Reinhard Hinkelmann

• Head of Department at Technische Universität Berlin

This paper aims to quantify potential changes in extreme precipitation under climate change scenarios in the city of Berlin, Germany, and their resulting impacts on urban flooding in a selected flood-prone area of the city. Furthermore, it investigates the effectiveness of the existing drainage system, infiltration from unsealed surfaces, and reten...

When a solid inclined surface is submerged in a quiescent stratified fluid, the combined effects of buoyancy forces and diffusion generate an upward gravity flow along the slope. Thermally stratified ice-covered lakes remain in a nearly quiescent state and are potentially prone to this effect. We use three-dimensional hydrodynamic modeling to inves...

Unsustainable land use practices degrade ecosystems, reduce biodiversity and hinder ecosystem services. The detection of unnoticed changes in our surroundings especially for their effects on natural habitats is key to conserve the bounties of nature. The current study is focused on assessing the temporal changes in land use and the resultant landsc...

This study explores the computational fluid dynamics (CFD) simulation of oxygen (O2) and hydrogen sulfide (H2S) mass transfer in a highly turbulent stirring tank. Using the open-source software OpenFOAM, we extended three-dimensional two-phase flow solvers with a rotating mesh feature to model the mass transfer processes between the water and air p...

Machine learning offers a powerful and versatile approach to flood susceptibility mapping, enabling us to leverage complex data and improve prediction accuracy. Given the plethora of available techniques and the challenges in selecting the optimal approach, this study investigates prominent ML algorithms for flood susceptibility mapping (FSM) in th...

The design of a hydrodynamic modelling tool called hms++ is detailed, with an emphasis on addressing key concerns for research software. These are identified as high performance on heterogeneous hardware, flexibility and extensibility of the model, ease of use for non-developers, and low maintenance requirements. By employing the linear algebra lib...

Flooding poses a significant threat as a prevalent natural disaster. To mitigate its impact, identifying flood-prone areas through susceptibility mapping is essential for effective flood risk management. This study conducted flood susceptibility mapping (FSM) in Chandrapur district, Maharashtra, India, using geographic information system (GIS)-base...

Study region: A reach of the Nile River located between Naga Hammadi barrage and Asyut barrage , Egypt Study focus: An accurate representation of hydrodynamics of an important water source helps cope with expected future climate changes, pollution incidents and water quality problems. Here, a comparison between HEC-RAS 1D and TELEMAC-2D model was c...

Urban flooding can differ significantly from rural flooding due to the influence of rapidly changing land use and rainfall patterns on runoff in urban areas. Consequently, understanding and managing urban flooding necessitate a comprehensive grasp of these influential factors. This study focuses on assessing the impact of land use and rainfall chan...

The extraction of the most dynamically important coherent flow structures using reduced order models (ROM) is a challenging task in various fluid dynamics applications. In particular, for high-speed round jet flows, the axisymmetric pressure mode of interest is known to be responsible for sound radiation at small angles to the jet axis and dominant...

Accumulations of woody debris, tree trunks and branches, so-called porous log jams (PLJ), can create heterogeneous pressure distributions along the stream bed that drive surface water in and out of the stream bed. This section of the porous river sediment is called the hyporheic zone (HZ) and is a biogeochemically active zone that plays a significa...

We created a C++ template library named "Kokkidio" that achieves near-ideal performance portability across the tested hardware (4 GPUs, 4 CPUs, all major vendors). It is built on Kokkos and Eigen, to combine the former's GPU performance with the latter's elegant, expressive syntax and CPU optimisations. The code is open-source (GPLv3) and available...

A static flood analysis (SFA) toolset is implemented with the purpose of performing simplified, event-based flood inundation modeling. The simulation process is divided into two steps: a topographic sink analysis of the terrain followed by flow accumulation (FA) of runoff volumes. Both procedures are coupled to account for sink storage effects. The...

The interaction between surface water and porewater across the sediment surface is a key determinant of the hyporheic zone's ability to support a healthy river ecosystem. At the hyporheic zone scale, advective pumping is a predominant factor influencing interfacial flux and is often induced by surface water flow around large roughness elements. In...

Long-term records of combined stream flow and water chemistry can be an invaluable source of information on changes in the quantity and quality of water resources. To understand the effect of hydroclimate and water management on the heavily urbanized Panke catchment in Berlin, Germany, an extensive search, collation and digitization of historic dat...

