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IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
OPTIMIZING BENEFITS FROM WATERSHED T HROUGH USE OF REMOTE SENSING 
R. S. Dwivedi"', K. V. Ramanz?, S. P. Wani" and R. R. Navalgund* 
a. National Remote Sensing Agency, Department of Space, Govt. of India, Balanagar, Hyderabad — 500 037, India 
b. International Crops Research Institute for Semi-Arid Tropics (ICRISAT), Patancheru 502 324, India 
Commission VII, WG VII/3.5 
KEYWORDS: Remote sensing, watershed, soil conservation, kharif fallow 
ABSTRACT : 
For a successful watershed development programme, baseline information on land and water resources, and socio-economic 
conditions is a pre-requisite. Besides, a well-defined and built-in mechanism for monitoring the success and progress of the 
programme, and effecting necessary mid-course corrections 
, if required, is equally important. Spaceborne multispectral 
measurements by virtue of providing synoptic view of a fairly large area at regular intervals, hold very good promise in providing 
reliable information on nature, extent, spatial distribution, potentials and limitations of land and water resources of a watershed 
which forms a sound database for generation of developmental plan by suitably integrating with socio-economic and other relevant 
information in a Geographic Information System (GIS) domain. Furthermore, the multi-temporal nature of satellite data enables 
objective monitoring of the progress and success of the watershed development programme. The article illustrates the potentials of 
space technology in various facets of watershed development through two case studies; one on assessment of the impact of soil and 
water conservation measures in a watershed, and another on identification of kharif fallows aiming at their optimal utilization. 
1.0 INTRODUCTION 
Watershed development programme aims at conserving soil 
and water thereby improving the productivity of land with the 
consequent improvement in the crop yield and stakeholders’ 
income. The process of watershed development entails the 
delineation of watersheds, and sub-dividing into smaller and 
manageable hydrological units, and prioritization for treatment. 
Baseline information on land and water resources is required 
for planning interventions and for monitoring the progress and 
success of the programme and effecting necessary mid-course 
corrections. By virtue of providing synoptic view of a fairly 
large area at regular intervals, spaceborne multispectral 
measurements offer immense potential in providing reliable 
information on land and water resources of a watershed. Such 
information forms a sound database for generation of action 
plan / developmental plan for land and water resources by 
suitably integrating it with socio-economic and other ancillary 
information in a Geographic Information System (GIS) 
domain. Additionally, spaceborne multispectral measurements 
along with GIS also enable prioritizing the watershed / (s) 
requiring immediate attention since the treatment of entire 
watershed simultaneously is not a feasible proposition. Once 
soil and water conservation programmes have been 
implemented, multi-temporal characteristics of spaceborne 
multispectral measurements enable monitoring its progress and 
success. 
As pointed out earlier, for optimal utilization of available land 
and water resources of a watershed, information on the nature, 
extent and spatial distribution is a pre-requisite. Until the 
1920s, such information had been collected through 
conventional surveys, which are labour-intensive, cost- 
prohibitive and impractical in the inhospitable terrain. During 
the 1920s and early 1970s, aerial photographs were used for 
deriving information on various natural resources (Bushnell, 
679 
1929; US Department of Agriculture, 1951; Howard, 1965). 
The launch of the Earth Resources Technology Satellite 
(ERTS-1), later renamed as Landsat-1, in 1972, followed by 
Landsat-2,-3,-4 and —5, SPOT-1,-2, -3 and —4; and the Indian 
Remote Sensing Satellites (IRS-1A/-1B/1C/ and-1D) with 
Linear Imaging Self-scanning Sensors (LISS-I,-II and-IIT) and 
Panchromatic sensor (PAN) have opened up a new vista in 
deriving information on land and water resources of a 
watershed. Several researchers have utilized aforesaid 
spaceborne measurements in deriving information on 
geological and geomorphologic and hydrogeomorphological 
features (Bhattacharya and Reddy, 1991; Reddy —et al, 
1996;Rao et al, 19962); soil resources (Singh and Dwivedi, 
1986; Karale, 1992); land use/ land cover (Landgrebe, 1979; 
Raghavaswamy et al., 1992, Rao et al.,1996b); forest resources 
(Dodge and Bryant, 1976; Unni, 1992; Roy et al.,1996); surface 
water resources (Thiruvengadachari et al, 1996) and degraded 
lands (Food and Agriculture Organization, 1978; Karale et al., 
1988 Dwivedi etal, 1997a and b; 2001). Furthermore, apart 
from generation of information on individual natural resources, 
spaceborne multi- spectral data have also been operationally 
used for integrated assessment of natural resources on a 
watershed basis and subsequent generation of action plans for 
land and water resources development and for assessment of 
the impact of implementation (Rao and Chandrashekhar, 1996). 
The article illustrates the potentials of space technology in 
various facets of watershed development through two case 
studies: one on assessment of the impact of soil and water 
conservation measures in a watershed, and another on 
identification of kharif fallows aiming at their optimal 
utilization. 
2.0 IMPACT ASSESSMENT OF SOIL AND WATER 
CONSERVATION MEASURES 
Soil and water conservation measures employed in an area 
result in the prevention of soil loss, improvement in soil