PHOTONIRVACHAK Jour.lnd.Soc.Photo-lnt. & Remote Sensing, Vol. 11, No. 3, 1983 I~UANTITATIVE MONITORING OF LAND USE CHANGES IN RELATION TO HYDROLOGY OF B H A V A N / B A S I N USING REMOTE SENSING TECHNIqt~ES - A CASE STUDY. S.Chinnamani , R.Kaliaperumal , S.Thillai Govindarajan and R.Sakthivadivel *Centre for Water Resources, College of Engineering, Perarignar Anna University of Technology, Madras. 25. **Remote Sensing Unit, Ground Water Wing, P.W.D. Government of T amil Nadu ABSTRACT
The paper summarises a part of the results of an on-going project for quantifying the land use changes in B h a v a n i basin (Geographic co-ordinates N lat 10055' - 11~ Long. 76030' - 77o45'). Landsat and aerial data have been used in monitoring the dynamic changes in land use patterns. Visually interpreted Landsat MSS data of two different dates in conjunction with the historic data acquired from the Survey of India topographic maps and field data were used in this investigation. Also land use changes over two Lest-sites in the basin were studied using aerial photographs. During the study, it has been observed that a direct correlation exists between the rainfall and the area irrigated. The repetitive coverage of the satellite data are found to be quite remarkabre, especially the 1:250,000 False Colour Composites (FCC) in assessing rapidly the temporal land use changes of a region at a cheaper cost. INTRODUCTION
The monitoring of land use changes in a basin is important because of its direct bearing on the water yield, sediment yield ani:l floods of that basin. Presently, no systematic and scientific compilation of information on land use and its changes over time is made on a regional basis. In the conventional data-collection methods, one has to depend mostly on. the revenue records supplied by the village officers which normally contain discrepancies due to personal errors, mode of data collection, biased information etc.
Modern remote sensing techniques can effectively overcome these deficiencies of the conventional methods of surveying and collecting the data. Aerial photographs and space images have the potential of supplying the needed data on land use changes which can be acquired repetitively at a lower cost. Bhavani basin, a major sub-basin of Cauvery with its varied geomorphic environs, climate and land use practices has been chosen for the present study with the obiect of quantifying the temporal land use changes in the basin and to demonstrate a costeffective methodology for collecting the data which may be used for rapid planning and management of water resources of a basin.
40
S.Chinnamani , R.Kaliaperumal , S.Thillai Govindarajan
and R. Sakthivadivel
LAND USE INVENTORY i.
From Landsat image analysis
A generalised reconnaissance - level land use map was prepared (Fig. 1). on a scale of 1:250,000 for the entire Bhavani basin using Landsat False-Colour Composites (Scence ID No. 1202-04h52 and 1219-04395, February 1973). Ten classes of land use and vegetation features such as urban areas, intensively cultivated crops, rainfed crops, barren areas, water bodies, Cultivation on top of hills, forests, grassland etc. were mapped. Similar land use map for the eastern part of the basin using the available Landsat FCC (Scene ID No. 20]5-00.275, February 1975) was prepared (Fig. 2). After this a field check was undertaken to verify the interpreted land use elements and the different land use categories were quantified. The areal extents in sq.km, of all the categories were found out using a graphsheet. ii.
