Climate Impacts on Water Resources in India

The linkages between water and health are direct, and one major issue is to determine how extreme weather/climate change could potentially impact our water, and hence public and animal health. Although there are numerous studies indicating increase in transmission of vector-borne diseases due to warmer temperature, how climate change will have long-term effects on water borne pathogen, microbial contamination, and public health is yet known. To understand the possible impact of air temperature and stream flows on pathogen levels in ambient water, this analysis built on a previous study of Pandey (Modeling in-steram E. coli concentrations. Iowa State University, Ames, Iowa, 2012), which executed a multiple year study focused on testing pathogen indicator (E. coli) in various locations in a river in Iowa. In this watershed-scale study, agriculture land use is the dominant use with limited urban impacts. The results showed the cyclical pattern of pathogen indicator concentrations in the stream water column, which was associated with air temperature patterns in summer and winter seasons. While precise understanding of extreme weather effects on microbial water quality is yet to be known, these results substantiate the fact that an increase in air temperature coincided with the increase in waterborne pathogens in streams, which may increase public and animal health risks through exposure to microbial contamination in water.

Shimla city is the capital of the hilly state, Himachal Pradesh. It is situated in the south of river Satluj. The drinking water supply to major portion of the city is met through Ashwani Khad and Dhalli water supply schemes. Ashwani Khad water treatment plant (WTP) receives water from a natural stream, Malyana sewage treatment plant (STP) treated water, and three open drains. During lean period, the treated water is supplemented with bore well water to fulfill the demand and is supplied to consumers after chlorination. Dhalli WTP receives water from Churat Nallah and Sayog catchment, and supplied to consumers after treatment. A mass level jaundice was reported in the Sanjauli-Malyana area of Shimla City during 2006–2007. In view of this, study of contamination in drinking water sources of Shimla City was carried out using hydrological and water quality data analysis. In the present paper, the causes of contamination in drinking water supply and options for ameliorative measures have been identified and discussed.

Water pollution is a global challenge calling for attention. The Upper Ganga Canal (UGC) System which plays a significant role in Northern India, as a source of water for irrigation, drinking water, and spiritual upliftment, is also not spared. Due to the increasing population in the vicinity of canal, the quantity of untreated effluent being discharged into the canal is also increasing, leading to deterioration in the quality of canal water. The main objective of this study was to assess the status of UGC for agricultural application using Water Quality Index (WQI). Irrigation with poor quality water may cause salinity, specific ion toxicity, or infiltration problems in soils. In this regard, forty water samples were collected from five locations during July 2015 to February 2016. The samples were investigated for physico-chemical parameters and trace metals. The irrigation water quality parameters for deciding the suitability of water was computed from the analyzed parameters. The results were integrated in the calculation of the WQI of the UGC water for irrigation purposes, considering the permissible values recommended by Bureau of Indian Standards and Food and Agriculture Organization of United Nations. The calculated WQI varies from 37 to 42 during the study period, with an overall WQI of 38.22. The estimated WQI suggests that, the canal water quality is good for irrigation purposes throughout the study period.

Anthropogenic forces have led to the deterioration of water bodies over the course of time. This calls for implementation of an effective water quality management scheme. The design of an optimal water quality monitoring network (WQMN) is one of the earliest steps required towards the development of efficient water quality management scheme. One of the most important components of a WQMN is the rationalization of water quality parameters (WQPs). Since the water quality is stochastic in nature, multivariate statistical techniques are best suited to capture the variability. Krishna River is one of the major river basins of India, which has been influenced by various man-made activities. Hence, in present analysis rationalization of WQPs for the Krishna River is carried out by using factor analysis (FA)/principal component analysis (PCA), followed by estimation of water quality indices for pre and post rationalized WQPs. Water quality monitoring data for Krishna River was procured from Water Resources Information System, India, consisting 16 monitoring stations with 16 WQPs averaged over the period 2001–2010. The results showed that out of the 16 WQPs, 8 parameters were principal WQPs. The monitoring of the rationalized parameters may result in significant reduction in cost while capturing majority of the variation in water quality.

