Study of Kaveri River Pollution Using Geospatial Techniques

Abstract

Present study envisages assessment of river water quality and identification of possible sources of pollution, covering a stretch of 60 km of Kaveri River from Krishna Raj Sagar (KRS) Dam to Sathyagala in Karnataka state using Geospatial Techniques

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Study of Kaveri River Pollution Using Geospatial Techniques
Shivam Trivedi & K. Ganesha Raj
Regional Remote Sensing Centre/NRSC/ISRO, Bengaluru, India
shivamtrivedi@nrsc.gov.in
Dnyandev Dhotrad & Dipak Samal
Centre for Environmental Planning and Technology (CEPT) University, Ahmedabad, India
KEYWORDS
Kaveri, river water pollution, geospatial techniques, point source, non-point source
ABSTRACT:
Rivers are the lifeline of any civilization, crucial for balancing the eco-system and essential for the survival of all
living organisms. Various anthropogenic activities are contaminating the river water through point and non-
point sources of pollution, mainly from domestic sewage and industrial effluents. Kaveri River originates at
Talakaveri in the foothills of Western Ghats and is the main source of water supply for Karnataka and Tamil
Nadu states. Present study envisages assessment of river water quality and identification of possible sources
of pollution, covering a stretch of 60 km of Kaveri River from Krishna Raj Sagar (KRS) Dam to Sathyagala in
Karnataka state. CPCB has reported a BOD level ranging from 3.1 to 6.7 for the stretch from Ranganathittu to
Sathyagala, indicating priority 4 out of 5. Geospatial technology offers great promise for generating spatial
information on natural resources and assessing the dynamics and long-term land use/land cover changes
through multi-temporal remote sensing data. To understand and assess the spatial changes in the study
region, satellite images from Landsat-5 TM (30m, Feb 2001) and Resourcesat-2 LISS IV MX (5.8m, Feb 2019)
were utilized. Stream network was derived from OSM/India-WRIS using Digital Elevation Model. River course
and major cities/ towns were delineated along the course of river in 10km buffer area from either side of the
river. Based on population growth rate, the total current population (as in 2019) in the study region was
estimated to be about 14.2 lakh (as compared to 11.3 lakh in 2001), Mysore being the largest city. Image
analysis and change assessment between 2001 and 2019 suggested an increase in built-up area (47%),
especially in and around Mysore; significant reduction of water bodies and minor changes in vegetation cover.
It has helped in understanding the spatio-temporal changes and impact of urbanization on river pollution, which
may be linked to enhanced generation of domestic sewage and other wastes.
To assess the river water quality for pollution parameters, field datasets of National Water Quality Monitoring
Programme (NWMP) from river water quality monitoring stations of CPCB/KSPCB were taken for years 2001
and 2016 for 4 and 6 monitoring stations, respectively. For 2019, as part of this study, a field survey was
conducted, and water samples were collected from 9 locations, including 6 previous locations. The water
samples were analyzed for Total Coliform (Most Probable Number, MPN/100ml), Fecal Coliform (MPN/100ml),
D.O. (mg/l), B.O.D (mg/l), pH and temperature as per the standard procedures. A detailed comparison was
made for water pollution parameters from these datasets for 2001, 2011 and 2019. Based on the overall
results, it was inferred that over the years, river water in this stretch has become highly contaminated,
especially in Srirangapatna. The point sources of pollution in the study region were concentrated on the stream
network that carry waste water from the surroundings and join the main river stream. As part of understanding
waste disposal mechanism in the region, it was observed that along these locations, either very few STPs were
located or altogether absent, suggesting that untreated waste water was directly let into the river. The non-
point sources of pollution were mainly considered to be the urban areas on either side of river bank, within
1km. Additionally, the agricultural runoff from rural areas containing fertilizers and pesticides also contributes
as a significant non-point source of pollution. The study has helped to understand how the river is getting
polluted, identifying polluted stretches of river and its possible point and non-point sources of pollution. The
monitoring stations/sampling locations were mapped, and results of water quality analysis were attributed in
GIS environment to understand the spatial distribution of pollutants along the selected stretch. Suitable
remedial measures were suggested to reduce river pollution and control its adverse impact on living
organisms. It is envisaged to extend the study to other polluted stretches of Kaveri River, suggesting high level
of pollution in river flow area.
