i s the max imum

in the a r ea w i th a s l ope o f 0 -2 and t he min imum in

the a r ea w i th a s l ope o f 2 - 6 . The nu mbe r o f pa t ches

increase wi th the s lope f rom 2 to 90 , but d ivers i ty

decr ease wi th the s lope . Dom inance in a s lope of 0 - 2

i s h ighe r and inc rea se s w i th the s lope a s u rban l and -

scape i s made f rom seve ra l l a rge r and con t inuous


8/11

A Study on Landscape Mosaic Structure in Urban-Rural Area in Northwest of China With RS and GIS

Table 5 Quantitative characteristics of landscape mosaic structure in different slope area

373

Slope Area ha) Patch number Diversity index H) Dominance D) Fragmentation F)0 - 2 11966.3 3288 2.036 6.062 27.477

2 - 6 1462.5 611 1.828 4.587 41.777

6 -1 5 2088.4 1217 1.779 5.325 58.275

15 - 25 2303. 8 1297 1.323 5. 845 56.29 9

25 - 90 18477. 3 1355 1. 026 6. 186 7.333

patches . The f ragme nta t ion is the smal les t in the area

wi th a s l ope o f 25 -9 0 , because g ra s s l and , ba re l and

and wood land a r e d i s t r ibu t ed he re con t inuous ly. I n t he

s lopes o f 6 - 15 and 15 -2 5 , t he f r agmen ta t i on is t hel a rges t s i nce t he re a r e so many sma l l pa t ches .

4 . 2 A l t i t ude Ana lys i s

S t a t is t i c a l r e su l t s o f l andscapes l oca t ed a t d i f f e r en t

a l t i t udes show tha t above 80 o f w a te r a r ea , u rb an

a rea and i ndus t r ia l a r ea f a r f rom se tt l emen t and abov e

40 o f o r cha rd and ru ra l s e t t l emen t i s d i s t r i bu t ed i n t he

a rea w i th an a l t i tude be low 1600m. The re a r e a lso

above 50 o f o r cha rd , g r a s s l and , s ca t t e r ed wood landand bare land tha t a re loca ted in the area wi th an a l t i -

t ude o f 1 6 0 0 - 1800m. In t he a r ea w i th an a l ti t ude o f

1 8 0 0 - 2 0 0 0 m g r a ss la n d a n d f a r m l an d a r e w i d e l y di s-

t r i bu t ed , wh ich accoun t fo r above 20 o f t he who le

r eg ion . Above 60 o f g r a s s l and and 40 o f f a rmland

a re d i s t r i bu t ed i n t he a r ea w i th an a l t it ude o f above

2000m . The quan t i t a ti ve cha rac t e r i s t ic s o f l andscapes a t

d i fferent a l t itudes are shown in Tab le 6 . In the area wi th

an a l t i t ude o f 1600 - 1800m , t he a r ea o f each l andscape

i s t he l a rges t and t he num ber o f pa t ches i s t he m ax i -mum. D iv e r s i t y (H ) beg ins to i nc rea se and ends t o de -

crea se wi th the a l ti tude . Do mina nce i s the s t ronges t in

t h e ' a re a w i t h a n a l t it u d e o f 1 6 0 0 - 1 8 0 0 m a n d t h e

weakes t be low 1600m. F ragmen ta t i on i n t he a r ea w i th

an a l t i t ude above 2000m i s t he l a rges t and much l a rge r

be low 1600m. Excep t fo r a r ea and dominance , o the r

three d ic ta tors a re the smal les t in the area wi th an a l t i -

t ude o f 1800 - 2000m. The r ea son i s tha t t he a r ea w i th

an a l t i tude be low 1800m has a gent le s lope and i s a f -

f ec t ed i n t ense ly by human ac t i v i ti e s , so d ive r s it y and

f r agmen ta t i on a r e much l a rge r and acco rd ing ly domi -

nance i s much sma l l e r. Tha t human consc ious ly improve

natura l condi t ions such as a r t i f ic ia l i r r iga t ion pro jec ts

a lso cont r ib ute to enr ich landscapes . Rainfa l l , l and-

scape d ive r s i t y and f r agmen ta t i on obv ious ly i nc rea se i nthe a r ea w i th an a l t it ude above 2000 m because o f ve r t i c a l

zone law. How eve r, i n t he a r ea w i th an a l t i t ude o f 1800 -

200 0m , t he numb er o f l andscape t ypes is the sma l l e s t and

consequen t ly dominance i s t he l a rgest because o f l e ss i n -

f l uence o f human ac t i v it i e s .

