Article

Erratum to “Effects of intensive urbanization on the intrusion of shallow groundwater into deep groundwater: Examples from Bangkok and Jakarta”

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Abstract

Asian megacities have severe pollution problems in both coastal and urban areas. In addition, the groundwater potential has decreased and land subsidence has occurred because of intensive groundwater pumping in urban areas. To prevent the adverse effects of urbanization on groundwater quality, it is necessary to confirm the changes in groundwater flow and contaminant transport caused by urbanization. We examined the effects of urbanization on contaminant transport in groundwater. The research areas were located around Bangkok, Thailand, and akarta, Indonesia, cities with populations of approximately 8 and 12 million, respectively. Each metropolitan city is located on a river delta and is adjacent to a bay. We measured the water level and collected water samples at boreholes at multiple depths (100 to 200 m) in 2004 and 2006 in Bangkok and Jakarta, respectively. The current hydraulic potential is below sea level in both cities because of prior excess abstraction of groundwater. As a result, the direction of groundwater flow is now downward in the coastal area. The Cl− concentration and δ18O distributions in groundwater suggest that the decline in hydraulic potential has caused the intrusion of seawater and shallow groundwater into deep groundwater. Concentrations of Mn and NO3−-N in groundwater suggest the intrusion of these contaminants from shallow to deep aquifers with downward groundwater flow and implies an accumulation of contaminants in deep aquifers. Therefore, it is important to recognize the possibility of future contaminant transport with the discharge of deep groundwater into the sea after the recovery of groundwater potential in the coastal areas.

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... The adoption of local water resources should be encouraged to achieve the sixth Sustainable Development Goal (SDG) by 2030 (clean water and sanitation for all) [7]. Comprehensively understanding the dynamics of fresh groundwater in coastal areas is important, because it is based on the delicate balance of the saltwater-fressssshwater interface and is considerably influenced by anthropogenic overpumping and sea-level fluctuations [8][9][10][11][12][13][14][15][16]. ...
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Conference Paper
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A study was undertaken to understand the groundwater flow conditions in the Bangkok Basin, Thailand, by comparing 14C-based and simulated groundwater ages. 14C measurements were made on about 50 water samples taken from wells throughout the basin. Simulated ages were obtained using 1) backward-pathline tracking based on the well locations, and 2) results from a three-dimensional groundwater flow model. Comparisons of ages at these locations reveal a large difference between 14C-based ages and ages predicted by the steady-state groundwater flow model. Mainly, 14C and 13C analyses indicate that groundwater in the Bangkok area is about 20,000 years old, whereas steady-state flow and transport simulations imply that groundwater in the Bangkok area is 50,000-100,000 years old. One potential reason for the discrepancy between simulated and 14C-based ages is the assumption in the model of steady-state flow. Groundwater velocities were probably greater in the region before about 10,000 years ago, during the last glacial maximum, because of the lower position of sea level and the absence of the surficial Bangkok Clay. Paleoflow conditions were estimated and then incorporated into a second set of simulations. The new assumption was that current steady-state flow conditions existed for the last 8,000 years but were preceded by steady-state conditions representative of flow during the last glacial maximum. This "transient" paleohydrologic simulation yielded a mean simulated age that more closely agrees with the mean 14C-based age, especially if the 14C-based age corrected for diffusion into clay layers. Although the uncertainties in both the simulated and 14C-based ages are nontrivial, the magnitude of the improved match in the mean age using a paleohydrologic simulation instead of a steady-state simulation suggests that flow conditions in the basin have changed significantly over the last 10,000-20,000 years. Given that the valid age range of 14C-dating methods and the timing of the last glacial maximum are of similar magnitude, adjustments for paleohydrologic conditions may be required for many such studies. RSUM: Les conditions d'coulement souterrain dans le bassin de Bangkok (Thalande) ont t tudies en