J. Borrego

A description of how metal pollution occurs in the Tinto-Odiel rias (Huelva-Spain) through the application of cluster analysis

In the last few decades, the study of space-time distribution and variations of heavy metals in estuaries has been extensively studied as an environmental indicator. In the case described here, the combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel Rivers, located in the southwest of the Iberian Peninsula. Based on the statistical treatment of the data from the analysis of the water samples from this system, which has been affected by processes of industrial and mining pollution, the 16 variables analyzed can be grouped into two large families. Each family presents high, positive Pearson r values that suggest common origins (fluvial or sea) for the pollutants present in the water analyzed and allow their subsequent contrast through cluster analysis.

Application of Cluster Analysis to the Geochemistry Zonation of the Estuary Waters in the Tinto and Odiel Rivers (Huelva, Spain)

The combination of acid water from mines, industrial effluents and sea water plays a determining role in the evolutionary process of the chemical makeup of the water in the estuary of the Tinto and Odiel rivers. This estuary is in the southwest of the Iberian Peninsula and is one of the estuarine systems on the northwest coast of the Gulf of Cádiz. From the statistical treatment of data obtained by analyzing samples of water from this system, which is affected by industrial and mining pollution processes, we can see how the sampling points studied form two large groups depending on whether they receive tidal or fluvial influences. Fluvial input contributes acid water with high concentrations of heavy metal, whereas industrial effluents are responsible for the presence of phosphates, silica and other nutrients. The estuarine system of the Tinto and Odiel Rivers can be divided into three areas – the Tinto estuary, the Odiel estuary and the area of confluence – based on the physical – chemical characteristics of the water.

Impact of millennial mining activities on sediments and microfauna of the Tinto River estuary (SW Spain).

In this paper, we analyze two short cores collected in the Tinto estuary (SW Spain), and describe the palaeoenvironmental evolution of this area during the last two millennia, along with the influence of historical mining activities and recent industrial pollution on sediments and microfauna (foraminifera and ostracoda). Although there were no significant changes in the distribution of microorganisms, a first pollution period (0-150 AD) was recorded in high sediment pollution by Cu in the shallow palaeochannels of the middle estuary. During this period and the following 1700 years, tolerant pioneer species of both foraminifera and ostracoda were found predominantly in the inner, protected areas of the estuary, while the bottom sediments were subjected to high hydrodynamic gradients, and consequently showed lower density and diversity of organisms. In the last 150 years, acid mine drainage processes, introduction of a new mining period, and the polluted inputs derived from two industrial processes resulted in increased heavy metal contamination of the bottom sediments, and corresponding extirpation of ostracodes and restriction of foraminifers to the inner zones of the estuary.

Effect of acid mine drainage on dissolved rare earth elements geochemistry along a fluvial-estuarine system: the Tinto-Odiel Estuary (S.W. Spain)

Hydropower is a potential large source of electricity supply in Wales. The Upper River Severn in Mid Wales is a typical stream where a high head hydropower scheme could be developed and the river system at Plynlimon has some of the longest records for weather and flow in Wales. A microhydropower potential of 99 kW is demonstrated at Plynlimon and the potential impacts of climate change are simulated to assess the effects on flows and power outputs of such schemes under climate uncertainty. Based on UK Climate Projections 2009 (UKCP09) projections, the impacts of climate change are to significantly decrease both the stream flows and energy production during summer months but to increase flows and power production in the winter, with a net tendency to cancel out over the course of a full year. A methodology for assessing impacts of climate change on hydropower is established, which could be applied more widely to other potential hydropower sites such as lowland rivers or high base flow rivers in other parts of the UK. This will be useful for developers, water companies and environmental agencies to assess hydropower potential, economic viability and environmental impacts of micro-hydropower, under future climate change. doi: 10.2166/nh.2012.012 s://iwaponline.com/hr/article-pdf/44/3/495/370465/495.pdf D. Carless (corresponding author) Southern Hydropower, King William House, London Road, Blewbury, Oxfordshire OX11 9PD, UK E-mail: dave@southernhydropower.co.uk P. G. Whitehead School of Geography and the Environment, University of Oxford, South Parks Road, Oxford OX1 3QY, UK

EVOLUTION OF ESTUARINE FACIES IN A TIDAL CHANNEL ENVIRONMENT, SW SPAIN : EVIDENCE FOR A CHANGE FROM TIDE- TO WAVE-DOMINATION

