Schulz Karsten

• Prof. Dr.
• Professor at BOKU University

Study Region The study area covers Austria (83 900 km2) and neighboring regions with transboundary river basins. Study Focus Knowledge of regional groundwater recharge patterns is essential for sustainable water resource management. Currently, Austria lacks fully spatially distributed groundwater recharge maps. The study’s aim was to develop a nati...

Poor agricultural practices among small-scale sub-Saharan African farmers can lead to soil erosion and reduce agricultural productivity. However, information on such practices is normally not well documented, making it challenging to design future mitigation strategies. We conducted a fine-scale agricultural survey on 200 farm households within the...

Parameter estimation is one of the most challenging tasks in large‐scale distributed modeling, because of the high dimensionality of the parameter space. Relating model parameters to catchment/landscape characteristics reduces the number of parameters, enhances physical realism, and allows the transfer of hydrological model parameters in time and s...

Study region Sio Malaba Malakisi river basin, East Africa. Study focus Poor rain-gauge density is a limitation to comprehensive hydrological studies in Sub-Saharan Africa. Consequently, Satellite precipitation products (SPPs) provide an alternative source of data for possible use in hydrological modeling. However, there is need to test their relia...

Typical applications of process- or physically-based models aim to gain a better process understanding or provide the basis for a decision-making process. To adequately represent the physical system, models should include all essential processes. However, model errors can still occur. Other than large systematic observation errors, simplified, misr...

The multi-national catchment of the Upper Danube covers an area of more than 100,000 km² and is of great ecological and economic value. Its hydrological states (e.g., runoff conditions, snow cover states or groundwater levels) affect fresh-water supply, agriculture, hydropower, transport and many other sectors. The timely knowledge of the current s...

GFZ (German Research Centre for Geosciences) set up the Zugspitze Geodynamic Observatory Germany with a worldwide unique installation of a superconducting gravimeter at the summit of Mount Zugspitze on top of the Partnach spring catchment. This high alpine catchment is well instrumented, acts as natural lysimeter and has significant importance for...

Water temperature in rivers is a crucial environmental factor with the ability to alter hydro-ecological as well as socio-economic conditions within a catchment. The development of modelling concepts for predicting river water temperature is and will be essential for effective integrated water management and the development of adaptation strategies...

For many ungauged mountain regions, global datasets of different meteorological and land surface parameters are the only data sources available. However, their applicability in modelling high-alpine regions has been insufficiently investigated so far. Therefore, we tested a suite of globally available datasets by applying the physically based Cold...

Zusammenfassung Die Fließgewässertemperatur ist ein essenzieller Umweltfaktor, der das Potenzial hat, sowohl ökologische als auch sozio-ökonomische Rahmenbedingungen im Umfeld eines Gewässers zu verändern. Um Fließgewässertemperaturen als Grundlage für effektive Anpassungsstrategien für zukünftige Veränderungen (z. B. durch den Klimawandel) berechn...

Zusammenfassung Die Verdunstung ist ein entscheidender Prozess im globalen Wasser‑, Energie- sowie Kohlenstoffkreislauf. Daten zur räumlich-zeitlichen Dynamik der Verdunstung sind daher von großer Bedeutung für Klimamodellierungen, zur Abschätzung der Auswirkungen der Klimakrise sowie nicht zuletzt für die Landwirtschaft. In dieser Arbeit wenden wi...

Zusammenfassung Das Schätzen von räumlich verteilten Parametern hydrologischer Modelle ist ein bereits lang erforschtes und anspruchsvolles Problem. Parameter-Transferfunktionen, die einen funktionellen Zusammenhang zwischen Modellparametern und geophysikalischen Gebietseigenschaften herstellen, sind eine potenzielle Möglichkeit, Parameter ohne Kal...

Nitrous oxide (N2O) is a long-lived greenhouse gas that contributes to global warming. Emissions of N2O mainly stem from agricultural soils. This review highlights the principal factors from peer-reviewed literature affecting N2O emissions from agricultural soils, by grouping the factors into three categories: environmental, management and measurem...

Study region: Sio Malaba Malakisi river basin, East Africa. Study Focus: Poor rain-gauge density is a limitation to comprehensive hydrological studies in Sub-Saharan Africa. Consequently, Satellite precipitation products (SPPs) provide an alternative source of data for possible use in hydrological modelling. However, there is need to test their rel...

