Land use patterns and urbanization in the holy city of Varanasi, India: a scenario

Rapid urbanization and increasing land use changes due to population and economic growth in selected landscapes is being witnessed of late in India and other developing countries. The cities are expanding in all directions resulting in large-scale urban sprawl and changes in urban land use. The spatial pattern of such changes is clearly noticed on the urban fringes or city peripheral rural areas than in the city center. In fact, this is reflected in changing urban land use patterns. There is an urgent need to accurately describe land use changes for planning and sustainable management. In the recent times, remote sensing is gaining importance as vital tool in the analysis and integration of spatial data. This study intends to estimate land use pattern in a planned and unplanned urban setup and also to analyze the impact of change in land use pattern in the Varanasi urban environment. The results indicate that the planned urban setup had a higher tree cover to that of unplanned area in the Varanasi City, although a considerable disparity existed within the planned urban setups. The results emphasize the need to critically review concepts of urban planning and give more consideration to the preservation and management of urban tree cover/greenspace.     

Waterborne outbreaks in diarrhoea endemic foci of India: a longitudinal exploration and its implications

Diarrhoea remains a global public health enigma raising deep concerns for the health planners since contaminated potable water often spoils the community health structure. We hereby report a 6-year odd continuing outbreak surveillance report based on potable water indices, during which 264 water samples were screened from different districts of West Bengal, India. Samples were analysed for the presence of different enteropathogenic bacterial species by conventional molecular tools and their sensitivity to antibiotics. 78.03% samples were positive for enteropathogenic bacterial organisms and 75% samples harbored Coliform. 45.45, 12.12, and 4.16% samples were positive for E.coli, V. cholerae, and V. mimicus, respectively. Diarrhoeagenic E.coli 7 EPEC, 10 ETEC, and 2 EIEC were isolated along with 2 V. cholerae O1 Ogawa (ctxA and tcpA ElTor positive), one each from tube well and pond. Interestingly, 4 V.cholerae non-O1/non-O139 also harbored hlyA gene. The detection of toxin genes among this bacterial pool of sampled water indicates the fallout of the potable water sources, thus enabling us to establish that it is none other than the contaminated potable water system which often wreaks havoc in the south Bengal diarrhoeal menace. The consequences are further complicated by the presence of drug-resistant pathogenic bacterial pool to fluoroquinolone, beta-lactams, and cephalosporins, in the accessible potable water, with threats of outbreaks exploding into an epidemic, given suitable environment, poor sanitation, and unhygienic practices. Therefore, we strongly recommend re-modelling of ‘point-of-use water disinfection’ measures and adequate personal hygiene for healthier community life.     

Study on the hydrogeochemical characteristics in groundwater, post- and pre-tsunami scenario, from Portnova to Pumpuhar, southeast coast of India

Natural hazards cause great damage to humankind and the surrounding ecosystem. They can cast certain indelible changes on the natural system. One such tsunami event occurred on 26 December 2004 and caused serious damage to the environment, including deterioration of groundwater quality. This study addresses the groundwater quality variation before and after the tsunami from Pumpuhar to Portnova in Tamil Nadu coast using geochemical methods. As a part of a separate Ph.D. study on the salinity of groundwater from Pondicherry to Velankanni, water quality of this region was studied with the collection of samples during November 2004, which indicated that shallow aquifers were not contaminated by sea water in certain locations. These locations were targeted for post-tsunami sample collection during the months of January, March and August 2005 from shallow aquifers. Significant physical mixing (confirmed with mixing models) within the aquifer occurred during January 2005, followed by precipitation of salts in March and complete leaching and dissolution of these salts in the post-monsoon season of August. As a result, maximum impact of tsunami water was observed in August after the onset of monsoon. Tsunami water inundated inland water bodies and topographic lows where it remained stagnant, especially in the near-shore regions. Maximum tsunami inundation occurred along the fluvial distributary channels, and it was accelerated by topography to a certain extent where the southern part of the study area has a gentler bathymetry than the north.     

