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This chapter summarizes the development of a decision support system (DSS) for spatial planning of marine finfish aquaculture sites in Southeast Asia. The DSS implements methods for site selection and estimation of carrying capacities. These methods are based primarily on results of dynamic models supplemented with in situ measurements and remote sensing information. They follow the FAO's Ecosystem Approach to Aquaculture for ensuring the proper planning and operation of aquaculture sites. In this study, the effectiveness of the DSS is demonstrated for a target aquaculture site in the northwest of Bali in Indonesia. Results of the study led to recommendations for relocation of farms to suitable areas and for reduction of fish production in farms operating above carrying capacity. Recommendations to increase fish production while ensuring sustainable ecological operation in the site were made. The DSS has broad applicability and will help to make decisions for aquaculture sites around the world. Abstrak Makalah ini menjelaskan tentang pengembangan sistem pendukung keputusan (decision support system/DSS) tentang penentuan tata ruang dalam budidaya laut di Asia Tenggara. Penerapan metoda DSS untuk pemilihan lokasi dan penentuan daya dukung perairan utamanya berdasarkan model dinamis yang dilengkapi dengan pengukuran mutu perairan in-situ dan informasi penginderaan jauh. Metode ini termasuk prosedur umum dalam kontek pendekatan ekosystem akuacultur oleh FAO untuk memastikan perencanaan yang tepat dan operasional yang benar di lokasi budidaya laut. Dalam studi ini efektivitas DSS didemontrasikan di lokasi budidaya laut yang terletak di perairan Utara-Barat Bali-Indonesia. Hasil dari penilaian lokasi ternyata keramba jaring apung (KJA) pembudidaya diletakkan diluar area perairan yang sesuai untuk budidaya laut dan produksi ikannya berlebih. Rekomendasi untuk penempatan KJA yang sesuai untuk meningkatkan produksi berkelanjutan telah dilakukan. Dengan demikian dapat disimpulkan bahwa DSS mempunyai penerapan yang sangat luas dan dapat membantu dalam penentuan lokasi budidaya di seluruh dunia.

This chapter presents the results of the investigations leading to the development and application of a general procedure for the characterization of tidal current energy resources in data-poor sites. It implements methods to identify suitable sites for tidal power extraction, estimate effective power potentials, and assess impacts of tidal turbine arrays on the environment. The process relies primarily on results from high-resolution, three-dimensional circulation models. Guidelines for the development of circulation models in data-poor sites are provided. Furthermore, a decision support system embedding the entire resource characterization procedure that has been developed to facilitate analysis and support authorities in the assessment and spatial planning of tidal turbine arrays is presented. Results of the application of the proposed procedure to the target sites selected by the Indonesian government led to the improvement of information base regarding the potential of tidal energy in Indonesia. Abstrak Makalah ini menyajikan hasil investigasi untuk pengembangan dan penerapan prosedur umum dalam melakukan karakterisasi terhadap sumber daya energi arus pasut di lokasi-lokasi yang datanya sangat sedikit. Proses yang dilakukan utamanya didasarkan pada hasil dari model sirkulasi tiga dimensi beresolusi tinggi. Model yang digunakan menerapkan metode untuk mengidentifikasi lokasi yang sesuai untuk ekstraksi tenaga pasut, memperkirakan potensi daya efektifnya, dan menilai dampak dari susunan turbin pasutnya terhadap lingkungan. Selain itu, di makalah ini disajikan pula sistem pendukung keputusan yang melibatkan seluruh prosedur karakterisasi sumber daya yang telah dikembangkan untuk memfasilitasi analisis dan mendukung pemerintah dalam penilaian dan perencanaan tata ruang dari penempatan rangkaian turbin pasut. Hasil dari prosedur yang diterapkan di lokasi-lokasi yang telah dipilih oleh pemerintah Indonesia memberikan gambaran tentang potensi energi arus pasut secara nasional.

