Multiple Water Sources Research Articles

Determining water allocation scheme to attain nutrient management objective for a large lake receiving irrigation discharge

Irrigation discharge is a relevant water resource for lake ecosystems in arid and semi-arid regions. However, high concentrations of nitrogen and phosphorus in the irrigation discharge raise concerns over potential lake eutrophication in these regions. A Delft3D hydrodynamic-water quality model was used to explore the effects of multiple water sources on water quality of a large shollow lake in the semi-arid west of Northeast China, which is surrounded by irrigated rice paddies. Eighteen scenarios in a combination of different precipitation rates, irrigation discharge operations, and flow conditions were simulated to analyze time and water allocation required in order to achieve nutrient standards of total nitrogen (TN) ≤ 1.5 mg/L and total phosphorus (TP) ≤ 0.1 mg/L. The results showed that time required for the optimal combination to achieve nutrient management objectives displayed an increasing trend from the east to west. In the best control scenario where the irrigation discharge was regulated into the lake, TN and TP concentrations could be reduced by 60% and 70%, respectively. Water diversion from a freshwater reservoir can effectively improve lake water quality even though sediment nutrient resuspension could occur in the eastern region of lake. The findings suggest that using multi-source water supplies can attain nutrient management objectives in order to reduce eutrophication risk for a lake that receives nutrient-rich irrigation discharge. The study also demonstrates the great usefulness of hydrodynamic-water quality modeling for assessing water resource allocation and science-based decision making in intensive agriculture practices.

Occurrence and risk assessment of volatile organic compounds in multiple drinking water sources in the Yangtze River Delta region, China

Volatile organic compounds (VOCs) are widely present in water environment, which can threaten ecological sustainability and human health. The concentrations of VOCs and their ecological risks in drinking water are of great concern to human beings. Therefore, 54 kinds of VOCs were investigated from 58 locations of the Yangtze River Delta Region (Yangtze River, Qiantang River, Huangpu River, Taihu Lake and Jiaxing Urban River). Out of 54 target compounds, only 31 VOCs were detected, with total concentrations ranging from 0.570 to 46.820 μg/L from 58 locations of all drinking water sources. Among all detected VOCs compounds, only toluene and styrene can cause high-level ecological risk at location TH-2 of Taihu Lake. According to the carcinogenic and non-carcinogenic risk index, compounds such as 1,2-dichloroethane, bromodichloromethane and 1,1,2-trichloroethane posed a higher carcinogenic risk, and 1,2-dichloroethane, trichloroethylene and toluene posed a higher non-carcinogenic risk. Olfactory risks of water bodies in the Yangtze River Delta region are negligible. Although the concentrations of VOCs in the Yangtze River Delta region did not exceed national standards in China and guidelines of the World Health Organization (WHO) for drinking water, the presence of some ecological and health risks indicated that future monitoring studies and control practices are important to ensure ecological safety of drinking water sources.

Outbreak of Pseudomonas aeruginosa producing VIM carbapenemase in an intensive care unit and its termination by implementation of waterless patient care

BackgroundLong-term outbreaks of multidrug-resistant Gram-negative bacilli related to hospital-building water systems have been described. However, successful mitigation strategies have rarely been reported. In particular, environmental disinfection or replacement of contaminated equipment usually failed to eradicate environmental sources of Pseudomonas aeruginosa.MethodsWe report the investigation and termination of an outbreak of P. aeruginosa producing VIM carbapenemase (PA-VIM) in the adult intensive care unit (ICU) of a Swiss tertiary care hospital with active case finding, environmental sampling and whole genome sequencing (WGS) of patient and environmental strains. We also describe the implemented control strategies and their effectiveness on eradication of the environmental reservoir.ResultsBetween April 2018 and September 2020, 21 patients became either infected or colonized with a PA-VIM strain. For 16 of them, an acquisition in the ICU was suspected. Among 131 environmental samples collected in the ICU, 13 grew PA-VIM in sink traps and drains. WGS confirmed the epidemiological link between clinical and environmental strains and the monoclonal pattern of the outbreak. After removing sinks from patient rooms and implementation of waterless patient care, no new acquisition was detected in the ICU within 8 months after the intervention.DiscussionImplementation of waterless patient care with removal of the sinks in patient rooms was successful for termination of a PA-VIM ICU outbreak linked to multiple environmental water sources. WGS provides highly discriminatory accuracy to investigate environment-related outbreaks.

