Although flooding is a natural phenomenon that helps to maintain the natural balance in the ecosystems, the economies of developing countries including Sri Lanka are under a severe threat by the damages caused by heavy floods. Gin River is one of the major rivers in Sri Lanka having 932 km² catchment area which is subjected to frequent flooding. Land use in the Gin catchment has been subjected to significant changes over the years and a comprehensive study has not been carried out to evaluate the impact of land use change on the flood characteristics of the basin. Therefore, to assess the impacts imposed by the temporal variations of watershed characteristics on its hydrological processes, this study was conducted using MIKE 11, lumped conceptual rainfall runoff model and MIKE 21, overland flow model integrated with MIKE FLOOD. Analysis of the Gin catchment’s land use maps of year 1999 and year 2016 revealed that 2% increase in forest area, 3.45% loss of agricultural land and 1.29% increase in built-up area. Study revealed that the change of land use of the Gin catchment brought significant impact on its flood flow regime. It was verified that the increase in forest cover in the upper reaches of the catchment has significantly reduced the flood volume by 22.5% and the peak discharge by 25.62% while the loss of agricultural land and the increase in the built-up areas in the lower reaches of the catchment has given rise to the flood volume by 3% and the peak discharge by 35.36%, stressing to conserve forest areas. This modelling setup could be further developed as an effective flood forecast tool, if the required hydro-meteorological data could be predicted using Global Climate Models (GCMs).

The residents of the water village in Tonle Sap Lake, Cambodia have traditionally used the lake water for their daily needs. However, due to the deteriorating quality of the lake water, local people are now forced to buy bottled water to make ends meet. Most of their meager wages is used to pay for bottled water, and they are stuck in vicious cycle of poverty. Previous research on rainwater harvesting found that household cost of living could be reduced if the local people could use rainwater. They would no longer need to buy bottled water and could therefore have more finances for other needs. Additionally, previously installed rain gutters have been challenging for the residents to maintain. Therefore, this study aims to develop a rainwater harvesting system which the residents can install and maintain by themselves. Research shows that when rain gutters are used during the rainy season, this would be most efficient for rainwater harvesting. In this research a model of a local house was made, and rain gutters installed to conduct some experiments.  In one experiment, a string was used to connect the gutter to the roof of the house, and in the other, a chain gutter was used instead of the conventional PVC pipe.  It was found that the gutters joined with string were stronger than those made with the chains. In terms of cost, using string as opposed to the traditional wood and nails was found to be cheaper in installing the rain gutters since no tools were required. In addition, the chain gutters can collect rainwater perfectly and are less expensive in the long run since they do not require frequent maintenance.

Research groups of Sendai Nika H.S.students have been doing fieldwork in Angkor Krau village, Cambodia. The village does not have sewers due to the conservation of Angkor archipelago, so the villagers can’t construct water flush toilets. The purpose of this study is to investigate the benefits of using ash for hygienic toilets in this village. A previous research group examined the use of bio toilet in this village because it ferments excreta and does not need much water. However, in the experiments stable fermentation did not occur because moisture control was difficult. A solution tothat problem is ecological sanitation toilet (EcoSan toilet). It separates feces and urine and can be used without water. Also, the way of using it is easier than bio toilet. The EcoSan system involves puttingashes on the feces, leaving feces in toilet tank for about half a year. Thereafter, take out processed feces which can be used as fertilizer. However, the details of the chemical reactions are unknown.Therefor the purpose of this study is to investigatethe role of ash in the process of decomposition of feces. Coliforms are used as the indicator of the pathogens in feces in experiments. Results of experiments when mixing ash with horse manure in both dry and wet conditions showed that ash can increase pH or moisture absorption and it has the ability to kill coliform bacteria which is the indicator of the pathogens in feces. The results of the study demonstrate that ash plays a very important role in killing fecal pathogens and increasing the efficiency of the EcoSan toilet.