The Eastern Mediterranean Sea is known as oil pollution hotspot because of high marine traffic and a growing number of oil and gas industrial activities inside, which makes efficient monitoring oil spills important in this area. Spaceborne Synthetic Aperture Radar (SAR) plays an important role for oil spill detection with its advantage of wide coverage and all-weather observations. However, discriminating whether the dark formations in the SAR imagery are from actual oil spills or look-alikes has been a challenging part. This study applied You Only Look Once version 4 (YOLOv4) object detection algorithm as an one-class (i.e. oil spill) object detector for learning oil spill features inside the Region of Interests (ROIs) and the background information from the rest of the image. The preliminary results pointed out that the pixel threshold for removing some tiny oil spills is suggested as they appeared regularly in the study area but are hardly visible. The average precisions (AP) of the trained model on validation and test sets are 67.80% and 65.37%, showing that the model is not overfitting on our training and validation sets. In addition, this study recommended some data augmentation strategies which might help improve the results.

A variational assimilation scheme was modified for practical application of wave simulation in German Bight. Sensitivity analysis showed that responses of sparsely distributed observing sites to the errors of boundary conditions on wave boundaries crucially depend on observing locations and wave conditions. Therefore, a scheme designed for low spatial observation coverage is proposed. The scheme assumes that control variables can be expressed by a set of spatially uniform variables (referred to as basic control variable) adding varying perturbations. The basic control variables are assumed containing all the errors, so assimilation can proceed through adjusting them only. Twin experiments with pseudo-observations were conducted to assess the feasibility of the scheme with basic control variables. The proposed scheme using a single observational location shows a comparable assimilation effect to the original scheme without the basic control variable assumption using 25 observational locations, reducing the spectrum root mean square errors by approximately 50% throughout the whole computation domain. The practical experiment was performed over 1 day, considering both wave boundary conditions and wind fields as control variables. The spectrum root mean square errors at the validation buoy decreased by more than 60% via the proposed assimilation scheme with observations from a single in situ buoy. Overall, although the basic variable assumption will overestimate the spatial correlation of the errors and consequently adjust the control variables improperly in some areas, the scheme remains a good option for nearshore wave simulation where sea states are strongly correlated when observations are spatially limited.

This study presents the development of a simple and generally applicable method for estimating ecological carrying capacity (ECC) of coastal finfish cage aquaculture at the system-scale in Southeast Asia and potentially other data-poor island nations. The ECC method relies primarily on results of dynamic models for simulation of organic loading due to multiple fish farms. In this study, the ECC method was successfully integrated within a methodology under development at Kiel University to holistically evaluate site suitability, ecological carrying capacities at farm-level and system-scale, as well as siting. Results of the application of the methodology for a target aquaculture site in northwest Bali, Indonesia, are presented in this study. Analysis of these results identified traditional fish farms located outside suitable areas and large-scale commercial farm clusters operating beyond ecological carrying capacity. Nonetheless, it was found that production output of the site in Bali is far below ECC and that it could be increased considerably without harming the environment. Recommendations have been made for reallocating the mispositioned farms as well as for reducing fish production of the farm clusters while expanding overall fish production to the east. The ongoing operational early warning monitoring at the site in Bali is being supplemented with regular monitoring of sediment quality in the seafloor and water quality in the aquaculture area to promote sustainable development. The proposed methodology has wide applicability and can be easily adapted to other regions for investigating present conditions and planning new aquaculture sites in pristine regions. The methodology is currently being up scaled to several target sites selected by the Indonesian Government to expand the activity.

Wind stress is the most important driving force for storm surge in coastal waters. Currently, the parameterization of wind stress is still not well developed and is the most uncertain parameters for storm surge models. In this paper, a storm surge model for the German Bight is developed using the model Delft3D. The data assimilation method, adjoint-free 4Dvar, which is relatively easier to be implemented than the adjoint method, is used to assimilate measured water level data into Delft3D. The storm surge prediction is more accurate when we adjusted the drag coefficient using the adjoint free data assimilation method, than in a companion forward model. The drag coefficient is consistent with results from previous studies. The wind drag coefficient is also calculated using results of a wave model. It has been found that the relation between the drag coefficient and wind speed is approximately linear in the deep water. But in the shallow water, wind drag coefficient shows larger variability due to the wave shoaling effect. The linear relation adjusted by data assimilation agrees well with that derived from a wave-related formula. It is also found that wave-related parameterization scheme is necessary for shallow waters.