In India, one of the major sources of water is the groundwater. Currently, its quality is being degraded due to many reasons such as intrusion of waste from various chemical factories and other industries. The objective of the study was to analyze the groundwater quality in the vicinity of the Kala Sanghian drain, Jalandhar. The drain carries waste from various industries in Jalandhar and is unlined which might affect the quality of the nearby groundwater. The physiochemical and heavy analysis was carried out on 30 samples collected from different locations of varying depths along the drain. It was observed that the values for some of the parameters are exceeding the permissible limit. The reason for dwindling quality of water in the area may be due to the discharge of the industrial waste into the Kala Sanghian drain. Hence, quick and reliable monitoring measures are essential for safeguarding the water quality. Geographic Information System was used to map the parameters values in terms of WQI in spatial domain which would help in better visualization of the problem and improved decision making.

Water Quality Index is an effective tool to measure the quality of water based on different parameters. In this study, a part of Pindrawan tank command area under Mahanadi river basin in Raipur district of Chhattisgarh was selected to assess the suitability of water for drinking purpose. 25 water samples were collected from various surface and groundwater sources of the study area for comprehensive water quality analysis and 11 physio-chemical parameters such as: pH, fluoride, chloride, total hardness, total dissolved solids, iron, calcium, sodium, potassium, electrical conductivity and alkalinity were considered for calculating Water Quality Index (WQI). WQI was computed using logarithmic method. Spatial distribution maps for different parameters were prepared using IDW technique in GIS interface. The study area was categorised from excellent to unsuitable for drinking water zones according to the computed WQI values. Out of 25 water samples analysed for drinking water quality, 2 samples were found to be unsuitable for drinking, 10 samples fall under good/excellent and 13 samples quality were poor. Water in the poor zone can be utilised for drinking after proper treatment. This study demonstrates the efficiency of GIS for analysing the complex spatial data for water quality mapping.

In the recent times, the rapid rise in urbanisation complemented with population growth is necessitating much attention for potable water across the world. Due to the unavailability of adequate fresh water resources, Groundwater became the only potable source to majority of places across the world. The dependency on ground water due to scarce fresh water resources is commonly observed in densely populated regions such as India. Due to the persistence of extravagant anthropogenic activities, the quality of the groundwater is observed to be at critical levels in regions such as India. The present study concentrates on a water quality indicator called Ground Water Quality Index (WQI) representing overall water quality based on physico-chemical characteristics of a water sample. As the WQI is quantified based on the weighted average of the physical-chemical concentrations of water quality characteristics, the study considered sixteen parameters to ascertain accurate results. The ground water samples were collected from Kadapa City in Andhra Pradesh, India and physicochemical tests were performed to evaluate WQI. It is observed in the present study that higher values of WQI indicating poor water quality has been found due to excessive concentrations of Hardness, Total dissolved solids, Electrical conductivity, Turbidity, Alkalinity, and Fluorides in the collected water samples. Furthermore, the study proposes Citrus limetta (Sweet lemon) peel powder as a coagulant and the variability of WQI Values with coagulant concentrations are investigated. In addition, sensitivity analysis to examine the impact of coagulant dosage, mixing speed and stirring time on WQI is executed and optimal levels of these conditions resulting in minimum WQI values are found. A comparative study is also accomplished to examine the effect of different proportions of Alum and Citrus limetta combination on WQI. The present study recommends Citrus limetta peel powder as a natural, environmental friendly, locally available, cheap, and effective coagulant to treat Groundwater and to improve water quality status.

The present research work deals with the study of some of the essential physicochemical parameters of water samples of “Taranga beel” (Beel is a local term which defines wetland) of Jagiroad, Assam, India. This study indicates a decline in the water quality of Taranga beel due to the paper industry’s influence in its vicinity. The collection of samples and the determination of various physicochemical parameters and heavy metal concentration was done according to the standard protocol. The physicochemical parameters such as Total Solids (TS), Total Dissolved Solids (TDS), Turbidity, pH, conductivity, Chemical Oxygen Demand (COD), Sulphate, Dissolved Oxygen (DO), Fluoride, and heavy metals such as Cd, Cr, Cu, Fe, Mg, Mn, Na, Ni and Pb were analyzed thoroughly. Among all the physicochemical parameters and heavy metals, the concentration of TS, TDS, Turbidity, DO, COD, Cr, Pb, Mn, and Fe were above the permissible limits prescribed by the Bureau of Indian Standards (BIS).

