741 
for identification of mineral prognostic areas. Two similar projects in Northern 
and Eastern regions of India viz., Project ' Bhu Sampada' and Project 'Singhbhumi' 
have also been initiated by the Geological Survey of India using LISS-I & II data. 
The above studies have indicated that LISS-I data is very good for regional 
geological study. The rock boundaries in most of the cases are differentiable 
easily and details on structural features such as folds, faults, fractures, dykes 
etc. are very clear both on LISS-I and LISS-II data. In most of the cases details 
derivable regarding rock types, structures and geomorphology on LISS-I and LISS-II 
data have been found comparable with those reflected in Landsat MSS and TM data 
respectively. However details depicted on IRS-1A data are much clearer and sharp 
(Ravindran, 1988, Bhattacharya et.al, 1988). 
2.7 Ocean Resources and Coastal Studies 
Ocean/coastal applications of IRS-1A data include wetland mapping, offshore sediment 
dispersal, mapping mangroves, coastal zone geomorphological mapping etc. Several 
studies using IRS-1A data for wetland and coastal zone mapping monitoring offshore 
sediment dispersal pattern have been carried out using visual and digital analysis 
techniques and results compared with those of Landsat and SPOT data products. A 
coastal atlas of the country (about 6000 km of coastline) using IRS-1A LISS-II data 
and Landsat TM data depicting coastal landforms, water features, suspended sediment 
levels etc. is under preparation by Department of Space. The results of the above 
studies indicate that details derivable on LISS-I & II data of IRS-1A are comparable 
with those of Landsat MSS and TM data respectively. In many of the cases details 
derivable from LISS-II data have been found better as compared with Landsat TM 
mainly due to better clarity of features on IRS LISS-II data. Regarding wetland 
mapping details upto level 2 and level 3 in many cases could be derived using LISS- 
II imagery. In a case study better separation of mangroves from marshy and saline 
from sandy areas was obtained on LISS-II data compared to Landsat TM on 1:250,000 
scale. The coastal zone mapping of Bombay area reported better clarity of features 
on LISS-II (1:100,000 scale) imagery than on the Landsat TM data of same scale and 
upto 7 categories fo coastal zone units could be discriminated as against 9 
categories from aerial photographs (Nayak, 1988) . Various digital techniques such 
as linear contrast stretching, generation of FCCs, principal component analysis and 
detailed spectral analysis using statistical parameters of IRS LISS-I have been 
performed to identify the areas having scattered remarks of Deccan Trap basic 
volcanic rocks in Lalitpur district of Uttar Pradesh (Krishnamurthy, 1990). 
2.8 Drought 
Applications of IRS-1A data for agricultural drought assessment and monitoring for 
combating drought include generation of Normalised Difference Vegetation Index Maps 
(NDVI maps) for assessment of drought affected areas, at the micro level in 
conjunction with NOAA data. Towards this biweekly NDVI maps for Kharif season are 
being generated. Whereas the above NDVI maps are at regional scale and provide 
information at state and district level. NDVI maps generated using LISS-I data give 
information on drought affected areas at sub district/ta 1uk level. Under 
'Integrated Land and Water Resources Planning' project, IRS-1A data is being used to 
generate basic resources information pertaining to drought affected regions. Under 
this project ground water and surface water potential, geomorphology, geology and 
soils, vegetation, landuse etc are integrated towards developing a scientific plan 
of action for drought alleviation on short and long term basis. Under this project 
initially 18 drought prone districts in the country have been taken up for the 
integrated study using IRS LISS-II data. 
2.9 Flood Prone Area Delineation and Flood Mapping 
In India, flooding in several major rivers during monsoon season (June-Sept)every 
year cause extensive damage (40 m.ha annually) . In order to have real time 
information on areas affected due to floods towards taking up rehabilitation 
measures, satellite data is being operationally used since 1986. All the major 
floods during 1988 and 1989 were mapped exclusively using IRS data. 
During the recent cyclone of May 1990 which affected the entire south east coast of 
India and caused extensive damage by inundating over 18,000 sq.km area and marooning 
600 villages, the IRS images provided an objective assessment of the severity of 
the damage. This damage assessment using IRS LISS-I data was the only way to 
quantify the crop damages due to flooding as the communication links were totally 
affected. 
CONCLUSION 
IRS mission envisages continuity of data to users and towards this plans are afoot 
to launch IRS-1B which is identical to IRS-1A during mid-1991 and the second