comparant les ges 14C mesurs et ceux simuls. Les ges mesurs ont t obtenus partir d'environ 50 chantillons d'eau de puits dans tout le bassin. Les ges simuls proviennent 1) de la position des puits sur les lignes de flux, et 2) des rsultats d'un modle 3-D d'coulement de nappe. La comparaison des ges aux positions des puits fait apparatre une grande diffrence entre les ges mesurs et les prdictions du modle d'coulement en rgime permanent. Dans l'ensemble, les teneurs en 14C et en 13C indiquent que les eaux souterrains du bassin de Bangkok sont ges d'environ 20 000 ans, alors que les simulations d'coulement en rgime permanent et de transport prdisent un ge compris entre 50 000 et 100 000 ans. Une raison probable du dsaccord entre les ges simuls et ceux mesurs est due l'hypothse d'coulement en rgime permanent du modle. Les vitesses d'coulement souterrain ont probablement t plus fortes dans cette rgion jusqu'il y a 10 000 ans, lors du dernier maximum glaciaire, du fait de la position plus basse du niveau marin et de l'absence de la couverture par la formation argileuse de Bangkok. Les conditions des palo-coulements ont t estimes, puis introduites dans une seconde srie de simulations. La nouvelle hypothse supposait que les conditions actuelles d'coulement en rgime permanent ont exist au cours des 8 000 dernires annes, et qu'elles ont t prcdes par des conditions d'coulement en rgime permanent reprsentatives de l'coulement au cours du dernier maximum glaciaire. La simulation palohydrologique "transitoire" a donn un ge moyen simul qui s'accorde mieux avec les ges 14C mesurs, particulirement lorsque l'ge 14C est corrig pour tenir compte de la diffusion au travers des niveaux argileux. Bien que les incertitudes sur les ges aussi bien simuls que mesurs ne soient pas ngligeables, l'ordre de grandeur de l'ge moyen fourni par la simulation s'appuyant sur la palohydrologie, au lieu de l'coulement permanent, laisse supposer que les conditions d'coulement dans le bassin ont nettement chang au cours des 10 000 20 000 dernires annes. Etant donn que la gamme d'ges 14C et la dure du dernier maximum glaciaire sont du m&#123me ordre de grandeur, les ajustement pour les conditions palohydrologiques peuvent tre ncessaires pour nombre d'tudes de ce type. RESUMEN: Se llev a cabo un estudio con el objetivo de caracterizar las condiciones del flujo de agua subterrnea en la Cuenca de Bangkok, Tailandia, mediante la comparacin entre las edades del agua basadas en medidas de 14C y las simuladas mediante un modelo. Las medidas de 14C se tomaron en cerca de 50 muestras de agua, en pozos repartidos por toda la cuenca. Las edades simuladas se obtuvieron utilizando 1) seguimiento de partculas a contracorriente, basado en la situacin de los pozos, y 2) resultados de un modelo de flujo tridimensional. La comparacin entre las edades en estos puntos revelan una gran diferencia entre las basadas en 14C y las predichas por el modelo de flujo estacionario. Fundamentalmente, los anlisis de 14C y 13C indican que la edad del agua subterrnea en el rea de Bangkok es de alrededor de 20000 aos, mientras que las simulaciones de flujo y transporte en condiciones estacionarias revelan una edad de 50000-100000 aos. Una posible razn para la discrepancia entre estas dos edades es la hiptesis de flujo estacionario realizada en el modelo. Las velocidades del agua subterrnea eran probablemente mayores en esta regin anteriormente a los ltimos 10000 aos, durante el ltimo mximo glaciar, que en la actualidad, debido a que el nivel del mar era menor y a la ausencia de la capa superficial de Arcilla de Bangkok. Por esta razn, se estimaron las condiciones de paleoflujo y se incorporaron a un segundo grupo de simulaciones. La nueva hiptesis era que las condiciones actuales de flujo se haban mantenido estacionarias durante los ltimos 8000 aos, pero que fueron precedidas por otras condiciones estacionarias representativas del flujo durante el ltimo mximo glaciar. Esta simulacin paleohidrolgica "transitoria" da lugar a una edad media simulada que se ajusta mejor a la edad basada en 14C, especialmente si esta ltima edad se corrige por difusin hacia las capas de arcilla. Aunque las incertidumbres tanto en las edades simuladas con el modelo como en las basadas en 14C no son sencillas de evaluar, la magnitud de la mejora en el ajuste de la edad media que se produce al utilizar una simulacin paleohidrolgica en lugar de una estacionaria sugiere que las condiciones de flujo en la cuenca han cambiado significativamente en los ltimos 10000-20000 aos. Dado que el rango vlido de los mtodos de datacin de 14C y que el tiempo transcurrido desde el ltimo mximo glaciar son de magnitud similar, los ajustes debidos a condiciones paleohidrolgicas sern necesarios para muchos de estudios como ste.
