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Spatial modelling approach to water pollution monitoring in the sugar belt of Maharashtra along the Krishna river
S. K. Soam,
soam@igfri.up.nic.in
Economic Botanist, Indian Grassland and Fodder, Research Institute,
Jhansi
J.P. Singh
Indian Grassland and Fodder, Research
Institute, Jhansi
Introduction
The rate at which we deplete and degrade our
fresh aquatic resources poses a great threat to our future life support system.
The rise in human population exploits more of natural resources and this is met
through the growth of industries specifically chemicals and petrochemicals,
urbanisation, deforestation and intensive agricultural practices. The industries
and urban sprawl discharge the waste into river. The deforestation process
itself aggravates the sedimentation transport into the streams. And the use of
chemicals in the crops for better production contaminates ground water through
percolation, and rivers and lakes through surface run-off. All these sporadic
degrading activities have lead to gradual deterioration in the quality of
surface and subsurface water. The loss of quality is causing health hazards and
death of human, livestock and death of aquatic lives, crop failure and loss of
aesthetics. Keeping in view the importance of good water quality, the Central
Pollution Control Board (CPCB), in 1976, initiated a series of integrated river
basin studies all over the country. CPCB in collaboration with the State
Pollution Control Boards (SPCB) established the Water Quality Monitoring (WQM)
network in the country. The CPCB has identified river stretches all over the
country, which have been polluted to the maximum extent. The Krishna river,
which is one such polluted rivers of the country, flows in the states of
Maharashtra, Karnataka and Andhra Pradesh. The present study is taken up for the
monitoring, identification and suggesting preliminary measures of water
pollution control in the Satara-Sangli stretch (stretch-I) of the Krishna basin
in Maharashtra with the help of Geographic Information System (GIS). The
stretch-I, also known as the country's sugar-belt, has been identified by CPCB
and MPCB (Maharashtra Pollution Control Board) for the restoration of water
quality under the National River Action Plan (NRAP).
Satara - Sangli
Stretch
General
The Satara-Sangli stretch of the Krishna
river in Maharashtra is known as the sugar belt of the country. The Krishna
river flows with a southeasterly trend in Maharashtra, traversing a distance of
280 kms from Mahabaleshwar through Satara to Sangli [latitudes 160 00' N - 180
00' N, longitudes 730 30' E - 750 00' E, altitude 150-600 m] on a rocky area.
The river is met by river Koyna, about 137 kms away from its source. Numerous
seasonal tributaries dissect the basin giving rise to a dendritic pattern of
drainage with a medium drainage density. The total geographical area of the
Krishna basin in Satara is 10,816 km2 (4%) and that of Sangli is 8,572 km2
(3.2%). The districts of Satara and Sangli experience a warm-humid climate with
an annual average precipitation between 600-800 mm. Eighty percent of the
rainfall in the Krishna basin is influenced by the south-west monsoon giving
rise to heavy rainfall on the west coast of the western ghats. The mean
temperature varies between 22.5 - 25 0C. Usually, the geological formations
consisting of Deccan traps are rich in basalt and dolomite type rocks. The soils
in the basin are in-situ in nature and a major portion comprises mainly of
medium black cotton (b.c) soils. These b.c. soils are the weathered derivations
of the Deccan Basalts. Extensive bleaching and weathering of b.c. soils has
given rise to red loamy and lateritic soils.
Landuse/
Landcover
Krishna basin covers a non-arable land area of 53010 km2 out
of which 22.4% falls in Maharashtra. In Satara 2.1% of the reporting area is
non-arable land while the same is 3.3% in Sangli. Forest land accounts for 1583
km2 (15.1%) in Satara and 488 km2 (5.6%) in Sangli. The total cultivable land in
these two districts of the Krishna basin is 13,844 km2 that is 65.3% in Satara
and 81.5% in Sangli. The districts of Satara and Sangli exhibit substantially
wooded tropical evergreen forest. About 75% of the total forest cover is
dominated by teak species. The common varieties of teak found in this category
are Tectona grandis, Terminalia torrentosa, Adina, Laemnea and Cleistanthus
collinus. Amongst all types of landuses, agriculture is dominant in Krishna
basin with over 50% total land actually under cultivation. Table 1 shows that
86% and 83% of the cultivable land is actually under plough in the districts of
Satara and Sangli. The intensity of cultivation is more clearly indicated by the
average number of crops grown in a year given by gross sown area divided by the
net sown area which equals to 1.10. The extent of irrigation applied for crops
in Satara and Sangli is 16.9% and 11.1% respectively. The major crops grown in
this area are cereals, pulses, jowar and sugarcane. Irrigation is done mainly
using stream diversions or canals (42%) and ground water source (58%). About 21%
of gross sown area is irrigated.
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