Variations in submarine groundwater runoff as a possible cause of decomposition of marine methane-hydrates in the Artcic

The formation conditions and the dynamics of groundwater in the upper hydrodynamic zone of the northern coast of European Russia, which discharge directly into the Barents and White seas, are analyzed. The normal annual water, ionic, and thermal runoff and the anticipated submarine groundwater runoff into the Arctic Ocean are evaluated. The stability of marine arctic methane-hydrates under the observed and anticipated climate changes is analyzed. A physical substantiation is given to the concept of climate-determined increase in submarine groundwater discharge as a possible cause of the intensification of arctic methane hydrate decomposition, which does not contradict empirical data.     

On Estimating Chemical Discharge into the World Ocean with Groundwater

A quantitative estimate is made for the first time for the role of some chemicals discharged with groundwater into seas and oceans in the formation of hydrochemical regime in the coastal zone. The estimate is based on the regional and global regularities in the formation and distribution of submarine groundwater discharge into seas and oceans. A concept is proposed regarding the existence of geochemical and biological barriers on the submarine groundwater–seawater interface, which cause significant transformation and losses of many chemical elements.     

Estimation of long-term trends in the discharge of organochlorine pesticides into seas by rivers of Russia

The mean annual water runoff and the amount and dynamics of the discharge of the organochlorine pesticides into seas by large rivers of Russia in 1981–2000 are estimated. The main factors governing the formation of the organochlorine pesticide runoff within the river basins located in different physico-geographic conditions are revealed.     

Groundwater discharge to the Pacific Ocean / Apports des eaux souterraines à l'Océan Pacifique

ABSTRACT

Studies of groundwater discharge to seas and oceans are important to hydrology and geology. Some concepts and notions of groundwater outflow to the world's oceans are presented. A method for evaluating submarine groundwater discharge is discussed. Discharge estimates for the Pacific Ocean along all its coastline and major islands are given. The general characteristics of groundwater discharge and the factors governing discharge values are described. The groundwater outflow to the Pacific Ocean is shown to follow latitudinal physiographic zonality.     

Magnetic declination measurements over European Russia and Siberia in the 18th century

The paper presents the history of measurements of the geomagnetic field parameters over the territory of Russia in the 18th century derived from archival and literature sources. Topographical mapping of the European territory and neighboring seas of the Russian Empire from the late 17th to the mid 18th century during which magnetic measurements were made was of great importance for determining magnetic declination. The magnetic declination in Siberia and its neighboring seas was measured for the first time during the first expedition of V. Bering in 1728 and then during his second expedition (the Great Northern Expedition) in 1733–1742. Magnetic measurements were carried out along the northern coast of Siberia and in the Bering Sea. The academic group of the expedition performed magnetic declination measurements over southern regions of Siberia (Krasnoyarsk, Irkutsk, Nerchinsk, Yakutsk, etc.) in 1735 and 1736. During the second half of the 18th century, Russian expeditions determined geographical coordinates of the cities of European Russia and carried out magnetic declination measurements for them. During these expeditions Inokhodtsev paid attention to the anomalous magnetic declination in the Kursk region. In his opinion, the anomaly could have been caused by the presence of iron ore.     

南海北部沙波运移的观测与理论分析

针对南海北部海域特点建立了模拟该区域小尺度沙波运移过程的准三维力学模型.以多波束海底地貌扫描数据和水文资料为基础,预测了研究区域沙波的运移,其结果在沙脊脊沟处与实际观测一致,而在脊背上与实际观测值存在差异.分析表明,本文所提出的物理模型可以用于预测南海海域以推移质泥沙运动为主的小尺度沙波运移规律.这一结果对该区域海底管线等工程设计是很有意义的.     

Deltas as Indicators of Natural and Human-Induced Changes in the Regimes of Rivers and Seas

The way in which the joint action of fluvial and marine factors control delta formation is illustrated by examples of the mouths of rivers discharging into the Black and Mediterranean seas. The processes of active delta out-building under the effect of cold, wet climatic conditions and human-induced erosion in river basins and the processes of sea-wave erosion of deltas under the effect of a significant decrease in the sediment discharge of rivers that was caused by impact of human activities in the second half of the 20th century are discussed.     