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The UNSAT-H, HELP3 and MACRO4.3 computer codes, which have been developed for simulating the water balance of the unsaturated zone of soils and unconsolidated sediments, are also capable simulating water flow in low-porosity media such as fractured rock. The codes can be used to model the ability of rocks and overlying soils in the vadose zone to protect the groundwater in the uppermost aquifer. The net infiltration rates simulated by the different codes are compared against recharge determined by the chloride-balance method in Namibia. The dual-permeability code MACRO4.3 was found to produce more realistic estimates of net infiltration than the UNSAT-H and HELP3 codes, which are based on a single-permeability or effective-continuum method. The net infiltration rate together with the water storage in the unsaturated zone and the groundwater depth are used to calculate the residence time of pore water in the unsaturated zone. This parameter determines the intrinsic vulnerability of the aquifer.
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Land subsidence from deep well pumping has been affecting Bangkok for the past 35 years. Its impact is particularly critical because of the flat low-lying topography and the presence of a thick soft clay layer at the ground surface that augment flood risk and foundation engineering problems, respectively. The subsidence reached its most critical state in the early 1980s when it occurred at a rate as high as 120 mm/year. The rate decreased in the subsequent period but the subsidence-affected area expanded following the growth of the city. Despite various attempts implemented to remedy the crisis, groundwater pumping from the thick aquifer system underneath the city continued to increase from 1.2 million m3/day in the early 1980s to more than 2.0 million m3/day at the turn of the century. Piezometric levels in the main aquifer layers had been drawn down by as much as 65 m. Monitoring data showed a clear correlation between the subsidence and piezometric drawdown. The data suggested that for 1 m3 of groundwater pumped out in Bangkok Plain, approximately 0.10 m3 of ground loss occurred at the surface. Significant development has been made in numerical methods for prediction of differential settlements between building foundations caused by the piezometric drawdown in the aquifers. The strict mitigation measures adopted recently, comprising a pricing policy for groundwater management, an expansion of tap water supply, and strict enforcement of groundwater laws, have resulted in a marked drop in groundwater use. However, the land subsidence will continue for a long while owing to the time-dependent consolidation behavior of the soft clay layer and clay aquitards.
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Effects of surface-water irrigation on an alluvial aquifer were evaluated using chemical and isotopic data including δ2H, δ18O, 3H, δ3He, Ar, Ne, N2, δ15N, and 234U/238U activity ratios in a transect of nested wells in the North Platte River valley in western Nebraska, USA. The data were used to evaluate sources and fluxes of H2O, and U, all of which were strongly affected by irrigated agriculture. Combined results indicate that the alluvial aquifer was dominated by irrigation water that had distinctive chemical and isotopic features that were inherited from the North Platte River or acquired from agricultural soils or recharge processes. Values of δ2H, δ18O, Ar and Ne indicate that most of the ground water in the alluvial aquifer was irrigation water that was derived from the North Platte River and distributed during the growing season. The irrigation water was identified by an evaporated isotopic signature that was acquired by the river in major upstream reservoirs in Wyoming, and by relatively warm gas-equilibration temperatures related to warm-season recharge. Apparent 3H–3He ages indicate that the ground water in the alluvium was stratified and mostly <30 a old, with apparent recharge rates varying widely from about 0.2 to >3.0 m/a. Age gradients and concentrations indicate that recharge occurred by a combination of focused leakage from irrigation canals (rapid local recharge, low ) and distributed infiltration beneath the irrigated agricultural fields (lower recharge, high ). Large amounts of U with relatively low 234U/238U activity ratios were present in the alluvial aquifer as a result of irrigation with U-bearing river water, and minor amounts of U with higher 234U/238U activity ratios were added locally from basal and underlying volcanic-rich sediments. Distributions of , , dissolved gases, and ground-water ages indicate that concentrations increased and values decreased in distributed recharge in the last few decades, possibly in relation to a documented increase in the agricultural use of artificial fertilizers. Canal leakage caused substantial dilution of within the alluvial aquifer, whereas denitrification occurred mainly near the bottom of the alluvium. The average residence time of the irrigation water within the aquifer was relatively short (about 9 a) and reactions such as respiration, denitrification and U exchange in the saturated zone had relatively little effect on the overall composition of the alluvial ground water in comparison to what they might have had in the absence of irrigation recharge.