The Zugspitze Geodynamic Observatory Germany has been set up with a worldwide unique installation of a superconducting gravimeter at the summit of Mount Zugspitze. With regard to hydrology, this karstic high-alpine site is largely dominated by high precipitation amounts and a long seasonal snow cover period with significant importance for water sup...

Water temperature in rivers is a crucial environmental factor with the ability to alter hydro-ecological as well as socio-economic conditions within a catchment. The development of modelling concepts for predicting river water temperature is and will be essential for an effective integrated water management and the development of adaptation strateg...

The relationship between nitrogen and discharge (N-Q) in a stream can be captured with high frequency nitrate nitrogen (NO3−-N) samplers. In Austria, the Raab catchment (998 km2) has high frequency NO3−-N data measured with a spectrometer probe. This study evaluated if the widely-used and typically calibrated eco-hydrological model Soil and Water A...

The relationship between nitrogen and discharge (N-Q) in a stream can be captured with high frequency nitrate nitrogen (NO3−-N) samplers. In Austria, the Raab catchment (998 km2) has high frequency NO3−-N data measured with a spectrometer probe. This study evaluated if the widely-used and typically calibrated eco-hydrological model Soil and Water A...

Estimating parameters for distributed hydrological models is a challenging and long studied task. Parameter transfer functions, which define model parameters as functions of geophysical properties of a catchment, might improve the calibration procedure, increase process realism, and can enable prediction in ungauged areas. We present the function s...

The Universal Soil Loss Equation (USLE) is the most commonly used model to assess soil erosion by water. The model equation quantifies long-term average annual soil loss as a product of the rainfall erosivity R, soil erodibility K, slope length and steepness LS, soil cover C, and support measures P. A large variety of methods exist to derive these...

Worldwide, there is a strong discrepancy between the importance of high alpine catchments for the water cycle and the availability of meteorological and snow hydrological in situ measurements. Good knowledge on the timing and quantity of snow meltwater is crucial for numerous hydrological applications, also far way downstream. For several decades,...

Vegetation diversity and health is multidimensional and only partially understood due to its complexity. So far there is no single monitoring approach that can sufficiently assess and predict vegetation health and resilience. To gain a better understanding of the different remote sensing (RS) approaches that are available, this chapter reviews the...

High mountain ranges are characterised by steep slopes and high precipitation rates, making Alpine catchments prone to frequent flood events. Fast runoff during heavy rainfall events, sometimes in combination with snow melt events, can cause severe damages in residential areas. Flood retention mainly depends on retention properties of the headwater...

Many approaches for modelling river water temperature are available, but not one exist that can be applied without restrictions. The applied method depends on data availability, dominant processes, scales and transferability. Process-based models are currently the best way to evaluate detailed management scenarios on reach scale and to understand u...

To find the adequate spatial model discretization scheme, which balances the models capabilities and the demand for representing key features in reality, is a challenging task. It becomes even more challenging in high alpine catchments, where the variability of topography and meteorology over short distances strongly influences the distribution of...

The original version of this book was inadvertently published with an incorrect affiliation.

The “dual probe heat pulse” (DPHP) method using actively heated fiber optic (AHFO) cables combined with distributed temperate sensing (DTS) technology has been developed for monitoring thermal properties and soil water content at the field scale. Field scale application, however, requires the use of robust and thicker fiber optic cables, corroborat...

Abstract. The large number of spatially distributed earth observation products, i.e. time series of surface emissions and reflectances at different wavelengths with increasing spatial resolution, contribute to the derivation of surface characteristics, e.g. vegetation or soil parameters in the environmental sciences. These derivatives usually build...

Abstract. The Universal Soil Loss Equation (USLE) is the most commonly used model to assess soil erosion by water. The model equation quantifies long-term average annual soil loss as a product of the rainfall erosivity R , soil erodibility K , slope length and steepness LS , soil cover C and support measures P . A large variety of methods exist to...

In the face of rapid global change it is imperative to preserve geodiversity for the overall conservation of biodiversity. Geodiversity is important for understanding complex biogeochemical and physical processes and is directly and indirectly linked to biodiversity on all scales of ecosystem organization. Despite the great importance of geodiversi...

Die Folgen des Klimawandels für die Gesundheit sind bereits heute spürbar und als zunehmende Bedrohung für die Gesundheit in Österreich einzustufen. Die stärksten Gesundheitsfolgen mit breiter Wirkung sind durch Hitze zu erwarten. Veränderungen in Ökosystemen begünstigen zudem das Auftreten von Pollenallergien und durch Vektoren übertragene Infekti...

