This study is based on restoration of Kinmen coast fishing village of hydraulic model test of a comparative analysis of the planned project, as a result of long-term by Kinmen County coast north-east monsoon and the impact of ocean currents. In recent years, many coastal erosion and land damage case of loss. In order to avoid continued erosion, Kinmen county government since starting in 1990 for rebuild seawall to protect the coast. This paper is mainly due to a new erosion of lake waters near the fishing village, and a result of Economic Planning and Development Council's request for a hydraulic model test and do the related planning and research. In order to achieve the purpose of beach erosion does not continue to be subject to planning. It can be found from previous research to study, the tidal effects of drift sand to the scene by investigate multi-based; and laboratories in order to describe the phenomenon of the different drift sand sharply degrees and to examine the different size. The purpose of this study is the tidal waves of the beach bed on the role, which will be part of tidal changes in water level simulation. Test results to a net drift of sand to make a comparative analysis of throughput and classified by Horikawa compared cross-section tank. The typhoon waves should be able to tell by the tidal waves but the bed is the rules of dramatic impacted. The monsoon is not much variance. In addition monsoon forecasting can be applied to multi-wave cross-section of the terrain slope changes. In addition it can be not exercised after the embankment of typhoon waves in Horikawa empirical section.

During the onslaught of a storm on the coasts of Taiwan in summer and autumn, large waves and storm surge have often caused beach erosion. In order to mitigate coastal disasters and erosion, soft-options have been promoted in recent years, to fulfill the purpose of shore protection, as well as to meet the new requirements of landscape, ecology and recreation. Consequently, semi-natural approaches have been adopted in stead of the conventional hard-structures. This thesis aims to report a study on the effects of detached submerged breakwater layouts and storm wave types on beach profile changes and berm retreat. In order to establish a practical procedure to assist the assessment of beach profile changes with submerged breakwaters during storm, we first collect and analyze the beach profile change data performed in large wave tanks (CE from the US and PI from Japan), and apply the well known SBEACH model to derive regression relationship between the two key parameters ( and ) in this model against the non-dimensional fall velocity ( ). The suggestion of Larson and Kraus (2000) to include hard bottom option in SBEACH with a set of modified and values, which may be different from that originally developed for a sandy beach environment, is then carried out using the beach profile changes results conducted experimentally with submerged breakwaters (Risio and Lisi, 2010). Consequently, we have conducted the numerical experiments systematically to study the beach profile changes using submerged breakwaters under various environmental combinations (with 10 different offshore distances, 10 breakwater heights, 10 crown widths and 4 types of storm wave conditions derived from storm return periods), from which a new set of and values are derived and used in SBEACH for the investigation of installing submerged breakwaters to mitigate potential beach erosion. Our numerical investigations using SBEACH for a beach with submerged breakwater reveal that: (1) Beach profile changes in erosion (0 m line and berm) and accretion (0 m line) due to regular waves are more significant than that of irregular waves. (2) Storm waves with a long return period cause more erosion to the shoreline (0 m line) and berm, while that with short return period may produce accretion to the shoreline. (3) The further a submerged breakwater away offshore, the more sediment transportation offshore and severe beach and berm erosion. (4).An increase of submerged breakwater height would result in accretion near the 0 line; except during a violent storm event, when an increase of berm height could reduce berm erosion. (5) An increase to the crown width of a submerged breakwater could only become effective to reduce wave energy and berm erosion, if an appropriate breakwater height is used; otherwise, a mere increase in width with insufficient height would increase wave height and berm erosion.

