Assessment of groundwater pollution risk as a characteristic of the stability of its quality

Definitions of hazard and risk of groundwater pollution are given. A deterministic method for the assessment of groundwater pollution risk using estimates of groundwater protection against and vulnerability to pollution and stability indicators of groundwater quality is considered. Also presented are the principal methodological approaches to the assessment of groundwater protection against pollution and the formation of the structure of indicators and indices characterizing the stability of groundwater quality. The structure of hazard, risks, and damages associated with groundwater pollution is shown. Expert appraisal method is used for the assessment of groundwater pollution risks.     

The Basic Principles and Recommendations for the Assessment and Mapping of the Degree of Groundwater Protection against Pollution

It is shown that the interaction between subsurface hydrosphere and other environmental components and the possible extent of its pollution through these components can be characterized by the degree of groundwater protection against pollution and can be represented on appropriate maps based on simple model estimates of pollutant movement through the lithosphere serving as a protection zone. The principles and methods used in evaluating and different-scale mapping of groundwater protection degree and their vulnerability with respect to pollutants with different toxicity are discussed.     

On the priority of toxicological ‘hazard’ of nickel in the sea

Ranking of the major pollutants in the World Ocean according to their ecological hazard is of great importance for monitoring programmes. A critical analysis is given of Ketchum's conclusion that nickel pollution in the sea presents the greatest ecological danger of all the heavy metals. This conclusion seems to have been the result of using in calculation unwarrantably low values of nickel toxic concentrations, listed in the Water Quality Criteria proposed by the US National Academy of Sciences.     

Distribution of petroleum hydrocarbons in soils and the underlying unsaturated subsurface at an abandoned petrochemical site,North China

Contamination characteristics of petroleum hydrocarbons in soils and the underlying unsaturated subsurface were analysed by investigating and sampling at different depth of five boreholes named SH1 through SH5 at a typical petrochemical site, North China. Topsoil volatile organic gas measurement revealed that SH‐3 was the center of one pollution plume. Soil samples analysis showed that aromatic hydrocarbons and chlorinated hydrocarbons were major pollutants. Their maximum concentration was found at 6.5 and 14.6 m of SH‐2, 13 m of SH‐5, and 18.5 m of SH‐3. These pollutants are mostly accumulated on the interface between two different lithological layers, especially between the sand and silt clay layers. Denitrifying and iron reducing were main biogeochemical processes in this site. Under the influence of groundwater level fluctuation, free NAPLs passed through the boundary and dissolved into the lower groundwater. Knowledge of these associations between contaminant distributions and affecting factors could have implications for soil and groundwater pollution prevention and control. Copyright © 2013 John Wiley & Sons, Ltd.     

Theoretical Principles and Methodical Approaches to Urban Area Zoning by Geoecological Restrictions

The need to take into account the geoecological restrictions in planning and designing urban territories is considered. Geoecological restrictions are analyzed and systematized. The criterion for assessing the priority of restrictions is the degree of their hazard for various recipients. An algorithm of a procedure for such assessment is given. Approaches to zoning by geoecological restrictions for newly developed and reorganized territories are proposed. Successive analysis and compilation of maps are considered. The map of zoning an urbanized territory by geoecological restrictions and its use for designing will facilitate the formation of an environment favorable for human activity and sustainable development of urban territories.     

Trends in the Chemical Pollution and Dynamics of Kaliningrad Bay

The dynamics and trends in the chemical pollution of water and the bottom sediment of Kaliningrad Bay in the Vistula Lagoon are examined. Mean annual and one-moment estimates of the conditions and level of this type of pollution of water resources in the bay are given, and distribution schemes of suspended matter and pollutants over the area are shown. Schemes for calculating the components of the nearshore wave energy fluxes and water currents are also given. Environmental–dynamic zoning of the area allowed the establishing of stably localized, hydrodynamically stagnant problematic zones with high levels of chemical pollution of the water and bottom sediments (which are zones of higher environmental risk).     