In this paper, results of a tidal stream resource assessment performed for the Strait of Larantuka, Indonesia are presented. The methodology followed is comprising of the estimates of power yield and evaluation of the effects of power extraction via high-resolution, three-dimensional flow models. Power densities exceeding 10kW/m2 are observed in the main channel. Current velocities, and wake characteristics of the turbines have been resolved reasonably well with low computational cost, considering different levels of energy dissipation. Although the results are promising, investigations using in-situ measurements alongside more advanced modelling techniques are still needed, and currently underway.

This paper summarizes the development steps of a 4D variational assimilation scheme for nearshore wave models. A partition method is applied for adjusting both wave boundary conditions and wind fields. Nonstationary conditions are assimilated by providing defined correlations of model inputs in time. The scheme is implemented into the SWAN model. Twin experiments covering both stationary and nonstationary wave conditions are carried out to assess the adequacy of the proposed scheme. Stationary experiments are carried out considering separately windsea, swells, and mixed sea. Cost functions decline to less than 5% and RMS spectrum errors are reduced to less than 10%. The nonstationary experiment covers 1 day simulation under mixed wave conditions with assimilation windows of 3 h. RMS spectrum errors are reduced to less than 10% after 30 iterations in most assimilation windows. The results show that for spacially uniform model inputs, model accuracy is improved notably by the assimilation scheme throughout the computational domain. It is found that under wave conditions in which observed spectra can be well classified, the assimilation scheme is able to improve model results significantly.

Dalledonne, G. L., and Mayerle, R., 2016. Modelling of storm impacts on the Shandong peninsula coast. This paper presents results of the investigation of the effect of storms on the morphodynamics of the Yantai coastal areas in the Shandong Peninsula, China. A two-dimensional depth integrated morphodynamic model for prediction of the morphological changes during extreme events was developed and applied. The model covers the entire Bohai Sea with increasing grid resolution towards the coastal areas near Yantai. Calibration and validation using tidal constituents and measured water levels and current velocities showed that the model is capable of predicting the hydrodynamics in good agreement with observations. Emphasis was given to the proper description of the spatial distribution of the seabed sediments and bed stratigraphy. The 20 most severe storms observed in the region from 2000 to 2013 were identified and reconstructed. Storm surges with increases in mean sea level of up to 1.7 m and signif...

The Strait of Larantuka, with highly energetic tidal stream currents reaching speeds of up to 3&ndash, 4 m/s, is a promising site for renewable electricity production from the ocean. This paper presents the results of an assessment regarding the potential hydrodynamic impacts, wake characteristics, and the performances of large scale turbine arrays in the strait. A high-resolution, three-dimensional baroclinic model is developed using the FLOW module of the Delft3D modeling system to simulate tidal currents. The energy of currents is assumed to be extracted by horizontal-axis tidal turbines, which can harness strong bi-directional flow, positioned on sequential rows and alternating downstream arrangements. Enhanced momentum sinks are used to represent the influence of energy extraction by the tidal turbines. Four different array layouts with rated capacities of up to 35 MW are considered. We find that, in the Strait of Larantuka, array layout significantly affects the flow conditions and the power output, mainly due to the geometric blockage effect of the bounded channel. With respect to undisturbed flow conditions in the strait, decreases in current speeds of up to about 0.6 m/s, alongside increases in the order of 80% near-shore are observed. While operating efficiency rates of turbines reaching around 50%&ndash, 60% resulted during the spring tide in the arrays with smaller rated capacities, the power output of the devices was negligible during the neap tide.