Pesticide residues in river Yamuna and its canals in Haryana and Delhi, India

Yamuna, a prominent river of India covers an extensive area of 345,843 km(2) from Yamunotri glacier through six Indian states. Residues of organochlorine pesticides (OCPs) namely, isomers of HCH and endosulfan, DDT and its metabolites, aldrin, dieldrin, were analysed in water of river Yamuna along its 346 km stretch passing through Haryana-Delhi-Haryana and the canals originating from it. beta-HCH, p.p'-DDT, p.p'-DDE and p.p'-DDD had maximum traceability in test samples (95-100%) followed by gamma-HCH, alpha-HCH and o.p'-DDD (60-84%) and o.p'-DDT, delta-HCH and o.p'-DDE (7-30%) while aldrin, dieldrin, alpha and beta endosulfan remained below detection limits (BDL). The concentration of SigmaHCH and SigmaDDT at different sites of the river ranged between 12.76-593.49 ng/l (with a mean of 310.25 ng/l) and 66.17-722.94 ng/l (with a mean of 387.9 ng/l), respectively. In canals the values were found between 12.38-571.98 ng/l and 109.12-1572.22 ng/l for SigmaHCH and SigmaDDT, respectively. Water of Gurgaon canal and Western Yamuna canal contained maximum and minimum concentration, respectively both of SigmaHCH and SigmaDDT residues. Sources of these pesticides and suggested measures to check pesticide pollution of this major Indian river, keeping in view its vital link with life, are discussed in this paper.     

Groundwater quality and its suitability for domestic and agricultural use in Tondiar river basin,Tamil Nadu,India

Assessment of suitability of groundwater for domestic and agricultural purposes was carried out in Tondiar river basin, Tamil Nadu, India. The study area covers an area of 315 km² and lies in a semiarid region. Groundwater is the major source for domestic and agricultural activity in this area. Groundwater samples were collected from 45 wells during pre-monsoon and post-monsoon period in the year 2006. The water samples were analysed for physical and chemical characteristics. Suitability of groundwater for irrigation was evaluated based on salinity hazard, sodium percent, sodium adsorption ratio, residual sodium carbonate, US salinity diagram, Wilcox’s diagram, Kelly’s ratio and permeability index. Ca-HCO₃, mixed Ca–Mg–Cl and Na–Cl were the dominant groundwater types. High hardness and electrical conductivity in this area makes the groundwater unsuitable for drinking and agricultural purposes. Concentration of trace elements (Mn, Cu, Zn, Pb and Ni) did not exceed the permissible limit for drinking and agricultural purposes. Majority of the groundwater samples were unsuitable for domestic and agricultural purposes except for 31% and 36%, which were suitable for drinking and irrigation purposes, respectively.     

Evaluation of groundwater quality and its suitability for drinking and agricultural use in Thanjavur city, Tamil Nadu, India

As groundwater is a vital source of water for domestic and agricultural activities in Thanjavur city due to lack of surface water resources, groundwater quality and its suitability for drinking and agricultural usage were evaluated. In this study, 102 groundwater samples were collected from dug wells and bore wells during March 2008 and analyzed for pH, electrical conductivity, temperature, major ions, and nitrate. Results suggest that, in 90% of groundwater samples, sodium and chloride are predominant cation and anion, respectively, and NaCl and CaMgCl are major water types in the study area. The groundwater quality in the study site is impaired by surface contamination sources, mineral dissolution, ion exchange, and evaporation. Nitrate, chloride, and sulfate concentrations strongly express the impact of surface contamination sources such as agricultural and domestic activities, on groundwater quality, and 13% of samples have elevated nitrate content (>45 mg/l as NO₃). PHREEQC code and Gibbs plots were employed to evaluate the contribution of mineral dissolution and suggest that mineral dissolution, especially carbonate minerals, regulates water chemistry. Groundwater suitability for drinking usage was evaluated by the World Health Organization and Indian standards and suggests that 34% of samples are not suitable for drinking. Integrated groundwater suitability map for drinking purposes was created using drinking water standards based on a concept that if the groundwater sample exceeds any one of the standards, it is not suitable for drinking. This map illustrates that wells in zones 1, 2, 3, and 4 are not fit for drinking purpose. Likewise, irrigational suitability of groundwater in the study region was evaluated, and results suggest that 20% samples are not fit for irrigation. Groundwater suitability map for irrigation was also produced based on salinity and sodium hazards and denotes that wells mostly situated in zones 2 and 3 are not suitable for irrigation. Both integrated suitability maps for drinking and irrigation usage provide overall scenario about the groundwater quality in the study area. Finally, the study concluded that groundwater quality is impaired by man-made activities, and proper management plan is necessary to protect valuable groundwater resources in Thanjavur city.     

