Shallow Tubewells Research Articles

Design and testing of a mechanized tube well installer

To combat water access problems, a mechanized means to install sustainable, driven tube wells was developed. A modified hydraulic post driver was mounted to a Purdue Utility Platform vehicle to provide the impact necessary for a driven tube well installation. The vehicle provided the positioning framework and hydraulic power for the post driver. Low-cost tube wells could potentially provide safe, clean water, increasing hygiene and reducing pathogens typically present in unimproved surface water or artesian sources used throughout the developing world. Five wells were installed at sites across West-Central Indiana, with the deepest well being driven to 7 m. One well was able to produce 13 L/min and remained sanitary after disinfection. This suggests that the well-driver vehicle could install shallow driven tube wells in developing countries.

Water usage and productivity of Boro rice at the field level and their impacts on the sustainable groundwater irrigation in the North-West Bangladesh

Groundwater-irrigated Boro rice is produced on 83 % of the net cultivable area (NCA) in North-West (NW) region of Bangladesh. Falling groundwater levels in many parts of the region raised concerns about the sustainability of groundwater irrigation. It is generally accepted that, in the absence of a comprehensive scientific study, uncontrolled groundwater use for Boro rice cultivation leads to water wastage and low water productivity. Therefore, it is crucial to know the actual field-level water usage and, irrigation water productivity, which will help identifying options to sustain groundwater irrigation. This study provides a comprehensive account of these aspects of Boro rice cultivation based on field observations at 420 farmers’ plots in 2015–16 and 2016–17 seasons across seven sites in the NW region. Necessary data, including land type, soil type, rice varieties, seeding and transplanting times, grain and biomass yields pump discharge, and irrigation amount were recorded. Average water productivity was 0.67 kg m−3 and 0.64 kg m−3 based on total available water (rainfall plus irrigation) in the fields, 0.80 kg m−3 and 0.95 kg m−3 based on supplied irrigation, and 1.60 kg m−3 and 1.78 kg m−3 based on estimated actual crop evapotranspiration (ETc) during 2015–16 and 2016–17, respectively. These water productivities are the highest among the major rice-growing Asian countries indicating limited scope for improving farmers’ water management practices. Comparison of the actual water supplied to the field and the estimated requirements shows that farmers are, in general, very efficient in supplying water to rice. In shallow tube well (STW) sites, water supplied by the farmers was very close to actual requirements, but rice plots in DTW sites had some over application. The average total amount of water available in the field to grow one kilogram of rice was 1,606 L (L) in 2015−16 and 1605 L in 2016−17. The Average irrigation water supplied to the field was 1402 L kg−1 in 2015−16 and 1086 L kg−1 in 2016−17. However, not all water supplied to the rice plots are consumed by the plants. Actual crop evapotranspiration is the real water use and based on that only 661 L in 2015−16 and 584 L in 2016−17 were required to grow one kilogram of rice. Percolation and seepage water return to the underlying aquifer as return flow. So, the current government policy of so called ‘water savings’ by reducing pumping of groundwater is unlikely to have any major impacts on the sustainable groundwater irrigation in the NW region.

Is Arsenic in Rice a Major Human Health Concern?

Arsenic (As) is a toxic metalloid associated with various negative human health impacts including cancer, skin lesions, cardiovascular diseases, and diabetes. Arsenic contamination of groundwater and soil is a major human health issue, particularly in South and Southeast Asia. Use of As-contaminated groundwater from shallow tube wells for irrigation of paddy rice, the staple food for people in this region, is one of the causes of As-related health impacts. The anaerobic growing conditions of flooded rice paddies and the unique physiology of the rice plants lead to increased As levels in rice. The World Health Organization (WHO) has set advisory levels of As in polished (i.e., white) rice grain at 0.2 mg/kg, but the EU and USA are yet to set legal standards for As in rice and rice-based products. Strategies for lowering As accumulation in rice revolve around two approaches—agronomic and biotechnological. Agronomic approaches, such as mineral supplementation of soil using iron, phosphorus, sulfur, silicon, water management, soil aeration practices, and the use of biological agents, are designed to lower As solubility, and uptake by rice. Rotation of the rice crop with As accumulating plants could also result in lowering soil As. Biotechnological approaches involve producing transgenic rice varieties by altering the expression of genes involved in As uptake, translocation, and sequestration in the plant. These approaches, combined with proper diet management and creating public awareness on potential health risks resulting from chronic exposure to As in rice, could play a key role in risk reduction.