Agriculture is the leading source of non-point source of water pollution mainly due to excess application of the fertilizers by the farmers to obtain more yield. The major portion of the applied fertilizer is being lost to the environment causing degradation of the land and water resources. One of the possible ways to deal with this problem in recent years comes out to be the application of nano-fertilizers in agriculture. Controlled release of nutrients is possible through the application of nano-fertilizers. Moreover, application of nutrients in nano form (nano-fertilizers) makes it easier for the plants to utilize the nutrients in a better way. But, the fate, mobility and transport of nano-fertilizers is still a question that is not been answered in recent times. An attempt was made in this study to know the mobility and transport of the nano-fertilizers such as nano-hydroxyapatite (nHAP) and urea doped nano-hydroxyapatite (Ur@nHAP) in the soil. Results from the soil column studies indicated that leaching of NH₄-N and NO₃-N were 55% less in case of Ur@nHAP treatment compared to Urea treatment and Ortho-P leaching was 128% less in case of both nano-fertilizer (nHAP and Ur@nHAP) treatments compared to Superphosphate treatments. The rate of transport of Phosphorus was found to be about half that of Nitrogen. Hence the application of nano-fertilizers to the soil may be environmentally safe and effective for crop production. However, more extensive studies with modelling tools may be needed  to understand the mobility and transport of nano-fertilizers in different soil types.

A promising method that can improve the bioavailability and biodegradability of polyaromatic hydrocarbons (PAH) is the use of biosurfactants. In this work, Biosurfactants produced from lactic acid bacteria were utilized for bioremediation of Benzo(a)Pyrene. Besides, lignocellulosic waste (Luffa acutangula) was also used as a carbon source for production of the cost effective biosurfactants. Initially, acid hydrolysis of lignocellulosic waste was done. Following, Lactobacillus plantarum, L. casei, L. acidophilus were employed for fermentation after nutrient supplementation separately. Then the Lactobacillus cells were submitted to extraction process with phosphate buffer saline (PBS) to evaluate the intercellular biosurfactants. Biosurfactants were measured based on surface tension reduction. The results showed that the surface tension and CMC of biosurfactants from L. plantarum, L. casei, L. acidophilus were 58, 51, 60 mN/m and 8, 12, 6 g/L respectively. The FTIR characterization showed that the produced biosurfactants was Glycoprotein/Glycolipid. The ¹H NMR results confirmed that the produced biosurfactant was Glycolipid only. The produced biosurfactants employed in industrial sludge, which was contaminated with 500 mg/kg of Benzo(a)pyrene. After mobilization process, sample was analyzed in GC resulting that 60% (approx.) degradability of Benzo(a)Pyrene. With the help of this technique, the biodegradability of PAH contaminated sites can be improved.

Studies were conducted during the wet and dry seasons to understand the settling velocity of cohesive suspended sediments in the Muthupet estuary, a Ramsar site in Tamil Nadu, India. Settling velocity was identified to be a function of suspended sediment concentration, turbulence and salinity gradient. An empirical model was developed for settling velocity with its influencing parameters for two scenarios based on the stratification parameter δS/<S> , which relates the difference in salinity between the bottom and the surface (δS) with the average salinity of the water column (<S>). The model was extended to another estuary with similar estuarine characteristics in terms of hydrodynamic classification, tidal range and freshwater flow regimes in the northwestern part of Morocco, the Bouregreg estuary. Settling velocity was observed to be an inverse function of suspended sediment concentration at the meandering zone. The relationship between settling velocity and suspended sediment concentration was difficult to predict due to dredging activities in the location near the mouth. The settling velocity exhibited a direct relationship with turbulence shear at low values of turbulence, while an inverse relationship was observed at higher turbulence shear. Thus, the model predicted settling velocity fairly well at the upstream location, but failed to prove its applicability at the downstream stations due to natural and anthropogenic interventions such as meandering and dredging respectively.

This communication primarily deals with the effect of water cooling condensing cover and helically coiled heat exchanger on single slope solar still integrated with Photovoltaic Thermal Compound Parabolic Concentrators (PVT-CPCs). The design parameters for the active distillation system have been optimized and furthermore production cost of distilled water (₹ 0.11/kg) is obtained. The computational work show that carbondioxide mitigated is 13 ton CO₂/annum and the revenue generated is $108/annum on the basis of energy. The proposed active distillation system gives higher efficiency of solar module (12.03% June, New Delhi, India) with higher distilled water (32.50 kg, daily) because of lower solar cell temperature (68 ℃) and cooling condensing cover.