Bering Sea storms regularly bring adverse environmental conditions, including large waves and storm surges of up to 4 m, to the west coast of Alaska. These conditions can cause flooding, erosion and other damage that affects marine subsistence activities and infrastructure in the low-lying coastal communities. Storm impacts also include interactions with sea ice in various states: large floes, shore-fast ice, the acceleration of sea-ice formation in frazil or slush state, and the formation of slush-ice berms. Slush-ice berms are accumulations of slush ice that develop under the right wind, water level, water and air temperature, and snow conditions. During a strong wind event, large amounts of slush may be formed and pushed onto the shore, where the slush can accumulate, solidify and protect communities from flooding and erosion. Slush ice berms can also be problematic, restricting access to the coast and presenting other hazards. Residents of Shishmaref and Shaktoolik, communities on the west coast of Alaska, observed the formation of slush-ice berms during storms that occurred in 2007, 2009 and 2011. These formations are important to the communities, and it would be useful to develop the capacity to predict their occurrence. However, scientific work has not been conducted on this phenomenon, with the result that a physical conceptual model describing the formation of slush-ice berms does not exist. In recognition of this need, a project thesis was designed, and had as its main objective to identify and document the environmental and synoptic weather conditions that lead to these types of events, and to develop a descriptive physical conceptual model of slush-ice berm formation. A key to this work was the engagement of traditional knowledge holders and local observers to gather data and information about slush ice and slush-ice berm formation, along with the specific dates when these events took place. This dissertation is organized around three major elements: development of a conceptual model of slush-ice berm formation; presenting the traditional knowledge gathered that led to the development of this model; and documenting the methods and tools used to engage traditional knowledge holders and local observers in this process. In this dissertation, the knowledge from traditional knowledge holders on slush ice formation is presented in the context of feeding into a physical scientific process – specifically, developing a descriptive physical conceptual model of slush-ice berm formation. It is expected that this type of research will contribute to slush-ice berm forecasting which would aid communities’ safety by improving assessment of environmental risk. / Graduate

Coastal regions are extensively utilized by constructing coastal structures and facilities, as a result of the economical potential they offer. In designing and construction of coastal structures, it is important to achieve an optimum design satisfying both the stability and the engineering economy requirements effectively, regarding the natural balance of the coastal region. In this study, first step model tests on the stability of the coastal protection structures of Eastern Black Sea Highway Project under construction, proved that the structure is not stable and safe under severe wave action. As an innovative approach, using Van der Meer&amp / #8217 / s approach and berm design guidelines alternative cross sections were generated.In the second step of the model studies, 8 different models were constructed using a model scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The newly designed and optimized berm type structure was proved to be successful and economical.

No description available.

On the basis of coastal disaster mitigation and protection, a beach must have sufficient width for preventing the destruction to public facilities, as well as protecting the safety of life and private property during storm events. The requirement of such a horizontal extent from the initial shoreline to the probable erosion landward to safeguard against the onslaught of a storm is referred to as ¡¥storm beach buffer width¡¦. Upon neglecting the effects of global warming and sealevel rise on a beach and berm with profile in equilibrium, numerical calculations are conducted first to validate the range of the most important parameters (K »P £` ) in the SBEACH model using the results of profile changes available from the CERC¡¦s large wave tank (LWT) tests in 1960s. These results are then applied to assess the profile changes for a beach with a vertical seawall and the other without sufficient berm, subject to the normal incidence of storm waves over a specific duration. Finally, a total of 48 cases with sufficient beach width are then investigated, from which a multiple linear regression model is proposed to determine the extent of berm retreat, as well as the location and height of a submerged offshore bar, for the benefit of coastal profession on preliminary design of storm buffer. Our modeling results using SBEACH reveal that: (1) A seawall without or with insufficient fronting beach could result in serious scour at its toe and even the total loss of the entire beach berm; (2) A beach with sufficient berm, natural or artificially nourished, is capable of protecting the back beach, despite the temporary erosion in the early hours of a storm action; (3) Under the same conditions of wave height and period, a wide buffer is necessary for a beach with small mean sand grain, and the berm height should be designed at 1.6 times of the designed storm surge level, in order to effectively absorb storm wave energy and maintain the provision of a storm buffer; and (4) The multiple linear regression model proposed in this study can be used to evaluate the scour depth and retreat of the berm, as well as the width of a storm beach buffer, upon the input of wave conditions and mean beach sand grain etc.

