Lutz Breuer

Lutz Breuer
Justus-Liebig-Universität Gießen | JLU

PhD, Professor

About

373
Publications
88,137
Reads
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7,917
Citations

Publications

Publications (373)
Article
Full-text available
Accurate quantification of landscape soil greenhouse gas (GHG) exchange from chamber measurements is challenging due to the high spatial-temporal variability of fluxes, which results in large uncertainties in upscaled regional and global flux estimates. We quantified landscape-scale (6 km2 in central Germany) soil/ecosystem respiration (SR/ER-CO2),...
Article
Full-text available
For the designation of nitrate vulnerable zones under the EU Nitrate Directive, some German federal states use inverse distance weighting (IDW) as interpolation method. Our study quantifies the accuracy of IDW with respect to the designation of areas with a groundwater nitrate concentration above the threshold of 50 mg NO 3 /l using a dataset of 57...
Article
An adequate strategy for water quality improvement must \nsider a range of political, economic, social, technological, environmental, and legal (PESTEL) concepts. Nature-based solutions have emerged as promising tools to improve water quality while considering these factors. In this context, fuzzy cognitive maps and the PESTEL approach have been me...
Article
Climate change scenarios predict an increased occurrence of droughts and heatwaves, as well as extreme rainfall events in Central Europe. Alley cropping, which is the inclusion of rows of trees and shrubs in agricultural land, could enhance the resilience of cropping systems, as these systems are expected to positively modify the microclimate and w...
Article
Full-text available
We focus on how different global temperature increases represented in IPCC reports have shifted over time. While the first four assessment reports had a roughly equal focus on temperatures above and below 2°C, the more recent fifth and sixth assessment reports have a considerably stronger focus on warming below 2°C. This is concerning as warming ab...
Article
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Schistosomiasis affects over 700 million people globally. 90% of the infected live in sub-Saharan Africa, where the trematode species Schistosoma mansoni and S. haematobium transmitted by intermediate hosts (IH) of the gastropod genera Biomphalaria and Bulinus are the major cause of the human disease burden. Understanding the factors influencing th...
Article
Although global- and catchment-scale hydrological models are often shown to accurately simulate long-term runoff time-series, far less is known about their suitability for capturing hydrological extremes, such as droughts. Here we evaluated simulations of hydrological droughts from nine catchment scale hydrological models (CHMs) and eight global sc...
Presentation
Die Grundwassernitratbelastung ist seit Jahrzehnten ein bekanntes Problem, doch die Diskussion über Ursachen und Lösungsansätze wird noch immer sehr kontrovers geführt. Zur Wiederherstellung und Erhalt des guten Zustands der Wassersysteme in Europa, wurde die EU-Wasserrahmenrichtlinie implementiert, die unter anderem eine Reduzierung der Nitrateint...
Article
However, knowledge about multiple-stressors effects on urbanised Andean streams is lacking. In southern Ecuador, we assessed how multiple stressors determine the structural (aquatic invertebrate metrics) and functional (organic matter breakdown and delta N of primary consumers) attributes of streams in a densely populated watershed without wastewat...
Article
In simplest terms, agroforestry involves growing trees on farms for a range of socio-economic and ecological benefits. Agroforestry as a land management technique has been practiced for thousands of years. As climate change and environmental impacts of agricultural intensification have become increasingly evident in recent years, agroforestry has g...
Article
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Pakistan’s agriculture is characterized by insecure water supply and poor irrigation practices. We investigate the economic and environmental feasibility of alternative improved irrigation technologies (IIT) by estimating the site-specific irrigation costs, groundwater anomalies, and CO2 emissions. IIT consider different energy sources including so...
Article
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Climate change, increasing environmental pollution, continuous loss of biodiversity, and a growing human population with increasing food demand, threaten the functioning of agro-ecosystems and their contribution to people and society. Agroforestry systems promise a number of benefits to enhance nature's contributions to people. There are a wide ran...
Article
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The intensification of food production systems has resulted in landscape simplification, with trees and hedges disappearing from agricultural land, principally in industrialized countries. However, more recently, the potential of agroforestry systems and small woody landscape features (SWFs), e.g., hedgerows, woodlots, and scattered groups of trees...
Article
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Recent advances in laser spectroscopy has made it feasible to measure stable isotopes of water in high temporal resolution (i.e., sub-daily). High-resolution data allow the identification of fine-scale, short-term transport and mixing processes that are not detectable at coarser resolutions. Despite such advantages, operational routine and long-ter...
Poster
Full-text available
We compare the probability of different warming rates to their mentions in IPCC reports through text mining. We find that there is a substantial mismatch between likely warming rates and research coverage. 1.5 °C and 2 °C scenarios are substantially overrepresented. More likely higher end warming scenarios of 3 °C and above, despite potential catas...
Article
Full-text available
Emissions of reactive nitrogen (N r ) give rise to a wide range of environmental problems. Nitrogen budgets for various systems and on different scales are an established tool to quantify the sources and fate of N r . The national nitrogen budget (NNB) for Germany calculates the nitrogen flows for eight pools: Atmosphere, Energy and Fuels, Material...
Article