Abstract The transition from tide- to wave-dominated environments is documented in Holocene estuaries along the mesotidal coast of Huelva, southwestern Spain. This transition is a consequence of the decreasing tidal prism caused by estuarine siltation, a process favoured by the inherited morphology of the prior fluvial valleys. The Domingo-Rubio tidal channel is a small estuary adjacent to the mouth of two wave-dominated estuaries along the coast of Huelva. Coring and vibracoring of both surficial and subsurface sediments allow the distinction of six lithofacies that form five depositional environments: (1) salt marsh; (2) active channel-margin; (3) washover-fan; (4) tidal channel; and (5) estuarine channel. The facies architecture reveals the infilling process of the tidal channel due to the interaction of both waves and tides. Wave activity is registered in the elongation of the spit, whereas tidal action produces facies associations characteristic of tide-dominated estuaries. The recent history of this estuary records three successive stages: (1) an initial tide-dominated open marine environment; beginning at 3090 ± 60 years B.P., with strong tidal currents in very energetic channels displaying a straight-meandering-straight morphology; (2) a wave-dominated period during which waves transport sand into the inner estuary and also along the mouth spit at about 2500 years B.P.; and (3) a second tide-dominated stage from 300 ± 80 years B.P. onward, during which weaker tidal currents distribute the sediment. Four factors controlled the transition from tide to wave domination: (1) the relief formed during deposition; (2) the decreasing tidal prism; (3) the inner facies distribution versus those of the outlet; and (4) the seaward spit elongation of adjacent estuaries.

Sedimentary Characteristics of the Holocene Tsunamigenic Deposits in the Coastal Systems of the Cadiz Gulf (Spain)

Juan A. Morales1, Jose M. Gutierrez Mas2, Jose Borrego1 and Antonio Rodriguez-Ramirez3 1Departamento de Geologia. Facultad de Ciencias Experimentales. Universidad de Huelva. Campus Universitario del Carmen, s/n. 21007 Huelva. 2Departamento de Ciencias de la Tierra. Facultad de Ciencias del Mar y Ambientales. Universidad de Cadiz. Campus Universitario Rio San Pedro, s/n. Puerto Real (Cadiz). 3Departamento de Geodinamica y Paleontologia. Facultad de Ciencias Experimentales. Universidad de Huelva. Campus Universitario del Carmen, s/n. 21007 Huelva. Spain

Statistical Contrast Analysis of Hydrochemical Parameters Upstream of the Tidal Influence in Two AMD-Affected Rivers

The Iberian Pyrite Belt (IPB), SW Spain, has been exploited since ancient times, and previous studies have compared different parameters in the Tinto and Odiel Rivers, the principal rivers that cross the IPB. We used classical statistics to draw contrasts between the two rivers. Samples were collected at two sites, one in the Tinto River, and the other in the Odiel, immediately upstream of tidal influence. Both rivers are strongly contaminated by acid mine drainage (AMD). However, the results suggest a distinctive, although somewhat parallel, geochemical behavior. The pattern of affinity between parameters differs because in addition to AMD, the Odiel River receives important contributions from non-contaminated catchments, while the Tinto River is the main receptor of drainage from the Rio Tinto mine. The applied statistical approach revealed that pH and electrical conductivity present a similar temporal evolution, which point to an identical geochemical signature; this indicates that both systems are similarly affected by contamination from the same pyritic area.ZusammenfassungDer Iberische Pyrit-Gürtel (Iberian Pyrite Belt, IPB) in Südwest-Spanien wird seit historischen Zeiten bergbaulich genutzt. Schon viele Untersuchungen beschäftigen sich mit Parametervergleichen zwischen den Hauptvorflutern im IBP, dem Rio Tinto und dem Rio Odiel. Wir nutzen klassische statische Methoden, um Unterschiede zwischen beiden Flusssystemen aufzuzeigen. Beide jeweiligen Untersuchungsstandorte im Rio Tinto und im Rio Odiel befanden sich oberstromig des Gezeiteneinflusses. In beiden Flüssen ist ein Einfluss vom AMD nachweisbar. Jedoch können an den Untersuchungsstandorten jeweils charakteristische und z. T. parallel verlaufende geochemische Verhältnisse erkannt werden. Die Ähnlichkeit zwischen den gemessenen Parametern differiert aufgrund des unterschiedlichen AMD-Einflusses. Während dem Rio Odiel maßgebliche Anteile aus nicht kontaminierten Einzugsgebieten zufließen, ist der Rio Tinto der Hauptvorfluter für Abflussanteile der Rio Tinto Bergwerke. Die statistische Auswertung macht deutlich, dass die pH-Werte und die elektrischen Leitfähigkeiten zeitlich ähnliche Entwicklungen aufzeigen und somit auf identische geochemische Signaturen hinweisen. Dieses zeigt, dass beide Flusssysteme durch die gleiche Pyritzone beeinflusst werden.ResumenLa faja pirítica ibérica (IPB), SO España, ha sido explotada desde tiempos remotos; estudios previos han comparado diferentes parámetros en los Ríos Tinto y Odiel que son los principales ríos que atraviesan la IPB. En este trabajo hemos usado estadística clásica para mostrar los contrastes entre los dos ríos. Las muestras fueron colectadas en dos sitios, uno en el Río Tinto y el otro en el Río Odiel inmediatamente río arriba de la zona de influencia de las mareas. Ambos ríos están fuertemente contaminados por AMD. Sin embargo, los resultados sugieren un diferente, aunque en alguna medida semejante, comportamiento geoquímico. El patrón de afinidad entre parámetros difiere porque el Río Odiel recibe importantes contribuciones desde afluentes no contaminados mientras que el Rio Tinto es el principal receptor del drenaje proveniente de la mina Río Tinto. La aproximación por estadística aplicada reveló que el pH y la conductividad eléctrica presentan una evolución temporal similar, que señala idénticas características geoquímicas; esto indica que ambos sistemas están afectados en forma similar por la contaminación proveniente de la misma área pirítica.抽象西班牙西南部的伊利比亚黄铁矿带(IPB)开采历史悠久,以往研究曾对比了横穿伊利比亚黄铁矿带(IPB)的Tinto河与Odiel河的水化学参数。本文采用传统统计学方法对比了两条河流水的水化学特征。研究分别于Yinto河与Odiel河受潮汐影响的上游取样。这两条河流都被酸性矿井水严重污染。但是,两种水样却显示出一种明显不同却有点类似的地球化学行为。由于除了AMD之外,Odiel河还接收大量未受污染流域来水,Tinto河水主要源于Rio Tinto矿井排水,两水样水化学参数之间关系明显不同。应用统计学的方法揭示,pH值和电导率呈现相似的时间演化过程,两水样具有相同的地球化学特征,表明两条河流经受着同一黄铁矿区的污染。