Long-term trends in the total and anthropogenic discharge of organic and biogenic substances by Russian rivers into the Baltic,Black, Azov,and Caspian seas and into Lake Baikal

The discharge of organic and biogenic substances by Russian rivers into the Baltic, Black, Azov, and Caspian seas and into Lake Baikal, as well as their anthropogenic component, and trends in variations in the runoff of ingredients are evaluated for individual periods in 1981–2000.     

Long-term trends in total and anthropogenic discharge of organic and biogenic substances by Russian rivers into the Arctic and Pacific seas

The discharge of organic and biogenic substances by Russian rivers into the Arctic and Pacific seas, their anthropogenic component, and the trends in variations in the runoff of some components in individual periods of 1981–2000 are estimated.     

Discharge estimation of submarine springs in the Dead Sea based on velocity or density measurements in proximity to the water surface

The Dead Sea is a closed lake, the water level of which is lowering at an alarming rate of about 1 m/year. Factors difficult to determine in its water balance are evaporation and groundwater inflow, some of which emanate as submarine groundwater discharge. A vertical buoyant jet generated by the difference in densities between the groundwater and the Dead Sea brine forms at submarine spring outlets. To characterize this flow field and to determine its volumetric discharge, a system was developed to measure the velocity and density of the ascending submarine groundwater across the center of the stream along several horizontal sections and equidistant depths while divers sampled the spring. This was also undertaken on an artificial submarine spring with a known discharge to determine the quality of the measurements and the accuracy of the method. The underwater widening of the flow is linear and independent of the volumetric spring discharge. The temperature of the Dead Sea brine at lower layers primarily determines the temperature of the surface of the upwelling, produced above the jet flow, as the origin of the main mass of water in the submarine jet flow is Dead Sea brine. Based on the measurements, a model is presented to evaluate the distribution of velocity and solute density in the flow field of an emanating buoyant jet. This model allows the calculation of the volumetric submarine discharge, merely requiring either the maximum flow velocity or the minimal density at a given depth.     

Simulation of submarine ground water discharge to a marine estuary: Biscayne Bay, Florida

Variable density ground water flow models are rarely used to estimate submarine ground water discharge because of limitations in computer speed, data availability, and availability of a simulation tool that can minimize numerical dispersion. This paper presents an application of the SEAWAT code, which is a combined version of MODFLOW and MT3D, to estimate rates of submarine ground water discharge to a coastal marine estuary. Discharge rates were estimated for Biscayne Bay, Florida, for the period from January 1989 to September 1998 using a three-dimensional, variable density ground water flow and transport model. Hydrologic stresses in the 10-layer model include recharge, evapotranspiration, ground water withdrawals from municipal wellfields, interactions with surface water (canals in urban areas and wetlands in the Everglades), boundary fluxes, and submarine ground water discharge to Biscayne Bay. The model was calibrated by matching ground water levels in monitoring wells, baseflow to canals, and the position of the 1995 salt water intrusion line. Results suggest that fresh submarine ground water discharge to Biscayne Bay may have exceeded surface water discharge during the 1989, 1990, and 1991 dry seasons, but the average discharge for the entire simulation period was only approximately 10% of the surface water discharge to the bay. Results from the model also suggest that tidal canals intercept fresh ground water that might otherwise have discharged directly to Biscayne Bay. This application demonstrates that regional scale variable density models are potentially useful tools for estimating rates of submarine ground water discharge.     

Lake water resources of the European part of the Russian Federation

The article gives the results of estimating lake water resources for federal districts in European Russia and constituent entities of the Federation, carried out in the Institute of Limnology, RAS, with the use of up-to-date satellite images and the program Google Earth. European Russia contains ~610000 natural water bodies >0.1 ha in area, including ~200000 lakes >1 ha in area, and 90000 water bodies of artificial origin. Lake water resources of European Russia amount to 1370 km³ of water, of which 99% are in Northwestern Federal District. Artificial water bodies contain ~250 km³ of water resources.     