A stochastic modeling approach for analyzing water resources systems

Many uncertain factors exist in the water resource systems, leading to dynamic characteristics of the water distribution process. Especially for the watershed including irrigation area with multiple water sources and water users, it is complicated that the joint risk among available water from each water source and multi-uncertainties under water resource allocation among multiple water users. In this research, an approach is developed that a copula-based interval multi-stage fuzzy stochastic programming (CIMFSP) model. This research aims at figuring out the planning of a case study for water-resources management. In the multi-sources water supply subsystem, the copula function is introduced to tackle the interaction of water availability between two water sources (i.e., A &B). Joint risk was set 0.05, 0.10, 0.15 to reflect the shortage risk of total available water at diverse levels. An interval parameter multi-stage fuzzy stochastic programming (IMFSP) model is developed for water resource distribution in a multi-users water-demand subsystem. Through this model, uncertainties presented as interval numbers and probability distributions, as well as fuzzy sets, were handled. The dynamics of the entire water resource system can be reflected by multi-stage discrete trees. A series of solutions can be generated under multiple scenarios (i.e., joint risk and α-cut levels). The modeling results will produce a series of alternatives under a battery of scenarios and help the decision-makers get an insight into the tradeoff between the system economic benefit and financial penalties under the corresponding risk level. This approach is valuable for improving the feasibility of optimal results in the watershed with irrigation region water resource management.

Regional agricultural water resources management with respect to fuzzy return and energy constraint under uncertainty: An integrated optimization approach

In this study, an integrated framework is proposed for agricultural water and land resources management under uncertain circumstances and energy-water nexus. The framework has two components: the optimized interval solutions generation of unknown market quotation and environment situation through the novel interval fuzzy-expectation programming, and the post-optimization decision-making of the tradeoff between system risk and return through risk-explicit interval programming. An optimization model based on the framework was developed from a real description for agricultural water resources system of Guangdong province under considering various crop, multiple water sources, and the related energy consumption in irrigation and drainage. The impact of energy consumption and risk level control on water resources allocation among different crops and system benefits were analyzed. The results indicated that the preference for surface water resources as the main water sources can effectively reduce regional irrigation energy consumption, and the planting area of each crop would have different variations duo to resources endowment constraints. Risk tradeoff-based results can provide valuable information and additional concern for developing low carbon-oriented agricultural water resources management schemes.

Visual quantitation of silver contamination in fresh water via accumulative length of microparticles in capillary-driven microfluidic devices

Silver is a heavy metal commonly used as bacteriostatic agents or disinfectants. However, excess amount of silver ion (Ag+) could lead to adverse biological effects on human health. To monitor silver ions in environmental samples, we report a visual quantitative method for analyzing the trace amount of Ag+. A sliver-specific RNA-cleaving DNAzyme Ag10C firstly makes the connection between magnetic microparticles (MMPs) and polystyrene microparticles (PMPs) forming a complex as “MMPs-Ag10C-PMPs”. When Ag+ is present, the Ag10C is cleaved, resulting in an increase of free PMPs. By dropping 3 μL of reacted particle solution to a capillary-driven microfluidic chip, MMPs and MMPs-Ag10C-PMPs are removed by a magnetic separator during the flow, while free PMPs can continue flowing until being trapped and accumulating at a particle dam with a narrow nozzle. The accumulation length of PMPs linearly increases with the increment of Ag+ concentrations in the range of 0–10 μM, and readable by the naked eye. We have achieved a limit of detection (LOD) down to 453.7 nM, which is significantly lower than the maximum contaminant level of 926 nM set by World Health Organization (WHO). More importantly, after validating the high selectivity against other metal ions and stable performance in different pH and water hardness, we demonstrate recovery rate >96.8% for tests of multiple fresh water sources, manifesting the feasibility in practical detection in real water samples.

Relationship between diarrhoea risk and the combinations of drinking water sources in the Kathmandu Valley, Nepal.