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1. INTRODUCTION
During last several decades, the water quality of the Indian rivers has been deteriorating due to
continuous discharge of industrial wastes and domestic sewage (Sivakumar et al., 2000; Raja et al.,
2008; Abbasi and Abbasi, 2012; Susheela et al., 2014). River water may be contaminated by various
means, chemically or biologically and may become unfit for drinking and other uses. A polluted river is
harmful to both environment as well as for all living beings, so understanding the causes of river
pollution and providing a suitable solution to reduce the pollution is an essential requirement. World
Health Organization (WHO) report stated nearly 66.3 crore people (9% of the world's population) do
not have access to safe drinking water, which in turn becomes the main reason for health issues.
Contamination of the river due to anthropogenic activities such as discharging of untreated industrial
wastes and sanitary wastes into the rivers, dumping of garbage etc, leads to river pollution. India is
one of the nations with most polluted rivers. As rivers are the basic need of any sort of life forms a
contaminated or polluted river is very harmful for the environment and the eco-system.
With India’s rapidly growing population, accompanied by increasing hazards of domestic and industrial
pollution to the inland waters of the country, scientists envisage a rapid degradation of water quality
unless concrete steps are taken immediately to abate pollution. Basically, water is used by all living
beings for all sorts of needs and purposes. Humans consume nearly 140 litres of water per day for
basic needs such as drinking, cooking, washing etc, and about 90% of it is converted into waste water
i.e. it is not consumed and ends up in drainages. Only the water that is used for cooking or drinking is
consumed. Industrial wastes also contribute to pollution and contain several pollutants like lead,
mercury, asbestos, sulphur & nitrates which are very harmful to both humans and aquatics life forms. If
it is let into water network untreated, it will increase the pollutants in the water and which when
consumed by humans or animals cause deadly disease and might even cause death. Sewage and
wastewater contamination cause increased BOD and COD levels in water which makes the water unfit
for drinking and other routine purposes. Understanding and identifying the pollution and preventing it
should be the prime focus of research studies.
Present study envisages assessment of river water quality and identification of possible sources of
pollution using geospatial techniques. It focuses on understanding the impact of urbanization and
industrialization on river pollution and identifying the major cities & towns causing the pollution using
temporal change study and understand the waste disposal mechanism of cities and towns in the study
area. The study also attempts to identify the sources and causes of Kaveri river pollution, locate point
and non-point sources of pollution for the study area and suggest possible remedial measures to
reduce the river pollution.
2. STUDY AREA
The Kaveri River originates in Talakaveri at an elevation of 1,341 m from sea level and it is the main
source of water supply for irrigation and drinking for Karnataka and Tamil Nadu states. Kaveri basin
covers major part of peninsular India, spreads over states of Tamil Nadu (54.05%), Karnataka
(42.23%), Kerala (3.53%) and Union Territory of Puducherry (0.18%) which is nearly 2.7% of the total
geographical area of the country and has a population of nearly 3.7Cr. It lies between 75°27’ to 79°54’
east longitudes and 10°9’ to 13°30’ north latitudes.
The Kaveri River also known as the ‘Dakshina Ganga’ of the south India, is also one of the most
sacred rivers of India. It is one amongst the seven sacred rivers like Ganges, Yamuna, Godavari,
Saraswathi, Narmadha and Sindhu. Along the Kaveri River there are number of ancient temples which
were witness to its religious and cultural significances and still are a significant place of worship and
rituals. The Kaveri River is one of the major sources of water for an extensive irrigation system, and for
hydroelectric power. A stretch from Krishna Raj Sagar (KRS) Dam to Sathyagala, is considered for the
present study (60km).
A 10km buffer on either side is considered from the banks of the river, from which the spatiotemporal
change will be identified and will be assessed. From a study conducted by the Central Pollution
Control Board (CPCB) the current BOD level in Kaveri River stretch from Ranganathittu to Sathyagala
is reported to range from 3.1 to 6.7 and it has been given a priority 4. In Karnataka there are 351 rivers
out of which 17 are polluted in which 4 are priority 3, 6 are priority 4 and 7 are priority 5. The polluted
river locations in a continuous sequence are defined as polluted river stretches. The area considered