Water productivity with localized irrigation using groundwater and reuse water in the cultivation of plant species

ABSTRACT This study aimed to analyze the water saving potential of replacing the traditional, furrow-irrigated banana crop in the Curu-Pentecoste Irrigated Perimeter with localized systems by inserting new cropping plans and sources of groundwater and reuse water. An analysis of the support capacity in shallow tube wells for irrigation was also performed, considering the scenario of full recharge and water scarcity. The economic analysis was performed using the profitability indicators of the investment analysis: benefit/cost ratio, net present value, internal rate of return and payback period. Water productivity data reveal that cropping plans associated with alternative sources of water from shallow tube wells and reuse of the excess surface irrigation water in localized systems are economically more attractive than traditional, furrow-irrigated banana crop. The support capacity of shallow tube wells reveals that the exploitation of this underground water resource in the region is a viable alternative for irrigation of small areas. With the exception of banana, the other scenarios analyzed showed positive cash flows from the second year.

Deep and shallow tubewell water from an arsenic-contaminated area in rural Bangladesh: risk-based status

For all living organisms on the planet Earth, safe drinking water is essential. Throughout the world, millions of people such as those in Bangladesh utilize ground water sources like deep tubewells or shallow tubewells as sources for safe drinking water. In this study, drinking water supplies for people in rural communities are investigated in one arsenic-contaminated area, Narail Sadar, Bangladesh, for the purpose of ensuring safe potable water. Trace metals, namely arsenic, iron, manganese, cadmium, zinc and lead in the water of deep (n = 22) and shallow (n = 27) tubewells, were determined by atomic absorption spectrophotometer following APHA standard analytical methods. The examined parameters of water samples regarding the deep tubewell were found to have the following ranges: arsenic 2–145 µg/L; iron 80–6710 µg/L; manganese 8–80 µg/L; cadmium 1–8 µg/L; zinc 3–433 µg/L; and lead below the detection limit of 6 µg/L. In the shallow tubewell, the statistics were: arsenic 2–321 µg/L; iron 110–8670 µg/L; manganese 8–620 µg/L; cadmium 2–9 µg/L; zinc 3–81 µg/L; and lead below the detection limit of 6 µg/L. Drinking water quality of Narail Sadar does not satisfy the guidelines published by the World Health Organization or the government standards in Bangladesh. Deep tubewell water is comparatively less contaminated by arsenic and other trace metals than the shallow tubewell water, a finding based on the hazard quotient, carcinogenic risk and water quality index. Regular consumption of arsenic-contaminated water may accelerate chronic arsenic-related toxicity and subsequently endanger people’s health.

Cost-benefit of promising adaptations for resilient development in climate hotspots: evidence from lower Teesta basin in Bangladesh

AbstractIt is very likely that climate change will increase the frequency and intensity of extreme events such as floods, flash floods, storms, heat and cold waves, riverbank erosion, and drought in the river basin of Hindu Kush Himalayan (HKH) region. This could mean detrimental impacts to the poor and marginal people in the lower Teesta basin (LTB) in Bangladesh. Though adaptation involves financial costs, the farmers' practicing adaptation in LTB experience diminished crop loss and damage. This study was aimed at assessing the promising adaptation practices, their economic return, and social welfare in the LTB through an extended cost-benefit analysis. The study suggests that among the adaptations, shallow tube-well (STW) based irrigation practice in both sandy and loamy soil has the highest marginal adaptation cost (MAC) but the lowest benefit-cost ratio (BCR). The deep tube-well (DTW) based irrigation practice generates superior benefits to the farmers compared to the STW based farming due to initial establishment by the government which is very expensive. Maize farming as an alternate and less resource consumptive cropping produces nearly five times higher economic benefits than the costs which can be acknowledged as the most profitable and resilient adaptation option in the LTB. Though MAC is relatively low for the short-duration variety (SDV) rice among the promising adaptations, its economic profitability is 62% lower than that of the maize cultivation. However, having higher BCR the maize cultivation generates US$86 higher welfare to the farmers than the SDV rice which may strengthen the farmer's preference of maize cultivation over the SDV rice. It can be stated with high confidence that strategic adaptation planning, soft credit, technological advancement, and subsidized agricultural inputs will encourage the farmers to carry out adaptation options which may reduce climate-induced loss and damages for the farmers and build socio-economic resilience in the LTB and other similar areas of South Asia.

