IAPRS & SIS, Vol.34, Part 7, "Resource and Environmental Monitoring", Hyderabad, India,2002
filling up of mine pit, failure of slope along dump, overburden-
a landuse feature under mining environmental dynamic.
Bicholim mining area covers 3596 space of iron ore belt in Goa.
Dempo has been quarrying it since 1956-57 in association with M/S
Swarna. Dempo group was established during 1941 in Goa as
multipurpose Industrial entrepreneur and reorganized its mining
activities since 1975 as Dempo Mining Corporation Limited
(DMCL). Bicholim mining area is associated with different land use
changes and selected for utilization of sequential aerospace data
towards their monitoring.
METHODOLOGY
Visual interpretation of aerospace data has been carried out. The
major Remote sensing keys for visual interpretation are topography,
drainage and tonal contrast towards identification of mining activity
and associated landuse changes. The developed Remote sensing
keys through visual interpretation are summarized in Table 1
(Gupta, 1978).
Table 1. Remote Sensing keys for identification of landuse changes
associated with Bicholim Iron ore mining activity
S. Name of ; ;
No | Landuse Identification Remarks
features Criteria
Land associated
IV : Dark sons, Shape Best on TM, Aerial
egetation | and associated
feature photograph
Best on TM, Aerial
) Paddy Medium tone photograph followed by
field shape better over Landsat MSS
and poor on IRS 1C
1ght t ;
3 ony ae Aerial photograph
Iron ore Dark tone, shape :
4 | ridge with | and associated Best on TM, Aerial
quarrying feature photograph
Dwelling Linearity tone Best on TM, Aerial
5 and road shape photograph
Water Associated
Sediment- ; Best on aerial
6 ation Drainage tone photograph Landsat MSS
Pond with Visible on all kinds of
7 water Tode shape aerospace data
Better on aerial
8 Muddy Medium tone photograph Landsat TM
and IRS 1C
9 Estuary Tone shape Benet ses MSS
The digital interpretation methodology could not be utilized on
account of unavailability of different kinds of aerospace data in their
digital format as well as lack of relevant hardware and software.
However the digital product along with stereo pair interpretation of
modern sensor system of orbiting satellite may provide information
upto maximum level of ground resolution. Such study is not only
helpful for demarcation of different land use with their
560
quantification over land portion, but also sedimentation process in
adjoining Arabian sea. This may provide status on sub-aquatic
vegetation towards fisheries resource as additional asset for
management of coastal resources.
DATA USED
The used temporal aerospace data for Goan iron ore are: Landsat
MSS data (December 1972 & March 1975), Aerial photographs
(February 1978), Landsat TM (January 1987) and IRS 1C
(November 1989, February 1997). The information collected
through aerospace data has been correlated with standard Survey of
India toposheet 48 I/3 (1963-65) of scale 1: 50,000. The details of
used aerospace data are summarized in Table 2.
RESULT AND DISCUSSION
Geo-morphology, mining, drainage and dwellings influence the
land use in and around Goan iron ore mining area. All these
influencing factors are deciphered on the basis of visual
interpretation of aerospace data in conjunction with relevant ground
truth. The temporal nature of aerospace data helps in detecting the
changes occurred towards individual land use along with its
primary quantification. The broad characteristics in terms of
regional Goa to local Bicholim iron ore mining for each influencing
factors are summarized as follows.
Geomorphology
The regional geomorphology of Goa is classified in two categories
namely coastal area and Inland area. The coastal area occurs along
Arabian sea and characterised by beach deposit, coastal plain over
land and long shore drift over seawater portion respectively.
Landsat 2 MSS Band 4 of March 1975 identifies two sets of beach
deposit representing erosional activity with presence of chimney
and stake over Calugute beach as well as retrograding nature by
dominance of littoral drift at Kolva beach. The Inland area occurs
along western portion of Western ghat and characterised by two sets
of lineament namely NNW-SSE and NW-SE. The NW-SE
lineament controls iron ore mineralization and by large belongs to
Banded Haematite Quartzite BHQ ridge. The ridge is partly
associated with intensive weathering cover and Lateritic capping.
The NW-SE lineament is identical over landsat II MSS Band 6 & 7.
BHQ is associated with sparse vegetation as landuse feature. The
regional geo-morphology as interpreted through landsat II MSS
data is illustrated as Figure 3 (Anand, 1982).
The geo-graphic area around Bicholim is 4.8 km?. The landuse
pertaining to iron ore mining was about 2 km’ during 1974-75
towards east of Bicholim ridge. The landuse due to iron ore
quarrying has been extended to 15 km? during 1997-98 with in the
span of 23 years as per correlation through temporal aerospace data
and ground truth.
Geology
The materialization for iron ore reveals that ore minerals have
dominancy of Haematite, Magnetite with occasional presence of
Limonite and Geothite. The gangue minerals are ferrogenous
phyllite, shale, clay, magniferrous clay and silica. These minerals