The present study was envisaged to estimate environmental flows (EFs) of Satluj river with limited ecological information. For this study, Satluj river basin up to Kasol gauging site has been considered and the EF assessment has been done at three locations viz. Rampur, Suni, and Kasol. The daily discharges of Satluj river at these sites for the years 1964–2011 were used for the analysis. The Global Environmental Flow Calculator (GEFC) developed by Smakhtin and Anputhas (An assessment of environmental flow requirements of Indian river basins p. 42, 2006); Smakhtin and Erivagama (2008) was used to estimate the EFs for different Environmental Management Classes (EMCs). The assessment of ecological status of the river in terms of EMC has been carried out as prescribed by Smakhtin et al. (Developing procedures for assessment of ecological status of Indian river basins in the context of environmental water requirements p. 40, 2007). The ecological status of Satluj River is found to be representative of EMC ‘C’ at all the three sites. The average monthly EFs at Rampur, Suni, and Kasol sites vary from 63.06 m³/s (February) to 397.92 m³/s (July), 71.32 m³/s (January) to 431.62 m³/s (July) and 77.78 m³/s (January) to 455.45 m³/s (July) respectively. The EF in terms of percentage of long-term natural mean annual runoff at Rampur, Suni, and Kasol sites range from 42.34, 41.50 and 41.49% respectively at Rampur, Suni, and Kasol sites.

Large number of river valley Hydro Power Projects (HPP) in Himalayan region are in different stages of implementation. Many of these Hydro Power Projects include diversion structures with long Head Race Tunnel. This results in reduction of river flow in downstream reaches. To keep the river live and to ensure perennial environmental flow in the river, a provision for release of minimum flow called “Environmental Flow” as per the Ministry of Environment & Forest (MOEF) norms are being considered while estimating the design energy of Hydro Power Projects. In India, many Hydro Power projects in the Himalayan region got MOEF clearance with 10% of minimum flow for 90% dependable year as Environmental Flow. As per the latest environmental clearances for Hydro Power Projects from MOEF, the release of Environmental Flows recommended are 30, 25 and 20% of 90% dependable year for Monsoon season, Non-Monsoon-Non-lean season & Lean season respectively. In this paper, a power potential studies have been carried out for Kolodyne HPP-Stage-II (460 MW), Rupsiabagar Khasiyabara HPP (261 MW), Loharinag Pala HPP (600 MW) and Lata Tapovan HPP (171 MW) for earlier and revised Environmental Flow guidelines. With the revised releases of Environmental Flows, the Design Energy for Hydro Power Projects reduces drastically and makes projects unviable in some cases.

A two-stage integrated microbial fuel cell (MFC)-aerobic membrane bioreactor (MBR) based wastewater treatment technology with ruthenium/activated carbon (Ru/AC) as cathode catalyst in MFC was investigated. The results showcased the maximum volumetric power density and coulombic efficiency were nearly 1.4 and 1.5 times higher in case of MFC-MBR system with Ru/AC as cathode catalyst (2.7 W.m⁻³ and 12.8 ± 1.2%) than the control MFC-MBR system without Ru/AC (2.0 W.m⁻³ and 8.2 ± 0.6%), respectively. Moreover, these integrated MFC-MBR systems offered chemical oxygen demand (COD) removal efficiency of more than 96% from the synthetic wastewater having initial COD of around 1 g.L⁻¹. This integrated MFC-MBR technology offers an immense potential to be developed as full-scale application to offer reliable wastewater treatment along with bio-energy recovery.

The slaughterhouse wastewater (SWW) is highly influenced by carbonaceous and nitrogenous organic matter aside from significant quantity of dissolved inorganics. There are different streams of SWW, composite of which is exceptionally perfect for secondary biological treatment. The amount of biodegradable organic substances present in the slaughterhouse stream recommends that the anaerobic treatment process could be actualized as the best decision. In this study, the biological treatment of SWW was observed using the Hybrid Upflow Anaerobic Sludge Blanket Reactor (HUASBR) at a laboratory scale setup under continuous mode operation. In this study the reactor was subjected to various Chemical Oxygen Demand (COD) loading rates in the range of (2.95–37.98) Kg COD/m³/d under the Hydraulic Retention Times (HRT) between 24 and 6 h. The outcome of the HUASB Reactor shows that maximum COD removal efficiency of 94% can be achieved at the OLR of 18.29 kg COD/m³/d under 10 h HRT.

