Narrow Results

The effluent discharge of domestic wastewater and industrial effluents into watercourses has necessitated the development of monitoring systems with the purpose of characterizing levels of pollution. Substantial levels of pollution in emerging nations have been exacerbated by rapidly growing populations and inefficient enforcement of sustainable management initiatives. The Water Quality Index (WQI) can help fill the gap between water quality reporting and monitoring by offering a simple and effective way to assimilate and communicate results from a large amount of data. WQIs are the kind of communication tools that can facilitate knowledge sharing between scholars and the general public. The degradation of natural water resources, such as lakes, streams, and estuaries, is the most significant problem facing humanity. Water that is not clean has far-reaching effects on all aspects of life. Water resource management is therefore essential if it is to maximize water quality. If data are analyzed and water quality can be predicted in advance, water pollution may be efficiently addressed. Although this subject has been the subject of numerous earlier studies, additional research is still required to fully understand the effectiveness, reliability, accuracy, and application of the present approaches to water quality management. In this research work, a comprehensive review has been conducted on water quality assessment using artificial techniques. It reviews 75 research works on water quality analysis. The data collected in each research work have been analyzed. Moreover, the type of water resource surface water, groundwater, drinking water as well has been analyzed. The parameters considered in each work are “Dissolved Oxygen (DO), Potential of Hydrogen (pH), Biochemical Oxygen Demand (BOD), Total Dissolved Solids (TDS), and Chemical Oxygen Demand (COD), chloride, hardness, alkalinity, nitrate–nitrite”. In addition, the Artificial Intelligence technique utilized for water quality analysis is also assessed. Finally, the research gaps identified in water quality detection are exhibited.

A critical process that involves a thorough examination of the physical, chemical, and biological properties of water to ascertain its suitability for different applications, such as drinking, farming, and industrial, is water quality assessment. Poor land use and pollutant discharge are two classic examples of how natural and anthropogenic factors can have a significant impact on water quality. Water quality is assessed using key indicators such as dissolved oxygen (DO), biological oxygen demand (BOD), and fecal coloniform (FC). In Multi-Criteria Decision-Making (MCDM) in water quality assessment, appropriate weights are assigned to criteria and preference functions reflect the preferences of decision-makers. This is where the Intuitionistic Fuzzy PROMETHEE II technique comes into play. In the assessment of water quality, Principal Component Analysis (PCA) deals with correlations between metrics. To summarize, the process of evaluating the quality of water entails examining its attributes and employing sophisticated techniques such as PCA and Fuzzy PROMETHEE II to make well-informed decisions for a range of uses.

A two-dimensional model for toxic contaminants was developed and incorporated into a laterally integrated hydrodynamics and transport model to investigate the effect of reservoir flow regime on contamination level in a reservoir after a toxic spill. The model describes the physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. Simulation results suggested that the persistence of a contaminant was significantly influenced by different flow regimes. It was found that the toxicant plume was more persistent in an interflow than in an overflow which moved more slowly and experienced greater volatilization and dissipation. This analysis can assist in spill control and reservoir management.

Recent concern about the effects of Zebra mussels has centred on potential loss of fish production and potential loss of fish edibility. The mussels are thought to cause these effects by diversion of energy flow and alteration of contaminant processing. Because management options are limited to controls on nutrients and fish harvest/stocking, it is important to determine the extent and degree of Zebra Mussel effects. Some effects of the mussels are obvious in sheltered shallow areas but the effects on the whole ecosystem are not known.

A series of research surveys done in 1993 is reported in this paper. The effects of the mussels seem to result in a loss of about 25 % of the standing algal biomass in some areas. Although an attempt was made to visit many areas of the lake, more extensive work is needed to find whole ecosystem effects. The difficulty in delineating the effects of the mussels is caused by the coincidental achievement of nutrient loading goals. Because the distribution of zebra mussels is uneven their effects may be found through extensive spatial surveys.

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This research study aims to conduct the analysis and implementation of efficient algorithms for simulations of micro and nanoparticle transport models in porous media, coupled with the Darcy–Forchheimer fluid model, modified to include electromagnetic effects. The schemes developed were implemented via a parallel infrastructure for benchmark problems with a flexible algorithm that is efficient, robust, and stable. These improvements in the reliability and efficiency of simulations of nanoparticle transport in porous media contribute to the creation of an efficient method to counteract the contaminants in groundwater, and ultimately increase the availability of clean drinking water.