In Nepal, the number of diarrhoea hospitalizations in all ages is seriously high. According to the World Health Organization, diarrheal diseases can be substantially prevented through safe drinking water sources. In the Kathmandu Valley, because of the shortage of piped water, local residents use alternative water sources, such as groundwater, jars and tanker water. However, these alternative water sources can be contaminated. This study aimed to clarify the relationship between diarrhoea risk and the combinations of drinking water sources. A survey using multiple questionnaires on diarrhoea occurrence, water sources and water treatment was conducted three time between 2015 and 2016. The odds ratios (ORs) of developing diarrhoea were significantly high for drinking jar (OR 6.1) and tanker water (OR 8.4) compared with not drinking. The combined drinking of jar and tanker water obtained the 1 log higher OR compared with drinking only piped water. Conversely, drinking groundwater had a low OR, implying that the residents refrained from drinking polluted groundwater. In conclusion, diarrhoea occurrence was related not only to the level of water contamination, but also to a behavioural factor, i.e. people's careful management of the choice of multiple water sources.

Optimizing Household Water Decisions for Managing Intermittent Water Supply in Mexico City.

One billion people worldwide experience intermittent water supply (IWS), in which piped water is delivered for limited durations. Households with IWS must invest in water storage infrastructure and often rely on multiple sources of water; therefore, these household-level purchasing and infrastructure decisions is a critical component of water access. Informed by interviews with IWS households, we use radial basis function networks, a type of artificial neural network, to determine optimal household water management decisions that maximize reliability of water supply while minimizing costs for a representative household in Mexico City that uses municipal piped water, trucked water, and rainwater. We find that securing reliable water supply for IWS households is greatly assisted by installation of household storage tanks of at least 2500 L. In the case of IWS households with limited storage options, the overall cost for water supply is reduced by scheduling water deliveries on nonconsecutive days. Rainwater harvesting systems were shown to be economically viable for households with limited water supply. This study demonstrates the importance of considering the management of multiple sources and household storage infrastructure when evaluating water investments in cities with IWS.

Coastal reservoirs as a source of nitrous oxide: Spatio-temporal patterns and assessment strategy

Coastal reservoirs are widely regarded as a viable solution to the water scarcity problem faced by coastal cities with growing populations. As a result of the accumulation of anthropogenic wastes and the alteration of hydroecological processes, these reservoirs may also become the emission hotspots of nitrous oxide (N2O). Hitherto, accurate global assessment of N2O emission suffers from the scarcity and low spatio-temporal resolution of field data, especially from small coastal reservoirs with high spatial heterogeneity and multiple water sources. In this study, we measured the surface water N2O concentrations and emissions at a high spatial resolution across three seasons in a subtropical coastal reservoir in southeastern China, which was hydrochemically highly heterogeneous because of the combined influence of river runoff, aquacultural discharge, industrial discharge and municipal sewage. Both N2O concentration and emission exhibited strong spatio-temporal variations, which were correlated with nitrogen loading from the river and wastewater discharge. The mean N2O concentration and emission were found to be significantly higher in the summer than in spring and autumn. The results of redundancy analysis showed that NH4+-N explained the greatest variance in N2O emission, which implied that nitrification was the main microbial pathway for N2O production in spite of the potentially increasing importance of denitrification of NO3−-N in the summer. The mean N2O emission across the whole reservoir was 107 μg m−2 h−1, which was more than an order of magnitude higher than that from global lakes and reservoirs. Based on our results of Monte Carlo simulations, a minimum of 15 sampling points per km2 would be needed to produce representative and reliable N2O estimates in such a spatially heterogeneous aquatic system. Overall, coastal reservoirs could play an increasingly important role in future climate change via their N2O emission to the atmosphere as water demand and anthropogenic pressure continue to rise.

Do Decentralized Community Treatment Plants Provide Clean Water? Evidence from Rural Andhra Pradesh, India

Though there is little evidence on its effectiveness, a decentralized community water system (CWS), such as a market-based kiosk, is thought to be appropriate where piped services are infeasible or unreliable. We assess changes in household behaviors, water quality, and health following the installation of a CWS in rural India, using quasi-experimental methods. Three negative findings stand out: (1) few households use the CWS, (2) water quality is lower among CWS users, and (3) childhood diarrhea is higher among CWS users. This appears to stem from reduced self-protection by users amid continuing reliance on multiple water sources. Decentralized supply solutions will not deliver environmental quality unless household protective behaviors are maintained.

