Bernhard Westrich

University of Stuttgart · Institute of Geotechnical Engineering, Institute of Hydraulic Engineering (formerly)

Renewable geothermal energy is an energy source that can be used for heating and cooling purposes. One common method of harvesting this energy is using engineering structures in contact with the ground, such as structural piles, diaphragm walls or tunnels (with geothermal loops integrated into the tunnel lining/invert (tunnel ground heat exchangers...

Presently near surface geothermal energy already covers an essential part of the German base-load capacity in the heat sector. Thermal activation of tunnels represents an interesting alternative and could be an economically useful solution which is complementary to the presently applied hybrid systems in ground engineering. The utilization of heat...

The Finite Element Method (FEM) is widely used in the simulation of geotechnical applications. Owing to the limitations of FEM to model problems involving large deformations, many efforts have been made to develop methods free of mesh entanglement. One of these methods is the Material Point Method (MPM) which models the material as Lagrangian parti...

Im Rahmen der wasserwirtschaftlichen Nutzung der Oberflächengewässer gewinnt die Frage nach der Wechselwirkung zwischen fließenden und angrenzenden stehenden Gewässern im Hinblick auf die Kontrolle und Erhaltung der Wasserqualität zunehmend an Bedeutung. Der wechselseitige Austausch von Wasserinhaltsstoffen (Suspensionen, Sauerstoff, toxische Stoff...

Erodierbare Sohlen, die Strahlströmungen ausgesetzt sind, können erhebliche Verformung, Auflockerung und Zerstörung erfahren. So können beispielsweise Schiffspropellerstrahlen Gewässersohlen in unerwünschtem Maße angreifen, andererseits ist die Erosionswirkung energiereicher Strahlen in der Naßbaggertechnik zur Auflockerung und Zerstörung feinkörni...

ln dem vorliegenden Aufsatz wird anhand einiger Beispiele aus dem Wasserbau dargestellt, an welchen Aufgaben und Problemen im Institut für Hydromechanik, Stauanlagen und Wasserversorgung derzeit gearbeitet wird. Das Spektrum des Forschungsprogramms ist erheblich breiter. Eine Reihe von Arbeitsgebieten wurde hier nicht oder kaum angesprochen. Die Er...

Der Bedarf der Industrie an Brauch- und Kühlwasser muß in hochindustrialisierten und dichtbesiedelten Ländern wie der Bundesrepublik Deutschland zu einem großen Teil aus Oberflächenwasser gedeckt werden. Bei der Entnahme von Rohwasser aus fließenden Gewässern läßt sich kaum vermeiden, daß gleichzeitig auch mitgeführte Feststoffe entnommen werden, d...

Tiefgetauchte Strahlen können auf beweglichen Gewässersohlen erhebliche Auskolkungen hervorrufen. Die Erosionswirkung ist stark abhängig von der Größe des hydrodynamischen Sohldrucks und der Durchlässigkeit des körnigen Sohlmaterials. Abhängig von der Intensität des Strahlangriffs bilden sich zwei charakteristische Kolkformen mit unterschiedlichem...

Die hydraulischen Probleme beim Entwurf der Bauwerke im druckfreien Teil des Kühlwasserkreislaufs (Entnahme- und Verteilerbauwerk, Kraftschlußbecken, Kühltasse) werden beschrieben. Es werden die Anforderungen an die hydraulische Leistungsfähigkeit des Kühlsystems zur Realisierung von Frischwasser-, Ablauf-, Kreislauf- und Mischkühlung skizziert, so...

Block ramps are structures consisting of boulders on steep slope and used for the stabilization of streams by dissipation of energy of flow by means of generating excessive turbulence. This paper deals with experimental study of turbulence over a block ramp. Three-dimensional velocities were measured by acoustic Doppler velocity meter at a constant...

The impounding of the Three Gorges Reservoir (TGR) at the Yangtze River caused large flooding of urban, industrial, and agricultural areas, and profound land use changes took place. Consequently, substantial amounts of organic and inorganic pollutants were released into the reservoir. Additionally, contaminants and nutrients are entering the reserv...

High spatial heterogeneity of physical and chemical sediment properties was observed in horizontal and vertical direction of the deposits in a groyne field of the middle Elbe. The respective sediment cores were less polluted on the top as compared to consolidated deeper layers, indicating a decreasing trend of ontamination in the river basin. In co...

