scholarly journals Toward Computational Accuracy in Realistic Systems to Aid Understanding of Field-Level Water Quality Issues

Physchem ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 243-249
Author(s):  
William A. Alexander
Keyword(s):  
Water Quality ◽  
Computational Modelling ◽  
Computational Power ◽  
Computational Accuracy ◽  
Surface Binding ◽  
Field Level ◽  
Technological Advances ◽  
Quality Issues ◽  
Computational Systems ◽  
Acute Event

Contemplating what will unfold in this new decade and those after, it is not difficult to imagine the increasing importance of conservation and protection of clean water supplies. A worrying but predictable offshoot of humanity’s technological advances is the seemingly ever-increasing chemical load burdening our waterways. In this perspective are presented a few modest areas where computational chemistry modelling could provide benefit to these efforts by harnessing the continually improving computational power available to the field. In the acute event of a chemical spill incident, true quantum-chemistry-based predictions of physicochemical properties and surface-binding behaviors can be used to help decision making in remediating the spill threat. The chronic burdens of microplastics and perfluorinated “forever chemicals” can also be addressed with computational modelling to fill the gap between feasible laboratory experiment timescales and the much-longer material lifetimes. For all of these systems, field-level accuracy models will avail themselves as the model computational systems are able to incorporate more realistic features that are relevant to water quality issues.

Addressing the challenges of standalone multi-core simulations in molecular dynamics

2017 ◽  
Vol 2 (7) ◽  
Author(s):  
R.O. Ocaya ◽  
J.J. Terblans
Keyword(s):  
Molecular Dynamics ◽  
Message Passing ◽  
High Performance ◽  
Computational Modelling ◽  
Third Party ◽  
Computational Power ◽  
Computational Accuracy ◽  
Single Node ◽  
Embedded Atom ◽  
Message Passing Interfaces

AbstractComputational modelling in material science involves mathematical abstractions of force fields between particles with the aim to postulate, develop and understand materials by simulation. The aggregated pairwise interactions of the material’s particles lead to a deduction of its macroscopic behaviours. For practically meaningful macroscopic scales, a large amount of data are generated, leading to vast execution times. Simulation times of hours, days or weeks for moderately sized problems are not uncommon. The reduction of simulation times, improved result accuracy and the associated software and hardware engineering challenges are the main motivations for many of the ongoing researches in the computational sciences. This contribution is concerned mainly with simulations that can be done on a “standalone” computer based on Message Passing Interfaces (MPI), parallel code running on hardware platforms with wide specifications, such as single/multi- processor, multi-core machines with minimal reconfiguration for upward scaling of computational power. The widely available, documented and standardized MPI library provides this functionality through the MPI_Comm_size (), MPI_Comm_rank () and MPI_Reduce () functions. A survey of the literature shows that relatively little is written with respect to the efficient extraction of the inherent computational power in a cluster. In this work, we discuss the main avenues available to tap into this extra power without compromising computational accuracy. We also present methods to overcome the high inertia encountered in single-node-based computational molecular dynamics. We begin by surveying the current state of the art and discuss what it takes to achieve parallelism, efficiency and enhanced computational accuracy through program threads and message passing interfaces. Several code illustrations are given. The pros and cons of writing raw code as opposed to using heuristic, third-party code are also discussed. The growing trend towards graphical processor units and virtual computing clouds for high-performance computing is also discussed. Finally, we present the comparative results of vacancy formation energy calculations using our own parallelized standalone code called Verlet–Stormer velocity (VSV) operating on 30,000 copper atoms. The code is based on the Sutton–Chen implementation of the Finnis–Sinclair pairwise embedded atom potential. A link to the code is also given.

The Difficulties and Promise of an Interagency Public Information Campaign for Water Quality Issues

1993 ◽  
Vol 28 (3-5) ◽  
pp. 65-68
Author(s):  
Michelle Miller
Keyword(s):  
Water Quality ◽  
Public Information ◽  
The United States ◽  
United States Department ◽  
Information Campaign ◽  
Department Of Agriculture ◽  
Voluntary Programs ◽  
University Of Wisconsin ◽  
Quality Issues ◽  
State And Local

The following case study addresses the difficulties and promise of developing a statewide interagency public information campaign to raise general awareness of water quality issues and governmental programs to address them. Due to only moderate success of voluntary programs to curb nonpoint source pollution, agencies are looking toward information and education programs to motivate the public toward conservation behavior. One of the biggest obstacles in developing an effective information/education program is institutional barriers to interagency cooperation, mirroring difficulties local conservationists encounter in their work to restore and maintain water quality at the watershed level. Cooperation between federal agencies, and resource commitment to public information is necessary at the federal level, as well as state and local levels. Agencies involved to date include the United States Department of Agriculture-Soil Conservation Service; Wisconsin State Departments of Natural Resources, and Agriculture, Trade and Consumer Protection and Administration; University of Wisconsin-Extension; Wisconsin Land Conservation Association.