When marine development works are conducted in coastal regions, it is necessary to consider the preservation of the environment in the vicinity. Construction of port structures results in new physical environmental conditions on the ecosystems around the port. The relationship between marine ecosystems and marine conditions has never been sufficiently investigated. The authors collected data on marine organisms and executed a field investigation.

The factors relating to the ecological environment of marine organisms (attached animals and seaweed) on port structures are sunlight, water quality, current, waves, the wall properties of the port structures, etc. The authors reanalyzed the relationships between the distributions of attached organisms such as the number of individuals, the number of species, value of diversity index, etc. and the habitat conditions such as wave height, water quality, structure types, etc.

The following conclusions were obtained.

(1) Large sized brown algae inhabit areas where the annual mean value of COD is less than 2 mg/l and the one-year probability maximum wave height is from 1 to 3 meters.

(2) In areas where the value of COD is more than 3 mg/l and the maximum wave height is less than 1 meter, attached animals inhabit dominantly.

(3) The diversity index of attached animals on a mild slope structure is larger than that on an upright structure.

Coastal waters in and around Puerto Galera Bay, Mindoro, Philippines, is drastically contaminated generally due to poorly constructed sanitation and household facilities and runoff from the hillsides associated with the tourism development. In this study, a field survey on tidal currents and water quality in and around Puerto Galera Bay was conducted with hydrodynamic numerical simulations of tidal currents, in which a nesting technique was employed for properly incorporating the effects of complicated tidal fluctuation outside the bay. The results reveal the existence of a highly asymmetrical pattern of tidal flow fluctuation having strong tidal residual flow and the vulnerability of the flow field to water quality deterioration within the semi-enclosed innermost bay area. The highly asymmetrical tidal flow fluctuation is attributed to the asymmetrical generation of detached eddying motion around Puerto Galera as a highly nonlinear phenomenon producing strong tidal residual currents. These results are useful in understanding the physical conditions of the bay, which are needed for consideration in the local government's coastal management plan.

The Limfjord is the largest Danish estuary and is connected to both the North Sea in the west and the Kattegat in the east. The connection to the North Sea was formed in 1825 by a storm surge, and has since been kept open partly artificially. The debate about the climate changes and thereby the increased risk of flooding in the estuary has revitalized the discussion whether this connection should be closed. In this paper, it is shown by numerical simulation that the establishment of a storm surge barrier across Thyborøn Channel can significantly reduce the peak water levels in the central of the fjord. The reduction is obtained by blocking the ingoing flow with a sluice in due time before the storm surge peaks in the North Sea. In order to avoid problems with reduced water quality and salinity, the water exchange should be controlled by only keeping the sluice open for ingoing currents for the rest of days during the year. Depending on the effective cross-sectional area of the sluice, the depth-averaged salinity in the Limfjord remains status quo for cross-sectional areas of 500 m², whereas the salinity increases with up to 1.5 PSU for larger openings.

Atrazine is the most commonly used herbicide in the spring for pre-emergent weed control in the corn cropping area in the Midwestern United States. A frequent high level of herbicide concentrations in reservoirs is a great concern for public health and aquatic ecosystems. In this study, a two-dimensional hydrodynamics and toxic contaminant transport model was applied to Saylorville Reservoir, Iowa, USA. The model simulates physical, chemical, and biological processes and predicts unsteady vertical and longitudinal distributions of a toxic chemical. Model results were validated by measured temperatures and atrazine concentrations. Simulated flow velocities, water temperatures, and chemical concentrations demonstrated that the spatial variation of atrazine concentrations was largely affected by seasonal flow circulation patterns in the reservoir. In particular, the simulated fate and transport of atrazine showed the effect of flow circulation on spatial distribution of atrazine during summer months as the river flow formed an underflow within the reservoir and resulted in greater concentrations near the surface of the reservoir. Atrazine concentrations in the reservoir peaked around the end of May and early June. A thorough understanding of the fate and transport of atrazine in the reservoir can assist in developing operation and pollution prevention strategies with respect to timing, amount, and depth of withdrawal. The responses of atrazine transport to various boundary conditions provide useful information in assessing environmental impact of alternative upstream watershed management practices on the quality of reservoir water.