Die Folgen des Klimawandels für die Gesundheit sind bereits heute spürbar und als zunehmende Bedrohung für die Gesundheit in Österreich einzustufen. Die stärksten Gesundheitsfolgen mit breiter Wirkung sind durch Hitze zu erwarten. Veränderungen in Ökosystemen begünstigen zudem das Auftreten von Pollenallergien und durch Vektoren übertragene Infekti...

Environmental modeling studies aim to infer the impacts on environmental variables that are caused by natural and human-induced changes in environmental systems. Changes in environmental systems are typically implemented as discrete scenarios in environmental models to simulate environmental variables under changing conditions. The scenario develop...

The main objective of this study was to calibrate and validate the eco-hydrological model Soil and Water Assessment Tool (SWAT) with satellite-based actual evapotranspiration (AET) data from the Global Land Evaporation Amsterdam Model (GLEAM_v3.0a) and from the Moderate Resolution Imaging Spectroradiometer Global Evaporation (MOD16) for the Ogun Ri...

While modeling approaches of evapotranspiration (λE) perform reasonably well when evaluated at daily or monthly timescales, they can show systematic deviations at the sub-daily timescale, which results in potential biases in modeled λE to global climate change. Here we decompose the diurnal variation of heat fluxes and meteorological variables into...

The effects of climate change on health are already being felt today and can be classified as an increasing threat to health in Austria. The most severe and far- reaching effects to be expected are health impacts due to heat. Also changes in ecosystems which influence the distribution, frequency, types and severity of pollen allergies and vector-bo...

The Chinese Tian Shan (also known as the Chinese Tianshan Mountains, CTM) have a complex ecological environmental system. They not only have a large number of desert oases but also support many glaciers. The arid climate and the shortage of water resources are the important factors restricting the area's socioeconomic development. This study presen...

Rainfall–runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data-driven models. In this paper, we propose a novel data-driven approach, using the Long Short-Term Memory (LSTM) network, a special type of recurrent neural network. The advantage of t...

This is the pre-print of the Austrian Assessment Report on health, demography and climate change (ASR18) - summary for decision makers and synthesis; language German. English version is in preparation.

Environmental modeling studies aim to infer the impacts on environmental variables that are caused by natural and human-induced changes in environmental systems. Changes in environmental systems are typically implemented as discrete scenarios in environmental models to simulate environmental variables under changing conditions. The scenario develop...

Der Hochgebirgsraum ist traditionell ein Raum mit wenigen bis keinen Messstationen. Vorortmessungen sind nur in ausgesuchten Gebieten oder nur punktuell verfügbar. Aus diesem Grund werden Landoberflächenmodelle, regionale Klimamodelle und Fernerkundungsdaten eingesetzt, um die benötigte Information zur erzeugen. Wie diese Daten im Gebirgsraum tatsä...

The diurnal forcing of solar radiation is the largest signal within the Earth system and dominates the diurnal cycle of the turbulent heat fluxes and evapotranspiration (λE) over land. Incoming solar radiation (Rsd) also shapes temperature, vapor pressure deficit and wind speed known as important controls on λE. Current process-based λE schemes use...

Ein großer Anteil der Durchflusspegel in Österreich weist eine anthropogene Beeinflussung durch Speicherbewirtschaftung oder künstliche Überleitungen auf. Die gemessenen Zeitreihen sind nur eingeschränkt zur Erstellung und Kalibrierung von hydrologischen Niederschlags-Abfluss-Modellen verwendbar, da diese Modelle üblicherweise ungestörte natürliche...

The article Hydrological modelling in the anthroposphere: predicting local runoff in a heavily modified high-alpine catchment, written by Johannes WESEMANN, Mathew HERRNEGGER and Karsten SCHULZ, was mistakenly originally published without open access. After publication in volume 15, issue 5, page 921-938 this was corrected and the article was made...

Rainfall-runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data driven models. In this paper, we propose a novel data driven approach, using the Long-Short-Term-Memory (LSTM) network, a special type of recurrent neural networks. The advantage of...

Spatially distributed high-resolution data of land surface temperature (LST) and evapotranspiration (ET) are important information for crop water management and other applications in the agricultural sector. While satellite data can provide LST high-resolution data of 100 m, the current development of unmanned aerial systems (UAS) and affordable lo...