for the study is a stretch of Kaveri River from Krishna Raja Sagara (KRS) Dam to Sathyagala. It is a 60
km stretch study area, the cities and towns with higher population than 10,000 are considered for the
study. Total area of the study region is 4398 km2 and the total length of the river including the
tributaries and distributaries is 387 km (Fig.1).
Figure 1. Study area location map (Kaveri basin and selected river stretch)
3. METHODOLOGY
The methodology broadly consisted of spatial and non-spatial data analysis along with field survey and
water sample collection, which is discussed below:
3.1. Spatial data analysis
Satellite remote sensing data from two different satellites were acquired for two time periods, i.e. for
2001 and 2019 (Table 1). These images were subjected to required corrections for further processing
and analysis. Classification and spatio-temporal analysis was done on the study area, mainly to
identify the impact of urbanization and industrialization on the study area and its impact on the
pollution of the river. Ancillary data in terms of administrative boundaries, Survey of India (SOI)
toposheets, Digital Elevation Model (DEM) have also been used.
Table 1. Satellite datasets utilized for the study
Date Satellite Sensor Spatial Resolution
Feb 2001 Landsat 5 Thematic Mapper sensor 30 m
Feb 2019 IRS Resourcesat -2 LISS IV (MX) 5.8 m
DEM was used to extract the stream network of the Kaveri River and it was compared with the stream
network obtained from the OSM (Open Street Maps) and the India-WRIS (Water Resource Information
System) and the stream network generated from the DEM was most suitable and hence considered

for this study (Fig.2). Delineation of river course and mapping of major cities/towns was done using the
satellite datasets. The nearby cities were also observed for the industrial and urban development in
the study area. Cities/Towns/Villages above 10,000 population were only considered.
Fig.2: Stream network generated through Digital Elevation Model
3.2. Non-spatial data analysis
Under the National Water Quality Monitoring Programme (NWMP), Central Pollution Control Board
(CPCB) has established water quality monitoring stations all over the country. Their present network
comprises of 2500 stations in 28 States and 6 Union Territories spread over the country. Along the
selected river stretch of Kaveri River, the monthly average pollution data was obtained from CPCB and
Karnataka State Pollution Control Board (KSPCB) for four points in 2001 and six points in 2016. The
sample collection by CPCB increased from four stations to six during these years. These locations
were sparsely distributed.
3.3. Field survey and sample collection
As part of this study, a field survey was carried out and river water samples were collected from the
locations (Fig.3) and they were tested for the following parameters - Fecal Coliform (mnp/100ml), Total
Coliform (MPN/100ml), D.O. (mg/l), B.O.D (mg/l), pH and temperature. The pointers in orange colour
indicate the locations where government has collected data for past couple of years and blue being
additional data sample points for collection in this study.
Fig.3: Selected locations for water sample collection
4. RESULTS AND DISCUSSION