The inland flood has caused enormous damage in urban areas. According to the Flood Statistics Survey in Japan, the ratio of damage caused by inland waters to general asset damage from 2006 to 2013 was 42.0% nationwide. An explanation of the distribution and characteristics of "frequently flooded areas" where floods frequently occur is an important issue when considering future hydraulic control projects. This study shows that the characteristics of inland floods in Yokohama, one of the largest cities in Japan.By quantifying the risk of inland water inundation from past inundation records in Yokohama City, a field survey in Yokohama, and comparing and verifying the actual damage situation at the site and the data obtained by simulation.As a result, 55% of the 20 elementary and junior high schools with the highest risk of inland waters in Yokohama were built after the 1960s, and the rapid urbanization limited the land on which schools could be built. Through investigating the past land use of Yokohama City, in many areas, places that were once forests and wastelands have been developed in the order of housing, commercial facilities, factories, and schools, and the priority of school construction is relatively low. In conclusion, many schools built after World War Ⅱ, especially after the 1960s, are vulnerable to inland floods due to their location. Also, even in the topographically fragile areas, inland floods are unlikely to occur if a water channel is secured, such as when there is a river nearby. In Yokohama City, microtopography such as slopes and valleys have a great influence on the occurrence of inland floods. The changing in specific structures and land use, new points where water can be easily collected are formed, causing inundation.

Education is essential to solving global issues, especially environmental education which includes the following significant points: clear-cut objectives, hands-on learning, and sustainability. At Bayon Junior High School located in Siem Reap, Cambodia, the river flooding occurring every year and the littering of plastic containers by the students after finishing their meal from the food stands have been some issues. To prevent further river contamination as the littered trash flows out with the floodwater, this study explores that the use of eco-friendly containers made by recycling the bagasse will solve these problems as part of environmental studies. Previous research by Nika High School students have proven that it is possible to recreate a sheet of paper out of bagasse using the traditional Japanese paper-making technique. This technique can be modified, and 5 sheets of bagasse paper can be used to form a bowl-shaped container. From this creation, students can earn some money which can not only motivate them but also propagate the sustainability of learning. However, there were some flaws that the amount of bagasse collected was below expectation and those fibers were rough and thick to be reproduced as paper. To overcome this problem, this research substituted half of the bagasse for banana which is abundant in this area. Besides, the banana’s starch can be used as an adhesive to bond the fibers which are more biodegradable than the laundry starch from the previous studies. As a result, it was possible to make a container out of banana and bagasse. Due to the coronavirus, this participatory activity has not yet been done. However, taking this data as evidence, the production of eco-friendly containers may teach the lessons of adapting to the floodwater contamination through recycling and eliminating the wastes and self-discipline to students to make them work voluntarily for preservation.   

In Japan, enormous flood damages frequently occurred due to the extreme rainfall events such as 2017 heavy rain in Northern Kyushu, 2018 Western Japan heavy rain, and Typhoon Hagibis in 2019. Among these, Typhoon Hagibis passed the eastern Japan and brought heavy rain in October 2019. The typhoon caused enormous flood damage with dike breaches in 71 rivers and a lot of dead and missing persons. The extreme heavy rains may be influenced byglobal warming. Kawase et al. (2021) pointed out that 10.9 % of total precipitation in the Typhoon Hagibis increased by the historical warming which atomo. Influences of the global warming were mostly investigated on the change of precipitation and river discharge, but on few examples of river flooding. The purpose of this study is to quantitatively evaluate the impact of historical global warming on river flooding in Japan induced by Typhoon Hagibis using a storyline event attribution. The target site chosen in this study is the Chikuma River, one of the rivers that experienced a great flood due to Typhoon Hagibis. For this, we conducted the control and non-warming numerical experiments based on the numerical weather simulation, runoff analysis, 1-D river flow simulation and 2-D flood simulation in which the former two are used with the Japan Meteorological Agency Nonhydrostatic Model (JMA-NHM, Kawase et al. 2021) and Rainfall-Runoff-Inundation (RRI) model, respectively. The results between the control and non-warming numerical experiments indicated that the peak values of river discharge and water-level difference in control experiment were larger than those in the non-warming experiments (30% and 110%, respectively). It is noted that the historical warming increased the inundation area by 13 times in the Chikuma River, suggesting the global warming enhances the flood disaster due to typhoon.