This paper presents the development of a simple and generally applicable hydrodynamic method for the estimation of production carrying capacity (PCC) of coastal finfish cage aquaculture. Dimensional analysis was used to find significant and general interdependencies between the hydrodynamics at fish farm locations and particulate wastes deposited on the seafloor by fish farms. Modeled ratios of deposition to emission of particulate wastes underneath fish farms were found to be primarily a function of the flow Reynolds numbers at the farming locations and the non-dimensional settling velocity of emitted wastes. In the non-dimensional model, farming conditions include daily feed rate, proportion of unconsumed feed, and carbon content in feed and fish feces. The relationship can be used to estimate the PCC of floating net cages imposing a threshold value for deposition. Results of in-situ assessments of the benthic impacts of several fish farms in an aquaculture site in the northwest of Bali, Indonesia were used to validate and demonstrate the effectiveness of the method. Predicted results were able to clearly identify fish farms operating beyond ecologically sustainable carrying capacity. The proposed method has broad applicability and could help make decisions regarding the estimation of production potential of individual farms in pristine areas, for providing first estimates in sites that have scarce data, and for assessment, expansion, and optimization of the currently operating aquaculture sites in Southeast Asia, China and potentially other data-poor island nations. As the method relies on dynamic models, it enables straightforward assessments over the entire aquaculture region.

This article presents a fast and suitable method to derive the spatial distribution of seabed grain sizes on tidal flats. A successful validation was carried out in the Dithmarschen Bight, a meso-tidal area of the German North Sea coast. In particular, the study is built on statistical correlations between observations of sediment sizes from 197 seabed samples and the numerical model output of flow-wave variables under specific marine and atmospheric forcings. The correlation between orbital velocities and mean grain sizes (d50) exhibited the best results, but it can be affected under low relative wave height ratios. The methodology was applied for the construction of a high-resolution map of grain sizes in the Dithmarschen Bight, which resulted in absolute and relative errors of 16 μm and 13%, respectively. The proposed relationship was also adopted to examine scenarios of field data scarcity.

This paper presents transport of a mixture of cohesive sediments and sand in the Paranagua Estuarine Complex in the south of Brazil. The estuary houses a navigation channel from the Atlantic Ocean to a busy harbour. The channel requires frequent dredging owing to sediment deposition to maintain navigable depth for vessels. A three-dimensional process-based model for sediment transport coupled with wave-current models based on the Delft3D modelling system is constructed for the estuary. Extensive field data concerning current velocity, water level, salinity and suspended sediment concentration were collected. The flow model that is necessary to run the sediment transport model was calibrated and validated using field measurements. In this paper only the results concerning the sediment motion are presented. Calibration and validation of the numerical model show that the results of sediment transport represent the field conditions well. Additional support for the validity of the computed results is provided by field data pertaining to bathymetry acquired in 2005 and 2006. The present study gives insight into the motion of cohesive sediments and the morphological behaviour of the estuary, and should help operators maintain the channel for navigation.

A multi-criteria assessment methodology that accounts for physical and environmental constraints is applied to assess the tidal stream power potential at eleven straits between Indian Ocean and inner Indonesian seas. In this paper, preliminary results of an assessment at the Strait of Larantuka are presented. The tidal stream power potential is evaluated on the basis of a calibrated and validated numerical model. It was found that the average tidal stream power density at some of the locations can exceed about 6kw/m2 and the practically exploitable energy yield from the Strait of Larantuka is about 20Gwh per year.

In this work, a two-dimensional numerical model based on Delft3D modelling system was setup to study the tidal characteristics of the Red Sea. Besides that, analyses of available observed time series of surface elevations were carried out. Sensitivity analyses of the numerical model were carried out by testing different model parameters aiming at selecting optimal settings. The model performance was evaluated against available time series of surface elevation observations. RMS error was found to vary from 0.03 to 0.1 meter, while the ADM values range from 0.02 to 0.05 meter. On the whole, the model is able to reproduce the tidal wave in the Red Sea, reflecting a consistent level of agreement with the observations and previous works. The model results suggest that the semidiurnal tidal waves play a major role in the region except in the central part of the Red Sea where amphidromic system exists. Major semidiurnal and diurnal tidal constituents were computed to generate co-charts and form factor. The results have revealed that the distribution of the co-charts of the major semidiurnal constituents M2, N2, and S2 show the existence of anticlockwise amphidromic system in the central part of the Red Sea at about 19.5°N, north of the Strait of Bab el Mandeb at 13.5°N and in the Gulf of Suez. The chart of the diurnal tidal constituent K1 showed a single counterclockwise system in the southern part of the Red Sea centred around 15.5°N. The form factor chart shows the appearance of diurnal character in the central part of the basin and the northern end of the strait. The hydrodynamics patterns under spring and neap tidal conditions were also analysed (during flood and ebb conditions). Model results showed that currents generally are weak and strongest currents are present in the strait of Bab el Mandeb and Gulf of Suez.

