3.1 Status and Transition of Land Use Land Cover from 1973 to 2015
LULC dynamics is assessed using temporal RS data. The study region (BNP with a 5-km buffer) has witnessed largescale land cover transformation from 1973 to 2015, due to unplanned developmental activities with large-scale anthropogenic activities. The fast economic and social transformation in the Bangalore metropolitan region has large-scale impacts on BNP and its environs. Temporal variations in NDVI values helped to quantify spectrally distinct vegetation and non-vegetation regions, which highlighted the loss of vegetation cover from 85.78 per cent (1973) to 66.37 per cent (2015) in the study region (Table 2, Figure 4). Land use analyses from 1973 to 2015 reflect the impact of urban expansion and the status of forests in the peripheries of BNP. The buffer region aids in biodiversity conservation, supports wildlife migration and acts as a refugee and a grazing ground for livestock. The western and eastern part of the study region (BNP with the buffer) consist of human habitations with agricultural activities. Figure 5 and Table 3 reflect changes in the forest cover of the BNP buffer region from 1973 to 2015. The large tracts of deciduous cover in the Kanakapura Taluk and Anekal Taluk have disappeared due to the unauthorized expansion of horticulture and agricultural activities in recent years. The region has lost moist deciduous cover, from 26.1 per cent to 13.8 per cent (1973–2015), and horticulture has increased, from 8.5 to 11 per cent. Large-scale land use changes with an increase in built-up areas from 0.4 per cent to 4.5 per cent in the periphery are due to illegal activities such as stone quarrying, granite and sand mining and medium-scale industries. The overall accuracy of land use maps for 1973, 1989, 1999, 2009 and 2015 was 87.86 per cent, 88.4 per cent, 88.8 per cent, 87.85 per cent and 91.66 per cent, respectively. Accordingly, the kappa coefficients were 0.84, 0.86, 0.86, 0.85 and 0.89, respectively.
Bangalore’s unrealistic metropolitan growth has intrinsic relations with vegetation loss in the peri-urban landscape of BNP. The increase in the population of Kanakapura Taluk and Maralwadi Town resulted in more transition of forests to other land uses. Encroachments in Kanakapura forests, revenue lands and gomala regions (grazing lands) have resulted in deforestation, and the formation of housing layouts has enhanced the instances of human-animal conflicts and loss of human life and crop. The region has 9,254.21 ha of degraded forest patches, which have to be reforested with native plant species to improve the food and fodder availability for wild fauna.
Year Category |
1973 |
1989 |
1999 |
2009 |
2015 |
Ha |
% |
Ha |
% |
Ha |
% |
Ha |
% |
Ha |
% |
Vegetation |
107087.8 |
87.98 |
104039.5 |
85.5 |
99992.2 |
82.2 |
94693.3 |
77.8 |
89419.0 |
73.46 |
Non-vegetation |
14633.13 |
12.02 |
17682.5 |
14.5 |
21728.7 |
17.8 |
27027.6 |
22.2 |
32301.9 |
26.54 |
Total area |
121720.9 |
Table 2. Land Cover Changes from 1973 to 2015
Figure 4. Land Cover from 1973 to 2015 in Bannerghatta National Park with 5-km Buffer
Figure 5. Land Use in BNP with 5-km Buffer (1973–2015)
Year Category |
1973 |
1989 |
1999 |
2009 |
2015 |
Ha |
% |
Ha |
% |
Ha |
% |
Ha |
% |
Ha |
% |
Dry deciduous forests |
32415.6 |
26.6 |
31609.3 |
26.0 |
26433.6 |
21.7 |
24042.3 |
19.8 |
22729.9 |
18.7 |
Moist deciduous forests |
31725.9 |
26.1 |
29694.3 |
24.4 |
25941.5 |
21.3 |
16916.1 |
13.9 |
16822.2 |
13.8 |
Grass/scrub forests |
4876.8 |
4.0 |
4500.4 |
3.7 |
4914.4 |
4.0 |
8967.2 |
7.4 |
9254.2 |
7.6 |
Water |
377.8 |
0.3 |
922.5 |
0.8 |
1170.8 |
1.0 |
1251.6 |
1.0 |
1834.0 |
1.5 |
Horticulture |
10361.3 |
8.5 |
11768.4 |
9.7 |
12707.1 |
10.4 |
13470.5 |
11.1 |
13363.2 |
11.0 |
Agriculture |