Airborne load of Cassia pollen in West Bengal, eastern India: its atmospheric variation and health impact

A Burkard personal volumetric sampler was used at Sriniketan, a town about 150 km northwest of Calcutta, in the state of West Bengal, in eastern India to record the frequency of three common airborne Cassia pollen types, Cassia tora, Cassia occidentalis, and Cassia fistula for two consecutive years (2004–2006). Correlation was made between the meteorological factors and the pollen concentration in the atmosphere. The study reports Cassia pollinosis by in vivo skin prick test in respiratory allergic patients. The highest positive reactions were exhibited by C. tora (34.7 %), C. fistula (33.3 %), and C. occidentalis (28.5 %). The allergic potential of these was investigated by in vitro enzyme linked immunosorbent assay test. Their protein components were analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, in the range of 15.8–81.5 kDa. In C. occidentalis and C. fistula, 11 bands were found, while it was 10 in C. tora. The results show that the Cassia pollen occur significantly in the atmosphere with the potential to elicit an allergic response in susceptible patients.     

Major Ionic Composition of Aerosol, Rainwater and its Impact on Surface and Sub-surface Waters, in and Around Mangalore, West Coast of India

Mining activities in Rakha copper mine (Jharkhand, India) were ceased in the year 2001, leaving a huge amount of untreated tailings in the nearby tailings pond. The copper tailings contained high concentrations of heavy metals (total Cu, Ni concentrations 1779, 564 mgkg⁻¹, respectively), and low contents of major nutrient elements and organic matter. Tailings are often very unstable, and a potential vegetation cover may reduce the erosion or immobilize the toxicants to surrounding environment by phytostabilization. However, high shoot concentrations of elements might disperse them and could be harmful to grazing animals. The objective of this study was to find out which of the three properties; low-accumulation, root accumulation or shoot accumulation of elements (Cu, Ni, Mn, Zn, Pb, Cd and Co), occur in the semi aquatic species Ammania baccifera growing on copper tailings. Roots of this species accumulated high levels of Cu, even more than 1000 mg kg⁻¹, DW. Metals accumulated by A. baccifera were mostly distributed in root tissues, suggesting that an exclusion strategy for metal tolerance widely exists in them. Thus, establishment of such plant on copper tailings can be a safe method to stabilize the metals.     

Limnochemistry and nutrient dynamics in Upper Lake, Bhopal, India

In limnetic ecosystem, water quality depends upon physical, chemical, and biological factors. Effects of temperature, light scattering, and absorption by suspended and dissolved matter, transport, and mixing of nutrients within the lake are the significant factors as far as water quality is concerned. Nutrient loading into the lake and internal cycling of nutrients is always a matter of concern and critical to number of processes. During the winter season, heat and momentum transfer at the lake surface and the temperature-density relation of water destabilize the water column and drive vertical mixing and transport processes. The deepening of the surface layer produces nutrient transfer from the hypolimnion into the euphotic zone of epilimnion. It may also resuspend sediments that would have settled under stratified conditions, or redistribute particles that may still be in suspension. Thus, there exists a complex connection between the hydrodynamics and water quality issues. Present study is an effort to understand how seasonal changes in the limnetic ecosystem regulate the limnochemistry and movement of nutrient. The study revealed that significant variations of nutrients and organic load were observed between epilimnion and hypolimnion during summer season, and the lake was found in hyper-eutrophic condition throughout the study period.     

An innovative technique for lake management with reference to aeration unit installed at lower lake, Bhopal, India

Water is key element in human life. All forms of life upon the earth depend upon water for their mere existence. Life & water may be aptly said to be two facets of the same coin. Most of the water bodies are getting polluted due to domestic waste, sewage, industrial waste and agricultural effluent. The present study is designed to ascertain the effectiveness of artificial aeration cum Ozonizer unit installed at Lower Lake, Bhopal for assessment of water quality. Various physico- chemical parameters like pH, Dissolved oxygen, Biochemical Oxygen demand, Chemical oxygen demand, nitrate, phosphate and bacteriological status were studied to assess the extent of deterioration in water quality of Lower lake and at the same time to assess the performance of the dual aeration system in improvement of water quality.     