Many-year variations in river delta structures

Data on several river deltas are used to analyze the regularities in their dynamics in the context of variations of water and sediment runoff, sea level, and hydroengineering activities in delta areas. The basis for this analysis includes the results of many-year studies of river deltas in Russia and the world. The specific features of the evolution of the structure and morphometry of bayhead deltas, forming in bays, lagoons, and estuaries are shown in the case of the Alikazgan delta in the Terek mouth area and the deltas of two watercourses in the Mississippi mouth area. Data on many-year variations of the morphometric characteristics of modern protruding deltas in open coastal zones are systematized, and the factors that have an effect on these changes are analyzed. The types of delta formation processes and the types of deltas are considered with regard to the factors involved. The majority of modern river deltas are found to slow down their progradation into seas under the effect of anthropogenic runoff decline; moreover, some deltas have started retreating and degrading.     

Nutrient budgets for European seas: a measure of the effectiveness of nutrient reduction policies

Socio-economic development in Europe has exerted increasing pressure on the marine environment. Eutrophication, caused by nutrient enrichment, is evident in regions of all European seas. Its severity varies but has, in places, adversely impacted socio-economic activities. This paper aims to evaluate the effectiveness of recently adopted policies to reduce anthropogenic nutrient inputs to European seas. Nitrogen and phosphorus budgets were constructed for three different periods (prior to severe eutrophication, during severe eutrophication and contemporary) to capture changes in the relative importance of different nutrient sources in four European seas suffering from eutrophication (Baltic Proper, coastal North Sea, Northern Adriatic and North-Western Black Sea Shelf). Policy success is evident for point sources, notably for P in the Baltic and North Seas, but reduction of diffuse sources has been more problematic.     

Perspectives of artificial recharge of groundwater in southern European Russia

The current state of the problem of artificial recharge of groundwater in Russia and other countries is analyzed. The factors that govern the zoning by the conditions of artificial groundwater recharge are considered. The territory of the southern European Russia was zoned by the conditions of artificial groundwater recharge and the results of this zoning were used to compile maps of perspectives of artificial groundwater recharge in southern European Russia.     

Using EUNIS habitat classification for benthic mapping in European seas: Present concerns and future needs

The EUNIS (European Union Nature Information System) habitat classification system aims to provide a common European reference set of habitat types within a hierarchical classification, and to cover all terrestrial, freshwater and marine habitats of Europe. The classification facilitates reporting of habitat data in a comparable manner, for use in nature conservation (e.g. inventories, monitoring and assessments), habitat mapping and environmental management. For the marine environment the importance of a univocal habitat classification system is confirmed by the fact that many European initiatives, aimed at marine mapping, assessment and reporting, are increasingly using EUNIS habitat categories and respective codes. For this reason substantial efforts have been made to include information on marine benthic habitats from different regions, aiming to provide a comprehensive geographical coverage of European seas. However, there still remain many concerns on its applicability as only a small fraction of Europe’s seas are fully mapped and increasing knowledge and application raise further issues to be resolved.This paper presents an overview of the main discussion and conclusions of a workshop, organised by the MeshAtlantic project, focusing upon the experience in using the EUNIS habitats classification across different countries and seas, together with case studies. The aims of the meeting were to: (i) bring together scientists with experience in the use of the EUNIS marine classification and representatives from the European Environment Agency (EEA); (ii) agree on enhancements to EUNIS that ensure an improved representation of the European marine habitats; and (iii) establish practices that make marine habitat maps produced by scientists more consistent with the needs of managers and decision-makers. During the workshop challenges for the future development of EUNIS were identified, which have been classified into five categories: (1) structure and hierarchy; (2) biology; (3) terminology; (4) mapping; and (5) future development. The workshop ended with a declaration from the attendees, with recommendations to the EEA and European Topic Centre on Biological Diversity, to take into account the outputs of the workshop, which identify weaknesses in the current classification and include proposals for its modification, and to devise a process to further develop the marine component of the EUNIS habitat classification.     