4 . 3 Com prehens ive Ana lys i s o f S lope and A l t i t ude

Fig . 5 shows tha t most landsca pes are d is t r ibu ted

a t a r e l a t i ve ly sma l l a r ea and above 40 o f pa t chesconcen t r a t e s i n t he a r ea w i th a s l ope o f 0 - 2 , abou t

6 5 o f p a tc h e s a t a n al t it u d e b e lo w 1 8 00 m , 2 5 o f

pa t ches a r e l oca t ed a t t he 1 s t and 2n d t e r r aces o f t he

Huang he R ive r, name ly t he r ive r va l l ey a r ea and 40

o f pa t ches a t t he 4 th and 5 th t e r r ace s , name ly t e r r ace &

gen t l e s lope a r ea . Gene ra l l y d i s t r ibu t ion f r equency o f

mos t t ypes o f l andscapes i s h ighe r i n t he a r ea w i th l ow

a l t i tude and gen t l e s lope . Acco rd ing ly f r equency is

l ower in t he a r ea w i th h ighe r a l t i t ude and s t eepe r s l ope .

Bu t wood land l andscape i s an excep t ion , wh ich i smos t ly d is t r i bu t ed i n t he sou the rn moun ta inous a r ea w i th

h ighe r a l t i t ude and s t eepe r s l ope .

5 T H E M A I N FA C T O R S A F F E C T I N G A N DC O N

TROLLING L A N D S C A P E S PAT I A L PAT T E R N

Using the spa t i a l ana ly t i ca l f unc t ions (Ove r l ay,

Buff e r and so on ) , we f i nd tha t t he r eg iona l l andscape

pa t t e rn i s ma in ly a f f ec t ed and con t ro l l ed by c l ima t i c

cond i t i ons , r i ve r co r r i do r, t opog raph ica l pa t t e rn and

huma n ac t i v it i e s .


9/11

374 X U J i a n - h u a L U Ya h A I N a n - s h a h e t a l .

Table 6 Quantitative characteristics of landscape m osaic structure in different altitudes area

A l t i t u d e m ) A r e a h a ) P a t ch n u m b e r P ) D i v e r s i t y H ) D o m i n a n c e D ) F r a g m e n t a t i o n p a t c h e s / k m 2 )

< 1 6 0 0 m 8 4 2 3 . 6 6 1 0 7 8 1 . 9 7 8 5 . 0 0 5 1 2 . 7 9 7

1 6 0 0 - 1 8 0 0 m 1 6 2 4 2 . 3 1 I 8 1 1 1 . 3 0 5 6 . 1 9 7 1 1 . 1 5 0

1 8 0 0 - 2 0 0 0 m 6 3 9 0 . 5 1 5 4 3 0 . 7 8 4 5 . 5 1 4 8 . 4 9 7

> 2 0 0 0 m 5 2 4 1 . 9 7 7 8 6 1 . 1 7 7 5 . 4 9 0 1 4 . 9 9 4

5O

.q 4

3

20

10

mz

zm=

0.2 2 6 6-15 15-25 25-9 0

S l o p ea ) S I o p e d i s t r i b u t i o n f r e q u e n c y

50

4O

3o

o1 0 - -

~q

1500-1600m

~q/

/

// , S

1 6 0 0 -1 8 0 0 m 1 8 0 0 - 2 0 0 0 m > 2 0 00 m

A l t i t u d eb ) A l t i t u d e d i st r i b u t i o n f r eq u e n c y

Fig. 5 The distribution frequencies of landscapes at different slopes and altitudes