Snow study is important because except the ocean, snow is the second largest interface between the atmosphere and Earth's surface and snow covers considerable part of the land during winter. Changes in snow cover extent and snowpack properties in recent decades in response to warming are ongoing and will likely continue in future. Spatial and temporal variations of snow cover properties are investigated during the number of winter seasons by means of in situ and remote (Lidar, UAV)  methods on the site of meteorological observatory of Lomonosov Moscow State University. This is done in order to understand the influence of winter weather conditions and snowpack properties spatial and temporal variations on snow water equivalent of snowpack, its thermal conductivity and underlying ground freezing depth variations in the light of the recent climatic and weather contrasts. The developed calculating scheme is used to explore the influence of air temperature and snow cover properties on ground freezing depth. The calculating scheme is based on three media heat conductivity problem (snow, frozen and thawed ground) with phase transition on the boundary interface of frozen and thawed ground. The results of calculations of ground freezing depth are compared with the observation results for bare and covered with snow surface of observation site ground and they are in good agreement. So the influence of the recent climate and weather contrasts and snow cover spatial and temporal variations on snow water equivalent and underlying ground freezing depth variations are investigated and the relations are reviled. This is really vital, because although climatic norms between 1961-1990 and 1991-2020 changed not very essentially, but some strong weather variation extremes and contrasts (such as very hot last 2020 year and weather anomalies of this 2020/2021 winter) are present in recent decades causing danger and risks for population and economics.

Disaster creates damages not only to business operations in the disaster area and also to the other areas through supply chains. Industrial area in Thailand, over 60% of companies and factories had affected from disasters. Therefore, the disaster response plan is needed in order to handle with unexpected situations. Business Continuity Management (BCM) is a framework to help company maintain their operations and quickly recover after disaster happened. However, a lot of companies still do not well realize the importance and effectiveness about it. Hence, this study did survey on disaster responses in major industrial areas, Thailand. The objective is to know the current existing response plans. What are the successes after company responded and what are the challenges company had found. Then findings will be used to support implementation of the new Area-BCM projects. We found that only half of company have BCM or emergency response plans, another half have under construction or no plan. In addition, many BCMs are incompletelymanipulated and less reviewed. Surprisingly, even the annual plan review and training lead to success in response with disaster, only 28% of company had conducted. The significant successful respond to disaster is cooperation with customers, suppliers and headquarters. This indicates collaboration with stakeholders should be added to future plan. It highlights the important part of Area-BCM which cover to all parties and resources. Moreover, quick decision making from management supported employees to take actions properly. Timely information sharing was also useful to minimize damages. At the same time, it has been a challenge because of late providing and power outages. The other challenges are uncontrol resources and human actions. The results show many companies still need more improvement of disaster plans. Consequently, Area-BCM should be implemented to fill these gaps and raise successful issues for effectiveness.

Owing to climate change, high frequency and magnitude of the hydrological drought risk have been predicted for the coming century in most locations over the world. Many efforts have been made across the world in the planning, monitoring, and mitigation of hydrological drought. Currently, different drought indices such as the Streamflow Drought Index (SDI), Standardized Streamflow Index (SSI), Standardized Runoff Index (SRI) are most commonly used to monitor hydrological drought quantitatively. However, hydrological drought still requires specific and effective tools for quantification and estimation considering its dependence on both climatic and catchment characteristics. In this study, the Dynamic Naive Bayes Classifier (DNBC) was employed for the assessment of onset and end of hydrological drought. The DNBC is a probability classifier based on the Bayes’ rule whose dynamics governed by a hidden Markov chain. We consider five classes that represent different severities of hydrological drought. The results showed that the probabilities of occurrence of different classes of hydrological drought based on the DNBC were quite suitable and can be employed to estimate the onset of each class and transition to other classes for hydrological droughts. For performance evaluation of classification results, a confusion matrix was made to calculate prediction accuracy and its results were also found appropriate. In comparison with SRI, the accuracies of estimating five classes by DNBC were 82%, 68%, 65%, 53%, and 38%, respectively. The overall results indicate that the DNBC is an effective tool in predicting the onset and end of hydrological drought events and can be employed for monitoring, improving preparedness and resilience to cope with the risk of this natural disaster. AcknowledgementThis work was supported by the National Research Foundation of the Korean government (Grant No. 2020R1A2C1012919).

