Estimation of water quality dynamics under long-term anoxic state in organically polluted reservoir by field observations and improved ecosystem model

2018 ◽  
Vol 16 (4) ◽  
pp. 665-686
Author(s):  
Tran Tuan Thach ◽  
Masayoshi Harada ◽  
Kazuaki Hiramatsu ◽  
Toshinori Tabata
Keyword(s):  
Water Quality ◽  
Ecosystem Model ◽  
Field Observations

Modelling the Effects of Acid Deposition: Estimation of Long-Term Water Quality Responses in Forested Catchments in Finland

1988 ◽  
Vol 19 (2) ◽  
pp. 99-120 ◽  
Author(s):  
A. Lepistö ◽  
P. G. Whitehead ◽  
C. Neal ◽  
B. J. Cosby
Keyword(s):  
Water Quality ◽  
Surface Water ◽  
Base Cations ◽  
Surface Water Quality ◽  
Mineral Weathering ◽  
Co2 Solubility ◽  
Forested Catchments ◽  
Deposition Rates ◽  
Magic Model

A modelling study has been undertaken to investigate long-term changes in surface water quality in two contrasting forested catchments; Yli-Knuutila, with high concentrations of base cations and sulphate, in southern Finland; and organically rich, acid Liuhapuro in eastern Finland. The MAGIC model is based on the assumption that certain chemical processes (anion retention, cation exchange, primary mineral weathering, aluminium dissolution and CO2 solubility) in catchment soils are likely keys to the responses of surface water quality to acidic deposition. The model was applied for the first time to an organically rich catchment with high quantities of humic substances. The historical reconstruction of water quality at Yli-Knuutila indicates that the catchment surface waters have lost about 90 μeq l−1 of alkalinity in 140 years, which is about 60% of their preacidification alkalinity. The model reproduces the declining pH levels of recent decades as indicated by paleoecological analysis. Stream acidity trends are investigated assuming two scenarios for future deposition. Assuming deposition rates are maintained in the future at 1984 levels, the model indicates that stream pH is likely to continue to decline below presently measured levels. A 50% reduction in deposition rates would likely result in an increase in pH and alkalinity of the stream, although not to estimated preacidification levels. Because of the high load of organic acids to the Liuhapuro stream it has been acid before atmospheric pollution; a decline of 0.2 pH-units was estimated with increasing leaching of base cations from the soil despite the partial pH buffering of the system by organic compounds.

Long Term Monitoring of the Macrobenthos of the Upper Clyde Estuary

1984 ◽  
Vol 16 (5-7) ◽  
pp. 359-373 ◽  
Author(s):  
Anne R Henderson
Keyword(s):  
Water Quality ◽  
Seasonal Variation ◽  
Organic Pollution ◽  
Long Term Changes ◽  
Pollution Loading ◽  
Faunal Density ◽  
History Of ◽  
Long Term Monitoring ◽  
Term Monitoring

The sublittoral macrobenthic invertebrate populations of the Upper Clyde Estuary are described. The estuary has a long history of organic pollution. The long term changes in species composition, faunal density and dominance patterns between 1974 and 1980 are presented. The fauna is dominated by brackish, pollution tolerant oligochaetes and polychaetes. Fluctuations in populations can be related to both seasonal variation in environmental conditions and long term improvements in water quality through a reduction in pollution loading to the estuary.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

DEVELOPMENT OF A SIMPLE BENTHIC-PELAGIC COUPLING ECOSYSTEM MODEL AND ITS APPLICATION TO THE REPRODUCTION OF 23YEARS OF WATER QUALITY

2018 ◽  
Vol 74 (4) ◽  
pp. I_511-I_516
Author(s):  
Toshiyuki TAKAO ◽  
Osamu SHIMOZAWA ◽  
Kazuo MURAKAMI ◽  
Ikuo ABE ◽  
Tomonari OKADA ◽  
...  
Keyword(s):  
Water Quality ◽  
Ecosystem Model ◽  
Benthic Pelagic Coupling

LONG-TERM WILDFIRE-RELATED CHEMICAL IMPACTS ON WATER QUALITY WITHIN THE MALIBU CREEK COASTAL WATERSHED

2020 ◽  
Author(s):  
Christian L. Hoover ◽  
◽  
Kyle H. Ikeda ◽  
Erin E. Schmitt ◽  
Michael F. Kushner ◽  
...  
Keyword(s):  
Water Quality ◽  
Coastal Watershed

Multivariate analysis of long term water quality changes of shallow Lake Balaton

2006 ◽  
Vol 29 (4) ◽  
pp. 2051-2055 ◽  
Author(s):  
G. Kiss ◽  
Gy. Dévai ◽  
B. Tóthmérész ◽  
A. Szabó
Keyword(s):  
Water Quality ◽  
Multivariate Analysis ◽  
Shallow Lake ◽  
Lake Balaton ◽  
Quality Changes

Oil pollution and fisheries

1982 ◽  
Vol 297 (1087) ◽  
pp. 401-411 ◽  
Keyword(s):  
Water Quality ◽  
Adverse Effects ◽  
Oil Pollution ◽  
Coastal Areas ◽  
Short Term ◽  
Fish Stocks ◽  
Local Impacts ◽  
Reduced Water ◽  
Long Term Adverse Effects

The term ‘pollution’ is taken in its broadest sense and effects are recognized to be due to interference, tainting and toxicity. Each of these types of impact is discussed and assessed. It is concluded that no long-term adverse effects on fish stocks can be attributed to oil but that local impacts can be extremely damaging in the short term and that produce from specific localities can be tainted and unmarketable for long periods. In some coastal areas oil can be one among several contributors to reduced water quality, and the implications of this are discussed.

Long-term water quality conditions and trends in 12 tropical coastal rivers in Northeast Brazil

2021 ◽  
Vol 193 (5) ◽  
Author(s):  
Carlos Noriega ◽  
Carmen Medeiros ◽  
Moacyr Araujo ◽  
Andrea Xavier Silva ◽  
Mauricio Costa ◽  
...  
Keyword(s):  
Water Quality ◽  
Northeast Brazil ◽  
Coastal Rivers
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