Why Do People Remain Attached to Unsafe Drinking Water Options? Quantitative Evidence from Southwestern Bangladesh

The acceptance of newly implemented, safe drinking water options is not guaranteed. In the Khulna and Satkhira districts, Bangladesh, pond water is pathogen-contaminated, while groundwater from shallow tubewells may be arsenic- or saline-contaminated. This study aims to determine why, as well as the extent to which, people are expected to remain attached to using these unsafe water options, compared to the following four safer drinking water options: deep tubewells, pond sand filters, vendor water, and rainwater harvesting. Through 262 surveys, this study explores whether five explanatory factors (risk, attitude, norms, reliability, and habit) pose barriers to switching from unsafe to safe drinking water options or whether they could act as facilitators of such a switch. Users’ attachment to using pond water is generally low (facilitators: risk and attitude. Barrier: norms). Users are more attached to shallow tubewells (no facilitators. Barriers: reliability and habit). The safe alternatives (deep tubewell, rain water harvesting, pond sand filter, and vendor water) score significantly better than pond water and are estimated to have the potential to be adopted by pond water users. Deep tubewell, rain water harvesting, and pond sand filter also score better than shallow tubewells and could also have the potential to replace them. These findings may be used to optimise implementation strategies for safer drinking water alternatives.

Sources of U and Th in groundwater of the paleobeach aquifer at Cox's Bazar, Southeast Bangladesh

To explore the influence of radioactive heavy minerals on thorium (Th) and uranium (U) contamination in groundwater, we performed geochemical and mineralogical investigations of core samples (from the ground surface to 18.9 m depth) from a paleobeach area in Cox's Bazar, southeastern Bangladesh. Geochemical data document elevated levels of total Th (6.3–202.3 mg/kg, average 32.9 mg/kg) and U (1.1–33.4 mg/kg, average 5.2 mg/kg), and lithological observations document monazite concentrations as great as 2.36 wt% and zircon concentrations as great as 3.82 wt%. These minerals were found in organic-rich fine to very fine sand in the uppermost meter of the sediment column (down to 1.2 m depth) rather than in coarser sandy sediment. Energy-dispersive spectroscopy of several monazite and zircon grains indicated that alteration was greater in oxic sediment (down to 3 m depth) than reduced sediment (deeper than 3 m). Monazite and zircon had relatively high concentrations of Th (3395.9–3937.5 mg/kg and 275.5–318.4 mg/kg, respectively) and U (850.7–990.6 mg/kg and 256.3–290.5 mg/kg, respectively). Chemical weathering (dissolution and reprecipitation) of detrital monazite and zircon grains, which releases U and Th into the groundwater, may be a major and growing concern for drinking water in the study area. Shallow tubewells (<20 m depth) waters were enriched in U (0.09–9.57 μg/L) and Th (0.02–127.09 µg/L) and that the enrichment mostly occurred in highly oxic environments (Eh = 0.35–0.5 V). We suggest that hydrological and biogeochemical conditions in the aquifer that follow land-use changes influence the release of Th and U into the groundwater of the study area.

Groundwater Zoning for the North-West Region of Bangladesh

For proper planning and management of groundwater of an area, zoning of groundwater is essential which can be done by using modeling tool. Groundwater zoning is very important, especially for irrigation project as well as drinking needs. So, the present study aims to assess the zoning of groundwater at the Joypurhat district located in the north-west region of Bangladesh. MIKE SHE modelling tool has been used for this study. A groundwater flow model has been developed with calibrating for the period of 2001 to 2006 and validating for 1995 to 2000. As Hand Tube Well (HTW) and Shallow Tube Well (STW) operate under suction mode and they can operate with full efficiency when groundwater table remains within 6m from ground surface, this depth has been considered as the safe yield criteria. Groundwater zoning has been done based on the safe yield criteria. At the end of April groundwater level goes below 6m from the ground surface in Kali, Khetlal, Akkelpur and Panchbibi upazila. These areas are considered as deep zone. On the contrary, Joypurhat Sadarupazila is considered as the shallow zone because groundwater level remains within the 6 m from the ground surface in this upazila.

