Coastal processes modify projections of some climate-driven stressors in the California Current System

Global projections for ocean conditions in 2100 predict that the North Pacific will experience some of the largest changes. Coastal processes that drive variability in the region can alter these projected changes, but are poorly resolved by global coarse resolution models. We quantify the degree to which local processes modify biogeochemical changes in the eastern boundary California Current System (CCS) using multi-model regionally downscaled climate projections of multiple climate-associated stressors (temperature, O2, pH, Ω, and CO2). The downscaled projections predict changes consistent with the directional change from the global projections for the same emissions scenario. However, the magnitude and spatial variability of projected changes are modified in the downscaled projections for carbon variables. Future changes in pCO2 and surface Ω are amplified while changes in pH and upper 200 meter Ω are dampened relative to the projected change in global models. Within the CCS, differences in global and downscaled climate stressors are spatially variable, and the northern CCS experiences the most intense modification. These projected changes are consistent with source waters lower in oxygen, higher in nutrients, and in combination with solubility-driven changes, altered future upwelled waters in the CCS. The results presented here suggest coastal process resolving projections are necessary for adequate representation of the magnitude of projected change in pH and carbon stressors in the CCS.

Development of CAGeD Observation Station and Its Impact on Coastal Process

Universiti Tun Hussein Onn Malaysia (UTHM) collaboration with the Center of Applied Geomatics for Disaster Prevention (CAGeD) had developed an observation station as a catalyst for oceanographic and environmental research work and landmark of development in Tanjung Laboh. In conjunction with the construction of the station, monitoring of coastal process was carried out to identify the characteristics of sediment as input to the transportation of sediment around the construction area of the station in Tanjung Laboh. 20 points of surface sediment sampling were carried out along 200 meters of Tanjung Laboh bay during high tide. At the same time, the current speed test was carried out at the same point to identify the relationship of current speed to the transportation of sediment. All collected sediment samples have performed a test using wet sieve analysis (hydrometer), dry sieve analysis and specific gravity. The result found that the specific gravity of sediment at the study area is 2.53 and categorized as marine clay. The particle size distribution of sediment at the study area is silty clay due to the dominant of silt fraction. The percentage of sediment characteristics can be influenced by current velocity and sediment transportation.

Analisis Regresi Pada Tren Perubahan Garis Pantai di Pantai Krui dari Digitasi Citra Landsat

Krui is a capital of Pesisir Barat Regency of Lampung Province which has important values on residential areas, business centers, government centers, and tourism destination. Kruis coast is adjacent to the Indian Ocean, which has the high wave characteristic cause the dynamic coastal process similarly to other sandy beaches on the west coast of Sumatera Island. The coastal process can be shown in the form of either coastline accretion due to sedimentation or shoreline reduction caused by the phenomenon of erosion and abrasion. The coastal process can be observed as a natural process to achieve an equilibrium of sediment transport along the coast. Also, Shoreline change is influenced by the height waves and the direction of incoming waves towards onshore depending on the season. The aims of this study is to get an overview of the shoreline changes that occur on the Krui Coast. Then it can be predicted the position of the coastline in the future. The regression model was chosen to estimate the position of shoreline in the future by utilizing a set of time-series data that refers to shoreline change within certain periods. Digitized Landsat-7 ETM+ satellite imagery is conducted in order to obtain shoreline position data in every year determinate as historical data. Based on this study, the rate of shoreline change in Krui Coast is within range of 0,12 meters/year to 41,35 meters/year, where is the shoreline change tends to increase. Keywords: Digitization, Landsat, Shoreline, Regression

Relationships between regional coastal land cover distributions and elevation reveal data uncertainty in a sea-level rise impacts model

Understanding land loss or resilience in response to sea-level rise (SLR) requires spatially extensive and continuous datasets to capture landscape variability. We investigate the sensitivity and skill of a model that predicts dynamic response likelihood to SLR across the northeastern US by exploring several data inputs and outcomes. Using elevation and land cover datasets, we determine where data error is likely, quantify its effect on predictions, and evaluate its influence on prediction confidence. Results show data error is concentrated in low-lying areas with little impact on prediction skill, as the inherent correlation between the datasets can be exploited to reduce data uncertainty using Bayesian inference. This suggests the approach may be extended to regions with limited data availability and/or poor quality. Furthermore, we verify that model sensitivity in these first-order landscape change assessments is well-matched to larger coastal process uncertainties, for which process-based models are important complements to further reduce uncertainty.

Prediction of shoreline change using a numerical model: case of the Kulon Progo Coast, Central Java

Kulon Progo Airport is an airport development project located in the coastal area near Yogyakarta, Indonesia, which is expected to complete in 2019. With the increase in population, huge land acquisition will be difficult, so the development of coastal areas for the airport became inevitable. Kulon Progo is located in the disaster-prone zone area of the earthquake and tsunami, the airport design must consider the risk management and mitigation from tsunami and earthquake disaster. Although the airport is already calculated the danger of earthquake and tsunami, the development of the coastal area also needs to consider the danger of the natural coastal process itself such as sedimentation and erosion. Shoreline changes due to the new infrastructure in the coastal area can disrupt the equilibrium of coastal process especially the longshore sediment transport. A satellite image shows that Kulon Progo shoreline retreats over 60 meters due to the heavy sediment longshore transport in the past 10 years. Breakwaters in Tanjung Adikarto fishing port also made a great contribution in huge sedimentation behind the infrastructure up to 90 meters. This research will conduct an analysis trough satellite and numerical model to observe the shoreline changes along Kulon Progo Coast. A numerical model shows a high erosion rate along the coast. High sedimentation also observed at the river mouth of Bogowonto and Serang Rivers.