Bioavailable concentrations of polycyclic aromatic hydrocarbons (PAHs) were investigated in water of Three Gorges Reservoir (TGR) using semipermeable membrane devices during the period of completely impounding water. ∑PAH concentrations in water of TGR in the period of completely impounding water were 15-381 ng L(-1). ∑PAH concentrations increased...

High spatial heterogeneity of physical and chemical sediment properties was observed in both horizontal and vertical directions of deposits in a groyne field of the Middle Elbe. The respective sediment cores were less polluted on the top compared to consolidated deeper layers, indicating a decreasing trend of contamination in the river basin. In co...

After impoundment of the Three Gorges Reservoir (TGR) in 2003, hydrological regimes of the Yangtze River, upstream and downstream of the Three Gorges Dam, have been changed enormously, leading to significant environmental, ecological and social impacts. Nutrients and pollutants from agriculture, industry and municipalities are of concern due to the...

Water of good quality is one of the basic needs of human life. Worldwide, great efforts are being undertaken for an assured water supply. In this respect, one of the largest water technology projects worldwide is the Yangtze Three Gorges Dam in China. There is a need for extensive scientific and technical understanding of the challenges arising fro...

The rapid economic development has caused heavy pollution in the Pearl River Delta Region (PRDR) and neighboring regions. In order to investigate the polluted characteristics, a coupled modelling approach has been deployed and the study area in the Pear River Delta is divided into two modelling systems: a river network that is simulated by a 1D hyd...

Sediment transport processes play an important role in the surface water systems coupled with rainfall-runoff and contaminant transport. Pollutants like heavy metals adsorbed mainly by fine sediment particles can be deposited, eroded or transported further downstream. When the toxic pollutants deposited before and covered by cleaner sediment are re...

Microbially produced extracellular polymeric substances (EPS) have been linked with many important ecological functions in natural sediments; yet, most information has been derived from marine systems. The present paper is the first comprehensive study on EPS (i.e., carbohydrates and proteins) dynamics in riverine sediments addressing spatial (six...

Block ramps are a short length of a steep channel armored with rocks, which produce high dissipation of energy. This technical note presents the results of experiments performed on a ramp having a staggered arrangement of hemispherical boulders with base material on its bed. Compared to row and random arrangements of boulders, a staggered arrangeme...

The PC-River Project provides software for the probabilistic design of flood defense structures. The Dutch Software PC-Ring was extended to fit not only to the Rhine delta but also river characteristics in the lowland and low-mountain regions. A new connection to hydraulic models and a semi-automatic uncertainty analysis of water levels simplify it...

Flood events can mobilize large amounts of sediments. Very often pollutant sources are mobilized simultaneously. In order to control the dispersion and deposition of sediment associated contaminants, green flood retention reservoirs can be designed and operated to mitigate the impact of contaminants deposited on inundated agricultural land. In the...

Following the 2000 European Water Framework Directive and recent insights into sediment management on a river basin scale, we discuss in this paper an exposure model aiming to support a risk assessment for chemicals on a basin-wide scale. It establishes spatial relations between causes (pollution sources) and effects (ecological risk), taking into...

Environmental issue of river water quality is still a vital environmental issue, even though ongoing emissions of contaminants are being reduced in several European rivers. The mobility of historically contaminated deposits is key issue in sediment management strategy and remediation planning. Resuspension of contaminated sediments impacts the wate...

Contaminated sediment mobility plays an important role in river engineering and water resources management. Numerical models are powerful tools to be used for analysis, prediction and remediation issues in sediment management. Erosion stability plays a key role for contaminated sediment mobility assessment. Experimental investigations on erosion st...

Particulate pollutant transport during flood events often results in contamination of floodplains, especially of areas in green flood retention reservoirs and polders due to sedimentation processes. The deposition of toxicants on mentioned areas and their impact on land use have not yet been accounted for adequately. In this work, the retention of...

Sediment stability is a critical component for the understanding of cohesive sediment dynamics. Traditionally, physico-chemical sediment conditions have been regarded as most important drivers of sediment stability. However, over the last decade, the stabilization of sediment by biological activity, particularly the influence of highly hydrated mat...