Environmental Challenges and the Measures Taken by the BMDA for Sustainable Agriculture and Environment in the Barind Tract, North-West of Bangladesh

Barind Tract, located in the North-West region of Bangladesh is a drought prone water stressed area. Barind Multipurpose Development Authority (BMDA) has made this desert like zone into a granary one through various activities including irrigation as major. Now, the agricultural pattern, cropping intensity, methods of cultivation, crop variety and yields – all show a positive change. The BMDA has significant impacts of reducing environmental impact as well as changing the living standard and socio-economic conditions of the rural people in Barind Tract. The present study aims to find out the environmental challenges faced by the farmers in the Barind Tract and the mitigation measures took by the BMDA as a large development partner for the sustainable development in the Barind Tract. As on environmental issue respondent in Puthia, Paba and Godagari zones identifies that low rainfall, extraction of ground water by DTWs (Deep Tubewells) and STWs (Shallow Tubewells), very thin flow of water in the rivers and also losses of groundwater from the aquifer to the river as base flow during dry season are the major causes of the scarcity of ground water in the Barind Tract. Droughts, high temperatures, less rainfalls, cyclones and thunderstorms and lightning also have been identified by respondents as the natural hazards affect their crop production and daily livelihood. To reduce the environmental challenges, no more new DTWs are being installed by BMDA (though private initiatives are still going on), emphasize on using more surface water from rivers and canals through low lift pumps, community based tree plantation programs in the project area, use renewable energy produced by solar panels and re-excavate canals and ponds for conservation of surface water. This study suggests that scientific assessment of groundwater resources with zoning for proper planning, increase augmentation of surface water as well as harvesting of rain water, crop zoning, increase cultivation of low water consuming crops and enhance groundwater recharge are now the demand of time for the study area.

Identification of Aquifer Properties in the Eastern Part of Kushtia District, Bangladesh

The present study has been undertaken to depict spatial distribution of different aquifer parameters in the eastern part of Kushtia district through a detailed hydrogeological survey. For this investigation, 119 lithologs and 92 pumping test data have been used. These data have been processed, analyzed, interpreted and krigged for the spatial assessment of the aquifer properties viz. transmissivity, hydraulic conductivity, hydraulic diffusivity, specific yield, radius of influence, and specific drawdown. It is seen from the investigation that the transmissivity and hydraulic conductivity values obtained from the pumping tests of the wells are varying from 1811 m2/day to 2568 m2/day and 32.5 m/day and 61.5 m/day respectively, the hydraulic diffusivity being ranging from 181,143 m2/day to 256,788 m2/day. The estimated specific yield of 17.97% - 23.46% supports that the area is dominated with coarse grained sands. This study reveals that the distribution of deep tube wells in the area are not within the radius of influence (638 - 760 m) each other, but few shallow and hand tube wells existed within the radius of influence. The estimated specific draw down is varying from 57 m/cumec to 126.1 m/cumec. From the overall analysis, it is found that the area is favorable for groundwater exploration.

Hydrogeochemistry and Usability of Groundwater at the Tista River Basin in Northern Bangladesh

Objectives: A study on groundwater of Lalmonirhat Sadar Upazila, Bangladesh has been conducted to explore the groundwater hydrochemistry and suitability for potable water and agricultural uses. Methods/statistical analysis: During the dry season, fifty groundwater samples were collected from different shallow tube wells adjacent to Tista River, Bangladesh. Water samples were analysed according to the standard procedures. We calculated some parameters required for assessing irrigation water quality. The correlation matrix, hierarchical cluster analysis (HCA), and principal component analysis (PCA) were used for better understanding of groundwater chemistry and categorizing the water samples. Findings: The Ca2+–Mg2+–CO3 2−–HCO3 − was the dominant water type, and carbonate weathering was the main hydro geochemical process in the study area. The contributions of ion exchange and reverse ion exchange were almost equal. Groundwater characteristics were influenced by precipitation and not affected by seawater intrusion. The results of all the measured and calculated parameters clearly indicated the suitability of all ground water samples for irrigation. Based on all analysed parameters including hardness, all waters were suitable for drinking and domestic uses. Applications: The groundwater of the study area might be suitable for irrigation, drinking and domestic uses until the waters are otherwise polluted. Keywords: Hydrogeochemistry, Groundwater, Irrigation, Drinking, Bangladesh