Book
This textbook provides an introduction to the study of hydrogeology, and maintains the process oriented approach of the earlier edition. The introduction is followed by chapters on: the origin of porosity and permeability; groundwater movement; equations of flow, boundary conditions and flow nets; groundwater in the basin hydrologic cycle; hydraulic testing; groundwater resources; stress, strain and pore fluids; heat transport in groundwater flow; solute transport; aqueous geochemistry; chemical reactions; colloids and microorganisms; mass transport equations; mass transport in natural groundwater systems and groundwater flow; contaminant hydrology; modelling of dissolved contaminant transport; multiphase fluid systems; remediation; and in situ destruction and risk assesment.
Article
Theoretically, three types of flow systems may occur in a small basin: local, intermediate, and regional. The local systems are separated by subvertical boundaries, and the systems of different order are separated by subhorizontal boundaries. The higher the topographic relief, the greater is the importance of the local systems. The flow lines of large unconfined flow systems do not cross major topographic features. Stagnant bodies of groundwater occur at points where flow systems meet or branch. Recharge and discharge areas alternate; thus only part of the basin will contribute to the baseflow of its main stream. Motion of groundwater is sluggish or nil under extended flat areas, with little chance of the water being freshened. Water level fluctuations decrease with depth, and only a small percentage of the total volume of the groundwater in the basin participates in the hydrologic cycle.
Article
The rate and mechanism of nitrate removal along and between groundwater flow paths were investigated using a series of well nests screened in an unconfined sand and gravel aquifer. Intensive agricultural activity in this area has resulted in nitrate concentrations in groundwater often exceeding drinking water standards. Both the extent and rate of denitrification varied depending on the groundwater flow path. While little or no denitrification occurred in much of the upland portions of the aquifer, a gradual redox gradient is observed as aerobic upland groundwater moves deeper in the aquifer. In contrast, a sharp shallow redox gradient is observed adjacent to a third-order stream as aerobic groundwater enters reduced sediments. An essentially complete loss of nitrate concurrent with increases in excess N 2 provide evidence that denitrification occurs as groundwater enters this zone. Electron and mass balance calculations suggest that iron sulfide (e.g., pyrite) oxidation is the primary source of electrons for denitrification. Denitrification rate estimates were based on mass balance calculations using nitrate and excess N 2 coupled with groundwater travel times. Travel times were determined using a groundwater flow model and were constrained by chlorofluorocarbon-based age dates. Denitrification rates were found to vary considerably between the two areas where denitrification occurs. Denitrification rates in the deep, upland portions of the aquifer were found to range from < 0.01 to 0.14 mM of N per year; rates at the redoxcline along the shallow flow path range from 1.0 to 2.7 mM of N per year. Potential denitrification rates in groundwater adjacent to the stream may be much faster, with rates up to 140 mM per year based on an in situ experiment conducted in this zone.