All North Sea countries are confronted by climate change impacts such as accelerated sea-level rise, increasing storm intensities resulting in as well higher set-up of storm surges as growing wave energy and a follow-up of morphological changes. Thus it is necessary to question the effectiveness of existing coastal protection strategies and to examine alternative strategies for coastal protection under a range of scenarios considered possible. Scenarios of accelerating sea-level rise leading to changes in sea level of up to 1 m or more by 2100 and higher set-up of storm surges with increasing wave energy have been used for planning purposes. Adaptation strategies for future coastal protection have been established in all North Sea countries with vulnerable coasts, observing two propositions: (1) structures are economic to construct in the short term and their dimensions easily adapted in the future to ensure flexibility in responding to the as yet undeterminable climate change impacts and (2) implementation of soft measures being temporarily effective and preventing counteraction to natural trends. The coastal protection strategies differ widely from country to country, not only in respect of distinct geographical boundary conditions but also in terms of the length of the planning period and the amount of regulations. Their further development is indispensable and emphasis must more and more be laid on strategies considering the effects of long-term development of coastal processes for future coastal protection. Filling gaps in knowledge is essential for developing sustainable adaptation strategies.

Mariculture (marine aquaculture) has been intensified and has created essential employment opportunities over the last two-decades in Indonesia, as well as many other countries in the world. This development has also augmented environmental concerns and questions about possible environmental impacts. Considerable amounts of nutrient waste in dissolved and particulate form were released by intensive fish faming into the environment through feed excess, soluble fish excretion and faeces production. One of the first steps to avoid the dangerous environmental impacts is careful site selection. Hence, before the implementation of fish farming mariculture activities, appropriate site conditions for culturing the species should be selected in order to minimize environmental impacts arising from the farming activities (sustainability) as well as to guarantee adequate conditions from the operational point of view (suitability). The paper focuses on the development of a Decision Support System (DSS) as a tool for the decision maker in coastal zone management and mariculture for the appropriate selection of mariculture site location. Extensive use of GIS as part of the Decision Support System was deployed in this study. The DSS is based on physical, chemical and sediment criteria as well as on data of conflicting coastal use. The GIS analysis results in a map indicating the suitable areas for the improved method of offshore cage mariculture. In this study, emphasis was placed on finfish species, however the methods and results may be employed for other species as well following some modifications. The DSS was applied for the western part of Java Sea, Indonesia. The data were acquired from direct field measurement, numerical modelling and existing information from particular agencies. Numerical modelling was used to obtain spatial and temporal distributions of hydrodynamic parameters (i.e. current velocities and water levels). The Delft3D modelling system (Delft Hydraulics, The Netherlands) was employed for this purpose. The DSS was developed under GIS application of ESRI® ArcGIS™ using weighted overlay method. Due to lack of data, some parameters were excluded from the analysis. The results showed the adequacy of the system for supporting governmental authorities in the implementation, environmental controlling, and estimation of overall carrying capacity for environmental sustainable marine fish farming.