Knowledge of current snow cover extent is essential for characterizing energy and moisture fluxes at the Earth's surface. The snow-covered area (SCA) is often estimated by using optical satellite information in combination with the normalized-difference snow index (NDSI). The NDSI thereby uses a threshold for the definition if a satellite pixel is...

The unit hydrograph (UH) has been one of the most widely employed hydrological modelling techniques to predict rainfall–runoff behaviour of hydrological catchments, and is still used to this day. Its concept is based on the idea that a unit of effective precipitation per time unit (e.g. mm h-1) will always lead to a specific catchment response in r...

Hydrological models within inflow forecasting systems for high-alpine hydropower reservoirs can provide valuable information as part of a decision support system for the improvement of hydropower production or flood retention. The information, especially concerning runoff, is however rarely available for the calibration of the hydrological models u...

Rainfall-runoff modelling is one of the key challenges in the field of hydrology. Various approaches exist, ranging from physically based over conceptual to fully data driven models. In this paper, we propose a novel data driven approach, using the Long-Short-Term-Memory (LSTM) network, a special type of recurrent neural networks. The advantage of...

The main objective of this study was to calibrate and validate the eco-hydrological model Soil and Water Assessment Tool (SWAT) with satellite based actual evapotranspiration (AET) data (Global Land Evaporation Amsterdam Model (GLEAM_v3.0a) and Moderate Resolution Imaging Spectroradiometer Global Evaporation (MOD16) for the Ogun River Basin (20 292...

Hydrologists are still faced with challenges of accessing and obtaining measured stream flow data in many tropical catchments. The general lack and scarcity of up to date stream flow information has made water resources management challenging and difficult in most of the river basins located in Nigeria, even in catchment areas that are of high stra...

The parameter uncertainty in the eco-hydrological model Soil and Water Assessment Tool (SWAT) was estimated using non-unique parameter sets for the Altmühl watershed (Bavaria, Germany). The Sequential Uncertainty Fitting Algorithm (SUFI-2) was used to calibrate SWAT. The non-unique parameter sets found were subsequently applied to SWAT concurrently...

The effects of climate change on health are already being felt today and can be classified as an increasing threat to health in Austria. The most severe and far- reaching effects to be expected are health impacts due to heat. Also changes in ecosystems which influence the distribution, frequency, types and severity of pollen allergies and vector-bo...

Current concepts for parameter regionalization of spatially distributed rainfall-runoff models rely on the a priori definition of transfer functions that globally map land surface characteristics (such as soil texture, land use, and digital elevation) into the model parameter space. However, these transfer functions are often chosen ad hoc or deriv...

The parameter uncertainty in the eco-hydrological model Soil and Water Assessment Tool (SWAT) was estimated using non-unique parameter sets for the Altmühl watershed (Bavaria, Germany). The Sequential Uncertainty Fitting Algorithm (SUFI-2) was used to calibrate SWAT. The non-unique parameter sets found were subsequently applied to SWAT concurrently...

Knowledge about the current snow cover extent is essential for characterising energy and moisture fluxes at the earth surface. The snow-covered area (SCA) is often estimated by using optical satellite information in combination with the normalized-difference snow index (NDSI). The NDSI thereby uses a threshold for the definition if a satellite pixe...

The unit-hydrograph (UH) has been one of the most widely employed hydrological modelling techniques to predict rainfall-runoff behavior of hydrological catchments, and is still used up-to-date. Its concept is based on the idea that a unit of effective precipitation per time unit (e.g. mm h⁻¹) will always lead to a specific catchment response in run...

Sensitivity analysis, uncertainty assessment and model calibration/validation are essential steps in the modeling work flow with any hydrological model application. For the Soil and Water Assessment Tool (SWAT, Arnold et al., 1998), SWAT-CUP has been established as the standard software for calibration and sensitivity analysis of SWAT projects. Alt...

The possibilities of applying the Soil and Water Assessment Tool (SWAT, Arnold et al., 1998) to environmental questions are diverse. Consequently, SWAT is a widely accepted modeling tool to examine interdisciplinary questions at the watershed scale. However, the models’ flexibility in its application comes with a high demand of input data. For inst...

Integrative models, such as the Soil and Water Assessment Tool (SWAT; Arnold et al., 1998), are useful to assess the impacts of system changes (e.g. climate change or land use change) on water balance components, nutrient loads and other environmentally relevant variables. To draw well informed conclusions from the model outputs, a profound knowled...