An open-source high-performance program for the numerical simulation of surface water flow (hms++) is introduced. It contains a robust, explicit MUSCL solver for the shallow water equations (SWE). hms++ provides a user- and HPC-friendly interface as well as a plugin mechanism for runtime extensibility. It is used in several research projects pertai...

The Hydroinformatics Modeling System (HMS) was used to simulate rainfall-runoff experiments to investigate the impact of different slopes and rainfall intensities for traditional and low-impact development (LID) surface conditions. HMS solves the depth-averaged 2D shallow water equations with robust numerical methods. Most importantly, depth-depend...

The combined effect of gravity and viscosity forces produces a flow along any inclined solid lateral wall in a density-stratified fluid. The flow becomes an important driver of circulation in ice-covered lakes isolated from wind forcing. We present numerical results from the Regional Ocean Modeling System (ROMS) investigating three-dimensional buoy...

Improving water management depends on adequately understanding the water use practices, their functioning and their impacts, e.g. increase in soil salinity and water quality. Drainage water reuse has been practised since the seventies in Egypt. However, the sustainability of the water reuse practice has been threatened by the negative impacts of re...

Eutrophication problem in El Gouna shallow artificial coastal lagoons in Egypt was investigated using 2D TELEMAC-EUTRO-WAQTEL module. Eight reactive components were presented, among them dissolved oxygen (DO), phosphorus, nitrogen, and phytoplankton biomass (PHY). The effect of warmer surface water on the eutrophication problem was investigated. Al...

An integral approach which can simultaneously model turbulent flow and transport at the sediment‐water interface has been recently developed and validated for homogeneous sediment which was achieved by comparing numerical results to flume experiments on flow and transport over a rippled streambed and through the sediment for neutral, gaining and lo...

Dissolved oxygen (DO) is one of the most significant environmental indicators of water quality. Preservation of reasonable DO concentrations is essential for a healthy aquatic life. In this research, numerical simulations of DO concentrations were discussed using TELEMAC-WAQTEL-O2 model. Firstly, the model was verified by comparing its results to a...

A reliable sediment transport capacity function provides response against challenges of soil erosion prediction on the Loess Plateau of China. The popular sediment transport capacity functions are questionable on loess slopes because the experimental conditions from which they were derived, like bed materials, gentle slopes, and surface roughness,...

Although both are crucial parts of the hydrological cycle, groundwater and surface water had traditionally been addressed separately. In recent decades, considering them as a single hydrological continuum in light of their continuous interaction has become well established in the scientific community through the development of numerous measurement...

Flash flood simulations help to assess and communicate risks, study structural mitigation measures, and develop effective and risk-based early warning systems. In rural catchments infiltration can significantly reduce the surface runoff and flood risk, depending on soil types and initial saturation, land use/land cover, and rainfall as well as floo...

In this paper, an automated calibration tool for shallow water models (ActSwm) was developed utilizing the open-source Python library SciPy. The developed tool links the hms model for rainfall-runoff simulations to global optimization algorithms as a single executable. Three fast global optimization algorithms (Differential Evolution, Dual Annealin...

__TL;DR:___________________________________________________________________________ Comparison of implementation variants for a 2D FVM solver of the Shallow Water Equations. Investigation of the impact on computational performance of: - different ways to parallelise (MIMD and SIMD) parts of the solution algorithm - cache blocking - block sizes and...

__TL;DR:___________________________________________________________________________ Comparison of two 2D FVM Shallow Water Equations solvers, hms and hms++ (both are in-house developments at Chair of Water Resources Management and Modeling of Hydrosystems, TU Berlin) in terms of accuracy and computational performance. New version (hms++) provides...

We used stable isotopes to help assess ecohydrological partitioning in different types of urban green space in the city of Berlin. We focused particularly on the role of the near-surface of soils as a crucial interface that determines shallow subsurface (“non-Hortonian”) flows and water cycling in cities. Grassland soils tended to be wetter than so...

The hyporheic zone (HZ) describes an interfacial zone of permeable sediments, located in river beds, riparian and floodplain areas, where surface water mixes with groundwater. It exerts major control over the quality of river water by impacting the exchange processes between surface water and the sediment compartment through dynamically exchanging...

This chapter aims to introduce the basic background of shallow water flow models and robust numerical methods as well as to represent different examples of applications. After briefly explaining the main characteristics of shallow water flow problems and pointing out the specific numerical requirements to appropriately simulate those processes, one...

This study aimed to evaluate the suitability of literature parameter values for the Green–Ampt infiltration model to be used in hydrodynamic rainfall–runoff simulations. The outcome of this study supports to decide which literature values should be taken if observed data for model calibration is not available. Different laboratory experiments, a pl...