Zonal features of the formation of water chemistry in small lakes in European Russia

Appreciable observational data were used to reveal zonal features of the formation of the chemical composition of waters in small lakes on the territory of European Russia along a transect from tundra to the arid zone. Inter-zonal variability in the parameters of the chemical composition of waters is determined. Zonal differentiation according to hydrochemical parameters is substantiated. The main differentiating elements of the chemical composition of waters in different natural-climatic zones are distinguished. The contribution of the main natural and anthropogenic factors, determining the present-day processes of water formation is analyzed. Different degrees of the effect of non-zonal factors (including anthropogenic ones) on the formation of the chemical composition of lake waters in the humid and arid zones are demonstrated.     

Transboundary aspect of assessing the impact of NPPs under construction on aquatic ecosystems: Case study of the Baltiiskaya NPP

The environmental feasibility assessment of the construction and operation of nuclear power stations in near-border areas must take into account the requirements of the international and European environmental legislation. For the study on environment feasibility assessment of the Baltic NPP to meet the international standards, the following steps were taken: the content and the application practice of UNECE Convention on Environmental Impact Assessment in a Transboundary Context (Espoo) to NPP substantiation were analyzed and compared with the Russian procedure of environmental impact assessment (EIA); water quality standards for water bodies used for fishery and the approaches to assessing the damage to aquatic bioresources in Russia, Lithuania (EU), and Belarus were compared. A transboundary network for monitoring aquatic ecosystems was developed in the zone of potential influence of the Baltic NPP, and a permanent mathematical model was developed and used to forecast the effect of the anticipated water discharge from the station on the hydrodynamic, chemical, and temperature regime of the Neman R., whose results were used to forecast the impact of water intake and discharge facilities of the Baltic NPP on the food base and migration character of ichthyofauna.     

Anthropogenic dispersion of anionogenic toxicants in groundwater in the European Russia

The result of studying the anthropogenic dispersion of As, Se, Sb, Cr, V, and Mo in subsoil waters in European Russia beyond industrial and urbanized territories are presented. The sources and ways of their penetration into aquifers, the extent and dynamics of dispersion, the contrast of mass fluxes, the forms of their migration and the most typical associations of toxicants are considered.     

A revisitation of TRIX for trophic status assessment in the light of the European Water Framework Directive: application to Italian coastal waters

The trophic status classification of coastal waters at the European scale requires the availability of harmonised indicators and procedures. The composite trophic status index (TRIX) provides useful metrics for the assessment of the trophic status of coastal waters. It was originally developed for Italian coastal waters and then applied in many European seas (Adriatic, Tyrrhenian, Baltic, Black and Northern seas). The TRIX index does not fulfil the classification procedure suggested by the WFD for two reasons: (a) it is based on an absolute trophic scale without any normalization to type-specific reference conditions; (b) it makes an ex ante aggregation of biological (Chl-a) and physico-chemical (oxygen, nutrients) quality elements, instead of an ex post integration of separate evaluations of biological and subsequent chemical quality elements. A revisitation of the TRIX index in the light of the European Water Framework Directive (WFD, 2000/60/EC) and new TRIX derived tools are presented in this paper. A number of Italian coastal sites were grouped into different types based on a thorough analysis of their hydro-morphological conditions, and type-specific reference sites were selected. Unscaled TRIX values (UNTRIX) for reference and impacted sites have been calculated and two alternative UNTRIX-based classification procedures are discussed. The proposed procedures, to be validated on a broader scale, provide users with simple tools that give an integrated view of nutrient enrichment and its effects on algal biomass (Chl-a) and on oxygen levels. This trophic evaluation along with phytoplankton indicator species and algal blooms contribute to the comprehensive assessment of phytoplankton, one of the biological quality elements in coastal waters.