Hydrochemical characterization of an acid mine drainage-affected reservoir: the Sancho Reservoir, Huelva, southwest Spain

Abstract The objectives of this study were to discover the relationship between variables in a water reservoir and the hydrochemical variations related to acid mine drainage (AMD), and to describe the horizontal stratification related to vertical salinity and variations in metals present in the region. The information obtained may be used for establishing risk evaluation criteria and to design future remediation strategies, which could be useful for new dams. The hydrochemical characterization was based on a sampling campaign performed in October 2011. A total of 28 samples, at 1-m-deep intervals, were obtained. The hydrogeochemical study of the polluted reservoir shows that the dilution effect is not sufficient to neutralize AMD contributions from mining activity. Sampling carried out from the surface water to the deepest points reveals stratification of the reservoir that allows it to be included in the group of monomictic and holomitic lakes. Editor D. Koutsoyiannis; Associate editor M.D. Fidelibus Citation Cerón, J.C., Grande, J.A., de la Torre, M.L., Borrego, J., Santisteban, M., and Valente, T., 2014. Hydrochemical characterization of an acid mine drainage-affected reservoir: the Sancho Reservoir, Huelva, southwest Spain. Hydrological Sciences Journal, 59 (6), 1213–1224. http://dx.doi.org/10.1080/02626667.2013.834341

Hydrogeochemical variables regionalization – applying cluster analysis for a seasonal evolution model from an estuarine system affected by AMD

This study describes the spatial evolution of the hydrogeochemical parameters which characterise a strongly affected estuary by Acid Mine Drainage (AMD). The studied estuarine system receives AMD from the Iberian Pyrite Belt (SW Spain) and, simultaneously, is affected by the presence of an industrial chemical complex. Water sampling was performed in the year of 2008, comprising four sampling campaigns, in order to represent seasonality. The results show how the estuary can be divided into three areas of different behaviour in response to hydrogeochemical variables concentrations that define each sampling stations: on one hand, an area dominated by tidal influence; in the opposite end there is a second area including the points located in the two rivers headwaters that are not influenced by seawater; finally there is the area that can be defined as mixing zone. These areas are moved along the hydrological year due to seasonal chemical variations.

Reply to the comment on “Formation of Chenier plain of the Doñana marshland (SW Spain): Observations and geomorphic model” by A. Rodríguez-Ramírez and C.M. Yáñez-Camacho [Marine Geology 254 (2008) 187–196]

article i nfo It is paradoxical that work in question (Rodriguez-Ramirez and Yanez-Camacho, 2008) has started a debate in the scientific community about the values of the reservoir effect used in the 14