Assessment of Bangladesh groundwater for drinking and irrigation using weighted overlay analysis

A weighted overlay analysis was conducted to calculate Water Quality Index (WQI) for drinking water using WHO and Bangladesh drinking water standards (BDWS) and for irrigation using irrigation water quality standards. The method used a normalized quality rating scale (qi) and relative weight (wi) for several water quality parameters to calculate WQI. This index-based suitability analysis was carried out to assess the overall water quality of groundwater in Bangladesh used for drinking and irrigation purposes.Drinking water quality index (DWQI) calculation was done based on As, Mn and hardness concentrations. For irrigation water quality index (IWQI) As, B, Cu, Fe, Li, Mn, Na, Zn and sodium adsorption ratio (SAR) were used. WQIs were calculated separately for the shallow tube wells (STW) (depth <150 m) and deep tube wells (DTW) (depth >150 m). The results revealed that 40.4% STWs and 88.7% DTWs have safe drinking water according to BDWS 57.6% STWs and 90% DTWs have safe drinking water based on WHO drinking water standards. Irrigation water quality index shows that 8.1% STWs and 23.1% DTWs have safe water quality. It has also been found that majority of deep tube wells have better water quality than shallow tube wells due to lower concentrations of contaminants in the deep tube wells compared to shallow tube wells. Some of the dissolved constituents in the groundwater of Bangladesh can potentially be great source of nutrients supplements required for plant growth. If the nutrients dissolved in groundwater replace the nutrients in fertilizers needed for plant growth, an average of US$12.61(BDT 1069) could be saved, which is approximately 19% of the total fertilizer cost.

Water Quality Studies of the Kapadak River Basin, South-Western Bangladesh with Special Emphasis on Environmental Degradation

The Kapadak River basin in SW Bangladesh lies on late Holocene-Recent alluvium of the Ganges deltaic plain in the north and Ganges estuarine plain in the south. The anion and cation trends in the analyzed shallow-tube well and river water are $${\bf{C}}{{\bf{l}}^ - }{\bf{ > HCO}}_{\bf{3}}^ - {\bf{ > NO}}_{\bf{3}}^ - {\bf{ > S}}{{\bf{O}}_{\bf{4}}}^{{\bf{2}} - }$$ and Na+>K+>Ca2+>Mg2+ respectively. The groundwater of the area is of sodium-calcium cation facies and chloride-bicarbonate to carbonate- sulfate anion facies. The river water is of sodium-potassium cation facies and chloride-bicarbonate—sulphate to chloride —sulphate-bicarbonate anion facies. The shallow tube well is contaminated with arsenic which exceeds the WHO recommended value for drinking water (10 µg/l). The shallow water contains salinity above the standard which is unsuitable for drinking as well as for agricultural activities. The concentration of arsenic, sodium, calcium, potassium, chlorine, bicarbonate, percentage of salinity and specific electrical conductance decreases with increasing depth. The shallow tube well water of the study area is very saline exceeding the permissible limit and requires treatment. The deep tube-well water contains lower amount of arsenic and sodium, lower percentage of salinity and specific electrical conductance in comparison to shallow tube-well water. As a result, the deep tube-well water is free from arsenic toxicity and has low to high salinity hazard, but is also hard that exceeds the tolerable limit of hardness of groundwater for drinking, public health and agricultural purposes and requires softening. The Kapadak river water is highly concentrated with sodium, potassium, magnesium, calcium, chloride, bicarbonate, and specific electrical conductance which cause the deterioration of river water quality for agricultural purposes. According to the values of TDS, EC, boron concentration, Na%, and SAR, the shallow tube-well water as well as river water is of poor quality and unsafe for irrigation purposes, while the deep tube-well water is poorly safe for drinking and irrigation purposes. As a whole in the study area groundwater quality degrades from north to south as southern part is inundated regularly by saline estuarine water. The chemical weathering of rock-forming minerals influences the groundwater quality. Entrapped saline water in the aquifers during the Holocene time is the main source of salinity in this area with minor contribution from dissolution of halides and saline estuarine water in the Kapadak river due to tidal inundation.

