Publications de Bernhard Wehrli

Fast Potentiometric CO2 Sensor for High-Resolution in Situ Measurements in Fresh Water Systems

We present a new potentiometric sensor principle and a calibration protocol for in situ profiling of dissolved CO2 with high temporal and spatial resolution in fresh water lakes. The sensor system is based on the measurement of EMF between two solid-contac ...

AMER CHEMICAL SOC2018

Developing an open-source database for the Zambezi river basin

Bernhard Wehrli, Anton Schleiss, José Pedro Gamito de Saldanha Calado Matos

The Zambezi river basin, one of the largest in Africa, holds significant hydropower potential, which has yet tobe exploited. To make the most of this opportunity and address the challenges it poses, local Stakeholders must coordinate efforts, politically, ...

2015

Optimizing turbine withdrawal from a tropical reservoir for improved water quality in downstream wetlands

Bernhard Wehrli, Alfred Johny Wüest

Large reservoirs in the tropics act as efficient nutrient traps and often develop hypoxic conditions in the hypolimnion. Both effects may have severe implications for aquatic ecosystems, such as limited primary production in downstream riparian agriculture ...

American Geophysical Union2013

Moving Targets, Long-Lived Infrastructure, and Increasing Needs for Integration and Adaptation in Water Management: An Illustration from Switzerland

Bernhard Wehrli, Armin Julius Peter, Clare Robinson, Janet Gordon Hering, Kristin Schirmer

2012

Impact of a large tropical reservoir on riverine transport of sediment, carbon, and nutrients to downstream wetlands

Bernhard Wehrli, Alfred Johny Wüest

Large dams can have major ecological and biogeochemical impacts on downstream ecosystems such as wetlands and riparian habitats. We examined sediment removal and carbon (C), nitrogen (N), and phosphorus (P) cycling in Itezhi-Tezhi Reservoir (ITT; area = 36 ...

Amer Geophysical Union2011

Sediment accumulation and carbon, nitrogen, and phosphorus deposition in the large tropical reservoir Lake Kariba (Zambia/Zimbabwe)

Bernhard Wehrli, Alfred Johny Wüest

Large dams affect the aquatic continuum from land to ocean by accumulating particles and nutrients in their reservoirs. We examined sediment cores to quantify sediment, organic carbon (OC), nitrogen (N), and phosphorous (P) accumulation, and to examine his ...

Amer Geophysical Union2011

Spatial Heterogeneity of Methane Ebullition in a Large Tropical Reservoir

Bernhard Wehrli, Alfred Johny Wüest

Tropical reservoirs have been identified as important methane (CH4) sources to the atmosphere, primarily through turbine and downstream degassing. However, the importance of ebullition (gas bubbling) remains unclear. We hypothesized that ebullition is a di ...

Amer Chemical Soc2011

Physical and biogeochemical limits to internal nutrient loading of meromictic Lake Kivu

Bernhard Wehrli, Natacha Tofield-Pasche, Alfred Johny Wüest, Beat Mueller, Martin Schmid

Lake Kivu is one of the large African Rift lakes situated between the Democratic Republic of the Congo and Rwanda. In its permanently stratified hypolimnion, unusually high methane concentrations have increased further in recent decades. Because methanogen ...

American Society of Limnology and Oceanography2009

Intermittent oxygen flux from the interior into the bottom boundary of lakes as observed by eddy correlation

Bernhard Wehrli, Alfred Johny Wüest

Turbulent oxygen transport from the overlying stratified water column into the bottom boundary layer (BBL) on the slope of a medium-sized lake was investigated using the eddy correlation (EC) technique. The seicheinduced oscillatory flow of the BBL, with a ...

American Society of Limnology and Oceanography2008

Microsensor for in situ flow measurements in benthic boundary layers at submillimeter resolution with extremely slow flow

Bernhard Wehrli, Alfred Johny Wüest

The currents in the lowest few millimeters of the bottom boundary layer of lakes are highly important for the dissipation of kinetic energy and for chemical processes such as oxygen transfer into the sediment. So far, no high-resolution flow velocity profi ...

Association for the Sciences of Limnology and Oceanography (ASLO)2007

Influence of temperature and high acetate concentrations on methanogenensis in lake sediment slurries

Bernhard Wehrli, Christof Holliger

Methanogenesis from main methane precursors H2/CO2 and acetate was investigated in a temperature range of 2–70 °C using sediments from Lake Baldegg, Switzerland. Psychrophilic, psychrotrophic, mesophilic, and thermophilic methanogenic microbial communities ...

Blackwell Publishing Ltd, Oxford2007

Internal carbon and nutrient cycling in Lake Baikal: sedimentation, upwelling, and early diagenesis

Bernhard Wehrli, Alfred Johny Wüest

The internal cycles of carbon, silica, nitrogen, and phosphorus in the South and North Basins of Lake Baikal were quantified in the frame of a multidisciplinary collaboration. Fluxes of particulate organic matter from the epilimnion to the deep water were ...

Elsevier2005