4.1. Classification and change analysis
The satellite images were digitally classified using unsupervised method finally into four broad classes
and change analysis was carried out for the years 2001 to 2019. The change study has helped to
identify how the urban growth has impacted the pollution of river (Table 2). With the help of the results
point and non-point sources of pollution were identified and the impact of change from 2001-19 on
river pollution was also identified. Obtaining the results helps to identify the level of pollution across the
river for the study area and it helps to suggest appropriate and suitable measures to prevent the
pollution.
Table 2: Change statistics for the study area
Classes Area in sq.km %
change
in area2001 2019
Water 281 208 25.98
Urban 151 287 -90.07
Vegetation 1588 1639 -3.21
Barren/Sparse vegetation 2412 2298 4.73
Total 4432 4432 0
4.2. Estimation of current population
The cities and towns considered for the study with a minimum population of 10,000 (Source- Census
2011). The cities falling under the considered criteria for the study are nine (Kollegal, Malavalli,
Mandya, Pandavapura, Srirangapatna, Krirshanrajanagara, Mysore, Bannur and T. Narsipur. Mysore
and Mandya are the most populated cities amongst these. The total population in 2001 was 11,33,368,
as compared to 12,77,715 in 2011 and estimated to be 14,18,070 in 2019. The total population has
increased since 2001 nearly 2.9 lakh has increased. All the cities have nominal changes but Mysore
has huge increase in population (nearly 2 lakh).
4.3. Comparison of water pollution parameters and field survey results
A detailed comparison was made for water pollution parameters from these datasets for 2001, 2011
and 2019. Based on the overall results, it was inferred that over the years, river water in this stretch
has become highly contaminated. Values of pollution parameters are compared for years 2001, 2016
and 2019 in Tables 3. BOD values ranged from 12 mg/l in Ranganathittu to 270 mg/l in Bannur (in
2019), suggesting that the water has very high content of organic matter, from untreated domestic
sewage and agricultural run-off from the surroundings.
Total Coliform was high in few locations, reaching upto 5764 MPN/100 ml in Srirangapatna, while
Fecal Coliform ranged from 803 to 2153 (in 2001) and 2219 to 6755 (in 2016). Srirangapatna location
also reported highest Fecal Coliform (6755 against permissible limit of 2500 MPN/100 ml) as many
religious rituals are performed on the river banks and ashes are immersed into the river. The
monitoring stations/sampling locations were mapped, and results of water quality analysis were
attributed in GIS environment to understand the spatial distribution of pollutants along the selected
stretch.

Table 3: Comparison of water pollution parameters
4.4. Point and non-point sources of pollution
The point sources in the study are concentrated on the stream network that carry waste water from all
around it and join the main river stream (Fig.4); artificial point sources are neglected because of time
constraints. The stream network carry domestic sewages form cities around it and even the waste
disposed in it along the path. It was observed that along these locations, either very few Sewage
Treatment Plants (STPs) were located or altogether absent, suggesting that untreated waste water
was directly let into the river. Among the selected sites, no STPs were available at Kollegal, Malavalli,
PandavaPura and Bannur locations, while 1 STP each was functional for Srirangapatna,
Krishnarajanagara and T. Narsipur locations. Mandya and Mysore had 2 and 3 STPs, respectively.
Fig.4: Point sources of pollution along the selected river stretch
The non-point sources of pollution are may mainly be considered the urban areas on the sides of river
banks within a distance of 1km (Fig.5). The wastes from urban area within 1km are very likely to end

