Theme – Surface Hydrology
Frontiers in Urban Hydrology and Outlook for 21st Century
Desa M., M.N.
Director, Humid Tropics Centre Kuala Lumpur,
Department of Irrigation and Drainage,
Km 7 Jalan Amapang, 68000, Ampang,
Kuala Lumpur MALAYSIA.
Urban hydrology research will be the main focus of attention in this millennium, especially in the humid tropics region. This is so related to climate change and urbanization that bring about unpredictable and uncontrollable hydrologic response in urban areas. Substantial development in hydrology had occurred and this was described to Dooge (1999). According to Dooge (1999), the development of hydrology research in the past can be categorized into four distinct periods i.e. period of empiricism (1900-1930), period of rationalization (1930-1950), period of theorization (1950-1975) and period of computerization (1975-2000). Activities during that period mainly focused on catchment scale with the problems of upscaling still remain unsolved. In the tropics however, continuous effort must be made to test out new theories and approaches with local data because there seems to be inherent problem concerning scale, which is site dependent. A clear understanding of the hydrological processes involved is therefore a paramount importance. Hence there appears to be ample room for research in urban hydrology in light of land use/cover change effects, climate change and ecology of urban rivers to name a few. New methods that established like the neural network, fuzzy logic, fractal, disaggregation and aggregation of rainfall, etc has to be tried out using local rain data. Urban water management for sustainable environment is the cornerstone of future research area, which will see amongst others recycling society as an important issue.
Role of Eco-Hydrology in Addressing the Freshwater Crisis
Water is the basis for all life. Every human activity- culture, religion, customs, aesthetics are linked to water. In modern world all developmental activities- urban services, food production, drinking water, industrial growth has connection to water resources. So proper understanding and assessment of the resources is of utmost importance in economic and social development, particularly in recent times when water is increasingly becoming a major constraint for sustainable development. Water issues – its availability, allocation, pollution are likely to dominate the social, economic and ecological agenda at global level.
Point and Non-point Sources of Groundwater Pollution: Case Studies Along the East Coast of India
Institute for Ocean Management,
Anna University, Chennai 600 025, India
This study focuses on the change in groundwater quality in both urban and rural areas along the East coast of India, due to the influence of various point and non-point sources of pollution, land use changes etc. Three regions (Chennai, Pondicherry and Sirkazhi) where the groundwater is used extensively for domestic, industrial and agricultural uses have been the focus to study the varying water quantity and quality. The Sirkazhi region is mainly dependent on the Cauvery River for irrigation. Recently culture of shrimps and other commercially important fishes have grown rapidly in this region. The continued inter-state water dispute that deprives the Cauvery delta of its share of freshwater for agriculture has made farmers to either sell or convert their prime agriculture lands for aquaculture. On the other hand, in the Chennai and Pondicherry regions, the groundwater is largely over exploited mainly for drinking purposes. It must be mentioned that the Chennai city depends almost entirely on monsoon for its drinking water supply and hence during periods of drought, the dependency on groundwater expands to proportions that cause both deterioration in the amount of water availability and its quality. This promotes the ingression of seawater into the groundwater aquifers in most regions.
Groundwater samples were collected from several locations for a period of one year covering pre-monsoon, monsoon, post-monsoon and summer seasons from both open and dug wells, in all the three regions. Laboratory analyses of Total Dissolved Solids (TDS), major ions (HCO3, Cl, SO4, and Na), nutrients (NO3-N; NO2-N; H4SiO4) and trace metals (Cu, Ni, Co, Pb, Fe, Cr, V, Mn, and Zn) weremade to study the spatial and temporal variability in water quality. The mobility and concentration of these elements were assessed, as they are important indices to quantify the level of pollution. The spatial distribution of these elements is an indicator of the different pathways of these elements entering the hydrological system during different seasons. The TDS and elements such as Cl and SO4, have exceeded the maximum permissible limits in drinking water at a few locations, suggesting that non point sources such as seepage from agricultural areas are responsible for this decline in groundwater quality.
