Claus Kohfahl

• Dr. habil
• Senior Researcher at Instituto Geológico y Minero de España

Acreman et al. (Wetlands 42:63, 2022) reviewed evidence for ecological damage to the Doñana wetlands (UNESCO World Heritage Site [WHS] and Ramsar site), Spain, associated with intensification of groundwater use, particularly for agriculture. Acreman et al. presented a multistep methodology for evidence-based risk assessment that involves identifica...

Estimation of natural recharge in aquifers is crucial for evaluating its water balance. However, long-term time series data are needed for climatic representativeness. Recently, some weighable lysimeters have been installed in the Doñana National Park, from which direct recharge data have been obtained for two periods: from October 2015 to Septembe...

Acreman et al. (2022) reviewed evidence for ecological damage to the Doñana wetlands (UNESCO World Heritage Site [WHS] and Ramsar site), Spain, associated with intensification of groundwater use, particularly for agriculture. Acreman et al. presented a multistep methodology for evidence-based risk assessment that involves identification of conserva...

Trace elements are serious pollutants in the natural environment and are of increasing concern due to the adverse effects at global scale. To refine the current understanding of trace metal distribution and variability in natural environments, concentrations of dissolved trace metals (Ag, Al, As, B, Ba, Be, Co, Cr, Cd, Cu, Fe, Hg, Mo, Ni, Pb, Sb, S...

The knowledge of soil moisture spatio-temporal variability is highly relevant for water resources management. This is especially significant in highly demanding areas of arid and semiarid regions where a sensitive ecosystem, agriculture and recreational areas can converge. This study reports an analysis of the spatial-temporal variability of soil m...

The δ²H and δ¹⁸O composition of 77 precipitation samples collected between January 2014 and April 2019 from two sites across the Guadalquivir Basin, SW Spain, were analyzed. The first site is located in an urban area of Seville at 100 km distance to the Atlantic coast and the second site is located in a dune area of the Doñana National Park a few k...

Resumen Para estimar y pronosticar los efectos de cambios meteorológicos en los recursos hídricos se requiere un entendimiento preciso del balance hídrico del suelo compuesto básicamente por precipitación, recarga hídrica, evapotranspiración y escorrentía. En los últimos años los lisímetros de pesaje de precisión han demostrado su gran capacidad pa...

The δ2H and δ18O composition of 77 precipitation samples collected between January 2014 and April 2019 from two sites across the Guadalquivir Basin, SW Spain, were analyzed. Sampling was performed within intervals of at least 14 days basis if rain occurred but frequently intervals were longer according to the rainfall incidence. Precipitation weigh...

The study presents daily values of inward and outward vapor flux crossing the soil-atmosphere boundary in dependence on meteorological parameters and soil moisture. Measurements of vapor flux, soil moisture and meteorological parameters were evaluated during days without rainfall between 2015 and 2019. Vapor flux data were obtained at 1 min interva...

Precipitation measurements are performed mostly by simple automatic rain gauges installed at a certain level above the ground surface, but these methods are often affected by significant measurement errors due to the deformation of the wind field above the rain gauge orifice. In recent years precision lysimeters have emerged, providing an efficient...

Daily temperature oscillations can cause adsorption (and desorption) of atmospheric water vapor by soils. The resulting daily fluctuations in the amount of liquid water in the soil can be measured by high‐precision weighing lysimeters. We analyzed the data of a lysimeter in a sandy dune sediment in southern Spain using Codebright, a thermohydraulic...

This chapter presents the monitoring and research of groundwater resources and natural recharge in the Doñana Natural Area. The subchapter "Monitoring networks for Groundwater Resources and Recent Management Issues of the Doñana" deals with the history and current state of the official monitoring networks for piezometry and hydrochemistry. In the s...

This chapter presents the monitoring and research of groundwater resources and natural recharge in the Doñana Natural Area. The subchapter “Monitoring networks for Groundwater Resources and Recent Management Issues of the Doñana” deals with the history and current state of the official monitoring networks for piezometry and hydrochemistry. In the s...

There is an increasing need for accurate groundwater-level (GWL) prediction to support effective seasonal water management. It is desirable for forecasting tools to be not only accurate but also accessible for decision-makers. We test the Prophet forecasting procedure, an open-source code released by Facebook, to address these challenges. It is bas...

A tailing impoundment situated in the mining district of La Carolina (Spain), which stores waste resulting from the washing of Pb and Ag sulphides, was studied 30 years after it was abandoned. Fibre optic sensors were installed to record humidity, temperature, electrical conductivity and oxygen content in the pores down to a depth of 35.5 m. The ox...

Dune belts are crucial for the recharge of coastal aquifers. In spite of their hydrological relevance for the maintenance of precious natural wetland and wildlife environments and a range of other ecosystem services, only limited knowledge of soil water dynamics in dune belts is currently available. This study presents soil water balance components...