up into the river, these pollutants may be solid wastes, biomedical wastes or chemicals wastes. The
waste are thrown into river which accumulate and the waste that are thrown surrounding the river
banks end up into the river either due to runoffs etc. The cultivation land or farm lands also contribute
to the contamination of the river; the fertilizers used in the farms are the pesticides are in the soil and
the ground which end up in river with the runoff of storm water. These fertilizers and pesticides mainly
impact on the chemical parameters of the river like the heavy metal contents, COD etc. The
contamination of the river through non-point sources is slow and in small quantities and over a large
area hence it is also called ‘Diffused’ source of pollution.
Fig.5: Non-point sources of pollution
5. CONCLUSIONS
The Kaveri River is the main source of water for drinking and irrigation for both Karnataka and Tamil
Nadu states. Over the years, river water has become highly polluted in several stretches. The water in
Kaveri has very high BOD and Coliform (mainly Fecal Coliform). The main reason for the high values
of these parameters is the pollution caused due to anthropogenic activities. At several locations, the
colour of the river has changed drastically with a foul smell caused due to the sewage disposal into the
river. In some parts of river, the water is unfit for irrigation also, as per WHO guidelines. There are a
few industries situated surrounding the banks of the river mainly textile and chemical industries that
also contribute to the pollution of the river which leads to adverse health impacts in human beings.
Kaveri is a source of drinking for many people and at several locations, where people still drink water
directly from the river untreated. Karekura location is one such place, with a BOD of 48 and Coliform
content of 23. Drinking water should have BOD less than 1; Coliform contains E-coli bacteria, which
are very harmful if consumed. The temporal study has helped to understand that B.O.D and Fecal
Coliform in the river water have increased drastically as compared to other parameters in the past 19
years. The main reason for this is the increase in the population, which in-turn generates increased
sewage, making its way into the river in untreated form. Satellite data gives us the synoptic view of the
study area facilitating in mapping the growth of cities/towns and the river course; and in understanding
the pollution dimension along the selected stretch.
6. SUGGESTIONS AND RECOMMENDATIONS
Based on the findings of the study, suitable remedial measures have been suggested to prevent and
reduce the river pollution. They include i) Treatment of sewage before letting it into the river ii) Setting
up of small STPs to reduce the impact of sewage on the water pollution even for villages iii) Industries
to have basic and initial treatment for the waste generated by them before letting it to the streams iv)
Ozone Waste Water Treatment v) Small settlements to have septic tanks to store the waste generated
instead of letting it to the nearby stream vi) Open defecation to be stopped vii) Proper landfill sites to
be arranged that are far from any water body, as it will help reduce dumping of waste into rivers viii).
Proper segregation of wastes to be done to reduce the impact and possible uses of recyclable

materials ix) Implementation of waste-to-energy plant to be considered as it combusts waste to
produce electricity x) Use of sewage treated water to recharge the ground water table or for irrigation
purpose to reduce waste reaching the rivers xi) Reduction in the disposal of oil or grease to storm
drains as they affect the water quality highly xii) Installation of rainwater harvesting in households to
reduce the use of municipal water hence saving water thrown down the drain and xiii) Minimize the
use of fertilizers and pesticides for farming.
REFERENCES
Abbasi, T. & Abbasi, S., (2012). Water Quality Indices. Chinnakalapet, Puducherry, India: Elsevier.
Raja.P, Muhindhar A, Elangovan.R and Palanivel.M. 2008. Evaluation of physical and chemical parameters of
river Kaveri, Tiruchirappalli, Tamil Nadu, India. Journal of Envirnomental Biology. Vol 29(5), pp 765-768.
Sivakumar, R., R. Mohanraj and P.A. Azeez, 2000. Physico-chemical analysis of some community ponds of
Rourkela. Pollut. Res., 19, 143-146.
S. Susheela, S. Srikantaswamy, D. Shiva kumar, Appaji Gowda and K. Jagadish, 2014. Study of Cauvery River
Water Pollution and its Impact on Socio-economic Status around KRS Dam, Karnataka, India. Journal of
Earth Sciences and Geotechnical Engineering, vol. 4, no. 2, 2014, 91-109.
http ://cpcb.nic.in / - Central Pollution Control Board.
https://www.kspcb.gov.in/defaulte.asp - Karnataka State Pollution Control Board.
http://www.tnpcb.gov.in - Tamil Nadu Pollution Control Board
http:// www.india-wris.nrsc.gov.in/wrpinfo/index.php?title=Main_Page - Water Resource Information Systems of
India
https://www.nrsc.gov.in / - National Remote Sensing Centre