scholarly journals Relative susceptibility of lakes to water-quality degradation in the southern Hood Canal area, Washington

10.3133/i853b ◽  
1974 ◽  
Keyword(s):  
Water Quality ◽  
Relative Susceptibility ◽  
Canal Area ◽  
Hood Canal ◽  
Quality Degradation

Decision Making Under Deep Uncertainty With Fuzzy Algorithm in Framework of Multi-Model Approach

2018 ◽  
pp. 1-34
Author(s):  
Yuriy V. Kostyuchenko ◽  
Yulia Stoyka ◽  
Iurii Negoda ◽  
Ivan Kopachevsky
Keyword(s):  
Water Quality ◽  
Risk Management ◽  
Decision Support ◽  
Soft Computing ◽  
Deep Uncertainty ◽  
Fuzzy Algorithm ◽  
Quality Degradation ◽  
Spatially Distributed ◽  
Distributed Measurement ◽  
Model Approach

Task of soft computing for decision support in field of risk management is analyzed in this chapter. Multi-model approach is described. Interrelations between models, remote sensing data and forecasting are described. Method of water quality assessment using satellite observation is described. Method is based on analysis of spectral reflectance of aquifers. Correlations between reflectance and pollutions are quantified. Fuzzy logic based approach for decision support in field of water quality degradation risk is discussed. Decision on water quality is making based on fuzzy algorithm using limited set of uncertain parameters. It is shown that this algorithm allows estimate water quality degradation rate and pollution risks. Using proposed approach, maps of surface water pollution risk from point and diffuse sources are calculated. Conclusions concerned soft computing in risk management are proposed and discussed. It was demonstrated, that basing on spatially distributed measurement data, proposed approach allows to calculate risk parameters with resolution close to observations.

Variabilities in the cost equivalency of decentralized treatment units designed to address network-derived water quality degradation

2006 ◽  
Vol 6 (4) ◽  
pp. 45-56
Author(s):  
J.W. Norton ◽  
W.J. Weber
Keyword(s):  
Water Quality ◽  
Water Distribution ◽  
Distribution Network ◽  
Treatment Plant ◽  
Water Distribution Network ◽  
Functional Requirements ◽  
Treatment Unit ◽  
Advantages And Disadvantages ◽  
Quality Degradation ◽  
The Cost

Factors impacting the cost equivalency point for deploying strategically-located treatment units within a distributed optimal technology network (DOT-Net) to manage network-derived water quality degradation are defined and quantified. The cost equivalency point is essentially the ‘breakeven’ allowable cost for implementing DOT-Net strategy as an alternative to upgrading a central treatment facility to ‘pretreat’ water sufficiently to manage quality degradation within a potable water distribution network. For the purposes of the analysis presented, water quality is assumed to degrade linearly with time as it flows through the distribution network. Disinfection by-product (DBP) formation, selected as a representative water quality degradation parameter, was modeled to predict service population DBP exposure and resulting cost of centralized treatment plant upgrades to meet water quality goals. The equivalency point was determined by apportioning the anticipated cost for upgrading the centralized treatment facilities over the fraction of service connections receiving deficient quality water. Both concentration of DBP precursor material and service population size are found to have limited impact on the equivalency point of a distributed treatment unit. The advantages and disadvantages of various treatment methods available for in-network water treatment are outlined and the ancillary functional requirements of the distributed treatment unit are delineated.

scholarly journals Water Quality of the Mun River in Thailand—Spatiotemporal Variations and Potential Causes

2019 ◽  
Vol 16 (20) ◽  
pp. 3906 ◽  
Author(s):  
Haoyu Tian ◽  
Guo-An Yu ◽  
Ling Tong ◽  
Renzhi Li ◽  
He Qing Huang ◽  
...  
Keyword(s):  
Water Quality ◽  
Agricultural Land ◽  
Kendall Test ◽  
Coliform Bacteria ◽  
Monitoring Site ◽  
Spatiotemporal Variations ◽  
Primary Parameter ◽  
Quality Degradation ◽  
Spatial Fluctuations

The water quality of the Mun River, one of the largest tributaries of the Mekong River and an important agricultural area in Thailand, is investigated to determine its status, identify spatiotemporal variations and distinguish the potential causes. Water quality dataset based on monitoring in the last two decades (1997–2017) from 21 monitoring sites distributed across the basin were analyzed using seasonal Kendall test and water quality index (WQI) method. The Kendall test shows significant declines in fecal coliform bacteria (FCB) and ammonia (NH3) in the upper reaches and increases in nitrate (NO3) and NH3 in the lower reaches. Strong temporal and spatial fluctuations were observed in both the concentrations of individual parameters and the WQI values. Seasonal variation of water quality was observed at each monitoring site. WQI values in August (flood season) were generally among the lowest, compared to other seasons. Spatially, sites in the upper reaches generally having lower WQI values than those in the lower reaches. Excessive phosphorus is the primary cause of water quality degradation in the upper reaches, while nitrogen is the primary parameter for water quality degradation in the lower reaches. Urban built-up land is an important “source” of water pollutants in the lower basin, while agricultural land plays a dual role, affecting across the basin.

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