Artificial coastal lagoons represent attractive multi-purpose water systems, which offer a great opportunity for tourism and industrial services. El Gouna city, located in Egypt has a system of artificial lagoons connected to the Red Sea and offers a great opportunity for tourism activities. Investigating the hydrodynamics of El Gouna lagoons is an...

Urban green space is increasingly viewed as essential infrastructure to build resilience to climate change by retaining water in the city landscape and balancing ecohydrological partitioning into evapotranspiration for cooling and groundwater recharge. Quantifying how different vegetation types affect water partitioning is essential for future mana...

Egypt has been reported to be among the most vulnerable countries to climate change. Egyptian agriculture depends entirely on irrigation; its sole source is the Nile River. Any increase in temperature may affect water resources, increasing the stress on agricultural production. Adaptation policies should therefore be developed to cope with the adve...

This study evaluates the potential of kriging-based (kriging and kriging-logistic) and machine learning models (MARS, GBRT, and ANN) in predicting the effluent arsenic concentration of a wastewater treatment plant. Two distinct input combination scenarios were established, using seven quantitative and qualitative independent influent variables. In...

This work is aimed at investigating flash floods in the region of El Gouna, Egypt, by using a 2D robust shallow-water model that incorporates the Green-Ampt model to find the most realistic infiltration setting for this desert area. The results of different infiltration settings are compared to inundation areas observed from LANDSAT 8 images as wel...

Complex networks of both natural and engineered flow paths control the hydrology of streams in major cities through spatio-temporal variations in connection and disconnection of diverse water sources. We used spatially extensive and temporally intensive sampling of water stable isotopes to disentangle the hydrological sources of the heavily urbaniz...

Water levels are essential components for the observation and management of water resources. However, the existing water level monitoring methods either require manpower, which is inefficient, or are restricted to a certain environment. This paper proposes a novel approach that can automatically monitor, recognize and calculate the water level base...

Tube dwelling of chironomids often dominates benthic communities in freshwater ecosystems with high population density and pumping rates. This strongly enhances exchange across the sediment-water interface and impacts biogeochemical processes. Such processes are investigated by tracking the flow initiated by chironomid’s pumping through and around...

The acceleration of urbanization requires sustainable, adaptive management strategies for land and water use in cities. Although the effects of buildings and sealed surfaces on urban runoff generation and local climate are well known, much less is known about the role of water partitioning in urban green spaces. In particular, little is quantitativ...

Reliable and accurate modeling of groundwater quality is an important element of sustainable groundwater management of productive aquifers. In this research, specific conductance (SC) of groundwater is predicted based on different individual and integrative machine learning, adaptive neuro-fuzzy inference system (ANFIS), and nonlinear mathematical...

The implementation of novel machine learning models can contribute remarkably to simulating the degradation of concrete due to environmental factors. This study considers the sulfuric acid corrosive factor in wastewater systems to simulate concrete mass loss using five machine learning models. The models include three different types of extreme lea...

Complex networks of both natural and engineered flow paths control the hydrology of streams in major cities through spatio-temporal variations in connection and disconnection of water sources. We used spatially extensive and temporally intensive sampling of water stable isotopes to disentangle the hydrological sources of the heavily urbanized Panke...

In this study, two nature-inspired optimization techniques such as firefly algorithm (FA) and butterfly optimization algorithm (BOA) are combined with adaptive neuro-fuzzy inference system (ANFIS) and group method of data handling (GMDH) models for optimal prediction of the complex phenomenon of volumetric concentration of sediment (Cv) in sewer sy...

Recently, there has been a notable tendency towards employing ensemble learning methodologies in assorted areas of engineering, such as hydrology, for simulation and prediction purposes. The diversity of ensemble techniques available for implementation in hydrological sciences has led to the development and utilization of different strategies in th...

We evaluate the potential of kriging-based (kriging and kriging-logistic) and machine learning models (MARS, GBRT, and ANN) in predicting the effluent arsenic concentration of a wastewater treatment plant. Two distinct input combination scenarios were established, using seven quantitative and qualitative independent influent variables. In the first...

This study appraises different types of conventional (e.g., GRNN, RBNN, & MLPNN) and modern neural networks (e.g., integrative, inclusive, hybrid, & recurrent) in forecasting daily flow in the Thames River located in the United Kingdom. The models are mathematically, statistically, and diagnostically compared based on the forecasted results for ten...