Impacts of Land Use, Land Cover and Land Development Changes on Surface and Ground Water Quality - A Case Study of Hyderabad
Y. Anjaneyulu1 and T. VijayLakshm2
1Professor & Head, Senior Author for Correspondence
2Center for Environment, IPGSR, Jawaharlal Nehru Technological University, Hyderabad
Many developmental projects, industrial /urbanization programs or policies are likely to have both qualitative and quantitative effects on both surface and ground water environment (rivers, lakes, estuaries, Oceans) which may result considerable impacts on aquatic faunal or floral species and aquatic ecosystem.
In evaluating surface-water pollution impacts associated with the construction and operation of potential projects, two main sources of water pollutants should be considered: (a) non point sources which are also called as "area" or diffuse sources. Refer to those substances which can introduced into receiving waters as a result urban- area, industrial-area, or rural runoff- example, sediment, pesticide, or nitrate entering surface because of runoff from agricultural farms and (b) point sources which are related to specific discharges from municipalities or industrial complexes - like 7 organic effluents or metals entering a surface water as a result of waste water discharge from a manufacturing plant. In addition to point sources non point-source pollution can be also significant contributor to the total pollutant loading, particularly with regard to nutrients and pesticides.
Identifying potential impacts of various point and non point sources on surface and groundwater resources require the delineation of the quantities of water usage, the type and the quantities of potential water pollutants to be utilized or generated during the project, and geographical terrain of the study area. In this paper, the various factors to be considered for the evaluation of impacts of surface and groundwater for quality are discussed with typical data of Hyderabad and surrounding areas as case study.
Evaluation of Groundwater Pollution Potential in Alluvial Terrains - A Case Study of Roorkee Town
D. C. Singhal
Professor, Department of Hydrology,
Indian Institute of Techonology,
Roorkee -247 667 (Uttaranchal)
Many alluvial areas of India depend for their water needs on the available groundwater resources. A need has been felt from time to time to protect the groundwater from sources of contamination, especially when the prevailing geological framework of these resources renders these resources amenable to pollution. Accordingly, it is imperative to develop a suitable methodology for evaluation of susceptibility to groundwater pollution from given sources, even when existing status of its quality may not indicate any impending deterioration.
The present paper seeks to develop a viable methodology for evaluation of pollution potential of groundwater resources in the alluvial areas using a case study of Roorkee town, Distt. Haridwar (Uttaranchal). A combination of hydrogeological and hydraulic factors having significant role in development of pollution potential will be evaluated from the geological and geohydrological conditions prevailing in the area. The methodology, thus finalized, can be utilized to work out the ground pollution potential and pollution hazard for other alluvial areas. This can lead to preparation of susceptibility to groundwater pollution maps of alluvial areas in the country.
Hydrogeological Risks of Arsenic Contamination in West Bengal Delta and GIS Applicability
Ashok K. Keshari
Water Resources Section, Department of Civil Engineering,
Indian Institute of Technology,
Hauz Khas, New Delhi 110 016
The growing groundwater arsenic problem worldwide presents a major challenge to water resources engineer, water resources planners and managers, hydrogeologists and geochemists. The groundwater contamination by arsenic in West Bengal delta, India is posing a serious threat to mankind, as the drinking water supply (or domestic consumption) is at the stake of great hydrogeological risk. In this paper, a GIS based approach has been presented to investigate the hydrogeological risks arisen from the arsenic contamination in groundwater regimes of West Bengal delta. The hydrogeological conditions, arsenic distribution, level of arsenic contamination and associated risk have been investigated and presented for the entire West Bengal delta. Results reveal alarming level of groundwater contamination by arsenic and associated risks in Nadia, Murshidabad, North 24-Parganas and South 24-Paraganas districts. There is high risk of arsenic poisoning in rural areas by their domestic consumption withdrawing water from shallow aquifers. The drinking water supply needs proper treatment in most areas, before its consumption by people and livestock. The study warrants an extensive evaluation and identification of contaminated tube wells and zones and to install hydraulically sealed tube wells to ensure arsenic free drinking water supply. The elucidated degree of contamination and spatial criticality will help in developing strategic remediation strategies for vulnerable areas and safeguarding human from adverse health effects.