The spread of smaller engines and markets in machinery services in rural areas of South Asia

This paper is concerned with the historical spread of small scale engines in Asian countries over the last 50 years. Small, mostly single cylinder internal combustion engines (up to 24 hp) that have been used to power pumpsets, boats, vehicles, threshers, ploughs, rotators and other tillage implements, hullers, etc. The paper argues that the spread of smaller scale tractors (power tillers), pumpsets etc. is a neglected topic in the literatures, in spite of the evidence that this equipment has often contributed a significant, if not the major, source of mechanical energy for agricultural production increases and rural economic development. The paper uses two analytical frameworks to position the analysis: firstly, conventional Leontief input output economics, which looks at the interrelationships between sectors in an economy where pumps, tractors, etc. are seen as rural capital goods, and secondly, the historical literature on Appropriate Technology. It is argued in this paper that in the last few years there has been a substantial resurgence in policy interest in appropriate technology, after many years of neglect. Brief illustrative examples are given of the spread of small scale equipment, (diesel engine irrigation pumpsets, two-wheel tractors, power tillers, mini tillers and shallow tube wells). The paper discusses: the diverse histories and patterns of rural mechanization between and within countries; markets in powered services from small engines; the importance of informal R&D in rural mechanization, as well as the past prevalence, recent interest in and problematic nature of South-South technology exchanges. The paper does not set out to enter into academic debates, but does refer to some of the data and analytical problems that characterize such analysis. It concludes by suggesting that the culture of local policy discourse between researchers and policy makers is a major determinant in understanding past changes, and hence is important for future policy purposes.

Examining the Economics of Affordability Through Water Diaries in Coastal Bangladesh

Monitoring affordability of drinking water services is constrained by data gaps from traditional approaches that rely on cross-sectional data from infrequent, nationally representative surveys. Estimates of income or expenditure ratios spent on accessing a main source of drinking water are poorly equipped to reflect affordability in rural contexts where poor people often resort to multiple sources of varying costs, quality and distance to cope with unreliable or absent water supplies. Here, we present findings from an 18-week water diary study that documented daily water choices and expenditures of a stratified sample of 120 households in coastal Bangladesh. This intensive, longitudinal monitoring is supported by household surveys, water infrastructure mapping, hydrogeological analysis of salinity, automated rainfall measurements and interviews with diary participants. We identify five water expenditure typologies, ranging from those who always rely on unpaid and often poor-quality sources like shallow tubewells, pond sand filters and rainwater, to those who purchase vended water for drinking and cooking all year-round, spending 3–7% of total household expenditure. These behavioral dynamics are shaped by environmental, infrastructure and cultural factors, with household wealth being a weak indicator of behavior. We conclude that affordability measures should recognize the quality of service available and chosen by users across seasons, rather than being fixated on income or expenditure ratios for a main source. Measuring the latter without considering the former impedes the design of service delivery models appropriate for providing safe and reliable water supplies, at costs that users and society are willing to bear and sustain.

Hydrochemistry of shallow groundwater and its assessment for drinking and irrigation purposes in Tarmiah district, Baghdad governorate, Iraq

The present study evaluates the hydrochemistry of shallow groundwater and its suitability for drinking and irrigation purposes in Tarmiah district, Baghdad governorate, Iraq. Tarmiah is located in the north of Baghdad and represents an important area for a study due to its human and agriculture activity in addition to lack of information. Twenty groundwater samples were collected from shallow tube wells and analyzed for various related physicochemical tests to produce the relevant piper diagram, Gibbs plot, and Schoeller index values. Piper diagram revealed that there is a broad variation in hydrochemical properties. Gibbs plot showed a remarkable impact on water chemistry due to evaporation. The Schoeller index values demonstrate that 60% of samples are with negative values which in turn show the disequilibrium in a chloro-alkaline relationship while the rest (40%) admit a direct base exchange reaction “cation-anion” as a result of their positive values. The hydrochemistry of the region is dominated by evaporation, silicate and carbonate weathering. To estimate whether the samples are drinkable or not, Water Quality Index (WQI) method was followed. On the other hand, Magnesium Hazard (MH), US salinity and Wilcox diagrams were used as a relevant indication for irrigation usability. The results have shown that the quarter of the samples were suitable for both studied purposes. Statistically, the multivariate methods were used by applying Q and R mode cluster analysis (CA) on the groundwater quality data. The conclusion upon this was finding three kinds of pollution levels for the whole samples. R mode CA revealed two main groups indicating that the study area is influenced by natural processes and anthropogenic sources.