Multiple water source use in low- and middle-income countries: a systematic review.

The Joint Monitoring Programme (JMP) 2017 Update and Sustainable Development Goals (SDGs) Baselines report classified 71% of the global population as having access to 'safely managed' drinking water. Current global monitoring efforts to track access to safely managed drinking water rely on collecting information on the 'primary' source of drinking water. However, there is evidence that households often rely on multiple sources to meet their water needs in many low- and middle-income countries (LMICs). This systematic review was designed to compile the literature related to the practice of multiple water source use (MWSU) for drinking water in LMICs. A total of 5,318 studies were collected, and after abstract and full-text review, 74 articles were identified for inclusion. Studies reviewed reported from 4 to 100% of the study populations practicing MWSU. Additionally, the practice of supplemental unimproved source use was reported globally, representing households with improved primary source water also accessing unimproved water sources throughout the year. These findings expose gaps in current global water monitoring efforts, revealing potential inflation of reports of 'safe drinking water access' and unaccounted exposure to drinking water from unimproved sources.

Effect of wastewater irrigation as an alternative irrigation resource on heavy metal accumulation in ginger (Zingiber officinale Rosc.) and human health risk from consumption

The present research was performed to examine and compare the level of heavy metals in ginger (Zingiber officinale) irrigated with canal water and wastewater. Soil and vegetable samples were collected from two different areas irrigated with multiple water sources. Atomic absorption spectrophotometer was used for evaluation of metals, zinc (Zn), nickel (Ni), copper (Cu), cobalt (Co), manganese (Mn), lead (Pb), iron (Fe), and chromium (Cr). The metal accumulations in soil samples were ranged from 0.09 to 6.01 mg/kg. The metal accumulations in plant samples were ranged from 0.15 to 6.14 mg/kg. The Fe was found to be the heavy metal with the highest accumulation value in both sampling sites. The bioconcentration factor for Pb was highest at Site 1 and the lowest for Zn at Site 2. Pollution load index greater than one was obtained for Cr and Cd at both sites. Health risk index for all heavy metals was lower than 1 except for Pb and found in the following sequence: Pb>Ni>Cu>Cd>Fe>Zn>Cr>Co>Mn. Therefore, proper management strategies should be taken to reduce the extent of metal contamination in the food crop.

Describing alpine lake influence on stream network temperatures: A statistical modelling approach

AbstractSystematic variations in atmospheric heat exchange, surface residence time, and groundwater influx across montane stream networks commonly produce an increasing stream temperature trend with decreasing elevation. However, complex stream temperature profiles that differ from this common longitudinal trend also exist, suggesting that stream temperatures may be influenced by complex interactions among hydrologic and atmospheric processes. Lakes within stream networks form one potential source of temperature profile complexity due to the spatially variable contribution of lake‐sourced water to stream flow. We investigated temperature profile complexity in a multi‐season stream temperature dataset collected across a montane stream network containing many alpine lakes. This investigation was performed by making comparisons between multiple statistical models that used different combinations of stream and lake characteristics to represent specific hypotheses for the controls on stream temperature. The compared models included a set of models which used a topographically derived estimate of the hydrologic influence of lakes to separate and quantify the effects of stream elevation and lake source‐water contributions to longitudinal stream temperature patterns. This source‐water mixing model provided a parsimonious explanation for complex stream‐network temperature patterns in the summer and autumn, and this approach may be further applicable to other systems where stream temperatures are influenced by multiple water sources. Simpler models that discounted lake effects were more optimal during the winter and spring, suggesting that complex patterns in stream temperature profiles may emerge and subside temporally, across seasons, in response to diversity of water temperatures from different sources.

