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1.
A method for identifying past radiation events from dated layers of bottom sediments in stagnant water bodies is described. Results of an experimental study (2005–2006) of the samples of bottom sediments in the pond of the Timiryazev dendropark in Moscow are considered. The sediment layers are dated with 210Pb. The same radionuclide is used as a tracer for calculating the rate of sedimentation in the pond, which is estimated at 0.3–0.4 cm/year. The maximum 137Cs values are detected in the 0–24 cm column at depths of 7 and 13 cm. The 137Cs peak at a depth of 13 cm is dated as 1963, which reflects the maximum global fallout from the atmospheric nuclear weapon tests. A small peak of this radionuclide at 7 cm is dated as 1986. It appears to be attributed to the long-range fallout after the Chernobyl NPP accident. The origin of the 137Cs maximum at a depth of 13–14 cm is confirmed by characteristic ratios of radionuclide pairs available in the global fallout in the Moscow region. The ratios of 90Sr/137Cs = 0.6 and 239,240Pu/137Cs = 0.03 in the 13–14 cm layer are characteristic of the global radioactive fallout from nuclear explosions. In the layers above this maximum, such ratios vary sharply toward the enhanced 137Cs content in the fallout.  相似文献   

2.
Russian Meteorology and Hydrology - Data of 137Cs measurements in the Kiev Reservoir after the Chernobyl accident were used for comparison of simulation results of two multi-chamber models of...  相似文献   

3.
Bryansk Polesie is the most 137Cs-contaminated region of the Russian Federation after the Chernobyl NPP accident, where in 2007 (i.e., 21 years after the accident), the radiation monitoring was conducted within the Russia-Belarus Union State Program. The paper is based on the comparison of data obtained in the settlements and at the nearby landscape sites outside the villages. The 137Cs content variability in the most spread in Polesie soils, the podzols, is considered using observations obtained at the monitoring sites in Svyatsk and Demenka. It is shown that 137Cs is fixed at the surface, in the upper soil horizons, which is explained by a high soil sorption capacity. Vast crest-sink floodplains with the great contrast range of the hydromorphic features, which cause great variability of the 137Cs vertical distribution, are typical for the Polesie landscape; this fact is confirmed by observations obtained at the monitoring sites located in Starye Bobovichi and Ushcherpie. It is shown that Polesie pine forest contamination maintains higher contamination density levels compared to the nearby settlements, pastures, and meadow lands in the fluvial plains. Extrapolation of the contamination density data obtained within the first decade after the accident as of 2007, performed with allowance for the correction for decay and the comparison of these estimates with the new data accumulated in the recent years, does not show any significant contradiction.  相似文献   

4.
The issues of assessing variability of 137Cs fallout of global and Chernobyl origin at reference sites are discussed with a purpose to use this isotope as a tracer for estimating the rates of erosion-accumulative processes. It is shown that local variability of soil contamination by 137Cs at reference sites is within 7–20%, which makes it possible to use the isotope as a tracer. When studies are conducted within drainage basins, the available trend of the atmospheric 137Cs fallout should be taken into account in assessing the soil and sedimentation redistribution.  相似文献   

5.
The estimates of 137Cs emissions from the accident happened in Elektrostal at the beginning of April 12, 2013 are presented. The transport of radionuclides and their dry and wet deposition on the surface are computed using the Lagrangian stochastic model of the NOSTRADAMUS software package worked out by Nuclear Safety Institute of Russian Academy of Sciences. Prognostic fields of wind (horizontal and vertical components) in the lower troposphere, precipitation, and vertical and horizontal turbulence diffusivity coefficients in the lower atmosphere (up to 4 km) were used as input data. Prognostic fields were obtained using the WRF-ARW numerical mesoscale model.  相似文献   

6.
The results of studies of an acid-base indicator of the snow cover pH in the Primorskii krai for 2004–2005 are analyzed. Long-term observations of precipitation pH in the Russian Far East region are also considered. The results of studies of the snow cover pH of 2005 differed from the earlier data by the lower values of the acid-base indicator. Synoptic analysis demonstrated that acid precipitation in the Primorskii krai could be due to long-range transboundary pollution transport from Central China. The tendency towards a decrease in the precipitation pH values over most of the Far East region is traced from long-term observations, which under conditions of the general economy recession and population decrease can be attributed to transboundary transport of acid precipitation.  相似文献   

7.
The aerosol deposition rate is computed for some chemical elements from the resuits of studies on the elemental composition of atmospheric aerosol and snow cover in the background and anthropogenic areas in the Primorskii krai as well as for the radionuclide 137Cs and suspended matter from the data of atmospheric radioactive pollution monitoring. Taking into account the differences in sampling methods, the rather close values of deposition rate were obtained for chemical elements and radionuclide.  相似文献   