Strategic Ground Water Management Planning for Rice Field in Rangpur Division, Bangladesh

Bangladesh is a land of agriculture and attain near self-sufficiency in rice production. In terms of rice, national output increased over 15 million tons in the last two decades. For obtaining this self sufficiency, groundwater accessibility is continuously increasing that results in expansion of deep and shallow tube wells. Available evidence suggests that the policy focus so far has been largely on “resource development”, and not on “resource management”. This has resulted in serious problems, most notably excessive drawdown in intensively irrigated areas, and the deterioration of groundwater quality. Due to this, an extensive field survey was carried out in Rangpur division (Country’s Northern part) during the year of 2018 to observe the ground water table depletion status in rice field and set up some top most strategies for reviving these problems in a sustainable way. It can be suggested that attention must be given to the development and management of surface water resources to ease pressure on groundwater. Apart from that, focus should be given on optimizing crop water demand through increasing water use efficiency by adopting water conserving management strategies and practices. As per authors’ suggestion, 6 basic strategies can be taken for long term sustainability of ground water management in Rangpur division. The strategies are: 1) Initiate right choice of rice varieties for the season 2) Implement modern water management technology (alternate wetting and drying (AWD), cut off Ratio) 3) Adopting Irrigation scheduling 4) Introduce organic fertilization 5) Apply rain water harvesting and 6) reservoir management.

Identification of 16S rRNA and Virulence-Associated Genes of Arcobacter in Water Samples in the Kathmandu Valley, Nepal.

This study aimed to determine the prevalence of Arcobacter and five associated virulence genes (cadF, ciaB, mviN, pldA, and tlyA) in water samples in the Kathmandu Valley, Nepal. A total of 286 samples were collected from deep tube wells (n = 30), rivers (n = 14), a pond (n = 1), shallow dug wells (n = 166), shallow tube wells (n = 33), springs (n = 21), and stone spouts (n = 21) in February and March (dry season) and August (wet season), 2016. Bacterial DNA was extracted from the water samples and subjected to SYBR Green-based quantitative PCR for 16S rRNA and virulence genes of Arcobacter. The 16S rRNA gene of Arcobacter was detected in 36% (40/112) of samples collected in the dry season, at concentrations ranging from 5.7 to 10.2 log copies/100 mL, and 34% (59/174) of samples collected in the wet season, at concentrations of 5.4–10.8 log copies/100 mL. No significant difference in Arcobacter 16S rRNA gene-positive results was observed between samples collected in the two seasons (p > 0.05). Seventeen (17%), 84 (84%), 19 (19%), 23 (23%), and 17 (17%) of the 99 Arcobacter 16S rRNA gene-positive samples were also positive for cadF, ciaB, mviN, pldA, and tlyA, respectively. At least one virulence gene was detected in 87 (88%) of the 99 Arcobacter 16S rRNA gene-positive samples. The presence of Arcobacter and the virulence genes in these samples illustrates the persistence of pathogenic bacteria in the environment and highlights the importance of regular monitoring of water for pathogens.

Assessment on connection between shallow and deep aquifers of Siraha and Saptari Districts using isotope analysis

Total 26 samples, 6 from river, 7 from deep tube well and 13 from shallow tube wells were analyzed for the isotopic composition and chemical composition of the water at different sources. The main focus of the study was to assess connection between aquifers, and recharge zone analysis of the local groundwater system in the Siraha and the Saptari Districts, west of the Koshi River. The δ18O composition of the Koshi River was found to be the lightest whereas the shallow tube wells at Haripur and Shambhunath were the heaviest. The δ18O composition at many locations showed identical values showing the correlation of water within the aquifers and also with the surface water. Based on the plot of δ18O vs δ2H, the shallow tube well at Asanpur and the deep tube well at Jamdahawere suspected to be recharged from the Kharak Khola. Similarly, the deep tube wells at Lalpur and Kusaha, the shallow tubes wellat Asanpur, Tudkiya and Raghunathpur, and the Mahuli Khola and the Khado Khola are interconnected. The deep tube wells at Tudkiya, Dhangadhi and Phulkakatti might have interconnection with the shallow tube wells at Khoriya and Golamukhsar.