This paper is concerned with the simultaneous measurement of terrain heights and currents using an airborne interferometric synthetic aperture radar (INSAR). For the first time, a hybrid two-antenna INSAR system with both along- and across-track baseline components is used to measure high-resolution digital elevation maps (DEMs) and current fields in a Wadden sea area. Coastal applications like the monitoring of sediment transport or the numerical modeling of morphodynamic processes require measurements of topography and currents. Classical in situ measurements of these parameters are both expensive and time consuming, or even impossible if higher spatial resolution is required. Pure along-track interferometers (ATIs) have demonstrated their ability to provide information on ocean currents, while across-track interferometric systems (XTIs) have been successfully used to measure DEMs. In this paper, a hybrid system with both ATI and XTI components is used to acquire synoptic measurement for the first time. An experiment with an airborne system taking data over a Wadden sea area is presented demonstrating the potential of the technique. A geometrical model is developed for the interferometric phase of hybrid INSAR systems. This model combines ATI and XTI techniques using a baseline that spans between two antennas consisting of along-track and across-track components. In this model, both the effect of topography and the radial velocity of the water surface enter into the resulting interferometric phase. To separate both components, the system takes data of the respective scene flying two or more tracks with different flight directions, e.g., antiparallel tracks. This approach leads to a set of linear equations that has a unique solution for the along- and cross-track phase. Finally, an additional phase bias has to be considered due to the radial velocity and the influence of squint. This is caused by a misregistration effect between both antennas, which is related to cross-track imaging of surface motion. The new INSAR technique is tested with data acquired during a campaign in February 1997 over the Weser Estuary at the German coast. The airborne INSAR system AeS-1 was used. The interferometer configuration consists of two SAR antennas separated by a mixed along-track and cross-track baseline. Two datasets acquired on antiparallel tracks are used. The calculated velocities were compared with a hydrodynamic model operated by the Federal Waterway Engineering and Research Establishment. The experimental results agree well with the numerical model. In particular, the mean velocity of 0.7 ms/sup -1/ matches in both datasets. Deviations in the fine-scale structure of the current field are discussed. Topographic analysis and validation are performed in a separate investigation. The impact of surface gravity waves and wind drift, which are known to cause significant artifacts in the ATI phase under certain circumstances, is discussed.

In this paper, an advanced methodology developed for the assessment of tidal stream resources is applied to several straits between Indian Ocean and inner Indonesian seas. Due to the high current velocities up to 3-4 m/s, the straits are particularly promising for the efficient generation of electric power. Tidal stream power potentials are evaluated on the basis of calibrated and validated high-resolution, three-dimensional numerical models. It was found that the straits under investigation have tremendous potential for the development of renewable energy production. Suitable locations for the installation of the turbines are identified in all the straits, and sites have been ranked based on the level of power density. Maximum power densities are observed in the Bali Strait, exceeding around 10kw/m2. Horizontal axis tidal turbines with a cut-in velocity of 1m/s are considered in the estimations. The highest total extractable power resulted equal to about 1,260MW in the Strait of Alas. Preliminary assessments showed that the power production at the straits under investigation is likely to exceed previous predictions reaching around 5,000MW.

This paper summarises results of investigations aiming at the improvement of the understanding about the wave conditions in the Paranagua Estuarine Complex (PEC) in the South of Brazil. The investigations were carried out in the framework of a joint-research project funded by the German Ministry of Education and Research and the Ministry of Science and Technology in Brazil. In this study a phase-averaged wave model was set-up and applied to the study area. The relevance of the main processes affecting wave generation and dissipation were investigated. Focus was given to the wave conditions in the vicinity of the harbour some 25km within the PEC. The fetch was found to have a major effect on wave generation in the study area. Significant wave heights up to about 0.6m resulted near the harbour during storms. The results obtained helped in advancing the development of the coupled process-based models for simulation of flow, waves and sediment transport in the PEC. It was found that although currents have a certain influence on the wave heights, the effect of the tidal variation resulted more significant. Moreover waves were found to affect the current velocities in shallow water areas and should therefore be included for enhancing the predictions of sediment transport rates particularly for more adverse wind conditions.Copyright © 2010 by ASME

The effectiveness of wave hindcasts as a means of providing representative and continuous forcing conditions for medium-scale morphodynamic models applied to the German North Sea coast is verified in this study. An existing process-based morphodynamic model covering a coastal area between the Eider and Elbe estuaries was implemented. The wave schematization along the model open-sea boundaries was derived from high-resolution wave hindcasts over a 40-year observation period at 21 locations. The analysis was based on the results of model simulations covering periods of about 10 years. With appropriate adjustments to the derived wave characteristics, the representative wave forcing conditions proved to be capable of correctly reproducing medium-scale morphodynamic behavior integrated over large areas. The hindcasted data also proved to be suitable in continuous simulations for predicting morphological changes on a seasonal basis.