8.
The analysis of possible mechanisms of 137Cs concentration changes in surface waters was performed in the process of preparation of reliable long-range forecasts of radioactive river contamination after the Chernobyl accident. The following mechanisms were considered: (1) radioactive decay; (2) advective transport with river waters; (3) irreversible sorption; (4) vertical migration deep into bottom sediments due to diffusion; (5) burial in clean bottom sediments. The data published on 137Cs monitoring at Dobrush, on the Iput’ River in Belarus were used in the analysis. It is shown that the best agreement with the experimental results is achieved when the second, third, and fifth mechanisms are used in calculations. However, a dominating mechanism still cannot be chosen at the present stage of our study. Most probably, all of these mechanisms act simultaneously.  相似文献   

9.
New data are obtained on cesium 137 contamination after the Chernobyl NPP accident of settlements, agricultural lands, and forest areas in four Russian regions most affected by the accident: the Bryansk, Kaluga, Orel, and Tula regions. The new information was used to qualify the database on radioactive contamination of these areas. The renewed database was used as a basis for compiling maps on the terrain contamination by cesium 137 in 2006 and a series of prognostic maps with a ten-year interval from 2016 to 2056. The assessment of the dynamics of a change in the zonal areas with different levels of contamination by cesium 137 and the time when the patterns of respective contamination levels disappear in these areas is specified.  相似文献   

10.
The results of pH measurement results are summarized for 1994–2004. These were obtained from the snow pollution and acidity monitoring network in the Russian Federation. A map of acid-base characteristics is compiled for the Russian territory. The zones of the most frequent cases of snow acidification are singled out. Dependence of pH values on the concentration of acid-forming anions neutralizing cation acids is established based on the ion balance analysis.  相似文献   

11.
Chernobyl radioactivity in precipitation was measured at Tsukuba, Japan, as were both surface-air concentrations and particle-size distributions of Chernobyl-released radionuclides. To understand the wet removal processes of the Chernobyl radionuclides, i.e.137Cs,103Ru, and90Sr, wet deposition velocities were calculated. The wet deposition velocities of the Chernobyl radioactivity for individual rainfall events varied largely. The wet deposition velocity is given as the product of washout ratio and rainfall rate. Typically, it was found that the washout ratios of90Sr are systematically larger than those of137Cs. In order to explain this fact, we examined the relationship between the washout ratios and particle sizes of radionuclide-bearing aerosols. A positive correlation between corrected washout ratios and particle size was found with a particle diameter range from 0.35 to 1.2 µm. The result strongly suggests that the factors controlling the wet removal of the Chernobyl radioactivity for individual rainfall events are surface air concentration, particle size, and rainfall rate, rather than precipitation amount, which is in agreement with previous understandings. This suggests that high contamination areas of radioactivity are formed during heavy rainfall events with high rainfall rates in the case of tropospheric injection such as the Chernobyl accident.  相似文献   

12.
基于GIS的巴西陆稻IAPAR-9种植气候区划研究   总被引：2，自引：1，他引：2       下载免费PDF全文
根据巴西陆稻IAPAR-9生长发育对气候条件的要求, 结合其在广西的多年引种试验结果, 分析确定了影响广西种植巴西陆稻的关键气候因子和气候区划指标, 采用GIS技术对区划指标进行小网格推算, 得出广西不同地理背景下1 km×1 km网格点上的有关气候要素值, 通过GIS的空间分析和多层复合方法, 对广西种植巴西陆稻进行气候区划, 并对区划结果评述和建议, 为广西发展巴西陆稻生产进行合理布局提供科学依据。  相似文献   

13.
Quantitative environmental criteria for the radiation protection of aquatic ecosystems, namely, reference concentrations of radionuclides in water are developed. If activity concentrations of radionuclides do not exceed these levels, aquatic biota can be considered completely protected from the negative effects of ionizing radiation. Reference concentrations of radionuclides in environmental objects can be compared directly with the measurement data on radioactive contamination parameters that allows using them for the monitoring data interpretation. Reference concentrations of anthropogenic radionuclides in the sea and fresh water are calculated using the environmental criteria and are compared to the values of reference concentrations computed using the hygienic criterion. It is demonstrated that the current levels of concentration of 90Sr, 137Cs, and tritium in the seas, rivers, and lakes of Russia are considerably lower than the values of reference concentrations of these radionuclides calculated using the environmental criterion.  相似文献   

14.
Glacier valleys across the Transantarctic Mountains are not properly taken into account in climate models, because of their coarse resolution. Nonetheless, glacier valleys control katabatic winds in this region, and the latter are thought to affect the climate of the Ross Sea sector, frsater formation to snow mass balance. The purpose of this paper is to investigate the role of the production of turbulent kinetic energy by the subgrid-scale orography in the Transantarctic Mountains using a 20-km atmospheric regional model. A classical orographic roughness length parametrization is modified to produce either smooth or rough valleys. A one-year simulation shows that katabatic winds in the Transantarctic Mountains are strongly improved using smooth valleys rather than rough valleys. Pressure and temperature fields are affected by the representation of the orographic roughness, specifically in the Transantarctic Mountains and over the Ross Ice Shelf. A smooth representation of escarpment regions shows better agreement with automatic weather station observations than a rough representation. This work stresses the need to improve the representation of subgrid-scale orography to simulate realistic katabatic flows. This paper also provides a way of improving surface winds in an atmospheric model without increasing its resolution.  相似文献   