The European Water Framework Directive (WFD) so far does not consider sediment quality and quantity as a major issue (Förstner and Owens, 2007). Objections against compliance monitoring for sediment, based on Environmental Quality Standards (EQS) for sediment, were caused by analytical limitations and anticipated costs involved in

Contaminants such as heavy metals or organic pollutants are adsorbed to fine sediment particles which are transported through the river system and deposited in the regions of low flow velocities. This results in potential sources of contaminants called “hot spots” which can be eroded by floods causing deterioration of the river water quality. There...

The Water Framework Directive (2000/60/EC) of the European Parliament requires the removal of toxic matters from surface waters. Using green flood retention reservoirs for the active trapping of flood induced released contaminated sediment could be one method to improve the aquatic environment. In this case study flow and sediment transport are sim...

1 “Sediment management requires a solid mix of pragmatism and sound science” The actual discussion on the role of sediments in the European water legislation is a typical example, how the development of environmental policies mixes legal requirements with socio-economic aspects, issues of technical feasibility, and sci- 2 entific knowledge . In fac...

New field data on cohesive sediment erosion is presented and discussed, with particular focus on partitioning the total erosion into resuspension and bed load. The data were obtained using a recently developed in situ flume of the National Institute of Water and Atmospheric Research, New Zealand. The erosion rate is estimated from direct measuremen...

For simulating real world effects on various temporal and spatial scales, an integrated approach has been developed combining hydrodynamic and chemical/biological factors which influence pollutant mobilization and transfer of – the interdisciplinary SEDYMO approach (‘SEdiment DYnamics and pollutant MObility in rivers’). The following sections give...

Background and Scope. Apart from their function as indicator or memory for local pollutant inputs, sediments, and especially sediment cores, can be used as a tool for assessing emission- immission relationships of contaminants on a river-basin scale. Methods. In the framework of the SEDYMO program, source effects, i.e. intensity of sediment erosion...

Sediments play an important role in river engineering and water resources management. In the past, many rivers in developed countries have been engineered by training and regulation works for navigation, hydropower generation and flood protection. In the past decades, municipal and industrial waslewaler discharge and various diffusive sources from...

A benthic in situ flume and a 1D biogeochemical sediment model to evaluate solute fluxes across the sediment-water interface have been developed. The flume was successfully used to determine oxygen and nutrient fluxes at various locations of the Neckar River in Germany. The experimental results were linked with vertical pore water concentration pro...

Sediments are an essential habitat compartment in rivers, which is a subject to dynamic transport processes. In many rivers, the fine deposited sediments are contaminated with heavy metals and organic compounds. Contaminated deposits are considered as potential hot spots because of the risk of the mobilization under erosive hydraulic conditions. Nu...

Background, Aim and Scope Riverine sediments store large quantities of hazardous contaminants, remaining a 'legacy of the past' world-wide. Natural events such as floods may cause the resuspension of polluted sediments and accordingly, the former immobilized contaminants might become bioavailable and toxic again. Hence, a comprehensive erosion risk...

Characteristic dynamic features of sediment-related processes in rivers include (i) dramatic effects of storm¬water events on particle transport, (ii) rapid and far-reaching effects of sulfide oxidation during resuspension, and (iii) biological accumulation and potential release of toxic chemicals. Pollutant mobility is the net result from stabiliz...

In practice, a catchment-wide assessment of historical contaminated soil and sediment should apply a three-step approach: (i) Identification of substances of concern (s.o.c.) and their classification into 'hazard classes of compounds'; (ii) identification of areas of concern (a.o.c.) and their classification into 'hazard classes of sites'; (iii) id...

Background: Triggered by the requirement of Water Framework Directive for a good ecological status for European river systems till 2015 and by still existing lacks in tools for cause identification of insufficient ecological status MODELKEY (http:// www.modelkey.org), an Integrated Project with 26 partners from 14 European countries, was started i...

Background and Scope. Apart from their function as indicator or memory for local pollutant inputs, sediments, and especially sediment cores, can be used as a tool for assessing emissionimmission relationships of contaminants on a river-basin scale. Methods. In the framework of the SEDYMO program, source effects, i.e. intensity of sediment erosion...

In order to contribute to a reliable, easy-to-handle and economically viable erosion risk assessment of contaminated riverine sites, the present study aims to implement master-variables best characterising the sediment stability. Thus, a wide range of sediment properties was related to the critical shear stress for mass erosion, determined in the S...