5 .1 C l ima te

F rom the mac ro - r eg iona l backg round , X igu D i s t r i c t

i s loca ted a t the t rans i t ional region of the thre e c l ima t ic

r eg ions , name ly ea s t e rn monsoon r eg ion , no r thwes t e rn

a r id r eg ion and t he Tibe t P l a t eau r eg ion . And th i s d i s -

t r i c t ha s a t yp i ca l cha rac t e r i s t ic o f con t inen t a l and

semia r id c lima te . The na tu ra l l andscape fo rmed in t he

c l ima t i c cond i t i ons i s s emi -a r id g r a s s l and (FANG,

199 4) , so g r a s s l and is a dominan t l andscape i n t he

whole d is tr ic t . W ith in the d is t r ic t the spa t ia l d i fferen ces

o f cl ima t i c cond i t i ons a r e ve ry d i st i nc t , e spec i a l l y ve r-

t i c a l c l ima te changes i n t he moun ta inous ar ea s . I n t he

no r the rn moun ta inous a r ea t he re i s enough sun l igh t and

in t ens ive evapo ra t i on , bu t spa r se r a in f a l l (2 90 -

3 20 m m /a ) , whe re i t i s ve ry d i f f icu l t t o cu l t i va t e t he

fa rmland by na tu ra l r a in fa l l. So f a rmland on ly

makes up o f 2 . 81 o f t he who le d i s t r ic t and is

mos t ly ( a bove 60 ) i rr i ga ti on l and depend ing on l i ft

i r r iga t i on f rom the H uangh e R ive r. I n t he sou theas t

Guanshan moun ta inous a r ea t empera tu re i s r e l a t i ve ly

low, bu t annua l r a in f a l l i s a s much a s above 500 ram.

So there are some fores ts in the shade h i l l s ides of

moun ta ins , and the dom inant sor t of spec ie s i s spruce .

S ix ty pe rcen t o f wood land in t he who le d i s t r ic t con -

cen t r a t e s he re .

5 . 2 R i v e r C o r r id o r a n d L a n d f o rm

The r eg iona l l andscape spa t i a l pa t t e rn i s abso lu t e ly

con t ro l l ed by r i ve r co r ri do r s and l and fo rm, by whose

e ff ec t s t he fou r sub - r eg ions a r e fo rmed , name ly t he r i ve r

va l l ey a r ea , t he t e r r ace & gen t l e s lope a r ea , t he

sou the rn moun ta inous a r ea and t he no r the rn moun ta in -

ous area . This objec t ive ly shows the spa t ia l pa t te rn of

l andscape . The r i ve r va l l ey a r ea na tu ra l l y becom es t he

cen t e r o f human ac t i v i ti e s because o f it s f l a t land ,

conven ien t tr a f f ic and c lo se r t o wa te r r e sou rces , so

va r ious l andscape pa t ches a r e d i s t r i bu t ed even ly i n t he

a rea and l andscape d ive r s i t y i ndex i s l a rge and domi -

nance i s weak . I n t he t e r r ace & gen t l e s l ope a r ea due t o

p l a t t e r l and , r e l a t i ve ly l ower a l t i t ude and m ore conve -

n i en t i r r i gat i on cond i ti ons , obv ious ly t he re concen t r a t e

f a rmland , o r cha rd and ru ra l se t t lemen t . I n the sou the rn

moun ta inous a r ea and no r the rn moun ta inous a r ea , on

accoun t o f the e f f ec t s o f s t eepe r s l ope , h ighe r a l t i t ude

and o f be ing f a r away f rom wa te r r e sou rces , t he i r l and -


10/11

A S tudy on Landscape Mosaic Structure in Urba n-Rural Area in N orthwest of China W ith RS and GIS

scap e typ es are not so many as those o f the two fore-

name d a r ea s . Landscap e d ive r s i ty i s sma l l e r and

dom inance i s st ronge r. I n t he no r the rn moun ta inousa rea domina t e s and i n t ense ly d is t r ibu t e s g r a s sl and , bu t

a r id fa rmland , g r a s s l and and woo d land in t he sou the rn

mounta ins .

375

woo dland or grass land. The o ther i s to sc ient i f ica l ly

p l an ru ra l s e t t l emen t and i ndus t r i a l ar ea , e spec i a l l y

indus t r ia l a rea far f rom se t t lement .

6 .1 Conve r t i ng Cu l t iva t ed Land w i th a S lope above 25

in to Wood land and Gras s l and

5 .3 Hum an Ac t iv i t i es and Tra ff ic Cor r ido rs

Al l the landsca pes in the d is t r ic t a re a ffec ted or

be ing i n t e r rup t ed t o some ex t en t by human ac t i v i t i e s ,

among wh ich f a rmland , o r cha rd , u rban a r ea , r u r a l

s e t t l emen t and i ndus t r i a l a r ea f a r f rom se t t l emen t ,s ca t t e r ed wood land a s we l l a s some wood land a r e a l l

com ple te ly ar t i f ic ia l landsca pes . How ever t ra ff ic corr i -

dors inc lud ing ra i lway, h ighway, rura l roads and e tc .

a re spec ia l a r t i f ic ia l landsc apes an d they are the l ink-

ages of var ious spa t ia l loca t ions of human ac t iv i t ies .