Although precise weighing lysimeters are mostly installed for agricultural purposes in crop-producing areas, these instruments are also useful in areas of ecological interest where soil and aquifer recharge-discharge processes need to be better understood. In September 2015 a high precision meteo-lysimeter was installed in a coastal dune of the Doñ...

The Geological and Mining Institute of Spain (IGME) has initiated a project of continuous measurement of natural recharge in the Doñana National Park, in which a high precision meteo-lysimeter, was installed. The main objective of the study is to quantify the recharge in dune belts, and to estimate its dependence on regional climate trends. The lys...

The use of non-conventional water (e.g., treated wastewater, desalinated water) for different purposes is increasing in many water scarce regions of the world. Its use for irrigation may have potential drawbacks, because of mineral dissolution/precipitation processes, such as changes in soil physical and hydraulic properties (e.g., porosity, permea...

In the southern part of the Duero Basin (Spain), naturally occurring arsenic and uranium in groundwater sometimes occur in concentrations exceeding the limits for potable water. Usually, concentrations of these elements are only slightly above the limit, but this is sufficient to invalidate its use as drinking water.

Las aguas subterráneas y la planificación hidrológica. Congreso hispano-luso. AIH-GE. Madrid, noviembre 2016. RESUMEN El contexto geológico condiciona en gran medida la presencia de determinados Elementos Traza Geogénicos Potencialmente Tóxicos (ETGPTs) en las aguas subterráneas. El sur de la Cuenca del Duero es un área semiárida, la calidad del ag...

Groundwater from shallow aquifers and surface water from rivers of the southern part of Poopó Lake basin within the Bolivian Altiplano have significant quality problems such as, high salinity and high concentrations of arsenic (As). The extent of As contamination is observed in the studied groundwater over large parts of the study area. Surface-wat...

Geochemical and geophysical techniques have been applied to investigate the potential environmental impact of the abandoned La Aquisgrana mine tailings, one of the most important sulfide-bearing tailings ponds of the Linares-La Carolina mining district (Spain). The geometry of the pile has been defined through geological field work and electrical r...

Numerical modeling approaches with varying complexity were explored to investigate coupled groundwater flow and geochemical processes in saline basins. Long-term model simulations of a playa system gain insights into the complex feedback mechanisms between density-driven flow and the spatiotemporal patterns of precipitating evaporites and evolving...

Abstract Oxygen measurements of soil air were carried out to determine daily variations and seasonality of oxygen in soil air and their dependence on ambient parameters such as groundwater chemistry, hydrodynamics and physicochemical sediment characteristics. Two field sites in the Doñana National Park were equipped with fibre-optic oxygen- and tem...

Drinking water quality and the presence of natural arsenic (As) were studied in a rural, less developed area of the southern part of the Poopó lake basin in the Central Bolivian Altiplano. People in this area use untreated surface- and ground-water directly as drinking water. Water is extracted from excavated wells and from few rivers occasionally...

This article reports on a field modelling study to investigate the processes controlling the plume evolution of para-toluenesulfonamide (p-TSA) in anoxic groundwater in Berlin, Germany. The organic contaminant p-TSA originates from the industrial production process of plasticisers, pesticides, antiseptics and drugs and is of general environmental c...

The drinking water production of a drinking water treatment plant in Berlin is partly affected by contaminated groundwater as a result of former sewage farm irrigation in its catchment area, operating for almost 70 years until the 1980s. The industrial organic contaminant p-TSA (para-toluenesulfonamide) was encountered in the contamination plume wi...

The groundwater downstream of a former sewage irrigation farm in Berlin is contaminated with ammonium (NH 4 ?) and para-toluenesulfonamide (p-TSA), besides other anthropogenic pollutants. In the field, in situ removal of NH 4 ? by gaseous oxygen (O 2) and air injection is currently being tested. A laboratory column experiment using aquifer material...

This study reports column tests and modelling results to assess the impact of hardpans and cemented layers on oxygen supply in mine waste sediments. The analysed sediment samples were obtained from a low-sulphide and low-carbonate polymetallic mine waste tailings impoundment located in the Freiberg mining district in Germany. The three samples were...

Editorial handling by I. Cartwright a b s t r a c t This research aims to improve the current knowledge of groundwater salinisation processes in coastal aquifers using combined hydrochemical and isotopic parameters and inverse hydrochemical modelling. Field investigations were conducted in Laizhou Bay, which is the area most seriously affected by s...

Environmental isotope techniques, hydrogeochemical analysis and hydraulic data are employed to identify the main recharge areas of the Mt. Vulture hydrogeological basin, one of the most important aquifers of southern Italy. The groundwaters are derived from seepage of rainwater, flowing from the highest to the lowest elevations through the shallow...