This study was carried out to design an incentive payment for an ecosystem services (IPES) scheme in the Baitadi Town Water Supply and Sanitation Project of Nepal. The main intention behind the designing of the scheme was to develop strategy for equitable use of water resources and involve communities, watershed and water user, in the sustainable management of water resources. We administered household survey in both the watershed community and water users to elicit their preferences regarding water source management and drinking water supply. A discrete choice experiment was employed in the case of water users which showed that, for them, water quality and quantity are the most important attributes. The estimated annual willingness-to-pay of water users for doubling water availability is NPR 482,076 (USD 4,505) and for doubling the water quantity and the supply of clean water that can be drunk directly from the tap is NPR 1.18 million (USD 10,988). The results of consultations with stakeholders indicate that the construction of public toilets, the regularization of grazing, off-season vegetable farming and drinking water distribution in the upstream area may contribute to maintaining the quality of water while keeping the watershed community satisfied with regard to water-sharing. These activities require NPR 1.17 million (USD 10,987) in the first year and NPR 425,640 (USD 3,978) annually from the second year on. The estimated willingness-to-pay and cost of the watershed activities indicate that implementing IPES in the Baitadi Town Water Supply Project is financially feasible and socially acceptable. Our study recommends the integration of the IPES design into the project design phase in future drinking water scheme, the best option being its integration into the initial environmental examination at the time of project design.

The Kura–Araks Basin is facing problems with insufficient water availability for all needs and poor water quality, which results in high rates of waterborne diseases. The riparians of the basin struggle with management of water resources within their national borders, as well as internationally, across the basin. With international rivers, interdependency among countries is created, where the upstream country can impact the quantity and quality of water downstream. This study focuses on the upstream–downstream relationship with the Kura River between Azerbaijan and Georgia. The analysis uses a game theoretical framework, which incorporates several issues in the negotiation space. Specifically, water quantity and water quality are analyzed separately and combined into an aggregated isolated game. The analysis compares the aggregated isolated game, where the outcome of each game is negotiated separately, with an interconnected game, where the two games are jointly negotiated. Using realistic parameters, results show that due to the repeated nature of some of the payoffs, cooperation is unlikely to be achievable in each game independently, since at least one country has an incentive to deviate. In contrast, the interconnected game can achieve full cooperation and increase the welfare of both countries.

For community water providers, safeguarding source waters from contamination offers an additional barrier of protection and a potential means of avoiding in-plant treatment costs. Whether source water protection efforts are cost-effective relative to in-plant treatment requires hydrologic, geologic, and climatologic knowledge of source watersheds, as well as an understanding of how changes in source water quality affect treatment costs. Quantitative evidence on the latter relationship is limited. This study estimates separate hedonic cost functions for water systems that primarily use surface water sources and those that primarily use groundwater sources using a database of United States (US) Community Water Systems. Cost functions relate annual variable treatment cost to production, factor input prices, capital stock, and source water quality, as proxied by land use within various ex-ante defined contributing areas (i.e., surrounding land areas affecting source water quality). For surface water systems, a 1% increase in urban land relative to forestland is correlated with a 0.13% increase in annual variable treatment costs. In this analysis, the relationship between costs and agricultural land is not statistically significant. Conversely, for groundwater systems, a 1% increase in agricultural land relative to forestland is correlated with a 0.24% increase in costs, whereas in this analysis the relationship between costs and urban land is not statistically significant. The cost-effectiveness of forestland preservation, based on sample means, varies considerably with the size of the contributing area, with no clear indication as to whether preservation is more likely to be cost-effective for surface water or groundwater systems.

Hedonic price models are commonly used to estimate implicit prices for lake water quality across small geographic regions that might be assumed to be a part of a common real estate market. Yet recent studies expand the geographic scale of the hedonic model potentially obscuring important differences in implicit prices across markets. We estimate implicit prices for lake water quality across multiple states in the northeast and upper Midwest in the United States of America at three different geographic scales: substate, state, and multistate. We find implicit price estimates are heterogeneous at both the substate and state-levels, which is not accounted for in state-level or multistate hedonic models. Our results show that estimates across a broad geographic scale can be driven by a single subregion within the defined area. Overall, the study demonstrates that using a single hedonic model over a large geographic area may obscure important heterogeneity in implicit prices used to estimate potential benefits for water-quality improvements.

A conceptual model to assess the literacy level of water consumers is presented. On the one hand, a literature search was performed using the ScienceDirect and B-On platforms, conjoining the terms literacy, awareness, water, water for human consumption, drinking water, environmental, disease prevention and public health, resulting in seven papers with the mingle of literacy and water and five on literacy and the environment being uncovered. On the other hand, the lack of papers and information on the subject caused us to consider developing a conceptual model to transform the processes of planning and operationalization of the studies of literacy of water consumers. The model can support the development and validation of measurement tools capable of apprehending different dimensions in the context of water literacy. A questionnaire was conceived and applied to a cohort of 147 respondents in order to assess water literacy. In addition, the articulation of the proposed model and Deming’s PDCA model was demonstrated in order to achieve excellence through the evaluation of the current reality to promote improvement solutions.