Particulate matter concentration in ambient air and its effects on lung functions among residents in the National Capital Region, India

The World Health Organization has estimated that air pollution is responsible for 1.4 % of all deaths and 0.8 % of disability-adjusted life years. NOIDA, located at the National Capital Region, India, was declared as one of the critically air-polluted areas by the Central Pollution Control Board of the Government of India. Studies on the relationship of reduction in lung functions of residents living in areas with higher concentrations of particulate matter (PM) in ambient air were inconclusive since the subjects of most of the studies are hospital admission cases. Very few studies, including one from India, have shown the relationship of PM concentration and its effects of lung functions in the same location. Hence, a cross-sectional study was undertaken to study the effect of particulate matter concentration in ambient air on the lung functions of residents living in a critically air-polluted area in India. PM concentrations in ambient air (PM_1, PM_2.5) were monitored at residential locations and identified locations with higher (NOIDA) and lower concentrations (Gurgaon). Lung function tests (FEV₁, PEFR) were conducted using a spirometer in 757 residents. Both air monitoring and lung function tests were conducted on the same day. Significant negative linear relationship exists between higher concentrations of PM₁ with reduced FEV₁ and increased concentrations of PM_2.5 with reduced PEFR and FEV₁. The study shows that reductions in lung functions (PEFR and FEV₁) can be attributed to higher particulate matter concentrations in ambient air. Decline in airflow obstruction in subjects exposed to high PM concentrations can be attributed to the fibrogenic response and associated airway wall remodeling. The study suggests the intervention of policy makers and stake holders to take necessary steps to reduce the emissions of PM concentrations, especially PM_1, PM_2.5, which can lead to serious respiratory health concerns in residents.     

Larval abundance and its relation to macrofouling settlement pattern in the coastal waters of Kalpakkam, southeastern part of India

The present work revealed that salinity, water temperature, and food availability were the most crucial factors affecting the abundance of larvae and their settlement as macrofouling community in the coastal waters of Kalpakkam. Quantitative as well as qualitative results showed that late post-monsoon (April–May) and pre-monsoon (June–September) periods were found to be suitable periods for larval growth, development, and survival to adult stages for most of the organisms. Clustering of physico-chemical and biological (including larval and adult availability) data yielded two major clusters; one formed by northeast (NE) monsoon months (October–January) and the other by post-monsoon/summer (February–May) months, whereas; pre-monsoon months (June–September) were distributed between these two clusters. Among all the major macrofouler groups, only bivalves established a successful relationship between its larval abundance and adult settlement. Principal component analysis indicated good associations of bivalve larvae with polychaete larvae and adult bivalves with adult barnacles. However, biotic relation between ascidians and bryozoans was observed both in the larval as well as adult community.     

Prevalence of certain inorganic constituents in groundwater samples of Erode district, Tamilnadu, India, with special emphasis on fluoride, fluorosis and its remedial measures

A total of 60 drinking water samples collected from Erode district, Tamilnadu, India were analysed for fluoride contamination, besides water quality parameters such as pH, electrical conductivity, total dissolved solids, total alkalinity, total hardness, fluoride, bicarbonates, calcium, magnesium, nitrate, sulphate, phosphate, sodium and potassium. The results obtained were found to exceed the permissible limits. The concentration of fluoride in the water samples ranged between 0.5 and 8.2 mg/l and revealed that 80% of the water samples contain fluoride above the maximum permissible limit. Similarly, the concentrations of nitrate, hardness, calcium and magnesium in some samples were also more than the permissible level. Pearson’s correlation coefficient among the parameters showed a positive correlation of fluoride with total hardness and calcium. It is inferred from the study that these water sources can be used for potable purpose only after prior treatment.     

Hazard assessment of metals in invasive fish species of the Yamuna River,India in relation to bioaccumulation factor and exposure concentration for human health implications

