Results and Discussion

Land cover analysis

Land cover analysis through NOVI shows the

percentage of area under vegetation and non­ l

vegetation. NOVI is based on the principle of spectral difference based on strong vegetation absorbance in the red and strong reflectance in the near-infrared part of the spectrum. Fig. 7 and Table 2 illustrates the spatio-temporal changes in the land cover of the region, which highlight the decline of vegetation cover from 96.62 (1976) to 93.6% (2009).

Table 2: Extent of vegetation cover during 1976, 1990, 2002 and 2009

Land cover(%)

I

Vegetation

I

Non-vegetation

1976

96.62

3.38

1991

94.43

5.57

2000

94.28

5.72

2009

93.60

6.40


Fig. 7: NOVI reflecting vegetation dynamics in Chikkamagalur.

Land use analysis : The changes in the land uses at landscape level during 1976 to 2009 are highlighted in the Figure 8 and Table 3. This shows the decline of forests from 50.74% (1976) to 36.33% (2009).

Table 4 lists category wise land uses in percentage and Table 5 provides the accuracy assessment details.

Fragmentation analysis

Land use data (classified data with 4 classes) were used as input to the fragmentation analysis and the analysis was done at district, division and taluk levels. Figure 9 illustrates the extent of forest fragmentation while Table 6 provides the summary statistics . Applying forest fragmentation analysis to a time series of land use data provided quantitative assessment of the spatial pattern and trends in forest fragmentation. The analysis indicated that domination of forests receded during 90's with the formation of patch and edge forest in all 5 divisions.

Forests in Chikkamagalur district are administered through five divisions - Chikkamagalur, Koppa , Bhadravathi, Kudremukh National park and Bhadra Wildlife Sanctuary. The quantification of extent of forest fragmentation has been done division-wise for the past four decades to enable the respective division administration to undertake appropriate forest restoration measures to minimize fragmentation of ecologically important ecosystems. Land use changes from forests to non-forests with intensified human interference had been very high especially in Bhadravath,i Chikkamagalur division. Interior forest decreased by 94.48 (1976) to 74.4 (2009). In Bhadravathi division interior forest decreased by 52.54 (1976) to 34.31 (2009) and patch increased by 5.73

(1976) to 13.52 (2009). Chikkamagalur division interior forest was about of 39.68 in 1976 which was



Fig. 8: Land use dynamics in Chikkamagalur district.

Table 3: Land use statistics in Hectares

Land use categories (Ha)

Years

I

Forest

I

Urban

I

Plantation

I

Agriculture

I

Water bodies

I

Others

1976

365,541.08

365.88

89,105.83

243,307.46

8781.52

14,894.00

1991

344,445.96

1228.60

102,724.69

231,948.04

12,534.45

26,889.70

2000

299,549.97

1548.91

150,583.68

228,137.15

14,240.50

25,790.61

2009

261,520.87

1783.18

171,558.74

238,985.04

13,339.59

32,486.38

Table 4: Land use statistics in Hectares

Land use categories (percentage)

Years

I

Forest

I

Urban

I

Plantation

I

Agriculture

I

Water bodies

I

Others

1976

50.74

0.05

12.35

33.61

1.21

2.06

1991

47.85

0.17

14.27

32.23

1.74

3.74

2000

41.61

0.21

20.09

31.69

1.98

3.58

2009

36.33

0.25

23.84

33.20

1.85

4.51

decreased to 23.75 in 2009. Interior forest in Koppa decreased by 52.82 (1976) to 32.27 (2009) and in Kudremukh interior forest decreased by 42.72 (1976) to 35.05 (2009).

Conclusion

Temporal Land cover analyses highlighted the decline of forest cover from 96.62 (1976) to 93.60% (2009).

Spatio-temporal land use analysis indicated the increase of built-up patches from 0.05 to 0.25% (2009). The results also reveal the fragmentation of forest patches due to the conversion of forest areas for agricultural and development activities. Forest fragmentation analysis showed the decline in interior forests from 1976 to 2009 and domination of edge and patch forest in all divisions. Land use changes from

1976 1991

2000 2009

. Patch

□ Transtitional

Edg e

D Pt>rfo rated

0 S 10 20 :l() <0 Interior


Fig. 9: Fragmentation of forests in Chikkamagalur .

Table 5: Kappa and overall accuracy

3l<"'4cfilfC'lcfi '<fiT

f,,,cfi4•1(1 , li&f m'GT it cA'

Year

I

Kappa Co-efficient

I

Overall accuracy

(%)

1976

0.77

84.43

1991

0.78

86.06

2000

0.80

87.12

2009

0.91

93.43

Table 6: Extent (in percentages) of forest fragmentation during 1976 to 2009.

Types of fragmentation

I

1976

I

1991

I

2000

I

2009

Patch

3.51

5.71

5.93

8.74

Transitional

9.43

12.14

13.59

14.79

Edge

29.32

37.23

37.64

35.87

Perforated

5.35

2.35

3.32

3.22

Interior

52.39

42.56

40.40

37.38

forests to non-forests with intensified human interference had been very high especially in Bhadravati and Chikkamagalur division. Koppa forest division showed more fragmented forest patches with increased edge and patch forest. The extent of interior forest declined in last few years in Kudhremukh National Park due to mining/ quarrying activities.

Bhadra wild life Sanctuary also showed decline in forest cover.