From aerial photo interpretations (Test-sites I and II)
Us!ng black and white aerial photographs of 1968 on 1:63,000 scale (approx), land use maps were prepared for the test-sites I and I1. The aerial extent in sq.km, of the interpreted land use classes were determined. Land use changes were compared between ~he years 1968, 1973 and 1975 in test-sites I and II (Tables 1 and 2) and between 1973 and 1975 in about 22 subbasins in the eastern part of the basin comprising a total area of about 3420 sq.km. (Table 3 and 4). CONCLUSIONS It is observed from the study that the rainfall has a marked influence on the land use changes and vegetation of the basin. Quantification of temporal land use changes using the repetitive Landsat images is found to be quite useful considering the drawbacks involved in the conventional data collection systems. The remote sensing techniques offer great potential for gathering the requisite data on resources and is cost-effective and saves a lot of Lime in the acquisition of authentic data. Aerial photo interpretations coupled with the collection of detailed ground truth is a must for making better interpretations, especially at micro-level, because of the resolution limitation inherent with the space images presently available. The temporal land use data obtained in this study will be used in a mathematical model to find out the effect of land use and other watershed changes on the hydrologic regime of the basin, the results of which will be reported later. ACKNOt@LEDGEMENTS The authors wish to thank Mr. C.A. ~rinivasan, Chief Engineer (General and Groundwater), P.W.D., Government of Tamil Nadu for having p e r m i t t e d to utilise the remotely
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Ouantitative Monitoring of Land Use Changes in Relation to Hydrology
43
sensed data products and equipment in the Remole Sensing Unit of the Groundwater Wing and extended all facilities for the study, RETERENCES
Kaliaperumal, R. 1980. A study of Geomorphology and Land use changes in Bhavani Basin using Remote Sensing Techniques - M.E. Thesis, Madras University. Richard S. Williams Jr. and William D. Carter. 1976. ERTS-I, Planet - U.S.G.S. Professional paper 929. Table-1
A new Window on our
: T e s t S i t e 1 - L a n d U s e Classes
(All land use quantities in percentage of sub-basin area)
Subbasin Number
Sub-basin Name
Subbasin area (sq.km.)
M5
AREKADUVINA
HALLA
57.34
M6
CHAGAREKADUVINA
33.67
Urban/built-up Area 1968 1973
Water bodies 1968
1973
2.15
HALLA
~A7
69.80
M8
SIKKATTI HALLA
56.31
M9
TEPPATURAI HALLA
73.69
Cultivation on top of hills
Forest/High
1968
1973
35.84
41.92
19.69
29.55
density
1.50
Forest/Low density 1968
1973
6.51
55.50
44.35
-
80.31
70.45
1968
1973
-
16.80
-
98.50
2.20
-
-
97.80
8.45
1.97
-
42.57
91.55
70.25 I OI~QO 55.46
12.95
Barren
1968
1973 13.73
SI.
Standing crops - River, canal, tank, well irrigationintensively c u l t i v a t e d
Rainfed crops - Dry farming
2.
3.
Water bodies
Forest/High density
Forest/Low density
Forest/Tropical dry thorn Grass Land
6.
7.
8.
9. 10. 8.51
-
-
5.40
3.16
-
-
2.83
3.32
2.99
5.36
0.71
3.99
a/.
6.48
0.87
35.42
46.26
1.50
2.90
ab
1975
February
1.12
-
23.54
61.21
49.83
29.36
1.50
-I~
1973
3.74
1978
Feburary
between 1968, 1973 and 1975 cannot be done.
Urban areas are not easily discernible with Landsat FCC analysed for
Barren/Open scrub
5.
Cultivation on top of hills
U r b a n / B u i l t - u p areas
Land-use classes
1.
No.
Feburary
Percent
1973
8.51
-
-
0.00
2.04
-
5.82
Decrease
2.99
2.53
-
-
1.78
0.87
11.88
1973
2.61
2.49
14.95
1975
Percent Increase Decrease
1973 and 1 9 7 5 , e n d therefore comparison of urban changes
-
2.83
3.32
1.08
-
-
-
11.38
1968
Increase
T ~ i e - 2 : l e s t Site il Land 1.1= Cl==es Test site Area - ~ =t.km. (All land use quantities in percentage of test site - II area)
105.18
64.60
Mll
M12 M13 B 7 B8 B9 B10 Bll B12 B13 B14 B15 B16 B17 B18 B19 B20 B21 B22 B23
4.07
214.01
4.52
6.97
38.95
41.60
137.48
42.73
-
36.17
86.35
106.73
10.05
19.68
49.42
12.25
54.11
51.02
7.14
1.67
92.80
297.18
36.49
50.03
2.03
122.84
71.56
51.72
3.00
193.42
32.92
55.72
0.53
626.47
231.75
50.97
2.26
458.82
56.72
5.20
4.33
-
1.82
-
-
cultivated
intensively
irrigated-
co psi
Standing
272.91
23.68
55.12
sq.km.
