Christophe Hissler

Luxembourg Institute of Science and Technology (LIST) | LIST · Catchment and Ecohydrology research group - ERIN department

Soil water content (SWC) is a fundamental variable involved in several hydrological processes governing catchment functioning. Comparative analysis of hydrological processes in different catchments based on SWC data is therefore beneficial to infer driving factors of catchment response. Here, we explored the use of high‐temporal resolution SWC data...

The exposome complements information captured in the genome by covering all external influences and internal (biological) responses of a human being from conception onwards. Such a paradigm goes beyond a single scientific discipline and instead requires a truly interdisciplinary approach. The concept of “historical exposomics” could help bridge the...

Isotopic signatures of xylem water in different tree compartments such as roots, boles and branches, differ due to physiological and physical processes occurring inside trees. Accordingly, we hypothesised that the extent of such differences among the isotopic signatures of tree compartments is coherent with the distance travelled by the water insid...

Accurate particle size distribution (PSD) measurements of suspended particulate matter composed of flocs and aggregates are important to improve understanding of ecological and geomorphological processes, and for environmental engineering applications. PSD can be measured in situ (in the field) using a submersible sensor, or ex situ (in the laborat...

New technologies significantly disturb the natural riverine cycle of some Rare Earth Elements and Yttrium (REY). Whereas large evidence exists on the anthropogenic impact on REY dissolved and colloidal loads in rivers, there is still a knowledge gap on how suspended load could be impacted. As the river suspended matter is a key driver for the quant...

Optical turbidity sensors have become standard instrumentation to estimate suspended particulate matter concentration (SPMC). However, turbidity readings respond to factors other than SPMC, such as particle size and shape, organic fraction, sediment density and color. Therefore, local and site dependent calibrations are needed to transfer turbidity...

It was time to take stock. We modified the humipedon classification key published in 2018 to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English; we also translated it into French and Italian. A standardized morpho-functional classification of humipedons (roughly the top 30–40...

Given the diverse physico-chemical properties of elements, we hypothesize that their incoherent distribution across the leaf tissues, combined with the distinct resistance to degradation that each tissue exhibits, leads to different turnover rates among elements. Moreover, litter layers of varying ages produce diverse chemical signatures in solutio...

It was time to take stock. We modified the humipedons classification key published in 2018, to make it easier and more practical. This morpho-functional taxonomy of the topsoil (humipedon) was only available in English: we also translated it into French and Italian. A standardized morpho-functional classification of humipedon (roughly the top 30-40...

Real time monitoring of suspended sediment (SS) carbon content and particle size information is essential to understand SS transport mechanisms and processes. However, limited in situ methods are available, and manual and unattended sampling makes high frequency observation challenging. Based on evidence that optical measurements of SS concentratio...

Given the diverse physico-chemical properties of elements, we hypothesize that their incoherent distribution across the leaf tissues, combined with the distinct resistance to degradation that each tissue exhibits, leads to distinct turnover rates between elements. Moreover, litter layers of different ages produce diverse chemical signatures in solu...

Since the ‘60s, stable isotopes of hydrogen and oxygen have proven to be excellent tracers for water flows in different ecosystems. Nowadays, such tracers still represent a formidable resource for eco-hydrologists who study water spatio-temporal dynamics and transit time distributions in the Critical Zone. Unfortunately, many issues remain unsolved...

F-specific RNA bacteriophages (FRNAPHs) are commonly used as indicators of faecal and viral contamination in waters. Once they enter surface waters, the exact role of suspended solids, sediments and hydro-meteorological factors in their fluvial fate and transport is poorly understood, and long-term studies (e.g., over years) are lacking. In this st...

Within the critical zone, regolith plays a key role in the fundamental hydrological functions of water collection, storage, mixing and release. Electrical resistivity tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based inve...

The Weierbach experimental catchment (0.45 km²) is the most instrumented and studied sub‐catchment in the Alzette River basin in Luxembourg. Within the last decade, it has matured towards an interdisciplinary critical zone observatory focusing on a better understanding of hydrological and hydro‐geochemical processes. The Weierbach catchment is embe...

The recycling of biogas residues resulting from the anaerobic digestion of organic waste on agricultural land is among the means to reduce chemical fertilizer use and combat climate change. This in sacco decomposition study investigates (1) the potential of the granulated biogas residue fraction to provide nutrients and enhance soil carbon sequestr...

The main land use/land cover changes (LULCC) have been associated with population growth and energy policiesin the São Paulo State, Brazil, since 1970. The LULCC can alter the behavior of trace elements in different environ-mental systems, with the riverbed sediments being the main reservoirs or sinks for trace elements, and thus be-come a valuable...

Within the Critical Zone, regolith plays a key role in the fundamental hydrological functions of water collection, storage, mixing and release. Electrical Resistivity Tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based inve...

Chemical weathering and soil erosion in large or small watersheds are used to understand the effect of evolution processes on the Earth's surface and climate. Currently, human-driven land use changes have substantial effects on landscape changes over a range of temporal and spatial scales. In this context, the Sorocaba River basin, São Paulo State,...