Geospatial Investigation into Groundwater Pollution and Water Quality Supported by Satellite Data: A Case Study from the Evros River (Eastern Mediterranean)

Managing water resources, in terms of both quality and quantity, in transboundary rivers is a difficult and challenging task that requires efficient cross-border cooperation and transparency. Groundwater pollution risk assessment and mapping techniques over the full catchment area are important tools that could be used as part of these water resource management efforts, to estimate pollution pressures and optimize land planning processes. The Evros river catchment is the second largest river in Eastern Europe and sustains a population of 3.6 million people in three different countries (Bulgaria, Turkey and Greece). This study provides detailed information on the main pollution sources and pressures in the Evros catchment and, for the first time, applies, assesses and evaluates a groundwater pollution risk mapping technique using satellite observations (Landsat NDVI) and an extensive dataset of field measurements covering different seasons and multiple years. We found that approximately 40 % of the Greek part of the Evros catchment is characterized as of high and very high pollution risk, while 14 % of the study area is classified as of moderate risk. Both the modeled and measured water quality status of the river showed large spatiotemporal variations consistent with the strong anthropogenic pressures in this system, especially on the northern and central segments of the catchment. The pollutants identified illustrate inputs of agrochemicals and urban wastes in the river. High correlation coefficients (R between 0.79 and 0.85) were found between estimated pollution risks and measured concentrations of those chemical parameters that are mainly attributed to anthropogenic activities rather than in situ biogeochemical processes. The pollution risk method described here could be used elsewhere as a decision support tool for mitigating the impact of hazardous human activities and improving management of groundwater resources.     

新地震区划图的几个基本问题

我国新的地震区划图(1990年版)是采用地震危险性慨率分析方法编制的。该图给出的是场点地震烈度值,该值在50年内被突破的概率为0.1。人们普遍关注该图与我国曾经编制的地震区划图(1957年版,1977年版)的区别,该图超越概率概念的内含和外延以及超越概率水平为什么采用50年超越概率0.1。本文围绕这些问题进行了讨论。分析结果表明,前两张地震区划图编图的基本着眼点都是地震预测,而新的地震区划着眼于场点的地震动预测。新的地震区划图是按场点地震危险性分析方法给出的,它所表示的地震危险性只能针对具体的场点,不能完全反映区域的地震危险性特征。而弄清场点地震危险性和区域地震危险性的差异是正确进行区域防灾对策的基础。作者希望这些讨论能对正确使用新的地震区划图有所裨益。     

中强地震活动区地震年平均发生率确定方法的比较

Two kinds of methods for determining seismic parameters are presented,that is,the potential seismic source zoning method and grid-spatially smoothing method. The Gaussian smoothing method and the modified Gaussian smoothing method are described in detail, and a comprehensive analysis of the advantages and disadvantages of these methods is made. Then,we take central China as the study region,and use the Gaussian smoothing method and potential seismic source zoning method to build seismic models to calculate the mean annual seismic rate. Seismic hazard is calculated using the probabilistic seismic hazard analysis method to construct the ground motion acceleration zoning maps. The differences between the maps and these models are discussed and the causes are investigated. The results show that the spatial smoothing method is suitable for estimating the seismic hazard over the moderate and low seismicity regions or the hazard caused by background seismicity; while the potential seismic source zoning method is suitable for estimating the seismic hazard in well-defined seismotectonics. Combining the spatial smoothing method and the potential seismic source zoning method with an integrated account of the seismicity and known seismotectonics is a feasible approach to estimate the seismic hazard in moderate and low seismicity regions.     

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.     

Probabilistic seismic hazard assessment of Italy using kernel estimation methods

A representation of seismic hazard is proposed for Italy based on the zone-free approach developed by Woo (BSSA 86(2):353–362, 1996a), which is based on a kernel estimation method governed by concepts of fractal geometry and self-organized seismicity, not requiring the definition of seismogenic zoning. The purpose is to assess the influence of seismogenic zoning on the results obtained for the probabilistic seismic hazard analysis (PSHA) of Italy using the standard Cornell’s method. The hazard has been estimated for outcropping rock site conditions in terms of maps and uniform hazard spectra for a selected site, with 10 % probability of exceedance in 50 years. Both spectral acceleration and spectral displacement have been considered as ground motion parameters. Differences in the results of PSHA between the two methods are compared and discussed. The analysis shows that, in areas such as Italy, characterized by a reliable earthquake catalog and in which faults are generally not easily identifiable, a zone-free approach can be considered a valuable tool to address epistemic uncertainty within a logic tree framework.     

