CORDIS provides links to public deliverables and publications of HORIZON projects.
Links to deliverables and publications from FP7 projects, as well as links to some specific result types such as dataset and software, are dynamically retrieved from OpenAIRE .
Deliverables
A modelling database has been created within the ESTABLISH project for the purposes of future model parameterisation and simulation validation.
The present description of the hydrological and ice regime of the Yenisey Gulf are based on published sources (mainly in Russian). The southern boundary of the Yenisey Gulf is the sea boundary of the Yenisey River delta. The sea boundary of the Yenisey Gulf passes through Dikson Island - northern cape of Sibiryakov island � Oleniy island. Common area of the water surface of the Yenisey Gulf is about of 19950 km squared. Datasets include information on
- River runoff: Water discharge of the river Yenisey is measured at the gauging section of the river (Igarka) from 1936. The main portion (more than 78 % of the total volume) of the river runoff is discharged in May-September. Mean annual runoff is about 580km3, minimum - 490km3 and maximum - 675km3 . Mean multi-year values of the monthly mean runoff of the Yenisey river at the gauging section and the interannual variability of the mean annual Yenisey river runoff based on the data from the Joint American-Russian Atlas [Ivanov, 1998] are presented.
- Ice regime: In the Yenisey Gulf there are three centers of ice formation: the sandbanks in vicinity of Sibiryakov island, western shallow coastal zone of the gulf from the cape Sopochnaya Karga up to the cape Leskin and the area of Brehovskiye sandbanks, where the ice appearance occurs in the beginning of October. At the middle of October drifting ice covers area of the gulf from the island Krestovsky up to Cape Shaytansky. In the middle of October in the region between the cape Sopochnaya Karga and the Krestovsky island fast ice is formed and then it extends for all area of the Yenisey Gulf during 1-2 days. To the beginning of November the fast ice extends up to sea delta boundary. The rate of the ice growth in the Yenisey Gulf is not uniform. The area with the most ice thickness is located in the southern part of the gulf. The average ice thickness in the Yenisey Gulf is about 1.60 - 1.90m. However the most ice thickness can reaches 2.70m.
- Sea level. Sea level variability in the Yenisey Gulf is caused by the river runoff, wind and tides. The spring flood wave passes in the Yenisey Gulf long before the ice cover breaking-up. The amplitude of the spring flood wave at the cape Sopochnaya Karga reaches up to 2-3m (in the very rich-water years - up to 5m). With advancing to the north the amplitude of the flood wave decreases up to 1.5m at the cape Leskin and up to 0.30-0.40m at the Dikson Island. Duration of a high water period at the sea boundary is about one week. The sea level oscillations caused by the surges usually reaching the maximum values at the sea delta boundary. The mean amplitude of the surges is about 1.0 - 1.5m here, but it can reach values up to 2.0 - 2.4m. The surge duration is usually 2 - 8 days. The maximum rate of the level changing reaches up to 0.2m per hour.
- Currents.Earlier records provide a comprehensive analysis of the currents of the Yenisey Gulf. At the sea boundary of the Yenisey Gulf the observed velocities of the non-periodic currents depends on the season and volume of the river runoff very weakly. But this dependence increases southward and at the sea delta boundary it is quite strong, particularly in the summer-autumn period. The mean and maximal observed velocities of the non-periodic currents in the different parts of the Yenisey Gulf have been collated.
- Thermohaline structure of the Yenisey Gulf: The vertical gradients of the water salinity in the Yenisey Gulf can reach up to 10-12psu/1m and the horizontal salinity gradients reach up to 0.5psu/1 km both in summer and in wintertime.
In wintertime, as a rule, the salinity in the bottom layer increases a little. In the middle part of the gulf in the bottom layer salinity 20-25psu in summer and 25-28psu in winter are observed. The more significant inter-seasonal variability of the thermohaline structure is observed in the area from cape Shaytansky up to delta sea boundary. In summer the fresh water in all water column is observed. But sometimes high water salinity (up to 22-25psu) was marked at the bottom in the depression near the cape Sopochnaya Karga. In wintertime the fresh water is observed in the upper water layer, but in the bottom layer, as a rule, the salinity values are 20-25psu.