Background and Scope. Characteristic dynamic features of sediment related processes in rivers include (i) dramatic effects of stormwater events on particle transport, (ii) rapid and far-reaching effects of sulfide oxidation during resuspension, and (iii) biological accumulation and potential release of toxic chemicals. Pollutant mobility is the net...

need a strong basis of sediment quantity data. In a dynamic system, this assessment should include not just those mate-rials that are currently sediments, but also materials such as soils, mine tailings, etc. that can reasonably be expected to become part of the sediment cycle during the lifetime of a management approach (Apitz and White 2003). The...

Background, Aims, and Scope Data from the Elbe River and its tributaries indicate, despite extensive improvement in water quality during the last 15 years, that the respective sediment situation of many priority pollutants has not reached an acceptable level. For the coming decades, risks for downstream sites and stakeholders will persist, mainly d...

The theoretical background, conceptual models, and prediction equations for oxygen exchange across the free water surface are presented. The re-aeration equations are assessed for their suitability to simulate the oxygen balance on the basis of the results of a gas-tracer experiment in the River Neckar.

Spatial and temporal distribution of sedimentation and erosion of fine suspended sediment in headwaters and reservoirs is controlled by flow field and sediment properties. These proper-ties vary significantly with sediment sizes and cohesiveness. In this study, the sedimentation and erosion phenomena for a headwater section of the River Rhine are n...

For Abstract see ChemInform Abstract in Full Text.

In order to model the transport of cohesive sediments and associated contaminants accurately, knowledge of erosion rates is indispensable; at present, these are mostly obtained from the literature and usually extended by field data. In contrast to these theoretical approaches we have developed a method to determine erosion rates directly from exper...

Particle-bound pollutants accumulate in river-bottom sediments, a process which results in a significant decrease in the ecotoxicological availability of toxicants for the majority of aquatic organisms. Under normal hydrologic conditions, the release of contaminants from bottom sediments is usually of minor importance. In contrast, flood events may...

The results of an experimental investigation of the time variation of scour hole and the flow characteristics of the quasi-equilibrium state of scour of a cohesive bed downstream of an apron due to a submerged horizontal jet issuing from a sluice opening are presented. Experiments were carried out with natural cohesive sediment for various sluice o...

In order to model the transport of cohesive sediments and associated contaminants accurately, knowledge of erosion rates is indispensable; at present, these are mostly obtained from the literature and usually extended by field data. In contrast to these theoretical approaches we have developed a method to determine erosion rates directly from exper...

Particle-bound pollutants accumulate in river-bottom sediments, a process which results in a significant decrease in the ecotoxicological availability of toxicants for the majority of aquatic organisms. Under normal hydrologic conditions, the release of contaminants from bottom sediments is usually of minor importance. In contrast, flood events may...

Deposition of suspended sediments in turbulent open channel flows is dominated by complex interaction of hydrodynamic processes in turbulent boundary layer and the self-organized macro and micro scale roughness at the bed. The present knowledge about physical processes controling sedimentation is still poor. Particularly with regard to the effects...

The present study demonstrates the usefulness of principal component analysis in condensing and interpreting multivariate time-series of water quality data. In a case study the water quality system of the lock-regulated part of the River Neckar (Germany) was analysed, with special emphasis on the oxygen budget. Pooled data of ten water quality para...

Flood retention reservoirs are subject to strong sedimentation, which affects the water quality and causes maintenance dredging. As for flood protection, reservoirs are operated as to store the peak of the flood and to reduce the outflow discharge whereas the mitigation of sedimentation requires the reduction of the storage capacity and the residen...

In this paper, an assessment strategy is introduced which allows one to evaluate the ecological hazard of contaminated sediments in connection with the risk of in-stream erosion. Special techniques for sediment sampling, non-intrusive density profiling, and depth related measurement of erosion are presented, which, in combination with ecological as...

A special mixing technique, called end-member mixing analysis (EMMA) is adopted to quantitatively assess the contributions of distinct instream sources to suspended sediments and particle-bound contaminants. Application to a flood event in the River Neckar, Germany, illustrates the usefulness of the technique. The results show that the erosion of r...

Nowadays, sediment deposits in many rivers are contaminated by ecologically harmful substances. During flood events, the release of contaminants from the sediments by erosion may considerably increase the contaminant load of the river and exert abrupt stress on the aquatic ecosystem. Conventional investigation methods (bathymetrical surveys, pollut...