Climate change might have direct impacts on water quantity in Egypt and lead to indirect effects on Mediterranean saltwater intrusion to groundwater, which exposes agriculture to vulnerability. This study investigated impacts of climate change on agriculture, with particular regard to food security and socioeconomy, and quantified the effectiveness...

To overcome the difficulty of collecting fine-grained terrain data that is important for flood modelling, this work presents a method for the application of UAV-based LiDAR techniques to drive high-resolution flood propagation and inundation modelling. This paper comprehensively introduces the UAV platform, LiDAR sensor and data processing techniqu...

This study aims to evaluate the suitability of literature parameter values for the Green-Ampt infiltration model to be used in hydrodynamic rainfall-runoff simulations. The outcome of this study supports to decide which literature values should be taken if observed data for model calibration is not available. Different laboratory experiments, a plo...

Since the construction of a weir at Iffezheim (Rhine-km 334) in 1977, a continuous deposition of sediments in the weir channel has been observed. The aim of this paper’s underlying investigations was to assess the long-term riverbed evolution of the Iffezheim reservoir in terms of deposition and erosion. The computational fluid dynamic model SSIIM-...

In this paper, different optimization algorithms (Basin-Hopping, Dual-Annealing, SHGO) were applied to automatically calibrate a shallow water model for rainfall-runoff simulation in two real case studies. The automated calibration approach showed a very good agreement with measurements and performed better than a conventional manual calibration, p...

The acceleration of urbanisation requires sustainable, adaptive management strategies for land and water use in cities. Although the effects of buildings and sealed surfaces on urban runoff generation and local climate are well known, much less is known about the role of water partitioning in urban green spaces. In particular, little is quantitativ...

The purpose of this study is to investigate the impact of check dams on catchment hydrological response in a small catchment on the hilly and gully area of Chinese Loess Plateau by applying a numerical model at 2 m resolution DEM. The results showed that check dams significantly increase the so-called runoff lag times (lag to generation, lag to pea...

Transport processes that lead to exchange of mass between surface water and groundwater play a significant role for the ecological functioning of aquatic systems, for hydrological processes and for biogeochemical transformations. In this study, we present a novel integral modelling approach for flow and transport at the sediment‐water interface. Th...

Exploring strategies to improve computational performance of a 2D FVM solver for the Shallow Water Equations (SWE) on CPUs, e.g. minimising redundant flux computations and vectorisation of cell-based computations

Sustainable urban drainage systems (SUDS) can significantly reduce runoff from urban areas. However, their potential to mitigate acute river impacts of combined sewer overflows (CSO) is largely unknown. To close this gap, a novel coupled model approach was deployed that simulates the effect of realistic SUDS strategies, developed for an established...

Flash floods along the Red Sea coast are getting more and more into consideration as with rising population and tourists, and the damages caused by flash floods are stronger impacting the life in this region. Investigations in El Gouna close to Hurghada concentrate on a basic description of the basin, geological features, and climate conditions and...

This study evaluates the performance of an integrated version of artificial neural network namely HS-ANN (which is a combination of neural network and heuristic harmony search algorithm) as an alternative approach to predict the sediment transport in terms of sediment volumetric concentration in sewer pipe systems. To overcome the complexities of c...

The collapse of a submerged granular pile under the action of the gravity force is investigated by means of a depth averaged model (hereinafter DAM). The granular pile is a mixture of solid particles and ambient liquid, totally covered by a layer of ambient liquid. The DAM is obtained by depth-averaging the mass and momentum equations of the mixtur...

Neurocomputing methods have contributed significantly to the advancement of modelling techniques in surface water hydrology and hydraulics in the last couple of decades, primarily due to their vast performance advantages and usage amenity. This comprehensive review considers the research progress in the past two decades, the current state-of-the-ar...

The processes of rill erosion and overland flow are significantly affected by freeze-thaw cycles. Meltwater concentrated flow laboratory experiments were carried out to assess the soil erosion of different frozen conditions based on the runoff energy consumption process which own to runoff energy against the sediment transportation and terrain evol...

Within this work, the impact of mitigation measures and infiltration on flash floods is investigated by using a 2D robust shallow water model including infiltration with the Green-Ampt model. The results show the combined effects of infiltration and mitigation measures as well as the effectiveness of bypass channels in addition to retention basins....

