FG Wasserwirtschaft und Hydrosystemmodellierung

19 Items

Recent Submissions
Adapting the water management to mitigate the impact of multiple stressors on an urban lake

Ladwig, Robert (2019)

Urban lakes are aquatic ecosystems that are influenced by a water management system and by a possibly strongly sealed urban catchment. The water management aims to fulfill multiple objectives: providing drinking water, sanitation and recreation for the people as well as keeping the ecosystem in a sustainable and resilient state. Urban lakes are facing several stressors. For instance, climate ch...

The assessment of hydrological impacts of climate change and their implications for water management across scales

Lobanova, Anastasia (2019)

The impacts of climate change can become a trigger for critical changes in the spatial and temporal distribution of water resources in many regions in Europe. This will lead from obviously negative effects in some regions to creation of opportunities in others. In the face of future changes: economic, social and environmental, both natural and triggered by anthropogenic activities, the effectiv...

A Novel Slope Failure Operator for a Non-Equilibrium Sediment Transport Model

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2018)

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 bed slide will occur if the bed slope reaches a ...

A depth-averaged non-cohesive sediment transport model with improved discretization of flux and source terms

Zhao, Jiaheng ; Özgen-Xian, Ilhan ; Liang, Dongfang ; Wang, Tian ; Hinkelmann, Reinhard (2019)

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. A modified Harten, Lax and van Leer Riemann sol...

Comparison of depth-averaged concentration and bed load flux sediment transport models of dam-break flow

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2017)

This paper presents numerical simulations of dam-break flow over a movable bed. Two different mathematical models were compared: a fully coupled formulation of shallow water equations with erosion and deposition terms (a depth-averaged concentration flux model), and shallow water equations with a fully coupled Exner equation (a bed load flux model). Both models were discretized using the cell-c...

An improved multislope MUSCL scheme for solving shallow water equations on unstructured grids

Zhao, Jiaheng ; Özgen-Xian, Ilhan ; Liang, Dongfang ; Wang, Tian ; Hinkelmann, Reinhard (2018-10-19)

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 compared to the original vector manipulation me...

Improved multislope MUSCL reconstruction on unstructured grids for shallow water equations

Zhao, Jiaheng ; Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2018)

In shallow water flow and transport modeling, the monotonic upstream‐centered scheme for conservation laws (MUSCL) is widely used to extend the original Godunov scheme to second‐order accuracy. The most important step in MUSCL‐type schemes is MUSCL reconstruction, which calculate‐extrapolates the values of independent variables from the cell center to the edge. The monotonicity of the scheme is...

Fully coupled robust shallow water flow and sediment transport model on unstructured grids

Zhao, Jiaheng (2019)

This Ph.D. thesis advances the fully coupling of robust shallow water flow and sediment transport modeling. The first part mainly focuses on the multislope MUSCL reconstruction for shallow water flow on unstructured grids. A limitation method for reconstruction of velocities avoids extremely high values for wet/dry fronts. The reconstruction methods are tested via analytical benchmarks and lab...

Modeling the impacts of climate extremes and multiple water uses to support water management in the Icó-Mandantes Bay, Northeast Brazil

Matta, Elena ; Koch, Hagen ; Selge, Florian ; Simshäuser, Max Nino ; Rossiter, Karina ; Silva, Gérsica Moraes Nogueira da ; Gunkel, Günter ; Hinkelmann, Reinhard (2018-07-25)

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 environmental problems. In this work, a depth-av...

Electronic Supplementary to Doctoral Dissertation

Lobanova, Anastasia (2018)

This Electronic Supplementary contains the SWIM Model set up, calibrated and validated for all eight river basins, together with executables, used to perform modelling experiments for Doctoral Thesis "The assessment of hydrological impacts of climate change and their implications for water management across scales: from the local to European scale"

Simulations of nutrient emissions from a net cage aquaculture system in a Brazilian bay

Matta, Elena ; Selge, Florian ; Gunkel, Günter ; Rossiter, Karina ; Jourieh, Ayman ; Hinkelmann, Reinhard (2016)

Hydrodynamics and transport simulations were conducted with the modeling software TELEMAC-2D on Icó-Mandantes bay, a branch of the Itaparica reservoir. The bay has a maximal operational water level amplitude of 5 m and is suffering from eutrophication and algae bloom. Therefore, we investigated low and high water level scenarios with two different high resolution meshes, with the purpose to dee...