Radar interferometry is known to be a useful technique for mapping terrain heights and surface currents. Several studies on along track or cross track interferometry provided highly accurate results. In the case of coastal applications a simultaneous measurement of topography and surface currents is beneficial. Therefore an approach for airborne interferometric measurements with a baseline consisting of an along and cross track component is presented. Analysis of experimental airborne interferometric data shows good results. The final accuracy is highly dependent on the accuracy of the navigation data of the aircraft.

The objective of this paper is to give an overview of the present status of the developments, limitations, difficulties, future trends and demands in the applications of the finite element models to real world problems. Apart from describing the three dimensional flow solvers employed and two applications to complicated real world problems, some important aspects such as pre-and post-processing, verification and validation of computer models as well as computer performance are also included.

A procedure, based on numerical models is proposed to investigate the processes involved during conditions of extreme water levels within the outer Elbe estuary at the German North Sea coast. Nonlinear interactions between the different processes are analyzed and adverse combinations are simulated yielding new scenarios. Various conditions in the astronomical tide, three major storm events over the North Sea, several external surges and an increase in the mean sea level are analyzed. Techniques for the modeling of each of the isolated processes are developed and individually verified. The isolated processes are temporally shifted relative to each other and superimposed in various combinations. The results obtained from the present method, provide new insights into the nonlinear interactions between the involved processes. Generally, the effects of the processes seem to be reduced in superpositions with high absolute water levels. However, due to the large scatter of the results no general relations are found. New extreme scenarios are determined by iterative maximizations of the peak water level of different superpositions around spring high tide.

In this paper the assessment of the preliminary results of a methodology to enable predictions of medium-term morphodynamics accounting for the effects of storms is carried out. The methodology integrates the approaches based on a morphological acceleration factor and on the empirical orthogonal functions to account respectively for the morphological changes on the medium and short term. In a very simplified fashion, the effects of the storms are represented by a superposition of most relevant bathymetrical changes. The effectiveness of the methodology was assessed for a coastal stretch along the German Baltic Sea. The analysis of the simulations of morphodynamics for a period of 10 years showed that the method is able to predict volumetric changes along the coastal stretches reasonably well. However it fails to describe the spatial variation of the morphological changes near the coast. Sensitivity studies show also that the results are significantly affected by the set-up scheme of the methodology. Preliminary results during the assessment of the methodology gave clues about the evolution of the morphology of the German Baltic Sea coast. The methodology can be used as a practical tool for initial assessments of tendencies of morphological evolution. Obviously, in this investigation, the method proposed to account for to the storms is a simplified representation of the reality. In this regard, further research is needed to include a more realistic representation of the chronology taking into account their intensity.

This paper investigates the predictive capability of a morphodynamic model in capturing the development of a tidal channel on the German North Sea coast which experienced migration in the last few years. A depth-averaged version of a process-based model, Delft3D, is used. A description of the set-up, calibration and validation of the process-based models is presented. Field measurements with a dense spatial and temporal coverage were used for the development of the models. Results from the hydrodynamic and sediment transport simulations were in agreement with observations. The morphodynamic model simulations were speeded up with a morphological acceleration factor in conjunction with a representative period. Results of model calibration and validation covering periods of several years proved the capability of the model to reproduce the migration of the tidal channel. According to the standards usually adopted for checking the accuracy of morphodynamic models, the performance of the model presented here was quite good. The model ability in predicting the migration in the medium-term was found to be dependent primarily on the accuracy of the starting bathymetry, characteristics of the substrata and of the mud sediment fraction as well as on the selection of the representative period. A reduction in the rate of migration of the tidal channel is predicted from 2008 till 2010.

This thesis presents a methodology of developing a quasi real time flow model in a coastal area. This model improves the water level conditions along the boundary of the flow model by the implementation of a set of neural network short term forecast.