Hydromorphodynamic models are powerful tools for predicting the potential mobilization and transport of sediment in river ecosystems. Recent studies have shown that they are able to predict suspended sediment matter concentration in small river systems satisfactorily. However, hydro-sedimentary modelling exercises often neglect suspended sediment p...

Our knowledge about the role of trees in the elements mobilization and recycling still needs improvements. In the poster presented at the Goldschmidt 2019 I showed some interesting results about the role that litter has in the elements sequestration and how its degradation could affect soil solutions chemistry.

Conversion of waste biomass to resource, through the environmentally sound multipurpose process of anaerobic digestion, allows the sustainable organic waste management, bioenergy and biofertilizer production, and therefore facilitates the transition to circular economy and mitigation of environmental pollution. The goal of this study was to assess...

Models must effectively represent velocities and celerities if they are to address the old‐water paradox. Celerity information is recorded indirectly in hydrograph observations, while velocity information is more difficult to measure and simulate effectively, requiring additional assumptions and parameters. Velocity information can be obtained from...

To provide sufficient quantities of food and feed, farming systems have to overcome limiting factors such as the nutrient depletion of arable soils. Nitrogen being the main mineral element required for plant growth, has led to the extensive use of chemical fertilizers causing nitrogen pollution of the ecosystems. This field study investigates the u...

Within the Critical Zone, regolith plays a key role in the fundamental hydrological function of water collection, storage, mixing and release. Electrical Resistivity Tomography (ERT) is recognized as a remarkable tool for characterizing the geometry and properties of the regolith, overcoming limitations inherent to conventional borehole-based inves...

Hydromorphodynamic models are powerful tools to predict the potential mobilization and transport of sediment in river ecosystems. Recent studies even showed that they are able to satisfyingly predict suspended sediment matter concentration in small river systems. However, modelling exercises often neglect suspended sediment properties (e.g. particl...

Purpose/Objectives. The occurrence and propagation of faecal-derived viruses in streams constitute a major public health issue. However, little in situ information is currently available on the transport and dynamic of viruses in water, including the role of each stream compartment (water column, suspended solid particle and riverbed sediment). Vir...

Many studies focusing on suspended sediment transport modelling in river systems only consider one class of sediment grain size. Rather recently, the SISYPHE sediment transport model has integrated sand-mud mixture transport processes using two classes of sediment. However, this new modelling framework still suffers from limitations, and increasing...

A flood event of the Orne River (Meurthe et Moselle, France) has been simulated using a 3D hydrodynamic model (TELEMAC) coupled with a sediment transport model (SISYPHE). SISYPHE has been further developed in order to integrate ten sediment grain sizes with mixed sediments,varying sediment densities with grain size and multiple inflow suspended sed...

For more than two decades, research groups in hydrology, ecology, soil science, and biogeochemistry have performed cryogenic water extractions (CWEs) for the analysis of δ²H and δ¹⁸O of soil water. Recent studies have shown that extraction conditions (time, temperature, and vacuum) along with physicochemical soil properties may affect extracted soi...

Regolith architecture and properties are key to streamflow generation. An accurate assessment of the geometry and properties of the main compartments of the regolith is of major relevance in hydrological studies. Factors such as the composition of the soil cover, the soil depth, and the weathering state and features of the subsoil, determine water...

For more than two decades, research groups in hydrology, ecology, soil science and biogeochemistry have performed cryogenic water extractions for the analysis of δ²H and δ¹⁸O of soil water. Recent studies have shown that extraction conditions (time, temperature, and vacuum) along with physicochemical soil properties may affect extracted soil water...

The soil pattern of the Lias cuesta landscape in central Luxembourg is strongly related to lithology, land cover and land use. On a short distance, many of the major soil types of the temperate zone can be found, as the substrates show a clear distinction and gradient from acidic to more neutral conditions in both fine and coarser textured material...

The Attert River basin in Luxembourg is characterised by a large variety of clean and mixed physiogeographical settings (i.e. topography, soil types, land use, bedrock geology, etc.). This in turn generates manifold configurations of rainfall-runoff transformation processes. Here, we provide experimental data from more than a decade of hydro-meteor...

Subsurface flow is often recognized as a dominant runoff generation process. However, observing subsurface properties, and understanding how they control flow pathways, remains challenging. This paper investigates how surface slope and bedrock cleavage control subsurface flow pathways in a slate bedrock headwater catchment in Luxembourg, characteri...

The bedrock controls on catchment mixing, storage, and release have been actively studied in recent years. However, it has been difficult to find neighboring catchments with sufficiently different and clean expressions of geology to do comparative analysis. Here, we present new data for 16 nested catchments (0.45 to 410 km2) in the Alzette River ba...

https://authors.elsevier.com/a/1U0hq1Dk5A9hZe Regoliths encompass different materials from the fresh bedrock to the top of the organic horizons. The occurrence and evolution of these materials are determined by deposition, erosion and weathering processes that are specific for each region. The origin and interaction of the regolith layers are stil...

The relationship between tracer velocities and wave or wetting front celerities is essential to understand water flowing from hillslopes to the stream. The connection between maximum velocity and celerities estimated by means of experimental techniques has not been explored. To assess the pattern of infiltrating water front and dominant flow direct...

