Simulation and Trend Analysis of the Water Quality Monitoring Daily Data in Nestos River Delta. Contribution to the Sustainable Management and Results for the Years 2000–2002

The transboundary River Nestos in the Balkan Peninsula is a surface water resource shared by Hellas and Bulgaria. The Public Power Corporation of Hellas (DEH) proceeded to the dams' construction of Thesaurus in 1997 and Platanovrissi in 2000, to satisfy the increased needs for power production and irrigation in the Regions of Eastern Macedonia and Thrace in the Hellenic Territory. DEH following the Ministerial Agreement of the Hellenic Parliament ‘`KYA 18492/19—09—1996’' funded a series of Research Projects concerned on the monitoring of the water quantity and quality data of Nestos from the Hellenic-Bulgarian borders to its estuaries in the Thracian sea. ‘`PERSEAS’' Research Group from Aristotle University of Thessaloniki, carried out the research, design, construction, installation, operation and maintenance of the ‘`R.E.MO.S.’' (Remote Environmental MOnitoring System) networks. Three REMOS networks have been installed in the areas of (a) the River Nestos deltaic channel, (b) Thesaurus dam-lake in the intramountainous valley and (c) Potamoi (Despat) and Pagoneri (Nestos) villages close to the borders between Hellas and Bulgaria. They record water level (H), water and air temperature (T), water conductivity (ECw), Redox potential (RP) and dissolved oxygen (DO) on a 24h basis, since the beginning of the year 2000. The research carried out in this paper, is focused on the REMOS station in the final course of Nestos in the deltaic area. The continuous monitoring and the data analysis yield useful results for the quality and quantity of the hydrologic regime of Nestos after the dams' construction, as well as for the trends detected of the quality parameters (ECw, RP and DO) and the water level, using the nonparametric Spearman's criterion. The best fitted model of time trend, for each variable, was chosen. The statistical sample of each one of the quality variables consisted of about 1000 values based on daily measures on a three years monitoring program (1/1/2000—31/12/2002). Further research and analysis for the other network stations of REMOS should provide useful results for the sustainable management of the transboundary River Nestos.     

An Evaluation of Selenium Concentrations in Water, Sediment, Invertebrates, and Fish from the Republican River Basin: 1997–1999

The Republican River Basin of Colorado,Nebraska, and Kansas lies in a valley which contains PierreShale as part of its geological substrata. Selenium is anindigenous constituent in the shale and is readily leached intosurrounding groundwater. The Basin is heavily irrigated throughthe pumping of groundwater, some of which is selenium-contaminated, onto fields in agricultural production. Water,sediment, benthic invertebrates, and/or fish were collected from46 sites in the Basin and were analyzed for selenium to determinethe potential for food-chain bioaccumulation, dietary toxicity,and reproductive effects of selenium in biota. Resultingselenium concentrations were compared to published guidelines orbiological effects thresholds. Water from 38% of the sites (n = 18) contained selenium concentrations exceeding 5 g L^-1, which is reported to be a high hazard for selenium accumulation into the planktonic food chain. An additional 12 sites (26% of the sites) contained selenium in water between 3–5 g L^-1, constituting a moderate hazard. Selenium concentrations in sedimentindicated little to no hazard for selenium accumulation fromsediments into the benthic food chain. Ninety-five percent ofbenthic invertebrates collected exhibited selenium concentrationsexceeding 3 g g^-1, a level reported as potentially lethal to fish and birds that consume them. Seventy-five percent of fish collected in 1997, 90% in 1998, and 64% in 1999 exceeded 4 g g^-1selenium, indicating a high potential for toxicity andreproductive effects. However, examination of weight profilesof various species of collected individual fish suggestedsuccessful recruitment in spite of selenium concentrations thatexceeded published biological effects thresholds for health andreproductive success. This finding suggested that universalapplication of published guidelines for selenium may beinappropriate or at least may need refinement for systems similarto the Republican River Basin. Additional research is needed todetermine the true impact of selenium on fish and wildliferesources in the Basin.     

