31 
(Rao et al., 1980), ravinous lands (NRSA, 1981), salt- 
affected soils (Venkatratnam, 1977, 1980 and 1983) and 
shifting cultivation areas (NRSA, 1979). Under IRS- 
Utilisation Programme the methodology for mapping 
soils using satellite data has been refined (Fig. 1). 
Subsequently, Landsat TM, SPOT and IRS satellites 
enabled to map soils at 1:50,000 scale at the level of 
association of soil series due to higher spatial and 
spectral resolutions (Karale et al., 1987; Kushwaha, 
1990; Sharma and Bhargava, 1987; NRSA, 1994 and 
1995a). In one of the major projects in Department of 
Space - “Integrated Mission for Sustainable 
Development” - the soil mapping has been taken up at 
1:50,000 scale for about 175 districts in the country (Fig. 
2). With the availability of PAN data with 5.8 m spatial 
resolution and LISS-II1 data at 23 m resolution from 
IRS-1 C/1 D satellites, attempts are being made to map 
soils at 1:25,000 or larger scale with PAN merged LISS- 
III data. 
At NRSA, the maps of salt-affected soils for entire 
country were prepared at 1:250,000 scale (Fig. 3) using 
satellite data from Landsat TM/IRS sensors with 
accepted nation-wide legend for mapping salt affected 
soils in association with central and state government 
organisations. The salt-affected soils are also mapped at 
1:50,000 scale on limited scale using satellite data 
(NRSA, 1995b and 1996). Multitemporal satellite data is 
being used in monitoring the salt affected soils on 
operational basis (Fig. 4). Satellite data has also been 
utilised in qualitative assessment of soil erosion in North 
Eastern states of Manipur, Tripura and Arunachal 
Pradesh and to monitor eroded and shifting cultivation 
areas in Tripura (NRSA, 1990). Similarly, remotely 
sensed data from TM and IRS-LISS-I/II, have also been 
used in studying ravinous lands, waterlogged areas and 
impact of mining on forest environment. 
Table 2. Status of soil mapping at 1:50,000 scale 
in the country. 
SI. 
No. 
Organization 
Area Surveyed 
(million hectares) 
1. 
NRSA 
5.018 
2. 
11RS 
7.502 
3. 
IMSD, DOS 
83.300 
4. 
NBSS&LUP 
23.550 
TOTAL 
119.370 
(The area covered (126.897 m. ha) under rapid reconnaissance 
soil survey by AIS&LUS and 18.032 m ha area covered by 
state soil survey organisations of Bihar, A.P. and Orissa at 
1:50,000 scale are not included in the above table) 
Table 3. Area under degraded lands. 
SI. 
No. 
Organisations / Agencies 
Area in 
m. ha 
1. 
National Commission on Agriculture 
(1976) 
175.0 
2. 
Institute of Offshore and Costal Research 
(INCOR), Visakhapatnam 
55.4 
3. 
Society for Promotion of Wasteland 
Development, New Delhi (Bhumbla and 
Khare, 1984) 
93.7 
4 . 
Wasteland Map of India by NRSA (1985) 
53.3 
5. 
NBSS & LUP (1994) Glassod Method 
187.0 
6. 
Department of Agriculture & Cooperation 
Govt, of India 1995 (Compiled) 
107.0 
7. 
Department of Environment, Govt, of 
India (Vohra, 1980) 
95.0 
8. 
National Wasteland Development Board. 
Ministry of Environment & Forests, New 
Delhi (1985) 
123.0 
Table 4. A comparative analysis of soil resources mapping 
at 1:50,000 scale through Remote Sensing and 
Conventional Approaches. 
♦ 
SI. 
No. 
Parameter 
Remote sensing- 
based maps 
Conventional 
survey based maps 
1. 
Approach 
Systematic Visual 
Interpretation 
Conventional Field 
Survey 
2. 
Cost 
Rs. 1.15/Hectare 
(NRSA) 
Rs. 8.35/Hectare 
(AIS& LUS) 
3. 
Cost of Soil 
Survey for 
One Topo- 
Sheet 
(700 sq. km) 
Rs. 1.5 lakhs 
(Including Data 
Cost) (NRSA) 
Rs. 5.85 lakhs 
(AIS & LUS) 
4. 
Time 
2 Months/ Topo- 
sheet (NRSA) 
7 Months/ Topo- 
sheet (AIS & LUS) 
5. 
Level of 
Information 
Soil Series and 
their Association 
Soil Series and 
their Association 
6. 
Quality of 
Delineation 
Physiographic 
boundaries well 
defined leading to 
improved soil 
scape boundaries 
Soil scape and 
Physiographic 
boundaries not 
precise