This has resulted in the erosion of top soil and
subsurface soil layers, which are protective profile
for sustenance of plant life. The areas nearby the coal
mines and overburden dumps have a thick coating of
coal dust on the surface. Near the confluence of
Saphi and Damodar river, the river bed is found
black on account of coal dust from nearby Piparwar
project.
Changes in land use / land cover: The change
detection studies have revealed that there is a
substantial change in land use/land cover during the
last one and half decades. Substantial forest has been
depleted/degraded because of the increased demand
of fuel requirement, house construction and
agricultural use due to increase in population
pressure. The coal mine / dump areas have increased
from 1975 to 1990 at the expense of degraded forest/
scrub land and agricultural crop land. Though, very
minimal forest area has been lost due to coal mining,
the situation in the northern blocks of Karanpura
coalfield is quite different, where many of the blocks
have substantial forest cover and fertile agricultural
land. The proposed coal mining in these blocks is
likely to cause the following major changes in land
use / land cover, apart from the loss of habitated
areas -
i) Loss of deciduous forest = 2,375 ha
ii) Loss of degraded forest / scrub land = 10,870 ha
iii) Loss of agricultural crop land = 17,320 ha
The above figures are based on block-wise area
statistics, since, at this stage, the actual area to be
affected by the mining outside the block boundaries
is not known.
Effect of mining on surface and ground water
Coal mining, both opencast and underground,
affects the surface and ground water conditions
seriously. The opencast and underground coal mines
invariably extend below the water table. Therefore,
whenever mining interrupts water table, enormous
quantities of water is pumped out to render mining
activity possible. This leads to lowering of regional
ground water table, thereby disturbing the hydrological
balance of the area. The loss of top soil and deforestation
also deplete the ground water table. The effect of mining
on the ground water table near the coal mines in
Karanpura coalfield could not be studied mainly because
of the lack of historical data of wells. However, it is well
proven in other coalfields, e.g. Jharia and Raniganj, that
mining does cause lowering of regional water table to a
considerable extent, particularly in the up-dip direction.
The quality of surface and ground water also
deteriorates significantly due to coal mining. In
Karanpura coalfield, the surface and ground water near
the coal mines/overburden dumps show increase in
electrical conductivity, total dissolved solids, NCf and
total hardness. It is also expected that coal mining in the
northern blocks may cause sulphate pollution in ground
water, as the coal seams are associated with the sulphide
minerals, particularly pyrite.
Coal Fire
The coal fire, apart from causing huge loss of coal
through burning, pollutes the environment substantially
by emitting noxious gases like C0 2 , CO, N0 2 , S0 2 and
unburnt hydrocarbons, affects the surface installations,
and also damages the quality of coal in nearby seams.
The problem of coal fire in Karanpura coalfield, though,
not as critical as in Jharia and Raniganj coalfields, needs
immediate attention before the situation becomes
beyond control.
Air Pollution: In coal-mining districts, the removal
and disposal of overburden and coal, the use of
explosives, transportation of heavy vehicles, and the
industrial complexes cause severe air pollution. The
mining operations inject aerosols (particles
suspended in the air) in the lower layer of the
atmosphere, i.e. the troposhere. Coal-fired thermal
power plants, furnaces, coal mine fire, and coal
washeries also release gases like S0 2 , N0 2 , C0 2 ,
CO, etc. into the atmosphere.
Satellites have been increasingly used to study the
smoke plumes emanating from the industrial
complexes. The dispersion of smoke plume
emanating from Patratu thermal power station in
Karanpura coalfield has been studied by using
multidate and multisensor satellite data of various
time periods starting from 1975 to 1990.
Jharia and Raniganj Coalfields: Jharia coalfield
situated in Dhanbad district of Bihar state is the store
house of the best quality coking coal in India. It lies
between latitudes 23°27’ to 23°52.’ N, and longitudes
86°06’ to 86°30’ E, occupying about 460 sq. km.
Raniganj coalfield in West Bengal state is bounded
by N latitude 23°25’ to 23°55’ and E longitude
86° 10’ to 87°50’, occupying about 2000 sq. km.
Though land degradation and environmental
problems due to coal mining activity remains nearly
the same like Karanpura coalfield, in Jharia coalfield,
coal mine fire is an acute problem, due to which
severe land subsidence takes place and mostly the
area is unsuitable for habitation. This leads to strong
socio-cultural and socio-economic problems for
rehabilitation.