Complex Isotopic and Hydrogeochemical Studies of Groundwater in the Kirov Region

Uranium-isotopic and multi-element hydrogeochemical methods are used to assess the natural pollution of fresh groundwater in horizons under development due to a modern intrusion of hypogene water with increased boron and fluorine contents in zones of old tectonic dislocations. The total index of the abovestandard (>MAC) pollution of groundwater in the region of the city of Kirov (the Kirov area) reaches 15. To reduce the effect of natural groundwater pollutants on the health of population, it is recommended that the groundwater intake should be regulated, purifiers should be used, and prospects revealed by the isotopic-and-hydrogeochemical data should be explored. The feasibility of modeling the groundwater formation and tracing the neotectonic dislocations in geological platforms is shown.     

Modelling water fluxes for the analysis of diffuse pollution at the river basin scale

Diffuse pollution is a significant and sometimes even major component of surface water pollution. Diffuse inputs of pollutants to the surface water are related to runoff of precipitation. This means that the analysis of diffuse pollutant fluxes from the land surface to the surface water requires an analysis of water fluxes. In this paper we have modelled the average long‐term total runoff, groundwater recharge index and groundwater residence times for two large European river basins (Rhine and Elbe). We applied and compared two independently developed and recently published methods. We found that with the available large‐scale databases and methods we could simulate successfully the regional patterns of the average long‐term total runoff. The reported groundwater recharge indices and groundwater residence times should be interpreted as estimates based on available knowledge and databases. They do not represent absolute values, but illustrate the possible travel times and spatial patterns of the different runoff components that have to be taken into account for the analysis of diffuse pollution at large regional and temporal scales. Copyright © 2000 John Wiley & Sons, Ltd.     

The pollution of groundwater and unsaturated zone rocks by oil products and PAH in urban areas

An approach to assessing the hazard of unsaturated zone rocks as a source of subsoil-water secondary pollution by oil products and PAH is considered based on environmental-geochemical studies of soils and rocks of the unsaturated zone, groundwater, and snow, which were carried out during the rehabilitation of the water environment of Lefortovskii Park (Moscow). The impact of the primary pollution sources is analyzed, and the formation of groundwater and rock pollution by oil products and PAH is considered. To assess the role of the unsaturated zone as a secondary source of pollution of surface and subsurface waters under the conditions of possible elimination of the primary sources, the transport of oil products (benzol and toluene) and PAH (pyrene) in unsaturated zone was simulated using WHI UnSat Suite Plus software package.     

Hydrogeological Zoning of the Central Minusinsk Basin by the Conditions of Formation of Fresh Groundwater Resources

A detailed hydrogeological zoning of the central part of the Minusinsk artesian basin is performed. Local basins confined to smaller plicated structures, as well as hydrogeological massifs of local scale, are recognized within large block structures. Direction of subsurface streams and their role in the formation of groundwater resources and composition are discussed. Forecast resources of fresh groundwater are estimated for every recognized structure.     

THE POSSIBILITIES OF GEOPHYSICAL METHODS APPLIED FOR INVESTIGATING THE IMPACT OF MAN ON THE GEOLOGICAL MEDIUM*

Geophysical methods can be applied to investigate the harmful effect of man's activities on the environment: the study of specific electrical resistivities and natural electric fields of filtrational origin makes it possible to control the penetration of exogenic pollutants into soil as well as desalinization and secondary salinization of soils; electrometric and seismometric methods allow to observe the groundwater level near water reservoirs thus evaluating the harmful effect of backing up natural groundwater flow; contrasting properties of bedrocks and rocks in a landslide body permit application of seismic and electrical prospecting methods. Observation of the changes in specific electrical resistivities with time on the slopes of quarries is an effective method of assessing slope stability and predicting landslide hazard. Mining activities, groundwater pumping, and oil extraction are the main causes of endogenic pollution of geological medium; surface and borehole geophysical methods make it possible to assess vertical and horizontal displacements of the interfaces between salty and fresh subterranean waters resulting from an extensive exploitation of water supply sources; activation of geodynamic processes associated with mining activities is determined from the data of ‘regime’ electrometric, seismometric, gravimetric, and inclinometric observations. Geophysical methods are applied widely for studying the intensification of physico-geological processes under the impact of man. A specific object of electrometric investigations is degradation of permafrost and intensification of karst processes in soluble rocks. The principal advantage of geophysical investigations lies in the possibility of creating high spatial and temporal density of observations permitting an extensive employment of statistical methods in the assessment of the impact of man on the geological medium.     

