Disclaimer Informa UK Limited, trading as Taylor & Francis Group, make every effort to ensure the accuracy of all the information (the "Content") contained in our publications. However, Informa UK Limited, trading as Taylor & Francis Group, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Informa UK Limited, trading as Taylor & Francis Group. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Informa UK Limited, trading as Taylor & Francis Group, shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.
Abstract. An important part within the German-Indonesian Tsunami Early Warning System (GITEWS) project was the detailed numerical investigation of the impact of tsunamis in densely populated coastal areas of Indonesia. This work, carried out by the German Research Centre Geesthacht (GKSS), in co-operation with DHI-WASY, also provides the basis for the preparation of high resolution hazard and risk maps by the German Aerospace Center (DLR).In this paper a method is described of how to prepare very detailed roughness maps for scenario computations performed with the MIKE 21 Flow Model FM in three highly resolved (∼10 m) priority regions, namely Kuta (Bali), Padang (West-Sumatra), and Cilacap (southern coast of Java). Roughness values are assigned to 43 land use classes, e.g. different types of buildings, rural and urban subareas, by using equivalent coefficients found in literature or by performing numerical experiments.Comparisons of simulations using differentiated roughness maps with simulations using constant values (a widely used approach) are presented and it is demonstrated that roughness takes considerable influence on run-up and inundation.Out of all simulations, the results of the worst case scenarios for each of the three priority areas are discussed. Earthquakes with magnitudes of M W =8.5 or higher lead to considerable inundation in all study sites. A spatially distinguished consideration of roughness has been found to be necessary for detailed modelling onshore.
Knowledge about the distribution of suspended particulate matter (SPM) is an important prerequisite for the description and prognostication of the ecological conditions of the North Sea. SPM concentrations in the water column regulate the penetration depth of light and, therefore, is an important parameter influencing the primary production of plankton. Fine sediment in the bottom acts like a dynamical buffer representing sources and sinks for nutrients simultaneously. Moreover, the determination of the distribution of SPM and fine sediment provides evidence of the disposition of pollutants, adhered to the particles. In cooperation with GKSS Research Center, the transport model for dissolved conservative substances of the Federal Maritime and Hydrographic Agency (Bundesanstalt für Seeschifffahrt und Hydrographie, BSH) was extended by a Suspended Particulate Matter module to take into account the processes of vertical exchange and horizontal distribution of SPM due to currents and waves. The success of such a model depends on an adequate description of the physical processes, as well as a careful preparation of maps of finegrained sediment in the bottom and other sources of SPM (e.g., fluvial input and cliff erosion). In this paper, we examine quantitatively and qualitatively SPM distributions during two periods in 2000 and 2001. The results of a simulation during a storm at the beginning of 2001 are examined in detail to show the role of single exchange processes. Another application of the SPM transport model is presented as the simulation of dispersion of suspended material after a big river flood.
Effect of waves and currents on the dynamics and seasonal variations of suspended particulate matter (SPM) in the North Sea is investigated by a three-dimensional Circulation and Transport Model for SPM (CTM-SPM) in 2002 and 2003, forced by waves and meteorological data. Calculated fine sediment exchange processes at the seawater-seabed interface are driven by the instant values of the shear stress velocity due to currents and waves. Modeled SPM concentrations are compared with in-situ measurements and satellite snap-shot images. As a result of the action of currents and waves, local bathymetry and the fine sediment content at the sea bottom, modeled time series show different short-term dynamics of SPM concentrations in various locations in the North Sea. On a longer time scale, currents and waves result in different seasonal distributions of the shear stress velocity typical for the calm (April -October) and the storm (OctoberApril) periods. Accordingly, our model calculates different seasonal distributions of SPM with the mean surface concentrations of about 2 mg l −1 in the calm and > 5 mg l −1 in the storm periods. Waves lead to a higher frequency of resuspension and erosion events and increase mixing intensity in the water column during storm periods. During calm periods, SPM distribution is mainly shaped by currents. A different pattern, characterized by high SPM concentrations in offshore areas, evolves instantly during transient storms events.
Monitoring and modeling of the distribution of suspended particulate matter (SPM) is an important task, especially in coastal environments. Several SPM models have been developed for the North Sea. However, due to waves in shallow water and strong tidal currents in the southern part of the North Sea, this is still a challenging task. In general there is a lack of measurements to determine initial distributions of SPM in the bottom sediment and essential model parameters, e.g., appropriate exchange coefficients.In many satellite-borne ocean color images of the North Sea a plume is visible, which is caused by the scattering of light at SPM in the upper ocean layer. The intensity and length of the plume depends on the wave and current climate. It is well known that the SPM plume is especially obvious shortly after strong storm events.In this paper a quasi-3-D and a 3-D SPM transport model are presented. Utilizing the synergy of satelliteborne ocean color data with numerical models, the vertical exchange coefficients due to currents and waves are derived. This results in models that for the first time are able to reproduce the temporal and spatial evolution of the plume intensity. The SPM models consist of several modules to compute ocean dynamics, the vertical and horizontal exchange of SPM in the water column, and exchange processes with the seabed such as erosion, sedimentation, and resuspension. In the bottom layer, bioturbation via benthos and diffusion processes is taken into account.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.