The main sources of sediment contamination. During the 2001 marine expedition, representatives from the four institutes collected sediment samples from the Kara Sea in different sections of the Yenisey Estuary and delta zone and analysed them for heavy metal and radionuclide concentrations.
Studying radioactive contamination, particular attention was paid to the chronology of sedimentation in the Yenisey Estuary and adjacent Kara Sea areas. Heavy metal studies included estimation of the riverine contribution to Kara sea bottom sediments (1) and revealing additional technogenic sources of contamination (2) based on trace element concentrations in sediments. Terrestrial investigations performed by GEOKHI obtained additional information on the radionuclide and heavy metal distributions in floodplain and coastal areas depending upon site location, distance from the sea and site-specific geomorphological and lithological features related to the recent history of the studied areas.
Data regarding 137Cs and 60Co concentrations in bottom sediments have been presented : analysis of detected 60Co suggests that the main current source of 60Co to the estuary is most likely bottom sediments and soils of the Yenisey floodplain contaminated with the earlier radioactive releases of the Krasnoyarsk Mining and Chemical Combine (KMCC). Comparison of current 137Cs concentrations in bottom sediments with 1993 data lead to the conclusion that inputs from KMCC to Yenisey Estuary bottom sediments do not exceed 50%.
Some focus has been placed on plutonium radioisotopes, the main radiologically significant radionuclides with complicated migration parameters, and their use as indicators of contamination sources. Analysis of surface grain-size data suggests that Pu-radionuclides are predominantly incorporated in the silt and clay fractions of sediments. Another important result concerned the spatial Pu distribution: activity of Pu radionuclides in sediments increased in the inner estuary zone leading to the preliminary conclusion that a river-derived Pu source exists. Compared to samples collected from the Kara Sea and Ob estuary, Yenisey sediments show a significantly lower Pu 240/239 isotope ratio indicating a clear influence from a weapon�s grade source in the Yenisey estuary. The results are consistent with low Pu 240/239 ratios in sediment samples collected from the Yenisey River, closer to the KMCC-complex at Krasnoyarsk. Recent analysis of Pu activity concentrations and isotope ratios in water samples and fitration fractions also showed an influence on Pu speciation from the colloidal fraction in river water that became less important as salinity increased. Particles had high 240/239 ratios (i.e., non-weapons grade sources). The water data also showed a greater influence from the Ob and Yenisey to the Kara Sea than sediment data has shown, with low 240/239 ratios extending northwards. Cs-137 and heavy metal measurements in selected sediment samples have been compared with much larger Russian database. Results showed a good correlation between sample cores collected at the same sites.
Analysis of Cs-137 vertical distribution in sediments enables reconstruction of historic releases from different radiochemical enterprises. Cs1-37 radioisotopes have been used to evaluate sedimentation rates and advantages over Pb-210 methods in biologically affected shallow systems, which suggest constant sedimentation rates and are sensitive to sediment disruptions, have been presented. Yenisey Estuary sedimentation rates estimated within the project fit well with earlier studies. Recent data (2001-2002) on Cs-137 concentrations in top layers of bottom sediments proves its significant decrease due to radioactive decay and the new deposition of less contaminated or clean sediments when compared to 1995 results. This indicates that KMCC has ceased to be the active source of radionuclide contamination in the Yenisey Gulf and adjacent Kara Sea territory. Modern radionuclide contamination of the Yenisey floodplain occurs due to in situ global fallout onto high floodplain levels (which are practically not subjected to flooding events) or transport within the basin by drainage waters. The most contaminated sediment layers are believed to have formed during radioactive releases from the KMCC and deposited in landscape accumulative zones mainly with fine grained sediments, in sloping locations with sedimentation rate gradients and in medium-level contaminated sediments. The latter can be formed either due to distant transport or the local mixing and redistribution of sediments.