This article reports fibre-optic oxygen measurements on a reactive mine waste heap located in the polymetallic sulphide mine district of Freiberg in south-eastern Germany. The heaped material consists of sulphide-bearing tailings from a processing plant of a lead-zinc mine. Mine waste material was deposited in the water phase after separation of mi...

This article explores double-diffusive convective fluid motion in an aquifer above a salt dome. Aside from the ambient regional flow regime, the hydraulic conditions in an aquifer connected with a salt formation are determined by differences in salinity. Whereas density-driven flow patterns induced by the effect of salt have been studied before we...

A finite element model was set up to determine degradation rate constants for p-TSA during rapid sand filtration (RSF). Data used for the model originated from a column experiment carried out in the filter hall of a drinking water treatment plant in Berlin (Germany). Model results were fitted to measured profiles and breakthrough curves of p-TSA f...

We characterize the precipitation and groundwater in a mountainous (peaks slightly above 3000 m a.s.l.), semi-arid river basin in SE Spain in terms of the isotopes 18O and 2H. This basin, with an extension of about 7000 km2, is an ideal site for such a study because fronts from the Atlantic and the Mediterranean converge here. Much of the land is f...

This study reports the impact of hydrological conditions on salinisation and nitrate concentrations of a coastal aquifer located at the Mediterranean Sea, southern Spain. Eighty-two samples of ground- and surface water taken during two extreme hydrological events between 1994 and 1996 at 25 different wells were evaluated with regard to hydrochemist...

A finite element model was set-up to determine degradation rate constants for p-TSA during rapid sand filtration (RSF). Data used for the model originated from a column experiment carried out in the filter hall of a drinking water treatment plant in Berlin (Germany). Aerated abstracted groundwater was passed through a 1.6m long column-shaped experi...

For teaching groundwater flow and transport we currently apply COMSOL Multiphysics software. We have two main goals. At first, to familiarise course participants with the basic concepts and phenomena of the subject. Second, to enable students to handle a modelling tool in general. We describe the fundamentals and give examples of exercises that inc...

The objective of this study was to investigate the impact of flow, transport and geochemical parameters in the unsaturated and saturated zones on the release of SO4 from overburden lignite spoil piles into the adjacent lake. A vertical one-dimensional model was set up using the reactive transport simulator SULFIDOX in order to account for the unsat...

The microbial degradation of pharmaceuticals found in surface water used for artificial recharge is strongly dependent on redox conditions of the subsurface. Furthermore the durability of production wells may decrease considerably with the presence of oxygen and ferrous iron due to the precipitation of trivalent iron oxides and subsequent clogging....

The objective of this study is to refine the understanding of recharge processes in watersheds representative for karstic semiarid areas by means of stable isotope analysis and hydrogeochemistry. The study focuses on the Granada aquifer sys-tem which is located in an intramontane basin bounded by high mountain ranges providing elevation differences...

This research reports the characterisation of ground-and surface-water inter-action in the Fuente de Piedra Salt lake basin in southern Spain by a combined approach using hydraulic, hydrogeochemical and stable isotope data. During three sampling cam-paigns (February 2004, 2005 and October 2005) ground-and surface-water samples were collected for st...

The objective of this study is the prediction of contaminant loads related to acid mine drainage from overburden spoil piles at open-pit lignite mines. An assessment of future sulphate discharge released from the unsaturated zone as a result of pyrite weathering was performed, based on measurements of soil-gas, pore water and sediment chemistry ove...

A u t h o r ' s p e r s o n a l c o p y Effective diffusion and microbiologic activity as constraints describing pyrite oxidation in abandoned lignite mines Abstract This paper reports detailed O 2 measurements of pyrite bearing sediments in a column study and their interpretation based on a hydrogeochemical modelling approach. The research focuses...

This paper reports the hydrogeochemical modelling of reactions that take place during the uptake of weathering products by a rising watertable into a partly oxidized pyrite bearing sediment. The anoxic material used for the column, which is 2 m long, was taken from a core while drilling into a pyrite bearing sediment with an average pyrite content...

The generation of acid drainage from overburden spoil piles at open-pit lignite mines impacts water quality in large parts of the Lusatian mining area in Germany. The Lohsa Mine was exploited until the early 1990s and is to be flooded by 2005. It will then be used as a reservoir basin for the river Spree. Future acidity and sulphate concentrations...

During and after the process of artificial recharge by flooding of former pit mines, oscillations of the water level, caused by seasonal effects or management strategies, are often inevitable. In the study area LOHSA in the new eastern federal states of Germany, the annual water oscillations due to management strategies are predicted to range betwe...

During and after the process of artificial recharge through the flooding of the lignite mine, Lohsa II, in Germany, annual oscillations of the surface water caused by seasonal effects and management strategies are predicted to range between 5 m and 8 m. These oscillations imply oxygen input by means of fresh water and air, which causes pyrite oxida...