Parameter Sensitivity of a Surface Water Quality Model of the Lower South Saskatchewan River—Comparison Between Ice-On and Ice-Off Periods

Little is known about seasonal differences (ice-on vs. ice-off periods) and the sensitivity of in-stream processes to surface water quality constituents in rivers that have a persistent ice cover in winter. The goal of this study is to investigate the sensitivity of nutrient transformation processes on surface water quality, especially rivers in cold regions where ice-covered conditions persist for a substantial part of the year. We established a sensitivity analysis framework for water quality modelling and monitoring of rivers in cold regions using the Water Quality Analysis Program WASP7. The lower South Saskatchewan River in the interior of western Canada, from the Gardiner Dam at Lake Diefenbaker to the confluence of the North and South Saskatchewan rivers, is used as a test case for this purpose. The study reveals that parameter sensitivities differ between ice-covered and ice-free periods and biological model parameters related to nutrient-phytoplankton dynamics can still be sensitive during the ice-covered season. For example, sediment oxygen demand is an important parameter during the ice-on period, whereas parameters related to nitrification are more sensitive in the ice-off period. These results provide insight into important water quality monitoring aspects in cold regions during different seasons.     

Sensitivity Analysis and Water Quality Modeling of a Tidal River Using a Modified Streeter–Phelps Equation with HEC-RAS-Calculated Hydraulic Characteristics

A modified Streeter–Phelps equation and the Hydrological Engineering Centers River Analysis System (HEC-RAS) were combined to assess water quality of the Tan-Sui River and its tributaries. The Tan-Sui River is the main source of water supply for northern Taiwan, and the water quality of its stream is significantly affected by tides. In this study, HEC-RAS was employed to assess the impact of tides on water quality and to calculate reoxygenation coefficients. The modified Streeter–Phelps equation was used to calculate water quality in terms of contaminant degradation and reoxygenation. Biochemical oxygen demand (BOD) and ammonia nitrogen (NH₃–N), the most important identified sources of water pollution in the rivers investigated, were evaluated. Dissolved oxygen (DO) was also simulated, since it is often used as a staple of water quality. Results showed that employing HEC-RAS for hydraulic calculations improves the modified Streeter–Phelps simulation. In river sections without tidal influence, water quality was sensitive to the BOD and NH₃–N degradation constants. Downstream of Chin-Mei Creek, while the BOD degradation constant decreased by 80%, BOD and DO concentrations increased from 7.1?mg/L to 10.7?mg/L and 5.0?mg/L to 7.2?mg/L, respectively, indicating that water quality was not as sensitive to variations of the BOD degradation constant as expected. The concentrations of DO and BOD at the river mouth had a significant impact on water quality for the tidal sections of the investigated rivers due to mixing of tidal and river waters. The BOD and NH₃–N degradation constants in the tidal sections had little impact on water quality simulations. This study demonstrated the innovative combination of the modified Streeter–Phelps equation and HEC-RAS to assess the impact of tidal variation and to simulate the water quality of a tidal river when available data is rather limited.     

Monitoring The Turbidity and Surface Temperature Changes and Effects of the 17 August 1999 Earthquake in the İzmİt Gulf,Turkey by the Landsat TM/ETM Data

The temporal turbidity and surface temperature changes and effects of the 17 August 1999 earthquake in the İzmit Gulf, Turkey have been investigated using Landsat TM/ETM data. The gulf is in the Mediterranean–Black Sea transition climatic zone and is partially surrounded by green vegetation cover and degraded and densely urbanized-industrialized areas. Landsat TM/ETM data acquired in 1990–1999 confirms increase in turbidity. Turbidity is always low in the southern part and high in the northern part of the gulf, because the more urbanized and industrialized areas are located in the northern part. The Landsat-7 ETM data acquired in the same year (1999) shows seasonal changes in turbidity. Moreover, the two high turbidity and surface temperature anomalies, one of which is parallel to the 17 August 1999 earthquake surface rupture (east–west) and the other which is in the northwest–southeast direction were mapped from Landsat-5 TM data acquired the day (18.08.1999) following the earthquake in the east end of the gulf. On the basis of turbidity implying the sea bottom movement, it is possible to state that a second rupture in the northwest and southeast direction could have occurred at the sea bottom during the earthquake. The distribution of the seismicity centers and the orientation of the lineaments in the area support this finding.     