Dredging is often conducted to maintain authorized depths in coastal navigation channels. Placement of dredged sediment in the form of nearshore berms is becoming an increasingly popular option for disposal. Compared to direct beach placement, nearshore berms have fewer environmental impacts such as shore birds and turtle nesting, and have more lenient sediment compatibility restrictions. Understanding the potential morphological and sedimentological evolution is crucial to the design of a nearshore berm. Furthermore, the artificial perturbation generated by the berm installation provides a unique opportunity to understand the equilibrium process of coastal morphodynamics. Matanzas Pass and Bowditch Point, located on the northern tip of Estero Island in west-central Florida were dredged in October 2009. The dredged material was placed approximately 600 ft offshore of Fort Myers Beach and 1.5 miles southeast of Matanzas Pass, in the form of an artificial berm. Time-series surveys and sediment sampling were conducted semi-annually in order to quantify sedimentological characteristics and morphological changes within the first year after construction of the berm. The artificial berm at Fort Myers Beach is composed mainly of fine sand. Patches of mud were found throughout the study area, with the highest concentrations being in the trough landward of the berm, and offshore southeast of the berm area. The highest concentration of carbonates was found in the swash zone, as well as at the landward toe of the berm, which coincides with the coarsest sediment. The overall mud content of the berm is lower than that of the dredged sediment, thus indicating a coarsening of the berm over time. The reduction in fines as compared to the original dredged sedimet could also indicate a selective transport mechanism that moves finer material offshore, and coarser material landward, a desirable trend for artificial berm nourishment. During the course of the first year, the berm migrated landward and increased in elevation. Onshore migration occurred mostly within the first 6 months. Along with onshore migration, the shape of the berm changed from a symmetrical bell curve to an asymmetrical shape with a steep landward slope. There is no clear spatial trend of volume change alongshore within the berm area, indicating that sediment transport is mostly cross-shore dominated. A salient was formed landward of the northern portion of the berm. Several gaps were created during berm construction due to dredging and placement techniques. These dynamic gaps are likely maintained by rip currents through them. This study showed that the Fort Myers Beach berm is active, due to its landward migration during the first year after construction.

Coastal defense structures have primary importance from obtainabilty of resources and benefits served by the coastal regions point of view. However, the construction of coastal defense structures demand a high amount of investment. Therefore, in order to reduce the risk of collapse of these structures, model studies should be carried during the design process. In this study, model investigations were carried out on Eastern Black Sea Highway Project regarding the serviceability and damage thus stability parameters. 5 different models were constructed as berm type rubble-mound breakwaters using Van Der Meer&rsquo / s approach and berm design guidelines, with a scale of 1/31.08 and they were tested both for breaking and non-breaking waves. The experiments took place in the Coastal and Harbor Engineering Laboratory of the Middle East Technical University, Civil Engineering Department. The models were constructed and tested with different berm widths and armor stone sizes forming the back armor layer in order to examine the effect of these design parameters on the stability and serviceability of the coastal defense structure to obtain the optimum alternative cross-section. Cumulative damage was minimum for the cross-section constructed with berm width 15 m assigning the width of the prototype. Water spray and run-up values were also not significant. The test results were confirming with Van Der Meer design approach.

Coastal defense structures are built in order to protect valuable coastal regions from the destructive effects of the waves. Due to the cost of coastal defense structures and the economical potential of the coastal regions, failure of such structures could cause loss of high amounts of investment. Therefore in the design and construction of coastal structures, it is of vital importance to achieve an optimum design which is not neither underdesigned nor overdesigned. In this study, Submerged Berm type coastal defense structures with several different cross-sections were tested for stability under storm conditions. Damage analyses of the different models were carried out to compare the structure characteristics under storm conditions and to obtain the most economical and stable cross-section. For the model studies, 5 different models were constructed by using Van der Meer&rsquo / s approach and berm design guidelines. Models were constructed with a model scale of 1:31.08 in the wave flume in the Coastal and Harbor Engineering Laboratory, Civil Engineering Department, METU. The newly designed and optimized berm type structure was proved to be successful and economical.

Les bords de route constituent un des principaux habitats herbacés et linéaires des paysages agricoles, ils jouent le rôle de refuge pour différentes espèces et constituent aussi un habitat favorable pour des espèces adventices jugées problématiques. L’objectif de cette thèse est de mesurer les effets de la structure du paysage et des pratiques de gestion sur la flore de l’interface route – champ cultivé. Nos résultats suggèrent que les communautés végétales de l’interface ont une réponse temporellement décalée vis-à-vis des changements paysagers. L’étude de la végétation exprimée et de la dispersion des graines montre que la fauche tardive n’est pas le levier de gestion optimal pour favoriser la diversité végétale du bord de route, et que les pratiques de fauche influencent aussi la flore de la bordure intérieure du champ. Afin de limiter les influences croisées des pratiques de gestion, nous suggérons des stratégies réfléchies à l’échelle de l’interface route – champ. / Road verges constitute the main herbaceous and linear habitats of arable landscapes. They represent a refuge for different species, but also constitute a habitat for weeds considered problematic. The aim of this thesis was to measure the effects of landscape structure and management practices on the flora of the road-field boundary. Our results suggest that plant communities of road-field boundary have a time lagged response to landscape changes. The study of the vegetation and of seed dispersal showed that late mowing was not the optimal method to promote plant diversity on road verges and that mowing practices also influenced the flora of the inner field margin. To limit the cross-influence of management practices, we recommend well thought out strategies at the scale of the road-field boundary.