Community-Driven Evaluation of E. coli Levels in Domestic-Use Underground Water Sources in Angono, Philippines

Objectives. The authors considered the community-based on-site water sampling-surveys case-study in Angono, Rizal, in the Republic of the Philippines. The study was designed to determine whether individual citizens within the community could successfully collaborate in order to develop a method for quantification of E. coli levels in water (especially underground water) for domestic use. Methods. We used techniques that had been validated in Japan for on-site evaluation of E. coli. These simple techniques enabled the on-site quantification of E. coli levels in multiple water sources, including underground water. Results. The techniques used in Japan were successfully adopted in the Philippines, and we cooperated with regional medical technicians, scientists, and citizens, in order to develop a system where ultimately, the people in Angono can perform all the tasks related to on-site water quality evaluation. From societal and economic perspectives, we were able to reduce the traditionally high laboratory cost (including testing cost and samples transit cost) of coliform bacteria and E. coli evaluation to a lower, fixed cost level that is affordable for regional health centers and other sites. Conclusion. The transfer of a simple inspection method technology, under the supervision of an experienced Japanese research team, allowed us to validate the E. coli on-site quantification strategy at a regional level as ”cocreation of science and society”. In addition, beyond technology transfer, our collaborative efforts with scientists, regional medical engineers, and citizens, led to the creation of an NGO (non-governmental organization) that serves citizens in the town of Angono with regard to water quality assessment and certification activities.

An outbreak investigation of acute Diarrheal Disease, Nagpur District, Maharashtra, India.

Acute diarrheal disease (ADD) accounts for 12 million cases and 1216 deaths annually in India. On July 13, 2016, an ADD outbreak was reported from Sawargaon village from Nagpur district, Maharashtra. The outbreak was investigated to describe the epidemiology and suggest control and preventive measures. A case was defined as a person experiencing at least one loose stool in Sawargaon village between July 9, 2016, and July 31, 2016. We searched for cases by enhanced passive surveillance. We collected stool samples for bacterial culture and tested water from multiple water sources for fecal coliforms. We also reviewed sanitary practices and rainfall data. A total of 889 cases were identified, with 51% female, 280 hospitalizations (31%), and two deaths. The median age was 27 years (range 6 months to 90 years). Cases started on July 9, a week after heavy rains. District authorities started chlorination of water sources on July 13 and cases declined soon after. Two of nine stool samples tested positive for Vibrio cholera O1 serogroup. Of the 18 water samples collected, 16 (88%) samples from multiple sources, including wells, hand pumps, and taps, were positive for fecal coliforms. Of 1,885 households in the village, 450 (24%) households had no toilets and open defecation was commonly observed in the nearby river bed. This ADD outbreak was likely associated with drinking contaminated groundwater, which probably occurred after heavy rainfall in an area of open defecation. We recommended providing chlorinated drinking water, promoting safe sanitation practices, including building more public and private toilets, and enhancing diagnostic laboratory capacity.

Dual Water Choices: The Assessment of the Influential Factors on Water Sources Choices Using Unsupervised Machine Learning Market Basket Analysis

An unsupervised machine learning model of association rule known as market basket analysis is proposed in this study to analyze the influence of various socio-economic factors on the choice of the water source. Data of 51 socio-economic factors collected from 295 individuals living in 65 households in Ambo city in the Oromia region of Ethiopians were used for this purpose. The results revealed (i) 64% of the family preferred multiple water sources (i.e., public tap and river water), (ii) the water was collected females in 92% of the households, and (iii) majority of people preferred bathing and laundering in the river (support = 32% and confidence = 87%). Direct utilization of river water is not a preferable choice for the user since it may lead to severe health issues and cause water pollution from bathing and laundering. Education and monthly income have a significant impact on the choices of water sources. Local management authorities can improve sanitation and public health management using the results obtained in the study. The paper only gives a glimpse of the important factors that should be considered for improving the way of life for the underdeveloped areas of the world using advanced machine learning techniques.

Water quality for livestock in northern Great Plains rangelands

Dissolved solids can negatively impact livestock drinking water. To characterize dissolved solid concentrations in the northern Great Plains, we studied 45 water sources over 11 yr. Ca, F, Mg, Na, and total solids sometimes exceeded recommended levels but rarely reached levels empirically shown to negatively impact livestock. Fe often attained concentrations that reduce water consumption, which can reduce feed intake and weight gain. Excessive Fe was likeliest in creeks and reservoirs. SO4 sometimes reached concentrations that reduce weight gain but rarely reached concentrations causing health problems. Excessive SO4 was least likely in reservoirs. A safeguard against water quality problems is ensuring livestock can access multiple water source types (e.g., wells and reservoirs) so that they can use taste and smell to choose acceptable water. Where this is impossible, water quality monitoring is of greater importance. Inexpensive electrical conductivity meters roughly estimate water quality and can identify watering locations requiring more detailed monitoring.