Transfer of radionuclides to terrestrial plants was studied. Several locations were studied covering a range of geomorphological settings. Landscape cross-sections were described through their geomorpholy, lithology and soil cover. Air dried and homogenized samples were analysed using HPGe detectors. Cs-137 levels in plants are comparatively low and correspond to levels found in regions subject to global and regional fallout. Mosses, their lower part in particular, appeared to be most enriched in radiocaesium, while lichens accumulated radionuclides to a lesser extent. Tundra plants exhibit remarkably high TF values (0.03-0.1 m2/kg) comparable to those obtained for peaty and swampy soils from temperate zones and tundra areas contaminated by Chernobyl fallout.
The transfer of heavy metals from soils to plants has also been addressed. Air dried and homogenized soil and plant samples were analysed with the help of XRF spectrometers. Heavy metal contents in the analysed vegetation samples were comparatively low and below the restricted levels for all studied elements except chromium. Heavy metal distribution in different estuarine zones and landscapes provide evidence of global and regional contamination signatures in vegetation. They can be followed in:
- Cu, Ni, Pb enhanced accumulation in mosses growing on watersheds and high flood plain ridges;
- Decrease in Cu, Ni, Pb concentration in the northern direction with distance from the Noril'sky Nickel Combine
- The absence of definite species-specific accumulation except for willow concentrating Zn ubiquitously.
The transfer of contaminants in aquatic ecosystems has been considered through the application of dynamic models. In the case of the Yenisey Estuary, a model has been applied and parameterised specifically for this area. The migration of fish, periodicity of spawning and velocity of travel in the river have been incorporated within the simulation. The simulation results show significant variability in fish activity concentrations corresponding to migrations. Another model has been applied to the Kara Sea. This second model is based upon analyses of appropriate food-chains in the region and is parameterised using biomass, respiration and feeding spectra. Activity concentrations in zooplankton, polar cod, benthos and harp seal have been derived.
Ecological studies have been conducted through the analyses of structure, abundance and composition of aquatic benthic communities. The data reported are derived from a field expeditions to the Yenisey Estuary. Multivariate statistical analyses were conducted to consider community structure, abundance and biomass. Some changes recorded in the bottom community are within the range of natural phenomena occurring in the sea. The state of the Yenisey Estuary ecosystems, assessed on the basis of benthic characteristics, shows that no significant changes have occurred.
The impact on man and the environment from ionising radiation has been addressed. Uptake and transfer through foodchains has been analysed using a simple biokinetic model. Allometric relationships have been widely used for model parameterisation. The activity concentrations in reindeer derived from model simulations are consistent with the known spatial distribution of activity concentrations in the Arctic. Dose conversion factors have been used to derive absorbed dose-rates. A simple comparison of this value with a scale of dose effects for terrestrial animals and background dose-rates for Arctic biota leads to the conclusion that environmental impacts of radiocaesium are not significant. A similar approach has been used for the aquatic environment using input from the aquatic transfer models. Again, dose-rates experienced by selected organisms were found to be negligible. Doses to man have been reconstructed for a 19-year period using assumptions about diet and parameters characterising dose coefficients and decreases in activity due to culinary preparation. The calculated doses were negligible.
Finally, the impact on man and the environment from exposure to heavy metals is addressed. Data was collated during field expeditions in 2001 and 2002. Heavy metal concentrations in most food products were below Russian permissible levels. The upper delta area was noted for the highest Cu and Pb content in fish liver, a high Ni content in some whitefish samples, maximum Cd in sturgeon liver, enhanced Cd content in reindeer meat. Data have been interpreted from the perspective of environmental impact by comparing reported levels with threshold levels at which biological effects have been observed. From a cursory analysis, any effects arising from heavy metal contamination are likely to be insignificant. In relation to impact on humans, recourse was made to earlier ESTABLISH work. Because most heavy metal are present at concentrations well below Russian permissible medical standards, health risks have been assessed as low.
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