36027.9 |
29.6 |
37222.3 |
30.6 |
40053.5 |
32.9 |
44975.1 |
36.9 |
45613.8 |
37.5 |
Urban |
490.6 |
0.4 |
581.6 |
0.5 |
1934.9 |
1.6 |
3216.0 |
2.6 |
5462.1 |
4.5 |
Barren land |
4461.8 |
3.7 |
4251.7 |
3.5 |
6833.9 |
5.6 |
6114.5 |
5.0 |
13536.6 |
2.9 |
Forest plantations |
921.4 |
0.8 |
1060.5 |
0.9 |
1011.0 |
0.8 |
1533.1 |
1.3 |
1566.3 |
1.3 |
Mining area |
61.8 |
0.1 |
109.9 |
0.1 |
720.3 |
0.6 |
1234.5 |
1.0 |
1538.7 |
1.3 |
Total area |
1,21,720.9 |
Table 3. Land Use Changes in Bannerghatta National Park with 5-km Buffer from 1973 to 2015
3.2 Modelling and Visualization of Forest Transitions
The prediction of likely land uses for 2021 and 2017 was done through CA-Markov, incorporating various land use decisions in transition rules (of 1999–2009 and 2009– 2015). Land use of 2015 is predicted (Figure 6) considering land use of 1999 (Table 4, with transition details of 1999– 2009), which was compared with actual land uses of 2015. This helped in validating the CA-Markov technique for predication, and the results are given in Table 5. A higher kappa value of 0.86 indicates a significant correlation and agreement between the simulated and actual land uses. Kno indicates the overall accuracy of the simulation as compared to the reference map. Klocation evaluates the accuracy of the simulation in specifying a particular location. Kstandard shows the location error with quantification as per reference map. The prediction of land uses for 2021 was done considering base land use data from 2009 to 2015. Similarly, the land use of 2027 was predicted based on land uses of 2015 and 2021 (simulated). The projected land use of 2027 shows an alarming picture of the loss of forest cover, from 41.38 per cent to 35.59 per cent, with an increase in urban area (4.49%–9.62%) due to irresponsible land use changes with housing projects in an ecologically sensitive region
(Figure 7). These anthropogenic activities would pose serious threats to the forest ecosystem in BNP, which has been aiding as a carbon sink (in lieu of higher greenhouse gas (GHG) emissions in Bangalore (Ramachandra, Bharath et al., 2015). The forests in southern parts project minimal disturbances (connected to the Tali Reserve Forests and Cauvery Wildlife Sanctuary), whereas northern portions show very disturbing trends of higher rates of transition. The uncontrolled and unplanned growth of Greater Bangalore would certainly spell doom to the survival of fauna and the sustenance of forest cover in BNP. The major growth poles are built-up expansions in the Anekal industrial area, Kalkere, Basavanapura and Weavers Colony, Uttarahalli Manavartha Kaval
Figure 6.Simulate and Projected Land Use of BNP 2015–2027
Given | Probability of Changing to
|
---|
Forest | Agriculture | Barren Land | Water | Built-up
|
---|
Forest | 0.783 | 0.1649 | 0.0252 | 0.0022 | 0.0246
|
---|
Agriculture | 0.025 | 0.9 | 0.025 | 0.025 | 0.025
|
---|
Barren land | 0.1573 | 0.259 | 0.4493 | 0.0026 | 0.1318
|
---|
Water | 0.1055 | 0.0803 | 0.0165 | 0.7011 | 0.0967
|
---|
Built-up | 0.025 | 0.025 | 0.025 | 0.025 | 0.9
|
---|
Table 4. Transition Probability Matrix Based on Land Use from 1999 to 2009
Year |
Simulated (2015) |
Projected (2021) |
Projected (2027) |
Ha |
% |
Ha |
% |
Ha |
% |
Forest |
49444.88 |
40.62 |
45895.57 |
37.67 |
43315.05 |
35.59 |
Agriculture |
58207.18 |
48.64 |
60410.02 |
49.67 |
60206.03 |
49.46 |
Barren land |
6668.57 |
4.66 |
5030.71 |
4.13 |
4460.76 |
3.66 |
Water |
2011.68 |
1.65 |
2033.13 |
1.67 |
2031.11 |
1.67 |
Urban |
5387.75 |
4.43 |
8350.63 |
6.85 |
11707.15 |
9.62 |
Total area |
121720.9 |
Table 5. Simulated, Projected Land Use of Bannerghatta National Park from 2015 to 2027 and Accuracy of the Analysis
Figure 7. The Regions Likely to Experience Higher Land Use Changes