Article
The aquifer can be subdivided into an upper 10- to 15-m thick oxic zone that contains O2 and NO3-, and a lower anoxic zone characterized by Fe2+-rich waters. The redox boundary is very sharp, which suggests that reduction processes of O2 and NO3- occur at rates that are fast compared to the rate of downward water transport. Nitrate-contaminated groundwater contains total contents of dissolved ions that are two to four times higher than in groundwater derived from the forested area. The persistence of the high content of total dissolved ions in the NO3--free anoxic zone indicates the downward migration of contaminants and that active nitrate reduction is taking place. Nitrate is apparently reduced to N2 because both nitrate and ammonia are absent or found at very low concentrations. Possible electron donors in the reduced zone of the aquifer are organic matter, present as reworked brown coal fragments from the underlying Miocene, and small amounts of pyrite at an average concentration of 3.6 mmol/kg. Electron balances across the redoxcline, based on concentrations of O2, NO3-, SO42- and total inorganic carbon (TIC), indicate that pyrite is by far the dominant electron donor even though organic matter is much more abundant. Groundwater transport and chemical reactions were modeled using the code PHREEQM, which combines a chemical equilibrium model with a one-dimensional mixing cell transport model. -from Authors
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In textbook format, the book is process orientated and divided into 16 chapters. An introduction providing preliminary information on the hydrologic cycle is followed by chapters on the following: origin of porosity and permeability; groundwater movement; elastic properties and equations of flow; hydraulic testing; groundwater resource; the role of groundwater in the basin hydrologic cycle; groundwater in the Earth's crust; heat, solute and particulate transport; aqueous geochemistry; mass transport; and contaminant hydrogeology, contaminant transport modelling and pollution remedy. A bibliography and subject index are provided. -S.J.Stone
Article
The aquifer system in the Thon Buri sedimentary basin below the deltaic flood plain of the Chao Phraya River, central Thailand, has been exploited for public water supply for the capital Bangkok since the early 1920s. Groundwater withdrawal, currently 1.4 million m(3)/d, has resulted in a maximum decline in hydraulic head of up to 40 m. This has induced land subsidence of as much as 1.7 m (1940-1992) in the eastern suburbs of the metropolis. Artificial injection of purified water within an area-wide network of recharge wells could constitute a remedy to slow the water level depression within the sedimentary basin, and thus the subsidence. This requires a prior shutdown of water withdrawal. The flow paths of the injected water can be traced by changes in the Sr-87/Sr-86 ratio of the groundwater and injected water mixture within the three main aquifers in the basin that are used for public supply. The ratios, monitored at five monitoring stations within the cone of depression, have been constant over 3 years. Injection of the calculated cone volume of 5.2 x 10(9) m(3) would take at least 10 years, depending on the injection pressure and the number and position of wells.
Article
Jakarta is the capital city of Indonesia with a population of about 12 million people, inhabiting an area of about 625km2. It is well known that several areas in Jakarta are subsiding rapidly. There are four different types of land subsidence that can be expected to occur in the Jakarta basin, namely: subsidence due to groundwater extraction, subsidence induced by the load of constructions (i.e., settlement of high compressibility soil), subsidence caused by natural consolidation of alluvial soil and tectonic subsidence. In addition to the leveling method, Global Positioning System (GPS) survey methods have been used to study land subsidence in Jakarta. In this paper, we characterize subsidence in the Jakarta basin using eight episodic/campaign GPS surveys between 1997 and 2005. The estimated subsidence rates are 1–10cm/year. The observed subsidence rates in several locations show a positive correlation with known abstraction volumes of groundwater extraction. These basin-wide series of GPS measurements show how this type of measurement can play an important role in multiple public policy decision making in this rapidly growing area.
Article
Several approaches were used to characterize ground water/surface water interactions near the Willamette River — a large (ninth order) river in Oregon, USA. A series of potentiometric surface maps demonstrated the presence of highly dynamic hydraulic gradients between rivers and the adjacent aquifer. Hyporheic zone gradients extended on the order of hundreds of meters. River gains and losses at the river stretch scale (tens of kilometers) were consistent with fluxes implied by the potentiometric surface maps, and apparently reflect regional ground water/surface water interactions. Gains and losses of up to 5–10% of streamflow were observed at this scale. On the river reach scale (1–2 km), gains and losses on the order of 5% of streamflow were interpreted as representing primarily local hyporheic exchange.