Chlorinated Hydrocarbons in Livers of American Mink (Mustela vison) and River Otter (Lutra canadensis) from the Columbia and Fraser River Basins, 1990–1992

We investigated chlorinated hydrocarbon contaminants in aquatic mustelid species on the Fraser and Columbia Rivers of northwestern North America. Carcasses of river otter (Lutra canadensis) (N=24) and mink (Mustela vison) (N=34) were obtained from commercial trappers during the winters of 1990–91 and 1991–92. Pooled liver samples were analyzed for organochlorine pesticides, polychlorinated biphenyls (PCBs), including non-ortho congeners, polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). Most samples contained detectable concentrations of DDE, PCBs, although there was substantial variability in patterns and trends among neighboring samples. Concentrations of DDE were in some mink and several otter samples from the lower Columbia River elevated (to 4700 g/kg wet weight); excluding one mink sample from the Wenatchee area, mean DDE levels generally decreased between 1978–79 and 1990–92. PCBs were present in all samples. PCB concentrations in otter livers collected from the lower Columbia were ten-fold lower than measured a decade previously; nevertheless, a sample taken near Portland had a mean concentration of 1500 g/kg, within a range of concentrations associated with reproductive effects in captive mink. Concentrations of 2,3,7,8-TCDD and TCDF were generally below detection limits, except for one otter collected near a pulp mill at Castlegar, on the upper Columbia, with 11 ng TCDD/kg in liver. Elevated concentrations of higher chlorinated PCDD/Fs, probably resulting from use of chlorophenolic wood preservatives, were found in both species; one otter sample from the lower Columbia had 2200 ng OCDD/kg. International TCDD toxic equivalent levels in mink (31 ng/kg) and otter (93 ng/kg) from the lower Columbia River approached toxicity thresholds for effects on reproduction in ranch mink.     

Assessment of organic pollution of an industrial river by synchronous fluorescence and UV–vis spectroscopy: the Fensch River (NE France)

To rapidly monitor the surface water quality in terms of organic pollution of an industrial river undergoing restoration, optical methods (UV–visible spectrometry and fluorescence) were applied in parallel to classical physical–chemical analyses. UV–visible spectra were analyzed using the maximum of the second derivative at 225 nm (related to nitrates), specific absorbance at 254 nm (SUVA₂₅₄), and the spectral slope between 275 and 295 nm (S _275–295) (related to the aromaticity and molecular weight of dissolved organic carbon). The synchronous fluorescence spectra (wavelength difference = 50 nm) exhibited a high variability in the composition of dissolved organic material between the upstream and downstream sections and also versus time. The principal components analysis of the entire set of synchronous fluorescence spectra helped to define three river sections with different pollution characteristics. Spectral decomposition was applied to the two most upstream sections: five fluorophores, classical in rivers impacted by domestic sewage and related to protein-like (λ _ex = 280 nm) and humic-like fluorescence (M-type with λ _ex ≈ 305–310 nm and C-type with λ _ex ≥ 335 nm), were identified. The irregular shape of the synchronous fluorescence spectra in the most downstream section is likely due to organic pollutants of industrial origin; however, their variability and the complexity of the spectra did not allow the further elucidation of their nature.     

