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River Sharavathi with a basin area of about 4500 sq. km is located in the central Western Ghats. Western Ghats with rich biodiversity of flora and fauna is considered one of the biodiversity hotspot and ideally suited for ecological investigations. Land cover and land use analyses is done for the river basin using temporal data acquired remotely through Indian Remote Sensing satellite (IRS 1C/1D) along with collateral data. The Linganamkki catchment area (upper basin) was divided into eight-sub basin depending on the vegetation type and drainage density. This delineation provided insight to the moisture preference of certain habitats. This result is substantiated with the field data, which includes stream flow in various streams and species in these sub basins. Sub basin results indicates vegetation with endemics and evergreen increases with perennial stream catchment or the region with high soil moisture content (higher stream flow) and comparatively decreases in the catchment with seasonal flow streams. Drier basins are related to either monoculture or open area (barren area / waste lands)
GIS technology and IRS-1C MSS data were used for land cover and land use analyses. Both sloped based and distance based vegetation indices were generated to delineate vegetation over non-vegetation area. Land use analyses was carried on with ground control points (GCP’s) and training data (ground truth samples). Total 300 samples of seven categories were collected all over study area with the help of GPS (global position system). Bio-resources software developed in C++ provides the spectral ranges of each category. Maximum Likely hood classification was adopted for its higher accuracy of classification. It provided the classified image having seven category i.e. built up area, Semi-evergreen, moist deciduous, plantation, water body, agriculture, and open field. The following table gives detailed of area under each category for whole study area and eight sub basin regions.
Locality |
Builtup
|
Sem-evg |
Moistdce |
Plant |
Water |
Agri |
Openfild
|
Study area |
12.50 |
16.16 |
25.03 |
9.74 |
7.13 |
8.49 |
20.96 |
Nandihole |
11.14 |
3.31 |
38.12 |
5.52 |
0.01 |
11.33 |
30.56 |
Haridravathi |
13.86 |
2.28 |
28.17 |
5.58 |
0.01 |
18.19 |
31.92 |
Mavinahole |
11.60 |
4.37 |
41.62 |
7.88 |
0.03 |
9.81 |
24.68 |
Sharavathi |
12.49 |
19.16 |
22.95 |
14.66 |
- |
10.32 |
20.42 |
Hilkunji |
5.57 |
43.27 |
22.46 |
11.56 |
- |
4.18 |
12.96 |
Hurulihole |
7.56 |
32.78 |
27.91 |
10.74 |
0.88 |
1.97 |
18.17 |
Nagodi |
7.46 |
52.14 |
16.58 |
13.66 |
0.01 |
1.08 |
9.07 |
Yedenalhole |
10.10 |
37.89 |
19.76 |
15.88 |
0.14 |
1.37 |
14.86 |
Sem-evg= semi evergreen, moistdec= moist deciduous agri= agriculture
Address:
Energy & Wetlands Research Group,
Centre for Ecological Sciences,
Indian Institute of Science, Bangalore 560 012, Karnataka, India
Phone: 080- 3600985 / 3092506
Fax: 91-80-3601428 / 3600085 /3600683{CES-TVR}
Email: cestvr@ces.iisc.ernet.in,
cestvr@hamsadvani.serc.iisc.ernet.in