Article
The Chalk aquifer of eastern-central England is seriously affected by nitrates leached from agricultural land and, like many similar aquifers, its future as a potable resource must depend considerably on the nature and rates of denitrification. The regional distribution of nitrate supports a viewpoint based on thermodynamic criteria that denitrification is actively occurring and that the problem will be short-lived. More detailed considerations based on major-ion and environmental isotope data, however, indicate that denitrification is not significant and that the apparent lowering of nitrate concentration (from > 10 to < 2 mg l−1 NO3-N) in the apparent direction of flow is due primarily to mixing between waters of different origins. Presence of reduced nitrogen species is possible evidence of denitrification in some older waters (> 4000 yr. B.P.). It is concluded that denitrification can not be relied upon to reduce elevated concentrations of nitrate in modern recharge waters.
Article
Groundwater is of major importance in providing municipal water-supply and for private domestic and industrial use in many urban centres. The subsurface has also come to serve as the receptor for much urban and industrial wastewater and for solid waste disposal, especially in the developing world. In result, there are rather widespread indications of degradation of the groundwater resource-base caused by excessive exploitation and/or inadequate pollution control. This paper is based primarily on the detailed investigation of six cities in Latin America and Asia. Fuller details are to be found in a related World Bank publication entitled `Groundwater in Urban Development' (Foster, Lawrence, & Morris, 1998). The objective of the present paper is to raise awareness of the interdependence of groundwater and urbanisation among urban policy-makers and to provide a framework for systematic consideration of groundwater in urban management.
Article
Nutrient input through submarine groundwater discharge (SGD) rivals river inputs in certain regions and may play a significant role in nutrient cycling and primary productivity in the coastal ocean. In this paper, we review the key factors determining the fluxes of nitrogen (N) and phosphorus (P) associated with SGD and present a compilation of measured rates. We show that, in particular, the water residence time and the redox conditions in coastal aquifers and sediments determine fluxes and ratios of N and P in SGD. In many coastal groundwater systems, and especially in contaminated aquifers, N/P ratios exceed those in river water and are higher than the Redfield ratio. Thus, anthropogenically driven increases in SGD of nutrients have the potential to drive the N-limited coastal primary production to P-limitation. River input of N and P to the coastal ocean has doubled over the past 50 yr. Results of a dynamic biogeochemical model for the C, N and P cycles of the global proximal coastal ocean (which includes large bays, the open water part of estuaries, deltas, inland seas and salt marshes), suggest that this has led to a factor 2 increase in primary production and biomass and a decline in water column N/P ratios, i.e. the system has become more N-limiting. With the same model, we show that an increase of SGD-N fluxes to ∼0.7–1.1 Tmol yr−1 (with a SGD N/P ratio of 100; equal to ∼45–70% of pre-human riverine N-inputs) is required to drive the coastal ocean to P-limitation within the next 50 yr.
Article
Pumping studies were conducted at five sites distributed over a 3000 ha area in the Gohana block in Haryana state of India. The project area is a part of the Indo-Gangetic plain and lies in a topographical depression susceptible to waterlogging, soil salinity and groundwater pollution from surrounding industrial towns. The crop productivity of irrigated lands in the project area is declining due to secondary salinization and shortage of surface irrigation supplies forcing farmers to depend on groundwater abstraction through shallow tubewells. Three wells of 30 m depth and two of 60 m depth were developed in the project area and the effect of pumping on temporal changes in groundwater depths and quality was studied over a period of 72 h. Groundwater samples, collected from different depths up to 30 m at each site while installing piezometers and at different times during pumping tests, were analyzed for electrical conductivity (EC), pH, ionic composition and heavy metals like arsenic (As), copper (Cu), zinc (Zn), manganese (Mn), cadmium (Cd), nickel (Ni), lead (Pb) and chromium (Cr). The results indicated varying values of EC, pH, sodium adsorption ratio (SAR) and residual sodium carbonate (RSC) which, in an average sense, were much above the limits prescribed for use of water for irrigation. Of the heavy metals, groundwater was heavily contaminated with As, Pb, Cd and Ni having maximum concentrations of 27.5, 1.53, 0.12 and 1.46 mg/l, respectively, which are much higher than maximum permissible limits. Contaminants had variable times of peak concentration, some with multiple peaks, denoting non-uniform contaminant concentrations and possibly different adsorption characteristics. The results emphasize that groundwater in the project area needs to be analyzed not only in respect of conventional quality parameters but also for heavy metal contamination for their safe use in agriculture. The source or the cause of such serious groundwater pollution problems in the region must be identified to minimize the hazardous effects of using such waters on a long-term basis.