Characteristics of δ18O and δ2H and their implication for the interaction between precipitation, groundwater and river water in the upper River Tuojiang, Southwest China

Abstract The Tuojiang River has multiple water sources and serious pollution problems, but its hydrological mechanism in the upper reaches is still unclear. To better understand the hydrological characteristics of the Tuojiang River, the isotopic compositions of its precipitation, river water and groundwater in the upper reaches have been investigated from May 2018 to April 2019. The results indicated that the isotope values of precipitation, river water and groundwater fluctuate significantly throughout the year with depleted value in the wet season and enriched value in the dry season. Spatially, the isotope values of river water increase gradually from upstream to downstream. River water is the main source of recharge to groundwater and precipitation is the minor one. The isotope-based hydrograph separation shows that the Mianyuan River and Pihe River contribute more greatly to Tuojiang River than the Shiting River and Yazi River. The mean residence time of river water from the Tuojiang River varies from 0.95 to 1.49 years, which indicates that rivers in the upper reaches of the Tuojiang River respond to precipitation quickly. This study proved the usefulness of stable isotopes to identify the different water cycle components and reflect the pollution problem in multiple water source confluence areas.

Using an ETWatch (RS)-UZF-MODFLOW Coupled Model to Optimize Joint Use of Transferred Water and Local Water Sources in a Saline Water Area of the North China Plain

In the saline water area of our research, deep groundwater was over-pumped for agricultural irrigation which resulted in a decline of the deep groundwater level and an increase in the shallow groundwater table. Soil salination was also aggravated due to the strong evapotranspiration (ET) in the shallow groundwater areas, where ET removes water vapor from the unsaturated zone (ETu), and the groundwater (ETg). Joint utilities of multiple water sources of transferred water and local shallow and deep groundwater are essential for reasonable management of irrigation water. However, it is still difficult to distinguish ETu and ETg in coupled management of unsaturated zone and groundwater, which account for the water balance in utilities of multiple water sources in a regional scale. In this paper, we used an RS-based ETWatch model as a source of evapotranspiration data coupled with UZF-MODFLOW, an integrated hydrological model of the unsaturated–saturated zone, to estimate the ETg and ETu on a regional scale. It was shown that the coupled model (ETWatch-UZF-MODFLOW) avoids the influence of ETu on the groundwater balance calculation and improves the accuracy of the groundwater model. The model was used in the simulation and prediction of groundwater level. The eastern North China Plain (NCP) was selected as the study area where shallow groundwater was saline water and deep groundwater cone existed. We compared four different scenarios of irrigation methods, including current irrigation scenario, use of saline water, limited deep groundwater pumping, use of multiple water sources of transferred water and local groundwater. Results indicate that the total ETg for the four scenarios in the study area from 2013 to 2030 is 119 × 108 m3, 81.9 × 108 m3, 85.0 × 108 m3, and 92.3 × 108 m3, respectively, and the proportion of ETg to total ET was 6.85%, 4.79%, 4.97%, 5.37%. However, in regions where the groundwater depth is less than 3 m, ETg accounts for 12% of the total ET, indicating that groundwater was one of the main sources of evapotranspiration in shallow groundwater depth area.

Daily changes in household water access and quality in urban slums undermine global safe water monitoring programmes.

Global drinking water monitoring programmes and studies on water quality in urban slums often overlook short-term temporal changes in water quality and health risks. The aim of this study was to quantify daily changes in household water access and quality in an urban slum in Malawi using a mixed-method approach. Household drinking water samples (n=371) were collected and monitored for E. coli in tandem with a water access questionnaire (n=481). E. coli concentrations in household drinking water changed daily, and no household had drinking water that was completely safe to drink every day. Seasonal changes in drinking water availability, intermittent supply, limited opening hours, and frequent breakdown of public water points contributed to poor access. Households relied on multiple water sources and regularly switched between sources to meet daily water needs. There were generally similar E. coli levels in water samples considered safe and unsafe by residents. This study provides the first empirical evidence that water quality, water access, and related health risks in urban slums change at much finer (daily) temporal scales than is conventionally monitored and reported globally. Our findings underscore that to advance progress towards Sustainable Development Goal (SDG) Target 6.1, it is necessary for global water monitoring initiatives to consider short-term changes in access and quality.