The depletion of water resources is increasing due to the excessive usage of surfactants and polyphosphates. These surfactants and polyphosphates promote the growth of nuisance causing microorganisms by providing a source of phosphate. Greywater contributes approximately 70–75% of the total domestic wastewater. Therefore, it is necessary to treat greywater and reuse it for gardening, irrigation, etc. The treated water can also be released into natural water bodies. Two biofilters were developed using activated carbon and wood chips in which coconut coir acted as support material. The average grain size of activated carbon and wood chips was found to be 1.0 mm–2.0 mm and 1.0 cm–2.0 cm respectively. The thin sheets of coconut fibers were collected from the local market whose density and permeability were measured. The activated carbon and wood chips of thickness 5.0 cm and 10.0 cm were sandwiched between the coconut fibers of 3.0 cm thick in two separate filter setups. A study was conducted for phosphate degradation in greywater using both the biofilters in the batch scale. Synthetic greywater was prepared by adding a known amount of detergent and liquid soap to potable water. Phosphate content in the greywater was analyzed using UV–Vis Spectrophotometer and chemical oxygen demand (COD) was determined by the closed reflux method. A batch of 5.0 L of water is retained in each of the filters with the retention time of eight days and the filtrate was analyzed for phosphate concentration and COD after every 24 h. Activated carbon removed 80% of phosphate and 72% of COD whereas woodchips could remove 45% of phosphates and 42% of COD when retained for 24 h. The removal capacity of biofilters was compared with the removal capacity of conventional sand filter, which reduced the phosphates and COD by 38% and 45% respectively. Studies were also conducted to assess the effect of hydraulic retention time on the removal of phosphate and COD concentration.

The present study was carried out with an objective to treat Greywater by a two-stage biological process i.e. anaerobic followed by aerobic each with a working volume of 3 L. It emphacises the results obtained during its operation for the last three months. Reactor was started with an HRT of 10 h and gradually reduced to 6 h in stages. The overall average efficiency by the system in terms of COD reduction, nutrients i.e. total nitrogen and phosphorous was around 83, 70 and 71% respectively. With the trend being followed by the reactors in the last three months, it is noticed that the system efficiency is gradually increasing and so we are evident that the system is gaining stability and thus may lead to better quality effluent with time. Investigations are being done with Photocatalysis as post treatment to further enhance the quality of water.

Water is the priceless endowment of nature which sustain life for billions of species on mother earth. We must make all efforts to preserve the precious gift of earth for sustainable existence in future. Main sources of natural fresh water supply are rivers, lakes, springs, ground water, rain water wells which are depleting rapidly with the increased pace of industrialization and due to the increasing pressure of burgeoning population on earth. While various water conservation Technologies in industries and particularly in Power Plants have been or are being employed to strive towards attainment of least amount of consumption of fresh water from earth surface, these measures alone are not enough, leaving the scope for something radical and novel practice or business model in entire water management chain for humans and industries including Power industries. Treated and recycled sewage water employing appropriate advanced processes for treatment of various types of waste water e.g. domestic sewage as well as industrial effluents, are also being growingly used now-a-days for various domestic & industrial applications, thereby reducing the pressure on fresh water. The present paper is intended for reading and practicing by modern power plant engineers towards attaining the goal of utmost water economy in Power Plants by adopting the sustainable practice of using recycled and treated municipal/urban sewage water which is otherwise disposed-off as waste water (treated or untreated) eventually finding its way to the river and natural water bodies on earth surface—thus contaminating continuously the pristine sources of water on one hand and indirectly helping the unabated escape of precious water to atmosphere through Cooling Tower and adsorption in solid ash after burning of coal in furnace. The water vapours will probably in course of time escape from earth surface rendering this wonderful compound a rare and scarce thing on earth.