Optimum seismic zoning for multiple types of structures

We consider zoning for the design criterion that minimizes the expected present value of the total cost, including the initial cost as well as losses due to damage and failure. The problem consists of the following: given the number of zones, their boundaries and design coefficients must be such that they minimize the expected present value of all structures built in the region. We will refer to solutions in one or more dimensions, depending on the number of the types of structures built in the region to be zoned. Two methods are proposed to solve the problems. The first method is based on the different combinations performed in order to attain optimum zoning. The second method uses an analogy to the evolution of biological systems. The work ends by applying the methods developed to a region of known seismicity. Copyright © 2003 John Wiley & Sons, Ltd.     

Contribution of baseflow nitrate export to non-point source pollution

As a common pollutant of nitrogen in groundwater, nitrate contamination has become a major concern worldwide. Baseflow, one of the dominant hydrological pathways for nitrate migration to streamflow, has been confirmed as a leading nitrate source for stream water where groundwater or subsurface flow contaminated heavily by nitrate. That is, sufficient improvements of water quality may not be attained without proper management for baseflow, even if non-point sources (NPS) pollutants discharged through surface runoff are being well managed. This article reviews the primary nitrate sources, the main factors affecting its transport, and the methodologies for baseflow nitrate estimation, to give some recommendations for future works, including: (1) giving sufficient consideration for the effects of climatological, morphological, and geological factors on baseflow recessions to obtain more reliable and accurate baseflow separation; (2) trying to solve calibration and validation problems for baseflow loads determining in storm flow period; (3) developing a simple and convenient algorithm with certain physics that can be used to separate baseflow NPS pollution from the total directly in different regions, for a reliable estimation of baseflow NPS pollution at larger scale (e.g., national scale); (4) improving groundwater quality simulation module of existing NPS pollution models to have a better simulation for biogeochemical processes in shallow aquifers; (5) taking integrated measures of “source control”, “process interception” and “end remediation” to prevent and control NPS nitrate pollution effectively, not just only the strict control of nutrients loss from surface runoff.     

Assessing environmental risks through fuzzy parameterized probabilistic analysis

A fuzzy parameterized probabilistic analysis (FPPA) method was developed in this study to assess risks associated with environmental pollution-control problems. FPPA integrated environmental transport modeling, fuzzy transformation, probabilistic risk assessment, fuzzy risk quantification into a general risk assessment framework, and was capable of handling uncertainties expressed as fuzzy-parameterized stochastic distributions. The proposed method was applied to two environmental pollution problems, with one being about the point-source pollution in a river system with uncertain water quality parameters and the other being concerned with groundwater contaminant plume from waste landfill site with poorly known contaminant physical properties. The study results indicated that the complex uncertain features had significant impacts on modeling and risk-assessment outputs; the degree of impacts of modeling parameters were highly dependent on the level of imprecision of these parameters. The results also implied that FPPA was capable of addressing vagueness or imprecision associated with probabilistic risk evaluation, and help generate risk outputs that could be elucidated under different possibilistic levels. The proposed method could be used by environmental managers to evaluate trade-offs involving risks and costs, as well as identify management solutions that sufficiently hedge against dual uncertainties.     

Risk assessment and ranking of heavy metals concentration in Iran’s Rayen groundwater basin using linear assignment method

Groundwater is an important source of freshwater for domestic, agricultural and industrial uses in Iran. Groundwater quality assessment and environmental evaluation are considered as critical issues in recent years. Intensive human activities have resulted in significant changes in environment leading to serious groundwater contamination. This research proposes a two-part systematic approach to tackle heavy metals contamination problem in Rayen Basin (southeast Iran). The first part consists of determining geochemical characteristics and evaluating groundwater quality through application of water quality index and heavy metal pollution indices (i.e. HPI and MI). The second part includes ranking sampling stations based on heavy metals concentration in groundwater using linear assignment method. Six types of water could be identified according to the dominant cations and anions in samples: Ca–HCO₃, Ca–SO₄, Na–Cl, Na–HCO₃, Na–SO₄ and mixed water type. Calculation of indices revealed that natural and anthropogenic activities are playing a vital role in degrading groundwater quality in the study area. The proposed methodology can help in groundwater resource management and preventative activities by identifying risk factors and recognizing their pollution level. The results of this research provide useful and effective information for water pollution control and management and can be used in environmental studies in order to protect groundwater resources in the future.