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Detecting the impacts of forest cover changes on hydrology is challenging given uncertainties in how changes will manifest in observed streamflow. Considering changes in the rate of change of observed streamflow (e.g., recession characteristics) may offer insights to hydrological shifts driven by forest cover change that are not seen when consideri...
Article
Full-text available
We compare the probability of different warming rates to their mentions in IPCC reports through text mining. We find that there is a substantial mismatch between likely warming rates and research coverage. 1.5 and 2°C scenarios are substantially overrepresented. More likely higher end warming scenarios of 3°C and above, despite potential catastroph...
Article
Full-text available
Reactive nitrogen (Nr) that is released to the environment has several negative implications for the atmosphere, hydrosphere, biodiversity and human health. A nitrogen (N) footprint is a measure that can help to assess and communicate the impact of personal lifestyle and consumption choices regarding their influences on Nr losses. The N-Calculator...
Article
Full-text available
Catchments are complex systems, which require regular monitoring of hydro-chemical parameters in space and time to provide comprehensive datasets. These are needed to characterize catchment behavior on a local level, make future projections based on models, implement mitigation measures and meet policy targets. However, many developing countries la...
Article
Full-text available
Estimating the maximum event water fraction, at which the event water contribution to streamflow reaches its peak value during a precipitation event, gives insight into runoff generation mechanisms and hydrological response characteristics of a catchment. Stable isotopes of water are ideal tracers for accurate estimation of maximum event water frac...
Article
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As demand for regional and organically produced foodstuff has increased in Europe, the need has arisen to verify the products’ origin and production method. For food authenticity tracking (production method and origin), we examined 286 samples of wheat (Triticum aestivum), potatoes (Solanum tuberosum), and apples (Malus domestica) from different re...
Preprint
Full-text available
Although global- and catchment-scale hydrological models are often shown to accurately simulate long-term runoff time-series, far less is known about their suitability for capturing hydrological extremes, such as droughts. Here we evaluated runoff simulations from nine catchment scale hydrological models (CHMs) and eight global scale hydrological m...
Article
Full-text available
Agricultural catchments in the tropics often generate high concentrations of suspended sediments following the conversion of natural ecosystems. The eroded fine particles are generally enriched with carbon (TC) and nutrients (TN and TP) originating from the topsoil of agricultural land. Sediment-associated TC, TN and TP are an important loss to the...
Article
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Tropical mountain ecosystems are threatened by climate and land-use changes. Their diversity and complexity make projections how they respond to environmental changes challenging. A suitable way are trait-based approaches, by distinguishing between response traits that determine the resistance of species to environmental changes and effect traits t...
Article
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Environmental models aim to reproduce landscape processes with mathematical equations. Observations are used for validation. The performance and uncertainties are quantified either by single or multi-criteria model assessment. In a case-study, we combine both approaches. We use a coupled hydro-biogeochemistry landscape-scale model to simulate 14 ta...
Article
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Hydrological theory often assumes an exponential relationship between storage and discharge, but how often do we find such a behavior in real catchments? We analyze catchment attributes, discharge and weather conditions from 1992 to 2018 for 88 catchments in Hesse, Germany. All catchments have similar weather conditions, but a wide range of catchme...
Article
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The understanding of water quality and its underlying processes is important for the protection of aquatic environments. With the rare opportunity of access to a domain expert, an explainable AI (XAI) framework is proposed that is applicable to multivariate time series. The XAI provides explanations that are interpretable by domain experts. In thre...
Article
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Citizen science is gaining popularity as a way to engage people to participate in environmental projects. In addition to potential challenges regarding data quality and the choice of variables, a key factor in the success of participatory monitoring projects is the active participation of volunteers, the "citizen scientists." To learn more about th...
Article
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The anthropogenic nitrogen cycle is characterized by a high complexity. Different reactive nitrogen species (NH3, NH4+, NO, NO2, NO3−, and N2O) are set free by a large variety of anthropogenic activities and cause numerous negative impacts on the environment. The complex nature of the nitrogen cycle hampers public awareness of the nitrogen problem....
Article
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Ecohydrological processes in tropical rainforests are insufficiently understood and existing studies yield contradictory results. We investigated relative contributions of different soil depths to tree water uptake of 83 trees and possible species‐specific differences in a 50x50 m forest plot at four dates in a tropical montane forest in Kenya usin...
Technical Report
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Under the new NEC Directive (EU) 2016/2284, Germany commits itself to reducing national emissions of NH3 by 5 % and 29 %, respectively in 2020 and 2030, with a linear reduction path between 2020 and 2030 compared to 2005. This report describes and assesses measures and scenarios for reducing NH3 emissions in agriculture and quantifies their effects...
Article
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Accurate determination of the water retention curve (WRC) of a soil is essential for the understanding and modelling of the subsurface hydrological, ecological, and biogeochemical processes. Volcanic ash soils with andic properties (Andosols) are recognized as important providers of ecological and hydrological services in mountainous regions worldw...