This paper examines the efficiency of lemon peel adsorbents for removal of dyes, and cassava peel biochar for removal of iron from synthetic wastewater under laboratory conditions. These are the eco-friendly and economical adsorbents. Experiments were conducted to find out the effects of initial concentration and pH. The biochar was prepared by pyrolysis of cassava peel at 500⁰ C for 4 h. The removal of total iron was found to be dependent on adsorbate initial concentration and pH. Percentage removal increased with increase in initial concentration of adsorbate. Optimum pH for removal was found to be 5. Optimum removal efficiency of 89.84% by cassava peel biochar on iron adsorption was obtained from the batch study. The removal efficiency of dyes was found to be dependent on pH for lemon peel adsorbent. The optimum pH was obtained to be 2 and 4 for Acid Violet 17 and Remazol Brilliant Blue R respectively. The optimum initial dye concentration was 40 mg/L. The efficiency of dye removal increased with the increase in initial dye concentrations, and then decreased after the optimum value. An optimum Iron removal efficiency of 89.84% by cassava peel biochar was obtained from the batch study, but decreased in column studies (73.09%).

Surrounding vegetation, animal, human and microbiological decomposition are the strong source of humic acid (HA) falling into the surface water bodies during the process of rain-generated runoff in monsoon. HA contains various functional groups such as carboxylic, phenolic, hydroxyl and quinine which are the major foulants. Contact of HA may have adversarial health issue to human being namely goiter, black foot and cancer disease. The Environmental Protection Agency (EPA) has prescribed maximum permissible limit of 2 ppm of HA content in the drinking water. Membrane technology is the prominent technology for HA removal. However, membrane fouling due to foulants is one of the major issues. In the present work hydrophilic polysulfone membrane was synthesized using water soluble polyethylene glycol monomethyl ether (PEGME) of 5000 molecular weight. Membrane was characterized for the structure, morphology, hydrophilicity, fouling and rejection percentage of HA. Blended membrane shows very high rejection percentage of HA and less fouling than plain membrane.

General Circulation Models (GCMs) enable one to understand how climate changes on a regional scale and are of great importance in planning for our habitat. Statistical downscaling is the commonly used downscaling method mainly due to its computational efficiency. Even though studies utilizing GCM outputs for watershed level studies for certain basins in India are available, only very few are reported for peninsular region of India. The present study is aimed at estimating the better performing GCM for a river basin of Kerala State, India, which is bounded by the orographic features on one side and sea on the other side. Such type of studies is of increasing importance presently as the rainfall patterns and climate are seen to have a striking change in the recent past in the state. Multivariate Linear Regression with Principal Component Analysis was performed in this study for statistical downscaling of rainfall in the study region. Two GCMs namely CGCM3 and BCM2 were used for development of the downscaling models. The model was calibrated and tested with 50 years of NCEP reanalysis data and was used for projecting the precipitation in the study region. The performance of these GCMs was compared for arriving at a better model for water resources planning in the region. It was seen that BCM2 performed better in projecting the rainfall in the area.

In this study, trend in minimum temperature, maximum temperature, diurnal temperature range (DTR) and potential evapotranspiration (PET) has been assessed for the period of 1901–2013 over 21 stations in Betwa river basin, part of Central India. Modified Mann–Kendall (MMK) test has been employed for detecting the long-term trend in time series of variables. Further, Sen’s slope estimator has been employed for estimation of magnitude of the trend. The results revealed increasing trend for minimum and maximum temperature at seasonal and annual bases barring monsoon season. DTR trends were found to be insignificant for all stations at winter, post-monsoon season and annual bases although a decreasing trend over a very few stations in pre-monsoon and monsoon seasons was observed. In case of PET, most stations exhibited insignificant trends, and only a few stations showed an increasing trend in pre-monsoon and winter seasons as well as on annual basis. This study may be useful in understanding the climatic conditions in the context of water resources planning and management.

Upper Ganga river basin is composed of complex topography and more likely to be affected by climate change. Mann–Whitney-Pettit method was used to detect the significant shift/change in precipitation in Upper Ganga river basin and to find the time of change. Fine resolution precipitation data provided by Climatic research unit (CRU) was adopted as reference data. Significant decreasing trends at all locations was found at 5% significance level using Mann–Kendall test (MK). Most of the locations indicated the year 1992 as change point at 5% significance level. Higher decreasing trends were observed in the lower reaches while upper reaches exhibited earlier change point.