Urban flood modeling using shallow water equations with depth-dependent anisotropic porosity

Özgen, Ilhan ; Zhao, Jiaheng ; Liang, Dongfang ; Hinkelmann, Reinhard (2016)

The shallow water model with anisotropic porosity conceptually takes into account the unresolved subgrid-scale features, e.g. microtopography or buildings. This enables computationally efficient simulations that can be run on coarser grids, whereas reasonable accuracy is maintained via the introduction of porosity. This article presents a novel numerical model for the depth-averaged equations w...

Shallow water equations with depth-dependent anisotropic porosity for subgrid-scale topography

Özgen, Ilhan ; Liang, Dongfang ; Hinkelmann, Reinhard (2016)

This paper derives a novel formulation of the depth-averaged shallow water equations with anisotropic porosity for computational efficiency reasons. The aim is to run simulations on coarser grids while maintaining an acceptable accuracy through the introduction of porosity terms, which account for subgrid-scale effects. The porosity is divided into volumetric and areal porosities, which are ass...

Upscaling the shallow water model with a novel roughness formulation

Özgen, Ilhan ; Teuber, Katharina ; Simons, Franz ; Liang, Dongfang ; Hinkelmann, Reinhard (2015-08)

This study presents a novel roughness formulation to conceptually account for microtopography and compares it to four existing roughness models from literature. The aim is to increase the grid size for computational efficiency, while capturing subgrid scale effects with the roughness formulation to prevent the loss in accuracy associated with coarse grids. All roughness approaches are implement...

Conceptual simplifications for long-term sediment transport simulations

Zhang, Qing (2018)

The aim of this PhD thesis is to assess the long-term evolution of the fine sediment budget in the Iffezheim reservoir, which is the last barrage of the impounded section of the Rhine River. Based on the observed flow and suspended sediment concentration as well as echo-sounding data, various methods were proposed to estimate long-term riverbed changes. The application of a high-resolution 3D m...

Multi-dimensional flow and transport modeling of a surface water body in a semi-arid area

Matta, Elena (2018)

Since approximately 2012, Northeast Brazil dramatically suffers from the harshest drought in the recent history, with serious consequences on water resources, anthropogenic uses and ecosystem services. Among else, the hydropower production, irrigation agriculture, water supply and net cage aquaculture are the principal uses adopted in the Itaparica Reservoir, located in the Sub-Middle São Franc...

Model-based design for restoration of a small urban river

Lange, Carsten ; Schneider, Matthias ; Mutz, Schneider ; Haustein, Martin ; Halle, Martin ; Seidel, Michael ; Sieker, Heiko ; Wolter, Christian ; Hinkelmann, Reinhard (2015)

A model-based design is presented for restoring the small urban river Panke located in Berlin, Germany. This new design process combines high resolution 2D hydraulic modeling with habitat modeling and river-ecological expert knowledge in a highly iterative way. Advances have been made for the habitat modeling: habitat suitability maps have been developed for fish and the habitat suitability for...

An efficient unstructured MUSCL scheme for solving the 2D shallow water equations

Hou, Jingming ; Liang, Qiuhua ; Zhang, Hongbin ; Hinkelmann, Reinhard (2015)

The aim of this paper is to present a novel monotone upstream scheme for conservation law (MUSCL) on unstructured grids. The novel edge-based MUSCL scheme is devised to construct the required values at the midpoint of cell edges in a more straightforward and effective way compared to other conventional approaches, by making better use of the geometrical property of the triangular grids. The sch...

Three-dimensional modeling of wind- and temperature-induced flows in the Icó-Mandantes Bay, Itaparica Reservoir, NE Brazil

Matta, Elena ; Selge, Florian ; Gunkel, Günter ; Hinkelmann, Reinhard (2017)

The Icó-Mandantes Bay is one of the major branches of the Itaparica Reservoir (Sub-Middle São Francisco River, Northeast Brazil) and is the focus of this study. Besides the harmful algae blooms (HAB) and a severe prolonged drought, the bay has a strategic importance—e.g., the eastern channel of the newly built water diversion will withdraw water from it (drinking water). This article presents t...