Claus Kohfahl

Claus Kohfahl

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 August 2019 in Hydrological Sciences Journal
Verified
Journal Article
Closed access
HAHector Aguilera
Hector Aguilera
CACarolina Guardiola Albert
Carolina Guardiola Albert
NNNURIA NARANJO-FERNÁNDEZ
NURIA NARANJO-FERNÁNDEZ
CKClaus Kohfahl
Claus Kohfahl
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 based on an additive model considering non-periodic changes and periodic components in a Bayesian framework with easily-interpretable parameters. Predictions of daily GWL data in an area affected by pumping near a tourist complex in the Ramsar wetland area of Doñana (Spain) are compared to other forecasting methods. Prophet outperforms most methods in predicting GWL making it a fast and flexible forecasting tool for hydrologists and water managers. Furthermore, it allows gaining insight into the influence of each component of the forecast separately, helping to assess the hydrodynamic response to external drivers such as groundwater pumping.

1 March 2019 in Science of The Total Environment
Verified
Journal Article
Open access
CKClaus Kohfahl
Claus Kohfahl
LMLidia Molano-Leno
Lidia Molano-Leno
GGGonzalo Martinez Garcia
Gonzalo Martinez Garcia
KVKarl Vanderlinden
Karl Vanderlinden
CACarolina Guardiola Albert
Carolina Guardiola Albert
LMLuis Moreno
Luis Moreno
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 measured during one hydrological year using a high precision meteo-lysimeter with lower boundary control installed in a coastal dune belt under a dry subhumid climate in southern Spain close to the Atlantic Ocean. The site is equipped with a cylindrical lysimeter of 1 m2 surface and 1.50 m height (METER Group, Inc. USA) and a weighing resolution of 10 g, 2 SC650 soil moisture sensors (Campbell Scientific, Logan, UT) and 1 automatic meteorological station. The lower boundary condition at the bottom of the lysimeter is controlled at 1.4 m depth by a bidirectional peristaltic pump to maintain field conditions. Results show a recharge rate of 64% of the precipitation measured by the lysimeter. Diurnal oscillations of the measured upper boundary flow during days without rainfall represented vapor adsorption and real evaporation rates ranging between 0.3 and 0.4 mm/day and 0.4 and 0.6 mm/day, respectively throughout the whole year summing up an annual vapor adsorption of 77 mm. The measured precipitation of the lysimeter exceeded pluviometer data by 13% as a result of vapor adsorption. The presented results provide a precise balance of soil water components in a coastal dune belt including the relevant contribution of vapor flow.

1 November 2010 in Science of The Total Environment
Verified
Journal Article
Closed access
CKClaus Kohfahl
Claus Kohfahl
TGTorsten Graupner
Torsten Graupner
CFChristian Fetzer
Christian Fetzer
APAsaf Pekdeger
Asaf Pekdeger

1 June 2017 in Chemosphere
Verified
Journal Article
Open access
VMVirtudes Martínez-Hernández
Virtudes Martínez-Hernández
RMRaffaella Meffe
Raffaella Meffe
CKClaus Kohfahl
Claus Kohfahl
IBIrene De Bustamante
Irene De Bustamante
The growing consumption of pharmaceuticals together with their incomplete removal in wastewater treatment plants (WWTPs) implies the occurrence of these compounds in natural water resources. To investigate the natural attenuation of selected pharmaceuticals (caffeine, acetaminophen, sulfamethoxazole, naproxen and carbamazepine) during vadose zone infiltration, unsaturated column (L 26.67 cm, Ø 7.62 cm) experiments, filled with a sandy-loamy soil, were performed using two input concentrations (100 and 1000 μg L-1). The software Hydrus 1D was used to simulate experimental data. Caffeine and acetaminophen were never detected at the column outlet indicating a low environmental concern. On the other hand, attenuation of the detected pharmaceuticals could be reproduced by a combination of retardation and removal approaches. Carbamazepine is among the selected contaminants the most persistent. A dependence of removal rates on input concentrations was detected for sulfamethoxazole (μw from 2.78 d-1 to 1.16 d-1) and naproxen (μw from 1.16 d-1 to 0.63 d-1) attributed mainly to decreased metabolism of microorganisms when a higher input concentration is applied. Two transformation products (TPs) (N4-Acetylsulfamethoxazole and epoxycarbamazepine) derived from sulfamethoxazole and carbamazepine transformation, respectively, were detected during the experiment with the highest input concentration.

1 September 2021 in Science of The Total Environment
Verified
Journal Article
Closed access
CKClaus Kohfahl
Claus Kohfahl
MSMaarten W. Saaltink
Maarten W. Saaltink
FBFernando Ruiz Bermudo
Fernando Ruiz Bermudo

1 December 2020 in Journal of Hydrology
Verified
Journal Article
Closed access
CKClaus Kohfahl
Claus Kohfahl
MSMaarten W. Saaltink
Maarten W. Saaltink