GCM downscaled climatic components are used to project extreme events such as drought and flood. GCM derived climatic derivatives induce uncertainties in the projection of extreme events caused by climate change. The uncertainties occur due to uncertain emission scenarios, downscaling approach, and model parameterization uncertainty.Several approaches are proposed to overcome this shortcoming but a recently developed bottom-up paradigm is useful in the specific scenarios of extreme event projection and mitigation. In this work convention top-down approach (using the downscaled climate derivatives) is compared with a recently developed bottom-up framework in the projection of extreme events. The bottom-up approach work on the exploratory modeling framework where synthetic climate scenarios generated using a delta change method. The proposed framework allows the extreme event’s predictions, utilizing the available climatic data (precipitation, and temperature). Furthermore, the concept of comparative hydrology is used to develop generalized predictions on catchment-scale for the Indian sub-continent. In this study, we focused on the impact of climate change on drought. We used a change in precipitation and temperature on the dynamics of drought indices like PDSI and SPEI across the Indian sub-continent. We compiled a dataset for 215 catchments physio-climatic characteristics, consisting of climatic, hydrologic, vegetation, and soil properties. The vulnerability of the catchment to drought with the change in climate using 30 years of data is assessed using data-mining algorithms. This study will help in understanding the vulnerability to drought of catchments under varying climatic conditions and will help stakeholders in mitigating the adverse effects of climate change.

Dryness is one of main factors to enhance generation and expansion process of wildfires, and it will be affected by climate change in the future.  In order to evaluate it, there are many dryness indices such as Keetch–Byram drought index (KBDI) and Palmer drought index (PDSI) with different dryness descriptions. The suitable dryness descriptions are generally different depending on region and climate, however, it was not well discussed in Japan. Therefore, in this study, we selected KBDI, PDSI, soil moisture (SM) from land surface model (LSM) and effective humidity (EH) as the dryness indices and evaluated by wildfire statistics. KBDI is an estimate of the soil moisture deficit and PDSI is based on a supply-and-demand model of soil moisture. Effective humidity is the humidity that takes into account the humidity of the past few days and is widely used for wildfire warnings in Japan. The results show that KBDI is not suitable index in Japan, because most wildfires occurred when KBDI is 0-20, which is usually considered as wet conditions. Secondly, correlation coefficients between wildfire statistics and PDSI, minimum SM, minimum EH were calculated. As SM and EH decrease, monthly number of occurrences and burned area were higher. In addition, since PDSI cannot consider the impact of snowfall and snow cover, the results of PDSI show a weak correlation with the monthly total burned area (MTBA) and monthly total number of occurrences (MTNO) in Tohoku and Hokkaido.

This study proposed a near-real time prediction model, based on soil moisture evolution data, with using physical-based hydrological model and various stochastic models in South China. The difficulties for a large scale basin are the multi-scale embedded variability features are diversified for different sub-regions. Therefore, the effective delineation of the coherent region is the first step. The proposed prediction model is a distributed approach in conjunction with the principle component analysis and wavelet transform, which is applicable for a regional scale. The whole modelling strategy is an effective approach for drought prediction in South China.

Low flow analysis provides crucial information for water resources development and environmental flow management.  Understanding low flows can also give a rise to long-term environmental, economic and social impact and play a major role in the hydrological risk management of the river basin. The low flow regime is significantly effective on water resources management especially for the countries like Turkey where demand for water is increasing. The purpose of this study is therefore to do low flow analysis by determining low flow characteristics of five gauging stations in Kucuk Menderes River basin in the western part of Turkey. The study uses a variety of tools which include flow duration curves, frequency analysis of low flows and percentile-based indices such as Q₅₀, Q₇₀, Q₉₀, Q₉₅ and Q₉₉. Flow duration curve which illustrates the frequency distribution of flows in a stream with no regards to their sequence of occurrence are drawn for the whole available record period and each year separately. With the use of flow duration curve, discharges exceeded at a certain time percentage (quantiles) in hydrological basins are determined and the boxplots of each quantile are obtained. Low flow frequency analysis shows the proportion of years when a flow is exceeded the average interval in years. Frequency analysis is applied on D = 1, 7, 14, 90 and 273 days-low flows by considering various probability distribution functions to eventually get low flows at 2, 5, 10, 50 and 100-year return periods. Results show that low flow-duration-frequency curves decrease quite fast towards very low flow values and even to zero. It means that the river basin is prone to get dry and face with severe hydrological droughts in the future.