Based on theoretical considerations, the pollutant trapping efficiency (PTE) of a river section was introduced to assess sediment contamination from pollutant discharge. Under simplified assumptions, PTE can be calculated by the sedimentation of suspended particulate matter (SPM), the inflowing concentration of SPM and the solidwater partition coef...

Based on theoretical considerations, the pollutant trapping efficiency (PTE) of a river section was introduced to assess sediment contamination from pollutant discharge. Under simplified assumptions, PTE can be calculated by the sedimentation of suspended particulate matter (SPM), the inflowing concentration of SPM and the solid-water partition coe...

The sediment, budget of a reservoir on the Neckar River, Germany, was investigated by means of experimental and numerical methods. Field measurements of channel bathymetry show that. sedimentation and erosion occur primarily in the lower backwater-influenced section of the reservoir, which stores approximately 350,000 m3 of fine-grained deposits. S...

Large scale sedimentation pattern in a medium size shallow water reservoir have been investigated by using a mathematical numerical model. Dredging of a flushing channel has proven to be a suitable measure for sedimentation mitigation. The flushing channel was designed by numerical optimization. The numerical results show the efficiency of the flus...

For a lock-regulated reach of the River Neckar at Lauffen, Germany, results from sediment core analysis are presented. It is observed that sediment layers with a high concentration of heavy metals, especially cadmium, are covered by younger, less polluted sediment layers. A principal component analysis separated the parameters measured into three g...

Hans Albert Einstein: Reminiscences If His Life and Our Life Together Edited by Elizabeth Roboz Einstein Iowa Institute of Hydraulic Research, Iowa City, 1991 ISBN 0-37414-033-8 P.B. US $ 12,50. Kurzbiographien, Hydraulik Und Wasserbau, Persönlichkeiten Aus Dem Deutschsprachichen Raum Edited by P.-G. Franke und A. Kleinschroth Karl M. Lipp Verlag,...

In coastal and inland rivers with high-water pollution the transport, sedimentation and resuspension of fine sediments becomes important for the water quality and its management. Deposition and resuspension of polluted sediments are the most important sink and source terms in a contaminant budget. Maintenance dredging and flood erosion may cause re...

Flow characteristics and hydraulic design guidelines for side channel spillways are described. In addition some basic design criteria for rock fill spillways are presented and some aspects related to the hydraulic loading of the structure are discussed.

In recent years, magnetic induction flowmeters have been increasingly used for wastewater discharge measurements. Deposition of solid matter and air bubbles in the measuring section are often sources of systematic errors. The effect of the disturbances on the accuracy of discharge measurement has been investigated under laboratory conditions. Some...

Tiefgetauchte Strahlen können auf beweglichen Gewässersohlen erhebliche Auskolkungen hervorrufen. Die Erosionswirkung ist stark abhängig von der Größe des hydrodynamischen Sohldrucks und der Durchlässigkeit des körnigen Sohlmaterials. Abhängig von der Intensität des Strahlangriffs bilden sich zwei charakteristische Kolkformen mit unterschiedlichem...

The flow field and erosion pattern of continuous and pulsating impinging jets has been studied experimentally. The mean velocity field as well as turbulent and pulsation components, wall pressure and wall shear stress distributions were investigated in an axisymmetric air jet impinging upon a rough wall. The results show how harmonic velocity pulsa...

Die hydraulischen Probleme beim Entwurf der Bauwerke im druckfreien Teil des Kühlwasserkreislaufs (Entnahme- und Verteilerbauwerk, Kraftschlußbecken, Kühltasse) werden beschrieben. Es werden die Anforderungen an die hydraulische Leistungsfähigkeit des Kühlsystems zur Realisierung von Frischwasser-, Ablauf-, Kreislauf- und Mischkühlung skizziert, so...

The mass exchange in water basins communications with a main current is investigated by some basic hydraulic experiments. The dependence of the flushing time on the size and geometry of the basin as well as the inlet location is studied for different idealized tidal flow conditions in the main stream current. The mass exchange is determined from th...

Advantages of using air models instead of water models are discussed. Calculations with a three-dimensional model based on improved similarity to natural environment are presented, and optimal location for construction work regarding channel angles and distance from river bank is suggested.