scholarly journals Perceptions and determinants of households' participation in a randomized evaluation on water quality testing and information in southern Ghana

Water Policy ◽  
2017 ◽  
Vol 19 (6) ◽  
pp. 1206-1224 ◽  
Author(s):  
Charles Yaw Okyere ◽  
Felix Ankomah Asante
Keyword(s):  
Water Quality ◽  
Economic Benefits ◽  
Randomized Experiment ◽  
Subjective Analysis ◽  
Factors Affecting ◽  
Variable Approach ◽  
Quality Testing ◽  
Quality Issues ◽  
Household Heads ◽  
Southern Ghana

Abstract In this paper, we analyze perceptions and determinants of households' participation in a randomized experiment on water quality testing and information in southern Ghana. Beneficiary households assessed the components of the intervention including its relevance and adequacy in improving understanding of water quality issues. Motivating and constraining factors to participation in the randomized experiment are also assessed. We also estimate the correlates of participation in the intervention. Social and economic benefits derived from the intervention based on perceptions are compared with impacts of the intervention using an instrumental variable approach. We found evidence that subjective analysis estimates of the effects of the intervention are higher than the objective analysis estimates. Households generally perceived the intervention to be relevant in improving their understanding of water quality issues. However, there are differing opinions based on random assignment into either child or adult treatment groups on most- and least-liked attributes of the intervention, and also motivating and constraining factors affecting participation in the intervention. The factors that statistically and significantly influenced participation in the intervention include educational attainment, ethnicity, religious denomination and marital status of the household heads, in addition to the location of residence.

Use of co-created causal loop diagrams and fuzzy-cognitive scenario analysis for water quality management

2021 ◽  
Author(s):  
Samaneh Seifollahi-Aghmiuni ◽  
Zahra Kalantari ◽  
Georgia Destouni
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Baltic Sea ◽  
Coastal Water ◽  
Scenario Analysis ◽  
Water Quality Management ◽  
Coastal Water Quality ◽  
Causal Loop ◽  
Causal Loop Diagrams ◽  
Quality Issues

<p>Current understanding is fragmented of the environmental, economic, and social processes involved in water quality issues. The fragmentation is particularly evident for coastal water quality, impacted both by local land catchment and larger-scale marine pressures and impacts. Research and policy so far has primarily addressed coastal water quality issues from either a land-based or a sea-based perspective, which does not support integrated management of the coupled land-coast-sea systems affecting coastal waters. For example, mitigation measures for improving the severe Baltic Sea eutrophication have mostly focused on land-based drivers, and not yet managed to sufficiently improve coastal or marine water quality. The strong human dimension involved in these water quality issues also highlights a need for participatory approaches to facilitate knowledge integration and drive synergistic strategic planning for sustainable management of coastal water quality. Considering the Swedish water management district of Northern Baltic Proper, including its main Norrström drainage basin and surrounding coastal catchment areas and waters, this study has used a participatory approach to evaluate various land-sea water quality interactions and associated management measures. A causal loop diagram has been co-created with different stakeholder groups, following a problem-oriented system thinking approach. This has been further used in fuzzy-cognitive scenario analysis to assess integrated land-coast-sea system behavior under changing human pressures and hydro-climatic conditions. Results show that synergy of several catchment measures is needed to improve coastal water quality locally, while cross-system/sector cooperation is also needed among all contributing national catchments to mitigate coastal eutrophication at the scale of the whole Baltic Sea. Furthermore, large-scale hydro-climatic changes and long-lived nutrient legacy sources also need to be accounted for in water quality management strategies and measures. System dynamics modelling, based on co-created causal loop diagrams and fuzzy-cognitive scenario analysis like those developed in this study, can support further quantification and analysis of the impacts of various mitigation strategies and measures on regional water quality problems and their possible sustainable solutions.</p>

Soil and Water Quality Issues in Arid Ecosystem and Their Management

2021 ◽  
pp. 235-248
Author(s):  
Dipak Kumar Gupta ◽  
Chandan Kumar Gupta ◽  
Kamla K. Choudhary ◽  
A Keerthika ◽  
M.B. Noor mohamed ◽  
...  
Keyword(s):  
Water Quality ◽  
Arid Ecosystem ◽  
Quality Issues ◽  
Soil And Water
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