ANALYSIS OF THE SPATIAL VARIABILITY OF THE FACTORS DESCRIBING THE WATER QUALITY TO ASSESS THE ECONOMIC IMPACT ON MEDIUM AND LONG TERM - CASE STUDY - DANUBE RIVER IN THE SOUTH-EAST AREA OF ROMANIA

2018 ◽  
Author(s):  
Gabriel Murariu
Keyword(s):  
Water Quality ◽  
Spatial Variability ◽  
Economic Impact ◽  
Danube River ◽  
The South

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.

scholarly journals River Water Quality and its Relation with Air Quality: A Long-Term Case Study in a Remote and Pristine NW Italian Headwater Catchment

2017 ◽  
Vol 5 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Marco Casazza ◽  
Franca Maraga ◽  
Gengyuan Liu ◽  
Massimiliano Lega ◽  
Laura Turconi ◽  
...  
Keyword(s):  
Water Quality ◽  
Air Quality ◽  
River Water ◽  
River Water Quality ◽  
Headwater Catchment

scholarly journals Bioeconomic analysis of the effects of modifying the trawl extension piece with T90 netting

2018 ◽  
Vol 82 (S1) ◽  
pp. 27 ◽  
Author(s):  
Iván Sola ◽  
Francesc Maynou
Keyword(s):  
Economic Impact ◽  
Transition Period ◽  
Bottom Trawl ◽  
Fishing Mortality ◽  
Target Species ◽  
Commercial Use ◽  
Red Mullet ◽  
Nw Mediterranean

We assessed the effect of the European discards ban on the profitability of bottom trawlers in a case study fishery (GSA06, NW Mediterranean) in the transition period 2017-2018, when the species that characterize the fishery, viz. hake and red mullet, fall under the discards ban. We used the results of Sola and Maynou (2018) to simulate the adoption of a modified bottom trawl design using a T90 extension net to reduce the catches of undersize hake and red mullet. Our results show that the economic impact of the former discards brought to land on the fisheries operators is expected to be low, regardless of the possible commercial use of these unwanted catches. Furthermore, the adoption of a more selective bottom trawl design would increase the escape of undersize individuals and likely reduce fishing mortality of the target species, contributing to stock rebuilding and providing higher income to the fisheries operators in the medium to long term.

scholarly journals The Assessment of the Surface Water Quality Using the Water Pollution Index: A Case Study of the Timok River (The Danube River Basin), Serbia

2012 ◽  
Vol 38 (1) ◽  
pp. 49-61 ◽  
Author(s):  
Jovana Brankov ◽  
Dragana Milijašević ◽  
Ana Milanović
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Oxygen Demand ◽  
Pollution Index ◽  
Surface Water Quality ◽  
Danube River ◽  
Water Pollution Index ◽  
The Danube River ◽  
The Republic

The Assessment of the Surface Water Quality Using the Water Pollution Index: A Case Study of the Timok River (The Danube River Basin), Serbia The Timok River (202 km long, 4547 km2 basin area) is located in East Serbia. It is a right tributary of the Danube River and one of the most polluted watercourses in Serbia. On the basis of the data provided by the Republic Hydrometeorological Service of Serbia, the paper presents an analysis of water quality and pollution using the combined physico-chemical WPI index (Water Pollution Index) calculated for two periods - 1993-96 and 2006-2009 at four hydrological stations: Zaječar-Gamzigrad (Crni Timok River), Zaječar (Beli Timok River), Rgotina (Borska Reka River) and Čokonjar (Timok River). The following parameters were taken into consideration: dissolved O2, O2 saturation, pH, suspended sediments, Five Day Biochemical Oxygen Demand (BOD5), Chemical Oxygen Demand (CODMn), nitrites, nitrates, orthophosphates, ammonium, metals (Cu, Fe, Mn, Hg, Ni, Zn, Cd), sulphates and coliform germs. The average WPI values were calculated for the observed periods based on the comparison of the annual average values of the listed parameters and defined standard values for the I water quality class (according to the Regulation on the Hygienic Acceptability of Potable Water of the Republic of Serbia). The highest pollution degree was recorded in the Borska Reka River, where heavy metal levels (especially manganese and iron) were significantly increased. These metals are indicators of inorganic pollution (primarily caused by copper mining). Also, increased values of the organic pollution indicators (ammonium, coliform germs, Five-Day Biological Oxygen Demand - BOD5) in the Borska Reka and the Timok rivers are the result of uncontrolled domestic wastewater discharge.

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