Preprint
Full-text available
Catchments in the tropics often generate high concentrations of suspended sediments following the conversion of forests to agriculture. The eroded fine particles are generally enriched with carbon and nutrients originating from the topsoil. Sediment associated carbon and nutrients are an important loss to the terrestrial ecosystem and tightly conne...
Preprint
The understanding of water quality and its underlying processes is important for the protection of aquatic environments enabling the rare opportunity of access to a domain expert. Hence, an explainable AI (XAI) framework is proposed that is applicable to multivariate time series resulting in explanations that are interpretable by a domain expert. T...
Article
Full-text available
Soil water stable isotopes are widely used across disciplines (e.g., hydrology, ecology, soil science, and biogeochemistry). However, the full potential of stables isotopes as a tool for characterizing the origin, flow path, transport processes and residence times of water in different eco‐, hydro‐, and geological compartments has not yet been expl...
Article
Full-text available
Land use change is known to affect suspended sediment fluxes in headwater catchments. There is however limited empirical evidence of the magnitude of these effects for montane catchments in East Africa. We collected a unique 4-year high-frequency data set and assessed seasonal sediment variation, water pathways, and sediment response to hydrology i...
Article
Full-text available
In many parts of Africa, soil erosion is an important problem, which is evident from high sediment yields in tropical montane streams. Previous studies in Kenya pointed to a large contribution from catchments cultivated by smallholder farmers. This led to the hypothesis that unpaved tracks and gullies are the main sediment sources in smallholder ag...
Article
Full-text available
Nitrate pollution in groundwater and its mitigation strategies is currently a topic of controversial debate in Germany, and the demand for harmonised approaches for the implementation of regulations is increasing. Important factors that need to be considered when planning mitigation measures are the nitrogen inputs into water bodies and the natural...
Article
Full-text available
Drought is a complex phenomenon whose characterization is best achieved from a multivariate perspective. It is well known that it can generate adverse consequences in society. In this regard, drought duration, severity, and their interrelationship play a critical role. In a climate change scenario, drought characterization and the assessment of the...
Article
Full-text available
Background Nitrogen (N) as a key input for crop production has adverse effects on the environment through emissions of reactive nitrogen. Less than 20% of the fertiliser nitrogen applied to agricultural land is actually consumed by humans in meat. Given this situation, nitrogen budgets have been introduced to quantify potential losses into the envi...
Article
Full-text available
Reliable information on water flow dynamics and water losses via irrigation on irrigated agricultural fields is important to improve water management strategies. We investigated the effect of season (wet season and dry season), irrigation management (flooded and non-flooded), and crop diversification (wet rice, dry rice, and maize) on soil water fl...
Article
Full-text available
Reliable information on water flow dynamics and water losses via irrigation on irrigated agricultural fields is important to improve water management strategies. We investigated the effect of season (wet season and dry season), irrigation management (flooded and non-flooded), and crop diversification (wet rice, dry rice, and maize) on soil water fl...
Article
Full-text available
The protection of water resources and development of mitigation strategies require large-scale information on water pollution such as nitrate. Machine learning techniques like random forest (RF) have proven their worth for estimating groundwater quality based on spatial environmental predictors. We investigate the potential of RF and quantile rando...
Article
Full-text available
Agriculture of Pakistan relies on the Indus basin, which is facing severe water scarcity conditions. Poor irrigation practices and lack of policy reforms are major threats for water and food security of the country. In this research, alternative water-saving strategies are evaluated through a high spatio-temporal water footprint (WF) assessment (19...
Preprint
Full-text available
Abstract. The understanding of water quality and its underlying processes is important for the protection of aquatic environments. Here an explainable AI (XAI) based multivariate time series analytical framework is applied on high-frequency water quality measurements including nitrate and electrical conductivity and twelve other environmental param...
Poster
Full-text available
The EFSA Guidance Document on Aquatic Risk Assessment (EFSA, 2013) indicates a key role for effect modelling in future aquatic risk characterization in a tiered risk assessment framework. Such approaches require correspondingly adapted exposure tools and scenarios ranging from simple edge-of-field to spatio-temporally explicit landscape-scale catch...
Presentation
Full-text available
This is (the introduction for) the presentation for EGU Online 2020, where we present the results of an experiment in which we tested the validity of diurnal variations in nitrate and dissolved organic carbon concentrations measured with in situ UV-Vis spectrophotometers. Find the full interactive presentation here: https://t1p.de/EGU2020-12537.
Presentation
Full-text available
Presentation for the EGU Online 2020. You can find the matching paper here: https://www.researchgate.net/publication/349027613_Simple_Catchments_and_Where_to_Find_Them_The_Storage-Discharge_Relationship_as_a_Proxy_for_Catchment_Complexity
Article
We compiled information on 26 numerical models, which consider the terrestrial phosphorus (P) cycle and compared them regarding process description, model structure and applicability to different ecosystems and scales. We address the differences in their hydrological components and between their soil P routines, the implementation of a preferential...