Monitoring of heavy metals was conducted in the Yamuna River considering bioaccumulation factor, exposure concentration, and human health implications which showed contamination levels of copper (Cu), lead (Pb), nickel (Ni), and chromium (Cr) and their dispersion patterns along the river. Largest concentration of Pb in river water was 392 μg L^?1; Cu was 392 μg L^?1 at the extreme downstream, Allahabad and Ni was 146 μg L^?1 at midstream, Agra. Largest concentration of Cu was 617 μg kg^?1, Ni 1,621 μg kg^?1 at midstream while Pb was 1,214 μg kg^?1 at Allahabad in surface sediment. The bioconcentration of Cu, Pb, Ni, and Cr was observed where the largest accumulation of Pb was 2.29 μg kg^?1 in Oreochromis niloticus and 1.55 μg kg^?1 in Cyprinus carpio invaded at Allahabad while largest concentration of Ni was 174 μg kg^?1 in O. niloticus and 124 μg kg^?1 in C. carpio in the midstream of the river. The calculated values of hazard index (HI) for Pb was found more than one which indicated human health concern. Carcinogenic risk value for Ni was again high i.e., 17.02?×?10^?4 which was larger than all other metals studied. The results of this study indicated bioconcentration in fish due to their exposures to heavy metals from different routes which had human health risk implications. Thus, regular environmental monitoring of heavy metal contamination in fish is advocated for assessing food safety since health risk may be associated with the consumption of fish contaminated through exposure to a degraded environment.     

Stormwater metal loading to a well-mixed/stratified estuary (Sydney Estuary, Australia) and management implications

Stormwater modelling indicated an average annual discharge from Sydney estuary catchment of 215,300 mL and loadings of 0.8, 0.5, 1.7, 3.2, 1.1, 3.6 and 17.7 tonnes for As, Cd, Cr, Cu, Ni, Pb and Zn, respectively. Priority for remediation should be given to creeks with high-metal loads in the upper and central estuary, as well as discharging to the western shores of Middle Harbour. Managerial strategies need to target dissolved and particulate metal phases to ensure effective remediation. The proportion of metals discharged under low- (<5 mm rainfall/day), medium- (>5 to <50 mm/day) and high-flow conditions (>50 mm/day) was approximately 10%, 60% and 30% of total loading, respectively. Under high-flow conditions the estuary becomes stratified and most metals are exported to the sea, whereas metals discharged during low-flow may be remediated by infiltration. Effective remediation will depend on the extent to which ‘first-flush’ metals associated with medium-flow conditions can be remediated.     

Assessment and Prediction of Soil Erosion and its Impact on the Storage Capacity of Reservoirs in the Bharathapuzha River Basin,India

Environmental Modeling & Assessment - Soil, one of the non-renewable resources on this planet, is being depleted at an alarming rate due to various anthropogenic activities. The effect of soil...     

Chemistry of groundwater in Gulbarga district, Karnataka, India

Groundwater quality of Gulbarga District is extensively monitored for two years of study period from October 1999 to September 2001. Twenty-five different sampling stations were selected for the study purpose in the city and five selected villages in the district. Gulbarga districts lies in the northern plains of Karnataka State, covers an area of 16,244 km² and lies between 16°-11′ and 17°-19′N latitude and 76°-54′E longitude The study revealed that the water sources in the area are heavily polluted. The major water quality parameters exceeding the permissible limits during all the seasons are total hardness, calcium hardness, magnesium hardness, alkalinity and MPN (Bacterial count) and other parameters have shown distinctive variation in different stations and season. Most of these parameters are correlated with one another. Statistical analysis of the data is presented.     

The application of satellite data for the quantification of mangrove loss and coastal management in the Godavari estuary, East Coast of India

The mangrove formations of Godavari estuary are due to silting over many centuries. The estuary covers an area of 62,000 ha of which dense Coringa mangrove forest spread in 6,600 ha. Satellite sensor data was used to detect change in the mangrove cover for a period of 12 years (1992-2004). It was found that an area of about 1,250 ha of mangroves was destroyed by anthropogenic interference like aquaculture, and tree felling etc. It was found that mangrove's spectral response/digital number (DN) value is much lower than non-mangrove vegetation such as plantation and paddy fields in SWIR band. By taking this as an advantage, spectral data was utilized for clear demarcation of mangroves from nearby paddy fields and other vegetation. Simpson's diversity index, which is a measure of biodiversity, was found to be 0.09, showing mangroves dominance. Ecological parameters like mud-flats/swamps, mangrove cover alterations, and biodiversity status are studied in detail for a period of 12 years. The increase in mangrove front towards coast was delineated using remote sensing data. The major advantages of remote sensing data is monitoring of change periodically. The combination of moderate and high-resolution data provided detailed coastal land use maps for implementing coastal regulation measures. The classification accuracy has been achieved is 90%. Overall, simple and viable measures are suggested based on multi-spectral data to sustain this sensitive coastal ecology.