Techno-Ecological Management of Lakes and Reservoirs using Remote sensing and Gis
Authors: H. Chandrashekar H. Chandrashekar , K.V. Lokesh K.V. Lokesh , Ranganna.G Pushpa.H 
Published: February 2025

Water is susceptible to get contaminated by any
foreign matter and this may be either natural or
artificial. Any alteration in the physical, chemical and
biological properties of water as well as
contamination of any foreign substances leads to
health hazard. The polluted natural water resources
are hazardous to aquatic life and also to human life.
The major sources of water pollution are domestic
waste from urban areas, rural areas and industrial
wastes, which are discharged into natural water
bodies.
Reservoirs and lakes occupy a prominent place in the
history of irrigation in South India. Tanks are
considered to be useful life saving mechanism in the
water scarcity areas which are categorized as Arid
and Semi-arid zones. The lakes and reservoirs, all
over the country without exception, are in varying
degrees of environmental degradation. The
degradation is due to encroachments, eutrophication
and siltation. There has been a quantum jump in
population during the last century without
corresponding expansion of civic facilities resulting
in deterioration of lakes and reservoirs, especially in
urban and semi urban areas becoming sinks for the
contaminants. The degradation of reservoir and lake
catchments due to deforestation, stone quarrying,
sand mining, extensive agricultural use, consequent
erosion and increased silt flows have vitiated the
quality of water stored in the reservoirs. The study
area vie., Byramangala reservoir catchment has an
areal extent of 340 sq.km,and command area of 28
sqkm It is encompassed by East longitude 770 23'45"-
770
34'16"and North latitude 120
45' 00"- 130
02' 40"at
a distance of about 40 km from Bangalore.
The paper discusses the physico-chemical and
bacteriological studies carried out on surface and
ground water and soil in the Byramangala reservoir
catchment and the command area. The surface water
and ground water in the catchment and command
areas were subjected to qualitative analysis for its
physical, chemical and biological characteristics. The
sampling was done at a monthly interval of three
months, i.e., in the month of April2012,
September2012, and January 2013.The results of
analyses of water samples reveal that water is
polluted at certain locations. The max and min values
of BOD are 108 mg/l and 48.5mg/l, the COD
264mg/l and86.3mg/l, TDS 1691mg/l and 990 mg/l,
DO are 2.5ppm to 1.2 ppm, Water quality Index
between 289 to 112.The presence of heavy metals
such as Fe, Mn, Zn, Cu, Pb, Cr in vegetation and soil
of command area is beyond the permissible limits at
certain locations. The total–coliform andfaecalcoliform in ground water and surface water at certain
locations and reservoir varies between 64x104
/100ml
to9600/100ml which indicates that water is highly
polluted with domestic and industrial effluents.
Techno-ecological approaches such asSoil scrape
filter, Succession pond, Green lake technology,
Green bridge technology will help to reduce pollution
levels in the Byramangala reservoir, its catchment
and command areas.