Reliable estimates of future water availability is a key for better management and planning of water resources under the changing climate. Over Victoria, the cool season (April – October) brings approximately two-third of the annual rainfall and is important for agriculture and replenishing reservoirs. However, since beginning of Millennium Drought in 1997, Victoria has been experiencing unusually low cool season rainfall (~12% below the 20th century average).  These persistent dry conditions challenged the underlying assumption of stationarity used in defining the historical (baseline) climate for future planning and management of water resources over Victoria. They also raise an important question, i.e., which historical period, if any, can be used for future planning and management of already scarce water resources across Victoria? Here we use observations and the simulations from 40 CMIP5 climate models under a variety of conditions to provide estimates of Victorian rainfall for near-, medium-, and long-term periods during the remainder of the 21st century. We use a variety of different methods, most utilising both simulations and observations, while a few use only past observations. We find that none of the historical periods give rainfall distributions that accurately approximate expected future rainfall distributions. The rainfall distribution based on the historical period 1900 – 2018, for example, tends to overestimate rainfall compared with projected distributions, while the distribution based on the recent dry period (1997 – 2018) is too narrow and consequently underestimates the range of possibilities projected. Additional rainfall distributions for are then provided, based on applying model-based scaling factors to several observational distributions. We will explain why our confidence in the accuracy of the distributions produced depends on the method used, and we will indicate which methods we have most confidence in.

Drought affected agriculture areas the most, absorbing around 80% of direct impacts with multiple effects on agricultural production, food security, and rural livelihoods (FAO). Studies about drought will rely heavily on the precipitation data, especially when drought can be understood as a condition when an area experiences a water deficit from its normal condition. However, the limitations in the Spatio-temporal availability of measured precipitation data (MPD) makes satellite-based precipitation data become alternative sources that can be utilized, especially it has a relatively high spatial resolution. This study aims to assess the use of Global Satellite Mapping of Precipitation (GSMaP) with 0.1° x 0.1° resolution for drought assessment by first examining the agreement between MPD and GSMaP dataset in West Java, Indonesia, and determine an appropriate temporal scale to be used. From the correlation analysis results of the point dataset and area dataset, it can be concluded that the appropriate temporal-scale that can be used for drought assessment is a 90-day period. Additional results based on the R-Square values found that the MPD dataset has a good spatial agreement with the GSMaP dataset that will be useful for drought assessment. The Standardized Precipitation Index (SPI) was conducted in Indramayu Regency, which was hit the hardest by drought, to determine the drought characteristics. The SPI analysis was also conducted separately based on the MPD and GSMaP dataset and resulted in both datasets being able to catch the drought event during the period 2003 and 2006 which coincides with the decrease of rice production and highly affected areas by drought. The GSMaP result was able to catch the drought event earlier and for a longer duration meanwhile, the MPD result has a higher drought severity index. Further research is needed to validate the correlation between drought events and crop yield.

