## 3 Results
### Landscape Transformation, Vegetation Cover Loss, and Mining Area Expansion over the Rajmahal Hills
Rest vegetation cover loss over the Rajmahal Hills, which was not caused by mining activity, is supposed to be caused due to other human interferences such as settlement encroachments, logging, construction works, road networks, etc.). A study by [PERSON] and [PERSON] (2014) also reported same kind of reasons (e.g., mining activity, settlement encroachments, etc.) behind the vegetation cover loss over the Rajmahal Hills, India. Figure 4: Spatial expansion of mining class over the Rajmahal Hills over the years 1990, 2000, 2010, and 2020. Zones Z1 to Z8 are the zoomed mining locations. Z1: Mundli stone mining region, Z2: stone mining region, Z3: Rajmahal coal mines, Z4: Chalpahar stone mining region, Z5: Borna stone mining region, Z6: Pachhwara coal mining region, Z7: Labapara stone mining region, and Z8: Gosainpahari stone mining region. The spatial extent of the waterbody was not dynamic during the study years and varied between 10-12 km\({}^{2}\). The waterbody patches in some years increased mainly due to waterlogging in the mine areas (Z3 and Z6 in Figure 3), specifically in 2020. Overall \(\sim\)1 km\({}^{2}\) increment in the waterbody was estimated during the study period (1990-2020) at an annual rate of 0.003%. On the other hand, the Others class also remarkably increased (\(\sim\)284 km\({}^{2}\)) over the span of 1990-2020 with an annual rate of 0.006%. The increment in the Others class could be due to the conversion of vegetation cover into bare land, settlement, and construction sites. The detailed LULC change statistics are discussed in the further paragraph. The detailed inter-class transformation of LULC features during three periods (i.e., 1990-2000, 2000-2010, 2010-2020, and 1990-2020) is provided in Table 4. Most of the vegetation area was converted into Others or Mining classes. Overall \(\sim\)22 km\({}^{2}\) of vegetation cover was destroyed (lost) in the last 30 years (1990-2020) and converted into a mining area. During 1990-2000, \(\sim\)2 km\({}^{2}\) of vegetation area was converted into mining, whereas \(\sim\)3 km\({}^{2}\) and 8 km\({}^{2}\) of vegetation area were transformed into mining area during 2000-2010 and 2010-2020, respectively, due to stone and coal mining activity over the Rajmahal Hills (Table 4). Only very few areas were observed where the mining area was converted into vegetation owing to the mine's reclamation activity or afforestation. Only 0.8 km\({}^{2}\), 1.12 km\({}^{2}\), and 0.47 km\({}^{2}\) of mining areas were found to be converted into vegetation from mining during 1990-2000, 2000-2010, and 2010-2020, respectively. Thus, it can be inferred that a significant area of vegetation has been lost due to opencast mining activity, whilst a very small area was ecologically recovered through mine reclamation. It can be noted that the sum of the changing area of any particular feature/class during 1990-2000, 2000-2010, and 2010-2020 will not equal to change area during 1990-2020. For example, Table 4 exhibits that vegetation to mining conversion is 1.64 km\({}^{2}\), 3.06 km\({}^{2}\), and 8.10 km\({}^{2}\) during 1990-2000, 2000-2010, and 2010-2020, respectively, which is not equal to the change area (22.29 km\({}^{2}\)) during 1990-2020. This is because, during long-term (1990-2020) change detection, the  
Figure 5: Field photographs of a few stone mining regions over Rajmahal Hills. Photographs were taken during 21–22 April 2023.  
inter-class changes during intermediate study periods are not considered, which is reflected in decadal change detection. Apart from converting vegetation to the mining class, remarkable areas of vegetation were converted into the Others class. Approximately 450 km\({}^{2}\) of vegetation area was converted into the Others class in the last three decades (1990-2020) over the Rajmahal Hills. While -219, 256, and 271 km\({}^{2}\) of vegetation cover were converted into the Others class (i.e., bare land, settlement, and construction) during 1990-2000, 2000-2010, and 2010-2020, respectively.