Rainfall is a most important factor for climate study. It is depending on various factors of hydrological cycle. Actual projection of rainfall pattern is quite difficult due to involvement of uncertainty with respect to space and time. Hence, it is very difficult to access actual occurrence of rainfall in daily basis. For climate study various agencies are developed number of climate data base as per long term historical hydro-meteorological data sets. Using these climatic data base, one can project the rainfall patters under particular uncertainty bands and understand the rainfall variability at particular space. Understanding the trend and variability of rainfall is also important to determine the supplemental water requirements for crops as well as water resources planning during their critical water deficit periods. The aim of this study is to investigate the past variation of rainfall and to identify the trend over Rokel-Seli river basin in Sierra Leone for a period of 45 years (1961–2005) of rainfall data. Rokel-Seli river basin is importance to the country’s economy as it supplies water to the Bumbuna hydroelectric power scheme as well as water for the agriculture, fisheries, mining and transportation and for ecological purposes. The long-term trend has been detected using the Mann Kendell (MK) and Modified Mann Kendall (MKK) test(s) for historical time series in terms of monthly, seasonal and annual basis. Further, shift change point has been detected for break point identification using SNHT and MWP test(s). Moreover, rainfall has been projected till 2050s under different climate scenarios with various CMIP5 emission conditions, i.e., RCP-2.6, RCP-4.5 and RCP-8.5. Project rainfall and its trends can be useful for future prospective of agriculture and water resources planning and mitigations under consideration of Climate change.

The presence of fluoride in excess of permissible limit in drinking water has been resulting into serious health problems in several countries. Studies have shown that the rift valley regions in Tanzania are the most affected areas, where only 18.4% of 190 water sources showed fluoride values <1.5 mg/L as per acceptable limit by WHO, 56.8% as per Tanzanian standards and 43.2% has extreme fluoride concentrations. In such case, the excess fluoride removal to make the water potable is the only remedy. Various defluoridation methods varying in terms of cost of treatment, materials, efficiency and technology are available. This paper discusses de-fluoridation technique using RGAC and CAC as the most suitable technique for rural communities in Tanzania. This method is not only economical but also simple to perform. The optimum fluoride removal conditions are 6 mL/min flow rate and 6 cm thickness of bed with 71.9% efficiency.

Availability of fresh water has always been an important factor impacting human population and civilizations. However, with the growth of population and economy, the pollution from anthropogenic activities is degrading the quality of water. The degradation in water quality is affecting the health of mankind and ecosystem. It is benign to understand the water quality parameters impacting the human health for judicious management of water quality. This chapter discusses about the significance of water quality parameter impacting the drinking water from aesthetic, health, and operational point of view, methods of analysis, and treatment techniques for reducing the contaminants.

Water is fundamental need for existence of life. The deterioration in quality of drinking water may lead to severe impacts on human health. Thus, the quality assessment drinking water sources is of paramount concern. This study presents a comprehensive evaluation of water quality of Upper Ganga Canal (UGC) in Roorkee, Haridwar, Uttarakhand, India. The water samples were collected every month from 18 sites of the UGC from November 2014 to October 2015 and assessed at seasonal level (winter, summer and monsoon) for 15 important physicochemical parameters and 10 toxic trace metals. The results were compared with guidelines prescribed by four authentic standards viz., BIS (Bureau of Indian Standards: Drinking water specifications, 2012), EPA (Parameters of water quality: interpretation and standards. Environmental Protection Agency, Ireland, 2001), ICMR (Manual of Standards of Quality for Drinking Water Supplies, 2012) and WHO (Guidelines for drinking-water quality: recommendations, 2004). The arithmetic weightage-based Water Quality Index (WQI) was also computed to evaluate the pollution status of the canal. The results reveal that the UGC water is not suitable for human drinking as the physicochemical parameters and toxic trace metals exceeded the permissible limits of the standards considered, at numerous sites. The parameters also possessed strong seasonal variation in concentration. The overall water quality index was beyond the permissible limits of human drinking at all the sites throughout all the seasons. Therefore, the water samples of the UGC are polluted and unfit for human drinking purpose. The exorbitant concentration of these parameters may be attributed to disposal of industrial effluents, domestic sewages and other human activities.