Groundwater (As) contamination in shallow reducing aquifers of Bangladesh has posed severe health threats to millions. Oxic water from seasonally and tidally fluctuating major rivers like Meghna interacts with reducing iron (Fe) and As-rich groundwater from shallow permeable regions. Such interactions lead to formation of a permeable natural reactive barrier (PNRB) that acts as a source or sink, where Fe and As may be adsorbed under oxic conditions, and mobilized under reducing conditions. Fe, As mobilization is largely influenced by the presence of sedimentary organic matter that fuels microbial reductive dissolution of Fe-(oxy) hydroxides. We characterized sediments from a PNRB on the riverbank, and from an adjacent shallow reducing aquifer. The major and trace elements including Fe and As in sediments were measured using XRF and acid digestions via HRICPMS. These sediments were incubated in deionized water at ambient conditions to determine the water leachable fraction of inorganic and organic constituents. Results show that riverbank sediments were primarily composed of fine sands and contained As between 5-10 mg/kg and Fe between 29,000-53,000 mg/kg. Manganese (Mn) in sediments that ranged between 475-860 mg/kg was positively correlated with Fe. Results from incubation experiments suggested that riverbank sediments contained 116±67 mg/kg water-leachable organic carbon with molar C:N between 6-37. Contrastingly, aquifer sediments contained substantially higher 1,294±263 mg/kg water-leachable org. C with molar C:N between 8-66. In general, riverbank sediments showed lower water-leachable concentrations (5.4 mg/L TDS) than aquifer sediments (90 mg/L, TDS). Results indicate that riverbank sediments undergo more flushing with oxic river water, contain fresh and labile organic matter, whereas, aquifer sediments contain older and recalcitrant and possibly more reactive organic matter. These findings will contribute towards developing a hydrologic and chemical reactive transport model to understand fate of As along a potential PNRB.

Bacteria that utilize redox transformations of As oxyanions to obtain metabolic energy or in cellular detoxification were cultured from various environments including aquifers and streams.  Microbiological transformations constitute a biogeochemical redox cycle for As that directly controls its environmental partitioning between the geosphere and hydrosphere.  Interest in the chemically similar toxic metalloid, Sb, has been growing due to increased mining and use in industry.  Antimony and As often co-occur in contaminated aquatic settings around mining and industrial sites.  Compared to As geomicrobiology, the role that microorganisms play in the environmental cycling of Sb has only recently become the subject of research.  Studies have shown that geomicrobiological processes influence Sb’s redox speciation and can drive the precipitation of biogenic Sb mineral phases from solution.  Oxidative and reductive biotransformations of Sb provide metabolic energy for prokaryotic growth via both heterotrophic Sb(V) reduction and chemoautotrophic Sb(III) oxidation.  However, the identification of structural genes responsible for Sb biotransformations, and their relationship to the genes which encode for As oxidation and reduction, is not well established.  We report geomicrobiological Sb oxidation and reduction coupled to heterotrophic and autotrophic growth in As-cycling bacterial strains cultured from freshwater environments, including contaminated aquifers of the Bengal Delta Plain, India.  We report the novel finding of microbiological Sb(V) reduction linked to cellular detoxification in Sb-resistant strains grown at elevated (millimolar) concentrations of dissolved Sb.  PCR amplification of arsC gene products, encoding for As resistance, indicate that this gene is also expressed during growth in the presence of Sb.  This provides the first evidence that arsC confers resistance and detoxification pathways for both metalloids.  Our results elucidate the significance of Sb-cycling microorganisms to the sequestration of Sb from the aqueous to the solid phase, and may contribute to the development of biological treatment strategies for Sb-contaminated water.

With the growing population of the United States, traditional aquifer based freshwater sources are continuously drawn from for a variety of consumer and industrial uses. Attention has now turned to tapping into previously ignored sources of water to help supplement the increasing demand. Brackish Groundwater (BGW) is defined as water that is between 1,000 to 10,000 mg/L of TDS. Although BGW sources have been relatively untapped, they could help supplement freshwater sources, particularly for commercial and industrial uses. It is estimated that over 8,500,000 km³ of BGW exists in aquifers across the USA. Texas has 18 different aquifers that store BGW and can be utilized for potable and industrial uses after reverse osmosis (RO) treatment. In this study, hydro-chemical data (McMahon et al., 2016; Stanton et al., 2017) for over 6,000 samples across Texas were investigated to understand the physical and chemical composition of BGW aquifers. Saturation indices were calculated for several salts and the maximum concentrations of these scalants were 1,022 mg/L for calcium, 5,110 mg/L for sulfate, and 2,958 mg/L of alkalinity. Geospatial analysis of saturation indices in the BGW sources revealed that the composition of the water varies between different aquifers and their geologic settings. In aquifers to the North, BGW is more likely to precipitate calcium sulfate species such as anhydrite and gypsum while in aquifers to the South, BGW is supersaturated with calcium carbonate species such as aragonite and calcite. Overall, our results indicate that treatment for BGW must be customized to the supersaturated minerals in it as the efficiency of desalination is impeded by excess of dissolved salts that form scales on the RO membrane. The findings of this study advance our understanding about BGW geochemistry and provide insight for improving the efficiency of BGW desalination.