Environmental economists have long been interested in the relationship between policy enforcement, technological progress, and economic growth. A multidirectional process exists where factors such as the economy, policy, technology, and environment interactively work. Based on the balanced panel data of 261 prefecture-level cities in China from 2000 to 2020, this study innovatively examines the diversified channels in the policy–technology system within the structural equation modeling framework. Conclusions can be drawn as follows. First, the policy uncertainties curb the technological improvement in the water sector, particularly in southern Chinese cities. Second, the incubation and adoption of water technology are closely intertwined, significantly affecting water quality. By clarifying the interaction of the factors in water technology diffusion, this study provides a comprehensive framework to investigate China’s water economics and policy uncertainties.

In this study, we measure the effect of restoration actions on the economic value of coastal communities. We use a residential sorting model to simulate residential moves between communities and then estimate the value of restoring shoreline uses in coastal communities. Our application measures the effect of cleaning up Great Lakes Areas of Concern (AOC) — which are heavily polluted coastal locations prioritized for restoration in the United States and Canada — on the willingness to pay (WTP) of residents in the U.S. state of Michigan. While prior research documents the effect of individual AOCs on residents, particularly in local housing markets, little research has examined systematically where restoration is occurring and whether it affects mobility at a regional level. The results in this paper suggest that restoration actions can affect mobility, with point estimates indicating households are willing to pay $54/year for the uses restored between 2005 and 2015 in Michigan’s AOCs.

Water scarcity impedes economic development and can be expensive or infeasible to resolve in many developing countries with recurring water service outages. In such circumstances, water supply organizations may be able to improve ancillary water service attributes to alleviate the burden of service interruptions. We use a discrete choice experiment to estimate households’ willingness to pay (WTP) for improved water quality, coordinated scheduling of planned service interruptions, water use restrictions, and improved dissemination of information about upcoming service interruptions in Puerto Rico. The results indicate that households’ WTP varies considerably across attributes and is greatest ($ 28/month per household) for ensuring adequate water quality. Preferences for water service improvements vary across geographic locations and latent user groups.

Australia is the driest country in the world, and the lower Murray–Darling Basin and Adelaide have experienced extreme water scarcity crisis, especially during the Millennium Drought (2000–2010). Many counter measures have been proposed or implemented like desalination plants and water buyback, etc., some progress has been made, but far away from a complete solution. Different from existing measures, this research aims at using coastal reservoir technology to shift from upstream water development to downstream development, in order to solve a series of water supply and ecological environment problems by redesigning a coastal reservoir in the downstream area. It is suggested that high-quality water is stored in a “coastal reservoir” inside the Alexandrina Lake for Adelaide’s water supply. The lake water outside the “coastal reservoir” is used for agricultural development. A preliminary feasibility study was conducted in terms of water quantity and water quality, river’s environmental flow and agricultural output. The results show that if a small size (550–630GL) coastal reservoir was created inside the Lake Alexandrina in the mouth of Murray River, the Adelaide’s water supply could be secured and its water quality be improved even during droughts like the Millennium Drought. Besides, if the agricultural development is concentrated around the lake, its water demand can be fully met from the lake, rather than the river, thus the agricultural development has little negative impacts on the river’s ecosystem, it is a win-win solution for agricultural development and river ecosystem. It is suggested that Australian government should provide stimulus package for upstream farmers to relocate to areas around the lake.

The World Health Organization has labeled the problem of arsenic contamination of groundwater in South Asia as “the largest mass poisoning in human history.” Various technical solutions to the problem fall into one of two broad categories: (i) cleaning contaminated water before human consumption and (ii) encouraging people to switch to less contaminated water sources. In this paper, we review research on the behavioral, social, political, and economic factors that determine the field-level effectiveness of the suite of technical solutions and the complexities that arise when scaling such solutions to reach large numbers of people. We highlight the conceptual links between arsenic-mitigation policy interventions and other development projects in Bangladesh and elsewhere, as analyzed by development economists, that can shed light on the key social and behavioral mechanisms at play. We conclude by identifying the most promising policy interventions to counter the arsenic crisis in Bangladesh. We support a national well-testing program combined with interventions that address the key market failures (affordability, coordination failures, and elite and political capture of public funds) that currently prevent more deep-well construction in Bangladesh.