Hydrochemistry and hydrology of the coastal dune area of the Western Netherlands

Harcopies can still be purchased; you can contact the author at pieter.stuyfzand[at]falw.vu.n

Позиція ЄС в урегулюванні арабо-ізраїльського конфлікту від початку ХХІ ст.

У статті розглянуто роль Європейського Союзу в урегулюванні арабо-ізраїльського конфлікту на початку ХХІ ст. Окремо увагу приділено особливостям позиції ЄС, що базуються на різному ставленні до сторін конфлікту країн-членів Євросоюзу. Аналізуються нові спроби активізації ЄС у процесі арабо-ізраїльського врегулювання після набуття чинності Лісабонського договору та введення посади верховного представника ЄС із закордонних справ і політики безпеки.В статье освещается роль Европейского Союза в урегулировании арабо-израильского конфликта в начале ХХІ ст. Значительное внимание уделяется особенностям позиции ЕС, базирующимся на различном отношении государств-членов Евросоюза к сторонам конфликта. Анализируются новые попытки активизации ЕС в процессе арабо-израильского урегулирования после вступления в силу Лиссабонского договора и введения должности верховного представителя ЕС по иностранным делам и политике безопасности.The article deals with the role of the European Union in the Arab-Israeli conflict regulation at the beginning of the 21st century. Special attention is paid to the peculiarities of the EU position that are based on the different attitude to the sides of the conflict from the state-members of the EU. The new attempts of the EU role activation in the process of the Arab-Israeli conflict regulation are being analyzed especially in the context of Lisbon treaty work and the establishment of the new post of the EU’s foreign policy chief

Uncertainty estimation of end-member mixing using generalized likelihood uncertainty estimation (GLUE), applied in a lowland catchment

End-member mixing models have been widely used to separate the different components of a hydrograph, but their effectiveness suffers from uncertainty in both the identification of end-members and spatiotemporal variation in end-member concentrations. In this paper, we outline a procedure, based on the generalized likelihood uncertainty estimation (GLUE) framework, to more inclusively evaluate uncertainty in mixing models than existing approaches. We apply this procedure, referred to as G-EMMA, to a yearlong chemical data set from the heavily impacted agricultural Lissertocht catchment, Netherlands, and compare its results to the traditional end-member mixing analysis (EMMA). While the traditional approach appears unable to adequately deal with the large spatial variation in one of the end-members, the G-EMMA procedure successfully identified, with varying uncertainty, contributions of five different end-members to the stream. Our results suggest that the concentration distribution of effective end-members, that is, the flux-weighted input of an end-member to the stream, can differ markedly from that inferred from sampling of water stored in the catchment. Results also show that the uncertainty arising from identifying the correct end-members may alter calculated end-member contributions by up to 30%, stressing the importance of including the identification of end-members in the uncertainty assessment

Hydrochemical system analysis of public supply well fields, to reveal water-quality patterns and define groundwater bodies:The Netherlands

Hydrochemical system analysis (HCSA) is used to better understand the individual state of and spatial patterns in groundwater quality, by addressing the spatial distribution of groundwater bodies with specific origins (hydrosomes) and characteristic hydrochemical zones within each hydrosome (facies). The origin is determined by environmental tracers or geomorphological and potentiometric maps, the facies by combining age, redox and alkalinity indices. The HCSA method is applied to all 206 active public supply well fields (PSWFs) in The Netherlands, resulting in the distinction of nine hydrosomes and eleven facies parameters-age (young, intermediate, old), redox ((sub)oxic, anoxic, deep anoxic, mixed) and alkalinity (very low, low, intermediate and high). The resulting classification of PSWFs provides a means to (1) predict their vulnerability; (2) optimize groundwater-quality monitoring programs; and (3) better delineate groundwater bodies, by considering groundwater origin and flow. The HCSA translates complex hydrochemical patterns into easily interpretable maps by showing PSWFs, groundwater bodies and hydrochemical facies. Such maps facilitate communication between researchers, water resources managers and policy makers and can help to solve complex groundwater resources management problems at different scales, ranging from a single well(field) or region to the national or European scale. © 2010 Springer-Verlag

Groundwater ages, recharge conditions and hydrochemical evolution of a barrier island freshwater lens (Spiekeroog, Northern Germany)

Freshwater lenses below barrier islands are dynamic systems affected by changes in morphodynamic patterns, groundwater recharge and discharge. They are also vulnerable to pollution and overabstraction of groundwater. Basic knowledge on hydrogeological and hydrochemical processes of freshwater lenses is important to ensure a sustainable water management, especially when taking into account possible effects of climate change. This is the first study which gives a compact overview on the age distribution, recharge conditions and hydrochemical evolution of a barrier island freshwater lens in the southern North Sea (Spiekeroog Island, Eastfrisian Wadden Sea). Two ground- and surface water sampling campaigns were carried out in May and July 2011, supplemented by monthly precipitation sampling from July to October. 3H–3He ages, stable oxygen and hydrogen isotopes and major ion concentrations show that the freshwater lens reaches a depth of 44 mbsl, where an aquitard constrains further expansion in vertical direction. Groundwater ages are increasing from 4.4 years in 12 mbsl up to >70 years at the freshwater– saltwater interface. Stable isotope signatures reflect average local precipitation signatures. An annual recharge rate of 300–400 mm was calculated with 3H–3He data. Freshwater is primarily of Na–Ca–Mg–HCO3– and Ca–Na–HCO3–Cl type, while lowly mineralized precipitation and saltwater are of Na–Cl types. A trend towards heavier stable isotope signatures and higher electric conductivities in the shallower, younger groundwater within the freshwater lens may indicate increasing atmospheric temperatures in the last 30 years

Field Testing of a Novel Drilling Technique to Expand Well Diameters at Depth in Unconsolidated Formations

Larger well diameters allow higher groundwater abstraction rates. But particularly for the construction of wells at greater depth, it may be more cost-efficient to only expand the borehole in the target aquifer. However, current drilling techniques for unconsolidated formations are limited by their expansion factors (<2) and diameters (<1000 mm). Therefore, we developed a new technique aiming to expand borehole diameters at depth in a controlled manner using a low-pressure water jet perpendicular to the drilling direction and extendable by means of a pivoting arm. During a first field test, the borehole diameter was expanded 2.6-fold from 600 to 1570 mm at a depth of 53.5 to 68 m and equipped with a well screen to create an expanded diameter gravel well (EDGW). In keeping with the larger diameter, the volume flux per m screen length was two times higher than conventional 860 mm diameter wells at the site in the subsequent 3 year production period. Although borehole clogging was slower on a volumetric basis and similar when normalized to borehole wall area, rehabilitation of particle clogging at the borehole wall was more challenging due to the thickness of the gravel pack. While jetting the entire borehole wall before backfilling holds promise to remove filter cake and thus limit particle clogging, we found that a second borehole (expanded 4.1-fold to 2460 mm) collapsed during jetting. Overall, the EDGW technique has potential to make the use of deeper unconsolidated aquifers economically (more) feasible, although further understanding of the borehole stability and rehabilitation is required to assess its wider applicability