Article
World Development Indicators, the World Bank's respected statistical publication presents the most current and accurate information on global development on both a national level and aggregated globally. This information allows readers to monitor the progress made toward meeting the goals endorsed by the United Nations and its member countries, the World Bank, and a host of partner organizations in September 2001 in their Millennium Development Goals. The print edition of World Development Indicators 2005 allows you to consult over 80 tables and over 800 indicators for 152 economies and 14 country groups, as well as basic indicators for a further 55 economies. There are key indicators for the latest year available, important regional data, and income group analysis. The report contains six thematic presentations of analytical commentary covering: World View, People, Environment, Economy, States and Markets, and Global Links.
Article
Mine water pollution is a major cause of surface- and groundwater pollution in former mining districts throughout Europe. It is a potential barrier to achieving good status water bodies, which is a requirement of the EU Water Framework Directive. In the UK, a concerted effort has been made over the last decade or so to address the scientific and practical challenges relating to the remediation of mine water pollution. However, most of this work has focused on remediation of point sources of pollution (typically arising from abandoned mines and shafts), while the behaviour of mine water at the groundwater-surface water interface (the "hyporheic zone") has received far less attention in relevant scientific and engineering literature. The extent of mine water pollution and capacity for its attenuation at the hyporheic zone has not been well quantified while, furthermore, the complex chemical and microbial processes occurring there (specifically with reference to mining-derived pollutants) have not been investigated in any depth. The absence of such data may relate, in a large part, to the difficulty in physically measuring volumes and concentrations associated with these river inputs/exports. A far greater body of literature addresses biogeochemical processes at the hyporheic zone (especially relating to manganese), albeit many such articles relate to aqueous metal dynamics in general, rather than mine water specifically. This paper presents a review of the natural attenuation processes that may limit the movement and availability of mining-derived pollutants at the groundwater-surface water (GW-SW) interface, and specifically within the hyporheic zone. A substantial part focuses on precipitation and adsorption processes at the hyporheic zone, as well as discussing the role of microbial processes in governing metal ion mobility.
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Investigation of land subsidence caused by deep well pumping in the Bangkok area
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Attenuation of mining-derived pollutants in the hyporheic zone Fig. 11 Schematic diagram of the current condition of groundwater flow and material transport at the aquifers in Bangkok and Jakarta Linking hyporheic flow and nitrogen cycling near the Willamette River—a large river in Oregon
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Bangkok, Thailand, Investigation of land subsidence caused by deep well pumping in the Bangkok area
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Schematic diagram of the current condition of groundwater flow and material transport at the aquifers in Bangkok and Jakarta Linking hyporheic flow and nitrogen cycling near the Willamette River—a large river in Oregon, USA
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Fig. 11. Schematic diagram of the current condition of groundwater flow and material transport at the aquifers in Bangkok and Jakarta. Hinkle SR, Duff JH, Triska FJ, Laenen A, Gates EB, Bencala KE, et al. Linking hyporheic flow and nitrogen cycling near the Willamette River—a large river in Oregon, USA. J Hydrol 2001;244:157–80.
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All rights reserved Land subsidence characteristics of Jakarta between 1997 and 2005, as estimated using GPS surveys Investigation of land subsidence caused by deep well pumping in the Bangkok area
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