And they a l so a f f ec t t he spa t ia l pa t t e rn o f o the r

m a n - m a d e l a n d s c a p e s (C H E Ne t a l . 1996 ) . A t a r ange

o f 5 k m t o e a c h s id e o f r a i l w a y s ( L a n z h o u - U r u m q i

r a il w a y a n d L a n z h o u - X i n i n g r a il w a y ) a n d n a t io n a l

h ighways (103 and 312 na t i ona l h ighways ) t he re i n -t ense ly d i s tr i bu t ed u rban a r ea , r u r a l s e tt l emen t and i n -

dus t r i a l a r ea , wh ich r e spec t i ve ly accoun t fo r 9 8 .8 9 ,

6 4 . 4 6 a n d 8 7 . 8 2 o f t h e w h o l e a r e a o f t h e i r s a m e

types . And 88 .06 o f o r cha rd i s i n t ense ly d i s t r i bu t ed

at a rang of 5km to each s ide of ra i lway, na t ional

h ighway and coun ty - ru ra l r oad . The t h r ee l andscapes o f

f a rmland , o r cha rd and ru ra l s e t t l emen t i n t e r l ace f r e -

quent ly in the d is t r ic t .

6 T W O P O I N T S O N L A N D S C A P E O P T I M I Z AT IO NA N D M A N A G E M E N T

The a im to s t udy r eg iona l l andscape i s t o open ou t

the f ac to rs , wh ich a f f ec t and con t ro l the l andscape

pa t t e rn , and t he i r mechan i sm by ana lyz ing the s t ruc tu re

cha rac t e r i s t i c s o f l andscape mosa i c i n t he d i f f e r en t r e -

g ions in orde r to provide the sc ient i f ic bases for opt i -

miz ing and manag ing l andscapes . Acco rd ing t o t he

above s tudy, we s t ress two bas ic problems on opt imiz ing

and manag ing l andscapes . One i s to conve r t cu l t i va t edland in the mounta ino us area wi th a s lope above 25 to

By ove r l ay ing s lope map and l andscape mosa i c

map , we f i nd t ha t t he r e is I 7 75 .54 ha o f f a rmland ,

accoun t ing fo r 29 . 87 o f t he who le f a rmland in t he

dis t r ic t , which i s d is t r ibuted in the southern and

nor th ern m ounta inous areas wi th a s lope above 25 .

F rom po in t s o f v i ew o f env i ronmen t conse rva t i on andra t i ona l l and u se , a l l the f a rmland shou ld be conve r t ed

in to wood land or grass land. Accord ing to land su i tabi l -

i ty evalua t ion , we g ive the two sugges t ions tha t in the

sou the rn moun ta inous a r ea , t he f a rmland on t he h i l l-

s ides fac ing to the Sun should be conver ted in to grass-

land and the farmland on the h i l l s ides not fac ing to the

Sun should be conver te d in to grass land; and in the

no r the rn moun ta inous a r ea , a l l t he f a rmland shou ld be

conver ted in to grass land.

6 .2 P l ann ing Rura l Se t t l emen t and Indus t r i a l Area

Our r e sea rch has p roved tha t r u r a l s e t t l emen t and

indus t r ia l a rea far f rom se t t lement a re d is t r ibuted d is -

pe r sed ly and a r e l a ck i n p l ann ing and t he re ex i s t s e r ious

i r r a ti ona l app rova l s and cons t ruc t i on . We ma ke sug -

ges t i ons f rom the p rob l ems men t ioned above t ha t r u r a l

cons t ruc t i on l and and i ndus t r i a l a r ea f a r f rom se t tl emen t

shou ld be p l anned and managed sc i en t i f i c a l l y. I n t he

terms of re la t ional laws , rura l se t t lemen t and indu s t r ia la r ea f a r f rom se t t l emen t shou ld be bu i l t o r r ebu i l t com-

pac t ly i n t he p l anned a r ea .

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Chinese)

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A study on landscape mosaic structure in urban-rural area in northwest China with RS and GIS -- A case study of Xigu region in Lanzhou city