HIGHLY RESOLVED DIRECTIONAL PROPERTIES OF WIND WAVES AND SWELL WITH VARIOUS SCALES

Wave directional spectrum is basic information as the forcing on the coastal process. The directional properties of coastal waves have been widely investigated through observations and the results are applied for design use of coastal structures and implementation of numerical wave model. But these studies focused only on wind waves under moderate sea conditions because the limitations of instruments such as buoys and wave staffs make them unsuitable for observing under various sea conditions including the severe sea. Thus there are few systematic studies for coastal engineering application which needs treatment for various sea state, from modest to severe sea. In this study, we observed the wave directional spectrum with the bottom mounted ADCP (Acoustic Doppler Current Profiler) which can record even under severe conditions. We investigated the directional properties of wind waves and swell with various scales.

THE NEED FOR PHYSICAL MODELS IN COASTAL ENGINEERING

Coastal process understanding is based on observations of physical processes in the field and laboratory from which theories are developed. Theories may be expressed mathematically and coded into numerical models. Compared with the cost of field data acquisition and laboratory experiments, the cost of numerical modelling is often perceived to be low. Therefore, there is a tendency to undertake coastal investigation and design using numerical modelling methods alone. However, there is still a need for physical modelling in coastal engineering.

Relationships between regional coastal land cover distributions and elevation reveal data uncertainty in a sea-level rise impacts model

Understanding land loss or resilience in response to sea-level rise (SLR) requires spatially extensive and continuous datasets to capture landscape variability. We investigate sensitivity and skill of a model that predicts dynamic response likelihood to SLR across the northeastern U.S. by exploring several data inputs and outcomes. Using elevation and land cover datasets, we determine where data error is likely, quantify its effect on predictions, and evaluate its influence on prediction confidence. Results show data error is concentrated in low-lying areas with little impact on prediction skill, as the inherent correlation between the datasets can be exploited to reduce data uncertainty using Bayesian inference. This suggests the approach may be extended to regions with limited data availability and/or poor quality. Furthermore, we verify that model sensitivity in these first-order landscape change assessments is well-matched to larger coastal process uncertainties, for which process-based models are important complements to further reduce uncertainty.

MAIN TRENDS OF THE SAMBIAN COASTAL SYSTEM (SOUTH-EASTERN BALTIC) DEVELOPMENT: HOLOCENE LITHODYNAMICS AND RECENT COASTAL PROCESSES

Synthesis of long-term geological research on the Russian region of the southeastern Baltic and its coastal zone has allowed for the establishment of boundaries and determination of the time of formation and the structure of the Sambian morpho-lythodynamic marine and coastal system. The systems studied include the coastal zone (at a the water depth of 30 m according to longshore storm wave current impacts) and adjacent silty-clay sedimentation basins. The development of the Curonian Spit area in the Late Pleistocene – Holocene was reconstructed based on marine geological and geophysical study and modelling. Comparative analyses of the geological settings of the Curonian and Vistula Spits and lagoons has shown that the mechanisms for their development are significantly different. By the late Holocene, the southeastern Baltic Sea consisted of several lithodynamic coastal systems. By 5 ka BP, both lagoon systems had formed. Evolution of the spits and lagoons during the last 5000 years caused the development of similar morphological features. The Vistula and Curonian lagoons transformed into sediment traps for alluvial deposits of the Neman and Pregola Rivers. Smoothing of the shoreline as a result of longshore sediment drift is a dominant coastal process.

MAIN TRENDS OF THE SAMBIAN COASTAL SYSTEM (SOUTH-EASTERN BALTIC) DEVELOPMENT: HOLOCENE LITHODYNAMICS AND RECENT COASTAL PROCESSES

Synthesis of long-term geological research on the Russian region of the southeastern Baltic and its coastal zone has allowed for the establishment of boundaries and determination of the time of formation and the structure of the Sambian morpho-lythodynamic marine and coastal system. The systems studied include the coastal zone (at a the water depth of 30 m according to longshore storm wave current impacts) and adjacent silty-clay sedimentation basins. The development of the Curonian Spit area in the Late Pleistocene – Holocene was reconstructed based on marine geological and geophysical study and modelling. Comparative analyses of the geological settings of the Curonian and Vistula Spits and lagoons has shown that the mechanisms for their development are significantly different. By the late Holocene, the southeastern Baltic Sea consisted of several lithodynamic coastal systems. By 5 ka BP, both lagoon systems had formed. Evolution of the spits and lagoons during the last 5000 years caused the development of similar morphological features. The Vistula and Curonian lagoons transformed into sediment traps for alluvial deposits of the Neman and Pregola Rivers. Smoothing of the shoreline as a result of longshore sediment drift is a dominant coastal process.