This research aims to evaluate ensemble learning (bagging, boosting, and modified bagging) potential in predicting microbially induced concrete corrosion in sewer systems from the data mining (DM) perspective. Particular focus is laid on ensemble techniques for network-based DM methods, including multi-layer perceptron neural network (MLPNN) and ra...

Rivers are important ecosystems under continuous anthropogenic stresses. The hyporheic zone is a ubiquitous, reactive interface between the main channel and its surrounding sediments along the river network. We elaborate on the main physical, biological, and biogeochemical drivers and processes within the hyporheic zone that have been studied by mu...

This paper presents different computational fluid dynamics applications using the multiphase solver interFoam which is implemented in the open source software OpenFOAM. The solver uses the volume of fluid approach. When modelling tracer transport in the proximity of the interface between two phases, the problem of non-physical tracer spreading acro...

In a context where the German Federal Ministry of Transport and Digital Infrastructure (BMVI) expects a 23% growth of traffic in inland navigation in Germany by the year 2030, a higher efficiency and an optimized logistics in traffic management are required. The BMVI-funded project Digital Skipper Assistant (DSA) had the objective to develop a clou...

In order to investigate the effects of the terrain slopes and rainfall intensity on the steady infiltration rate of permeable pavement, an experiment with the combinations of three types of permeability, three kinds of rainfall intensity, different cross slope and longitudinal slope are undertaken. Through analyzing the experimental data, it is ind...

Several potential problems associated with emissions such as odour nuisance may occur in sewer systems and wastewater treatment plants (WWTP). Improved understanding of prediction of emitted gases (e.g. hydrogen sulphide, H2S) is of great importance for better evaluation of such problems in WWTPs. The present paper provides a survey of the feasibil...

Exchange processes of surface and groundwater are important for the management of water quantity and quality as well as for the ecological functioning. In contrast to most numerical simulations using coupled models to investigate these processes, we present a novel integral formulation for the sediment-water-interface. The computational fluid dynam...

For the past 70 years, researchers have dealt with the investigation of odour in sewer systems caused by hydrogen sulphide formations and the development of approaches to describe it. The state-of-the-art models are one-dimensional. At the same time, flow and transport phenomena in sewers can be three-dimensional, for example the air flow velocitie...

Biological corrosion of sewers and sewage treatment plants constitutes a serious problem and its effects result in the loss of billions of dollars every year [1]. Changing demography and more efficient use of water resources will lead to the reduction of the average volume of waste water and leads to higher residence times in the sewer canals. Due...

This paper presents novel flux and source term treatments within a Godunov-type finite volume framework for predicting the depth-averaged shallow water flow and sediment transport with enhanced the accuracy and stability. The suspended load ratio is introduced to differentiate between the advection of the suspended load and the advection of water....

Reservoirs have a wide variety of uses that have led to frequent conflicts over ecological conservation and contamination, especially as land management has intensified. Oligotrophication must be implemented in numerous tropical reservoirs that experience advanced eutrophication to maintain aquatic ecosystem functions. To quantify impacts on ecosys...

This paper describes an improved vector manipulation multislope monotone upstream-centred scheme for conservation laws (MUSCL) reconstruction for solving the shallow water equations on unstructured grids. This improved MUSCL reconstruction method includes a bigger stencil for the interpolation and saves time for determining the geometric relations...

Complex transport mechanism and interaction between fluid and sediment make the mathematical and numerical modeling of sediment transport very challenging. Different types of models can lead to different results. This paper investigates a non-equilibrium sediment transport model based on the total load. In this type of model, it is assumed that a b...

Aiming at resolving the numerical problems caused by the improper friction source term treatment when simulating overland flow using 2D shallow water flow models, a proposed implicit method computing the friction source term is developed in this work. The method is able to not only accurately evaluate the tricky thin overland flow by considering th...

The hydropower production, water supply and aquaculture services of the Itaparica Reservoir are of immense importance for the Brazilian Northeast. Uncontrolled water resources consumption (e.g. irrigation, water supply), climate and land use change effects deteriorated the water quantity and quality in the reservoir, leading to socio-economic and e...

Focus of this study is to investigate the capabilities of a neural network in predicting medium range wa-ter levels in some critical gauges of the Rhine Basin, being the river of greatest importance for inland nav-igation in Central Europe.

Heavy rainfall events from June till August 2017 (up to 200 mm) preceded the formation of phytoplankton blooms at Lake Tegel. We aim to investigate the mechanism behind the formation of these blooms by applying a depth-averaged 2D hydrodynamic model to Lake Tegel. We hypothesize that increased nutrient-rich river discharges were the main factor cau...