73.69
areas
area
number
M10
builtup
M9
Urban
Sub
basin
Sub-
basin
11.15
-
3.10
7.98
10.63
6.24
14.27
6.14
24.58
8.48
14.87
20.92
34.19
42.29
23.57
44.07
35.53
-
-
-
-
-
farming
dry
crops-
Rainfed hills
2.11
49.14
11.65
-
-
-
3.36
20.68
0
-
-
4.53
-
-
0.60
-
-
22.56
23.73
0 79
16.16
1.97
on t o p of 3/4
Cultivation
2.78
0.40
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
5.26
scrub
open
Barren
13.57
1.94
28.59
-
-
6.97
-
-
4.35
8.49
0.21
3.30
2.70
2.28
-
9.95
-
bodies
Water
21.70
38.83
13.86
10.29
22.39
44.63
65.60
60.93
9.48
84.38
48.64
30.67
-
-
15.88
-
3.34
67.04
65.48
13.79
49.13
42.57
desnity
High
Forest
(All land use q u a n t i t i e s in p e r c e n t a g e of sub-basin area)
T o t a l area "of the basin c o n s i d e r e d = 3,420 sqJ
T a l b l e - 3 : L a n d Use Classes - Feil=num~ 1 9 7 ] (Based on Landsat image analysisi
16.07
74.76
30.81
29.45
6.72
1.12
6.61
5.20
10.79
7-1.24
34.71
55.46
density
Low
Forest
4.18
0.31
4.22
10.09
22.66
thorn
dry
Tropical
Forest
land
~rass
458,82
626.47
193.42
8
9
B
B
B 10
214.01
106.73
137.48
B21
B22
023
818
38.95
86.35
817
41.60
49.42
B16
B20
54.11
B15
819
92.80
297.18
B14
71.56
272.91
B 7
B 13
23.88
M13
122.84
64.60
M12
231.75
105.18
Mll
B12
55.12
811
73.69
9
4.52
-
-
-
-
-
-
1.67
-
-
-
-
3.00
0.53
2.26
1.82
-
-
-
-
-
areas
sq.km.
M
irrigated
up
area
number
Rainfed
-
-
7.16
2.00
21.90
9.60
5.87
9.96
36.53
31.60
-
13.50
-
21.28
12.96
17.60
9.96
42.23
7.60
27.61
26,64 5.81
30.64
27.95
54.81
37.00
75.71
80.56
-
-
-
-
-
farming
dry
crops
11.06
46.82
36.42
39.84
17.61
-
-
-
0.79
-
-
cultivated
intensively
crops
built-
basin
Standing
Urban
Sub
basin
hills
5.98
11.52
-
31.25
23.42
27.16
26.00
25.85
1.26
16.97
2.89
6.80
-
-
2.78
-
-
38.19
21.73
13.79
12.79
2.81
on t o p of
Cultivation
-
-
-
-
-
-
-
-
-
-
21,86
5.56
3.44
3.52
6.38
-
-
-
-
-
scrub
open
Barren
6.03
-
11.62
2.00
-
-
5.40
1.25
3.37
0.21
2.92
0.90
1.06
-
7.10
-
Bodies
Water
(All land use q u a n t i t i e s in p e r c e n t a g e of sub-basin a r e a )
Sub-
~Ivll0
Cla=T=ia~ F e l : ~ r a r y 1975 (Based on Landsat image:.' analysis)
-
-
24.73
7.98
3.18
8.44
-
29.87
2.37
69.62
42.86
17.88
-
-
9.26
-
9.87
56.62
73.13
28.31
39.84
17.99
desnity
High
Forest
T o t a l a r e a of t h e basin c o n s i d e r e d = 3,420 sq.km. (Eastern p a r t of the basin)
Table--4 : L a n d ~
30.77
79.59
17.79
56.77
30.22
41.84
50.53
7.05 24.36
32.37
4.23
0.31
5.19
5.14
50.01
47.37
79.20
density
Low
Forest
21.10
8.89
25.20
3.49
Thorn
Dry
Forest
Land
Grass