Groundwater is an important natural component of fresh water resources which plays a momentous role in meeting the water needs of various user-sectors like domestic use, agricultural sector and industrial sector in a region. At present scenario ground water fulfills 85% of domestic water demand in rural areas, 55% of irrigation water demand of farmers, 50% of domestic water demand in urban areas and 50% of process water demand of industries. However provision of water for the domestic usage is the basic demand out of all and access to safe drinking water is the most important criteria under this user-sector. So in this regard for the optimal use of ground water, safeness of water in terms of its quality is needed to be assessed. Typical land use practice as well as land use alteration is an important driver of ground water quality determination. Extensive urbanization, agricultural customization, soil treatment, mining activities etc can contaminate ground water. In present study, safe water availability has been studied in Raniganj coal field (RCF) region. In RCF most of coals (76.07%) are produced by opencast mining method and rest (23.93%) is from underground method. Here both of the methods cause the ecological burden on environment especially on ground water quality and landscape stability. So in quintessence of investigating the safe water availability, water quality index (WQI) and drinking water quality index (DWQI) have been calculated for the region on the basis of ground water samples collected and spatial distribution of safe drinking water has been mapped using GIS. Finally, a statistical correspondence of land use /cover practice over ground water quality as well as drinking water quality distribution have been established to show its control.

Natural enrichment of poisonous arsenic (As) is ubiquitous in hydrological systems. However, the scale of problem is most severe in West Bengal. The current study deals with a high resolution hydrogeochemical monitoring study for 18 months. The investigation has been designed to conduct at the two sets of piezometers (2 × 5). One site is selected at the As contaminated areas where pond is a signature of geomorphological feature (site-A). Another site is adorned with irrigation well to be used for community water supply (site-B, discharge rate ~1.38X10³ m³/m²/day). The lowest depth of piezometer at site-A is 16 m, the same is 15 m at site-B. On the other hand highest depth of the piezometer at site-A is 37 m and is 100 m at site-B. The key finding is that dissolved As concentration is highest in site-A when compared with site-B. The significant finding is the enrichment of various aqueous solutes in shallowest part of site-A for example sulphate, chloride, ²H and ¹⁸O. This indicates the possibility of surface derived recharge. At both sites decreasing trend of DOC (dissolved organic carbon) with increasing depth and enrichment of ammonium ion with increasing depth reveals reducing condition in deeper aquifer. Due to regular high groundwater withdrawal the recharge rate is comparatively faster at site-B. As a result the electrical conductivity has been low to moderate representing fast sediment-water interaction by reducing residence time. This phenomenon also indicates the limited mobilization of As, depending upon local reducing factor, equilibrium of the system, mixing and possibility of local fresh organic recharge. This study also suggests that reductive dissolution of Fe oxyhydroxides is the major process. So, different degree of sediment-water interaction, aquifer flushing and high rate of groundwater withdrawal and mixing of redox equilibrium can explain arsenic mobilization through aquifers.  

Contaminants and concentration of Hydro-chemical and mineralogical of groundwater are more essential for the groundwater table and level which is served to human and animals and also more important to the agriculture field, sanitation to supply the water. Geochemical characterization of major aquifers in terms of the measured parameters like arsenic, pH, Carbonate, chloride, TDS, and groundwater table. Assessment of the degree extent and mechanism of contamination along with their spatial and temporal variability of the Murshidabad district. Block-wise elaboration of the Spatio-temporal variation of dissolved geogenic contaminants along with the factors responsible for such variability, to pin-point the future sites of groundwater development. To establish a Hydrologic, Hydro-stratigraphic, and Hydro-chemical framework for the study area with the help of previous data and data generated through this work along with their block-wise explanation. Assessment of the impact of crops with geochemically contaminated groundwater and the mechanism of propagation of contaminants. The research was fulfilled with the help of systematic and analytical methods.   Systematic water & soil sampling, chemical analysis, multivariate analysis, and numerical model generated with the help of SPSS and ArcGis software base.