Double peak hydrographs are widespread phenomena but poorly understood mechanistically. In many cases, saturation-excess overland flow in the near-stream areas is assumed to control the initial peak, while the delayed peak is explained by subsurface flow in the soil or sediment cover or groundwater flow on fractured bedrock. Here we explore the mec...

While being of highest relevance in catchment studies, subsurface regolith observations remain severely measurement limited. There is a pressing need for detailed information on the structure, properties and weathering states of the soil to bedrock continu um. Groundwater plays a key role in the fundamental hydrological functions of catchments, i.e...

Approximately 40% of the volume of domestic sewage generated in the São Paulo State is untreated and released into water bodies, causing serious pollution problems that affect the water quality and especially the suspended sediments transported by rivers. Thus, this paper investigates the seasonal influence on the origin and fluxes of Cu, Co, Cr, Z...

A double peak hydrograph features two peaks as a response to a unique rainfall pulse. The first peak occurs at the same time or shortly after the precipitation has started and it corresponds to a fast catchment response to precipitation. The delayed peak normally starts during the recession of the first peak, when the precipitation has already ceas...

In order to precisely quantify the contribution of anthropogenic activities and geogenic sources to the dissolved and suspended loads of rivers we have combined for the first time Rare Earth Element (REE) concentrations with Sr-Nd-Pb isotope ratios. We observed enrichments in Anthropogenic Rare Earth Elements (AREE) for dissolved (Gd) and suspended...

It is well known that sediment properties, including sediment-associated chemical constituents and sediment physical properties, can exhibit significant variations within and between storm runoff events. However, the number of samples included in suspended sediment studies is often limited by time consuming and expensive laboratory procedures after...

A reliable understanding of catchment hydrology requires an accurate knowledge of the structure and composition of underlying soil and bedrock. Factors such as the depth and composition of the soil cover, and the weathering and features of the bedrock, all determine the pathways of infiltrating rainfall, the residence times of water in the subsurfa...

Diatoms are unicellular eukaryotic algae that are widely distributed in aquatic environments. In particular, their presence is abundant in stream flows, whereas the instance and transport of cells through subsurface flow is controversial. In this work, we study the transport of diatoms through soils by designing laboratory percolation experiments o...

Double peak hydrographs (also known as bimodal events) are a catchment's delayed response to precipitation. " Double peaks " have been reported in a dozen or so experimental catchments around the world, including the well-studied Slapton Wood catchment in UK and the Ina watersheds in Japan. Catchments showing double peak behaviour have varied in si...

As all rare earth elements (REEs) have an increasingly important role in high tech industries, they are now recognized as emergent pollutants in river systems impacted by anthropogenic activity. Over the past 20 years, significant anthropogenic contributions were reported for Gd, La and Sm, and we may expect that REE contamination in rivers is to f...

Carbonate weathering mantles, like terra fusca, are common in Europe but their formation and evolution is still badly understood. We propose to combine geological, mineralogical and pedological knowledge with trace element and isotope data of a weathering mantle as a novel approach to understand the evolution of terra fuscas. Sr-Nd-Pb isotopes and...

Weathering mantles are widespread and include lateritic, sandy and kaolinite-rich saprolites and residuals of partially dissolved rocks. These old regolith systems have a complex history of formation and may present a polycyclic evolution due to successive geological and pedogenetic processes that affected the profile. Until now, only few studies h...

Enrichments in Gd and LREE/HREE fractionation have been observed for the dissolved and colloidal fractions in waters of the Alzette River during low flow conditions. They can be related to the effluents of the waste water treatment plants (Gd/Gd*: 8-380 and LaN/YbN: 0.02-0.07). Mean daily flux balance calculations at the basin scale show that durin...

The synthesis of experimental understanding of catchment behaviour and its translation into qualitative perceptual models is an important objective of hydrological sciences. We explore this challenge by examining the cumulative understanding of the hydrology of three experimental catchments and how it evolves through the application of different in...

The Weierbach catchment is characterized by a unique geological substratum of schist and phyllites. The winter streamflow response to a rainfall show two distinct peaks with markedly different time scales (Van den Bos et al., 2006b), whereas the summer response present only the first one. The hydrograph show that the first peak is near concomitant...

The Luxembourg sandstone, a dual-porosity reservoir, hosts the most important groundwater resource of the country. Understanding its hydrogeological functioning is considered as of highest priority. In large parts of the country, the Luxembourg sandstone aquifer, notched by deep valleys and thus perched on its impervious base, supply around 400 spr...

The Luxembourg sandstone, a dual-porosity reservoir, hosts the most important groundwater resource of the country. Understanding its hydrogeological functioning is considered as of highest priority. In large parts of the country, the Luxembourg sandstone aquifer, notched by deep valleys and thus perched on its impervious base, supply around 400 spr...

Fine sediments represent an important vector of pollutant diffusion in rivers. When deposited in floodplains and riverbeds, they can be responsible for soil pollution. In this context, this paper proposes a modelling exercise aimed at predicting transport and diffusion of fine sediments and dissolved pollutants. The model is based upon the Telemac...