15.
A multi-chamber model of radioactivity migration in reservoirs was developed. It describes transport of radioactive substances in water and in bed sediments taking into account sorbtion of radionuclides on suspended particles. The model provides higher resolution than simplified chamber models do. At the same time, unlike complex two- or three-dimensional dynamic models, it does not require hard-to-obtain data such as detailed data on bathymetry, currents and winds. The model was included into the Sybilla program code that was developed in the framework of the Rosatom project called PRORYV. The model was verified against the observed data on the contamination of the Kiev Reservoir with 137Cs in 1986.  相似文献   

16.
七大江河流域面雨量计算方法及应用   总被引：41，自引：10，他引：41  
徐晶  林建  姚学祥  毕宝贵  吴昊 《气象》2001,27(11):13-16
参考我国水文部门和各省气象台的做法，比较客观地确定了全国七大江河流域（松花江、辽河、海河、黄河、淮河、长江、珠江）及其支流域的边界，将全国划分为71个子流域，并实现了各支流域内计算机自动选取代表测站。同时研究了各种面雨量计算方法的优缺点，最后选定泰森多边形法为面雨量计算的主要方法。2000年6－9月在中央气象台进行了面雨量预报业务试运行，每天定时完成将24小时常规雨量资料和加密雨量资料合并作为实况资料，并将中央气象台短期降水预报指导产品24、48小时雨量预报场转换成站点降水，在此基础上计算各支流域的实况和预报面雨量，同时实现了面雨量实况和预报在MICAPS下的显示。  相似文献   

17.
Scientific and methodological issues of assessing interannual variability of bioclimatic potential (BCP) in the Russian Federation are under consideration; mathematical models, technology of assessing the BCP from the multiyear mean data and individual years are presented. The calculations and assessments of the BCP and its components are performed by the constituent entities of the Russian Federation from the multiyear mean data and individual years over the period of 1997–2006. It is shown that in several constituent entities of the Russian Federation, the BCP for each year of a 10-year period of the BCP was either below or above its multiyear mean. It is also shown that in the constituent entities of the Russian Federation, where the deficiency of thermal resources is observed, some increase in the BCP due to this factor is observed, however, it has not yet reached such values, which would not limit the effective use of other constituents and the BCP as a whole.  相似文献   

18.
Emissions from Russian domestic civil aviation for the period of 2000–2012 are assessed for the following gases: carbon dioxide, methane, nitrous oxide, carbon monoxide, nitrogen oxides, and sulfur dioxide. The integrated assessment of their impact on the climate system is performed using the values of the global warming potential. The CO2 equivalent was used as a common measure of emissions. It is established that the modern impact of Russian civil aviation on the Earth climate is insignificant.  相似文献   

19.
The estimate of the release of radioactive substances (133Xe, 131I, and 137Cs) into the atmosphere from the Fukushima Daiichi nuclear disaster is presented. It was obtained using the FLEXPART Lagrangian dispersion model and the data of local ground-based measurements of radiation dose rate. The computation period covers the active phase of the nuclear disaster that lasted 20 days after the tsunami. To get the quantitative characteristics of emissions of radioactive substances, the inverse modeling based on the Bayesian approach is used. The emissions were estimated for three altitudes. The total emissions are equal to 2.1 + 0.4 kg (14 000 + 2700 PBq) for 133Xe, (3.8 + 0.4) x 10-2 kg (174 + + 18 PBq) for 131I, and 5.7 + 1.2 kg (18 + 4 PBq) for 137Cs that is consistent with the results of other studies. Retrieved emissions were used to provide the forward modeling for mapping the areas of radionuclide deposition. The developed method of retrieving the emission of radioactive substances makes a useful instrument that operationally estimates and localizes the areas of potential pollution in case of nuclear accidents and could be used for making decisions on the population evacuation.  相似文献   

20.
Radionuclide composition of soils near craters produced by excavation explosions “1003” and “1004” in 1965 at the Semipalatinsk test site is characterized as of 2005. A conclusion is made that radionuclides 137Cs, 152Eu, 154Eu, 155Eu, 241Am, and 60Co do not penetrate deeper than the upper 2 cm of the chestnut solonetz-like soil. The patterns after the explosions studied can be traced over the terrain near the crater ejecta to present. Contamination levels rapidly decrease with the distance from the ground zero. It is demonstrated that technogenic soils in the region of nuclear tests in a dry-steppe zone can be a source of dust and secondary air contamination.  相似文献   

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