clearly depends on maintaining the global greenhouse
equilibrium, an important component of which is
conservation of forests (Rao, 1996). To define
conservation on forest ecosysteiti, understanding of the
biospherical processes, their spatial inter linkages and
continuous monitoring of the human interventions are
necessary. Satellite remote sensing plays an important
role in determining the above needs, alongwith
enhancing and monitoring through repetitive coverage
over different spatio-temporal scales. The integrated
information derived from the satellite data set assists in
evolving of appropriate action plans for initiating
sustainable development. Hence, to redefine effective
forest management and environmental protection, an
integrated approach using biophysical and socio
economic information need to be developed at national
level. Geoinformatic would play an important role in
ensuing millennium, the geospatial data will provide
valuable information through process modelling and
monitoring.
1.1 Forest Management
Forests are known to be the most important
renewable natural resources. However due to socio
economic and socio-political reasons, India has faced
one serious problem of forest degradation in the tropical
world. Present world average of forest per person is
7000 sq. mt as against Indian average of 700 sq. mt. As
stated the forest resources and forestlands need to be
managed in such a way that they meet the socio
economic and forest produce needs, not only of this
generation but for future too. In this context, forest
management strategy in India should be based on very
reliable database on forest area, their productive
potential and ameliorating sites. The detailed forest
cover type maps which are often required for laying of
individual felling coupes, planning of roads, fire lines,
wildlife habitat management for day to day management
are not available today. Hence a quick repetitive and
accurate information about forest cover is required at the
local, regional (state) and national levels for various
purposes. Satellite remote sensing and Geographic
Information System (GIS) have demonstrated that
together with the ground data they have potential to
provide comprehensive information on various facets of
forest management in India (Fig. 1). The present paper
attempts to analyse the experiences of two decades of
the application of Satellite Remote Sensing in India with
particular reference to forestry. The spatial modelling
approaches that provide the ability to support decisions
in forest management are also highlighted.
2. DEFORESTATION ‘HOT SPOT’ MAPPING
National Remote Sensing Agency (NRSA) for the
first time used 1:1 million images for the periods 1972-
75 and 1980-82 and forest cover have been classified
into three categories viz., Closed, Mangrove &
Open/Degraded (NRSA, 1983). Based on Satellite
Remote Sensing, national database is available to
analyse the national forest cover. This data has been
compiled in the form of Forest Information System
(FRIS) at the Indian Institute of Remote Sensing (IIRS).
Generation of Information on forest cover in India at
national level has been done on 1:1 million and
1:250,000 scale using visual interpretation of false
colour images.
Forest Survey of India (FSI) uses satellite images
to map forests on 1:250,000 scale. This experience has
been extended in evolving the national programme to
monitor national vegetation regularly. This data has been
compiled at district level alongwith socio-economic
information in the form of FRIS at IIRS. Based on the
trends of deforestation, population growth, cattle
population, grazing pressure, forest fire incidence,
‘Hotspots’ have been mapped in different districts.
3. FOREST STOCK MAPPING
Stock maps depict forest types, density,
encroachments, cultivation patches, regeneration status
and reveal information about available resources.
Conventional ground surveys are time consuming and
strenuous. Visual or digital classification and
interpretation methodology for updating stock maps
from high resolution satellite data like IRS-1C PAN
have shown possibility of achieving more informative
stock maps than conventional ones.
The state Forest departments like, Karnataka,
Maharastra, Rajasthan, Andhra Pradesh and Madhya
Pradesh have started using satellite remote sensing data
for mapping on 1:50,000 scale and overlaying
compartment boundaries to obtain stock information.
This approach needs further consolidation by
incorporating digital approaches in data enhancements
or classification. For intensive forest management, this
mapping should be done on 1:25 000 scale using IRS
LISS III and PAN hybrid images. Though the strategies
have shifted from commercial forestry to conservation
forestry, people oriented productivity in terms of non
wood forest products have to be estimated for their yield
regulation. Hence, estimating growing stock in terms of
wood and non-wood forest produce is a priority.
Multistage sampling approach using remote sensing
provides most reliable estimate of forest resource
stockings (Chacko, 1964). Ultimately, stratified
populations (at different levels) are sampled to estimate
total stock. This approach with multi-resolution sensor
systems can provide higher accuracy estimation.