Over the past decades that the Soil and Water Assessment Tool (SWAT, Arnold et al., 1998) is in use, the SWAT community has been developing tools that allow the set-up (e.g. ArcSWAT, or QSWAT), execution, or calibration/validation (e.g. SWATCUP) of SWAT projects to be facilitated and accessible as well as user-friendly. Although, these tools provid...

Vegetation is often represented by the leaf area index (LAI) in many ecological, hydrological and meteorological land surface models. However, the spatio-temporal dynamics of the vegetation are important to represent in these models. While the widely applied methods, such as the Canopy Structure Dynamic Model (CSDM) and the Double Logistic Model (D...

The cost effective maintenance of underwater pressure pipes for sewage disposal in Austria requires the detection and localization of leakages. Extrusion of wastewater in lakes can heavily influence the water and bathing quality of surrounding waters. The Distributed Temperature Sensing (DTS) technology is a widely used technique for oil and gas pi...

In order to minimise the negative impacts in forested (karst) areas of combined forestry operations and water resource use, a sustainable management is needed. Forest roads, their construction and logging activities can have various effects on streams and the groundwater. These are presented and analysed in this literature review which encompasses...

In this study, high-resolution thermal imagery acquired with a small unmanned aerial vehicle (UAV) is used to map evapotranspiration (ET) at a grassland site in Luxembourg. The land surface temperature (LST) information from the thermal imagery is the key input to a one-source and two-source energy balance model. While the one-source model treats t...

In order to minimise the negative impacts in forested (karst) areas of combined forestry operations and water resource use, a sustainable management is needed. Forest roads, their construction and logging activities can have various effects on streams and the groundwater. These are presented and analysed in this literature review which encompasses...

Flood risk management is founded on the regular assessment of damage potential. A significant parameter for assessing damage potential is the number of at-risk objects. However, data sets on exposure are often incomplete and/or lack time-references. Airborne remote sensing data, such as orthophotos, offers a regularly-updated, time-referenced de...

Impacts of human civilization on ecosystems threaten global biodiversity. In a changing environment, traditional in situ approaches to biodiversity monitoring have made significant steps forward to quantify and evaluate BD at many scales but still, these methods are limited to comparatively small areas. Earth observation (EO) techniques may provide...

The near surface air temperature is the primary indicator for climate change. Reanalysis as the surrogates for large-scale observations are widely used in the Tibetan Plateau because of the sparse meteorological network. However, an average bias of −3.54 °C and root-mean-square error (RMSE) of 4.31 °C were found between ERA-Interim monthly 2-m temp...

Snow cover dynamics in alpine regions play a crucial role in view of the water balance of head water catchments. The temporal storage of water in form of snow and ice leads to a decoupling of precipitation and runoff. Changes in the volume and the temporal dynamics of the snow storage lead to modified runoff regimes and can influence the frequency...

For understanding water and solute transport processes, knowledge about the respective hydraulic properties is necessary. Commonly, hydraulic parameters are estimated via pedo-transfer functions using soil texture data to avoid cost-intensive measurements of hydraulic parameters in the laboratory. Therefore, current soil texture information is only...

For understanding water and solute transport processes knowledge about the respective hydraulic properties is necessary. Commonly, hydraulic parameters are estimated via pedo-transfer functions using soil texture data to avoid cost intensive measurements of hydraulic parameters in the laboratory. Therefore, current soil texture information is only...

The evaluation of model performance is a central part of (hydrological) modelling. Much attention has been given to the development of evaluation criteria and diagnostic frameworks. (Klemeš, 1986; Gupta et al., 2008; among many others). Nevertheless, many applications exist for which objective functions do not yet provide satisfying summaries. Thus...

This contribution presents a framework, which enables the use of an Evolutionary Algorithm (EA) for the calibration and regionalization of the hydrological model COSEROreg. COSEROreg uses an updated version of the HBV-type model COSERO (Kling et al. 2014) for the modelling of hydrological processes and is embedded in a parameter regionalization sch...

For many interdisciplinary questions at the watershed scale, the Soil and Water Assessment Tool (SWAT; Arnold et al., 1998) has become an accepted and widely used tool. Despite its flexibility, the model is highly demanding when it comes to input data. At SWAT’s core the water balance and the modeled nutrient cycles are plant growth driven (impleme...

Conceptual rainfall-runoff models, in which runoff processes are modelled with a series of connected linear and non-linear reservoirs, remain widely applied tools in science and practice. Additionally, the concept is appreciated in teaching due to its somewhat simplicity in explaining and exploring hydrological processes of catchments. However, whe...