Fluoride in the Ground Water of Sri Lanka
H. A. Dharmagunawardhane
Department of Geology,
University of Peradeniya, Sri Lanka
Presence of high fluoride in groundwater in Sri Lanka could be related to the geology of the area exemplified by: 1. Occurrence of apatite deposits (Anuradhapura) 2. Serpentinite deposits (Udawalawe) 3. Emanations from thermal water (Mahaoya). The concentration of fluorine dissolved in groundwater may further depend on the local physiography climatic conditions and other dissolved ions in groundwater.
Dissolved Ion Concentrations in the Surface and Groundwaters of Neyveli Mining Region
Al. Ramanathan1, S. Chidambaram2, K. Srinivasamoorthy2 and P. Anandhan2
1School of Environmental Sciences, JNU, New Delhi-110067;
2Department of Geology, Annamalai University, Annamalainagar – 608 002.
The surface and the ground waters in the mining area were studied in detail. The higher concentration of sulfate ions in the surface water is due to the impact of the pumped ground water (reacted with FeS2) in the Cuddalore sandstone. TDS is higher in monsoon period in surface water. Vellar river samples also show enrichment of TDS in monsoon indicating the influence of weathering process. H4SiO4 is higher and excess during monsoon suggesting the kaolinisation and other clay forming process. Fly ash pond shows excess of H4SiO4. The cations were dominantly released due to weathering. Factor analysis shows secondary leaching effects due to evapotranspiration followed by natural weathering process in surface waters. The shallow groundwater indicates that the SW monsoon samples have higher HCO3 concentration followed by NE monsoon and premonsoon seasons. Cl, SO4, NO3 and F shows the enrichment in premonsoon and summer season followed by monsoon periods. The major cations are in the following order Na<Ca<Mg<K. The dominance of (Na+K) over Mg & Ca is due to silicate weathering. In the deep groundwater, the order of abundance of ions shows the same trend as that of the shallow waters. Cl is abnormally high in all four seasons. In monsoon HCO3 is higher compared to other seasons suggesting the occurrence of maximum chemical weathering. Higher concentration of TDS, EC, Cl, SO4, Na, PO4 in SW and SE part clearly shows the influence of mine water, agricultural activities and lithological input. Statistical analysis of the groundwater indicates the dominance of leaching of the secondary salt precipitation as the major chemical process controlling the water chemistry followed by silicate and carbonate weathering processes. NE part shows higher concentration of groundwater in all seasons compared to the SW part in the study area.
Phosphorus Availability in the 21st Century
High-grade phosphate ores, particularly those containing few contaminants, are being progressively depleted and production costs are increasing. Its content is still relevant today pending a review and an update.Today the annual global production of phosphate is around some 45 million tonnes of P2O5, derived from roughly 144 million tonnes of rock concentrate. Approximately 93% of the phosphate rock mined is used to produce mineral fertilizers and animal feed; the remainder is used to produce elemental phosphorus and other industrial phosphates. Considering the overwhelming shore of fertilizers and animal feed in global phosphate consumption, it is evident that the development of future world phosphate production will be driven by the development of agriculture, which in turn is driven by global population growth and its food requirement. It, therefore, follows that agriculture’s share in the use of phosphate will increase in the future.
Groundwater Scenario in India: Opportunities and Challenges Towards Its Sustainability
Environmental Geology Lab, Department of Geology,
University of Rajasthan, Jaipur-02004, India
Ground water is increasingly becoming more sought after and dependable form of water resource in India. However the evidences points that this resource is becoming more and more vulnerable due to overexploitation and contamination. The paper presents the vulnerability scenarion and discusses measures towards its sustainability.
Remote Sensing Application in Water Quality monitoring and Modeling
V. K. Choubey
National Institute Of Hydrology,
Jal Vigyan Bhavan, Roorkee (Uttaranchal), 247 667.
An attempt has been made to quantify the relationship between the variation in IRS-IA-LISS-I (Indian Remote Sensing Satellite-1A Linear Imaging Self Scanning System) radiance data and field measured change in secchi disc depth (water clarity). Secchi disc depth was measured for 47 predetermined sampling locations on reservoir surface water. At extinction depth (secchi depth) water samples were collected from all the sampling locations. Suspended sediments of 8 locations representing various reaches of the reservoir were selected for mineralogical, particle size and optical property analysis.