Water quality and heavy metal monitoring in water and sediment samples of the Küçükçekmece Lagoon, Turkey (2002–2003)

Physical and chemical parameters have been analyzed in water samples from a brackish water lagoon, Küçükçekmece, located on the western outskirts of Istanbul. Samples were collected every two months for a year from nine sampling stations. Of the parameters measured, temperature, pH, salinity, nitrate and phosphate showed changes when compared with the previously published data. The lagoon was found eutrophic as it was reported previously. Sulphate and COD levels were higher when compared with the standards established by the Turkish Water Pollution and Control Regulation. Additionally, concentrations of heavy metals (Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn) in water and bottom sediments were measured and compared with the standards established by the Turkish Water Pollution and Control Regulation and with the previously published data. The results were analysed statistically with respect to location and any relationships between the concentration of the elements in corresponding water and sediment samples were examined. Principal Component Analysis of water samples allowed us to discriminate three areas affected mainly by heavy metal contamination, possibly due to industrial, commercial and/or urban activities. Generally, the concentrations of the heavy metals were higher at stations near the three estuaries, suggesting a direct influence of the three creeks on the pollution of the Küçükçekmece Lagoon. Although elevated levels of Cd were recorded in several water samples, it was not detected in sediment. On the other hand, a particularly high level of Cr pollution was recorded most of the water and sediment samples.     

Spatial Patterns and Rankings of Contaminant Concentrations in Herring Gull Eggs from 15 Sites in the Great Lakes and Connecting Channels, 1998–2002

Mean values of eight contaminants in Herring Gull (Larus argentatus) eggs were calculated for 15 Great Lakes sites for the 5 year period 1998–2002. The sites were ranked according to the concentrations of each of seven compounds relative to fish flesh criteria for the protection of piscivorous wildlife, and a single overall rank of contamination was calculated for each site. Based on this weighted ranking scheme, we found that sum PCBs, dioxin and DDE contributed the most (60.2, 30.5% and 8.5%, respectively) to the overall rankings. The weighted ranking scheme showed that eggs from Channel-Shelter Island (Saginaw Bay, Lake Huron), Strachan Island (St. Lawrence River) and Gull Island (northern Lake Michigan) ranked as the three most contaminated sites, while Agawa Rocks (eastern Lake Superior), Chantry Island (southern Lake Huron) and Port Colborne (eastern Lake Erie) ranked as the three least contaminated sites. Two of the three most contaminated sites are Areas of Concern; none of the three least contaminated sites are Areas of Concern.     

Spatial–temporal dynamics of NDVI and Chl-a concentration from 1998 to 2009 in the East coastal zone of China: integrating terrestrial and oceanic components

Annual normalized difference vegetation index (NDVI) and chlorophyll-a (Chl-a) concentration are the most important large-scale indicators of terrestrial and oceanic ecosystem net primary productivity. In this paper, the Sea-viewing Wide Field-of-view Sensor level 3 standard mapped image annual products from 1998 to 2009 are used to study the spatial–temporal characters of terrestrial NDVI and oceanic Chl-a concentration on two sides of the coastline of China by using the methods of mean value (M), coefficient of variation (CV), the slope of unary linear regression model (Slope), and the Hurst index (H). In detail, we researched and analyzed the spatial–temporal dynamics, the longitudinal zonality and latitudinal zonality, the direction, intensity, and persistency of historical changes. The results showed that: (1) spatial patterns of M and CV between NDVI and Chl-a concentration from 1998 to 2009 were very different. The dynamic variation of terrestrial NDVI was much mild, while the variation of oceanic Chl-a concentration was relatively much larger; (2) distinct longitudinal zonality was found for Chl-a concentration and NDVI due to their hypersensitivity to the distance to shoreline, and strong latitudinal zonality existed for Chl-a concentration while terrestrial NDVI had a very weak latitudinal zonality; (3) overall, the NDVI showed a slight decreasing trend while the Chl-a concentration showed a significant increasing trend in the past 12 years, and both of them exhibit strong self-similarity and long-range dependence which indicates opposite future trends between land and ocean.