The LISS-I radiance value in band 1 (0.45-0.52 mm) band 2 (0.52-0.59 mm) and band 3 (0.62-0.68 mm) were used in a regression analysis. The absorption infrared band 4 (0.77-0.86 mm) was not included in the analysis. In these the dependable variable was seechi depth (SD) and the LISS-I radiance data was the estimator variable. Forty-seven data sets of 20th Oct.1988 from Tawa reservoir surface water were used to obtain an estimator equation for SD. The verification of the estimator equation was tested by applying it to a data set of twenty-one measurements of 28th Sept. 1988 for this reservoir. The coefficient of correlation between observed and estimated values for the 28th Sept. 1988 data set was r=0.92 for SD, indicating that the equation could accurately predict the water clarity (SD) for this reservoir on new occasions from IRS-IA-LISS-I spectral data. It is shown that mineral composition and optical properties of suspended sediments influence the reflected radiance of water clarity. It is concluded that IRS-IA-LISS-I data provide a useful means of mapping water quality in reservoir.
A Study on Fluoride and Other Water Quality Parameters of Ground Water of District Agra (U.P.)
Sahab Dass, Meetu Agarwal, Y. S. Chaudhary and Rohit Shrivastav
Department of Chemistry, Faculty of Science,
Dayalbagh Educational Institute (Deemed University),
Dayalbagh, AGRA - 282 005
High pH and high bicarbonate concentration mainly control fluoride concentration in water and the major sources identified are anthropogenic activities and leaching of soil and fertilisers. The role of fertiliser leaching in groundwater is also evident by the fact that phosphate and potassium, which are the major constituents of fertilisers come together in the same factor. Dental fluorosis was observed in most of the villages even where fluoride concentration in drinking water was below 1.0 ppm while skeletal fluorosis was observed in few villages. Evidence of extensive prevalence of dental fluorosis in this area strengthen the need for further research to examine the potential role of food and other sources of fluoride to human beings and if necessary, attempts should be directed towards redefining the permissible levels of fluoride in drinking water.
A Study on the Hydrogeochemistry of Fluoride Bearing Groundwaters of Erode District, Tamil Nadu
S. Chidambaram1, AL. Ramanathan2, K. Srinivasamoorthy1 and P. Anandhan
1Department of Geology, Annamalai University, Annmalai nagar. 608002.
2SES, JNU, New Delhi – 110067
The problem of high fluoride in groundwater has now become one of the most important toxicological and geoenvironmental issues in India. During the last 3 decades high fluoride concentration in water resources resulting in the disease called "Fluorosis" is being highlighted considerably throughout the world. The present study deals with the chemistry of fluoride concentration in groundwater in Erode district. The result was based on 156 water samples from two different aquifers in 4 different seasons. The dominant rock types of the region are biotite hornblende gneiss and Charnockite. In the places of rock dominance with apatite especially in pegmatite, granite and charnockite, the fluoride concentrations are higher. So the hydrogeochemistry of the groundwater in these two dominant aquifers of the region indicate the behavior of the fluoride ion in them. Geochemical studies reveal the variations in the (H4SiO4/HCO3), (F/Alkali) and (F/Ca+Mg) molal ratios and the ionic strength of the groundwater in the aquifers. The correlation and statistical analysis show that the concentration of ions in the BHG is lesser due to the frequent flushing take place there. Fluoride concentration is generally lower than prescribed limit in most of the groundwater samples, except few areas where the F concentration is >1.5 ppm. In some places groundwater needs fluoridation to enhance fluoride levels in groundwater. The study reveals that the fluoride concentration is controlled by the lithology of the area.
Geochemical Modeling of Ramanathapuram Coastal Aquifer, Tamil Nadu Using GIS
K. Vaithiyanathan, B. Gowthaman, J. Prabhakar and J. F. Lawrence
Department of Geology,
Presidency College, Chennai 600 005.
This study evaluates the ground water quality of Ramanathapuram Coast. The study area falls in the southeastern part of India. To evaluate Hydrogeochemistry of the coastal track of the study area 50 sampling locations have been identified and collected. All samples have been analysed for various physical and chemical parameters. The percentage values of different ions have been plotted in reconstructed diamond of Piper’s Trilinear diagram. Thematic maps have been prepared using GIS techniques. An integrated map has been generated which shows the area invaded by saline water along the coast.