shoreline detection capability of cosmo skymed and high resolution multispectral images

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河口デルタ海岸線の形成と変形に関する研究

Tohoku University田中仁課

Characterization of coastal environment by means of hyper- and multispectral techniques

The management of the coastal environment is a complex issue, which needs for appropriate methodologies. Erosional processes and longshore currents present in the submerged beach represent a serious danger for both people and human infrastructures. A proper integration between traditional and innovative techniques can help in the characterization and management of the beach environment. Several different multispectral and hyperspectral techniques were used to retrieve information about the hydro and morphodynamic settings of the Pisa province coast (Tuscany, Italy). Results were validated using about 130 samples collected along the study area, between the mouths of the Serchio river and the Scolmatore canal. The composition of sand samples was evaluated by means of petrographic microscopy and grain size analyses. The same samples were analyzed using an Analytical Spectral Device (ASD) Fieldspec. The obtained sediment spectral library was used to evaluate the differences in mineralogical composition, which can be related to different source areas. Results coming from spectroscopy were compared to those obtained from the petrographic and grain size analysis. Furthermore a multispectral aerial image was used to evaluate sediment distribution along the submerged beach, to map the geomorphic features and to detect the presence of longshore and rip currents. This works suggests that optical remote sensing technique can be profitably used in order to reduce the need for expensive and time consuming conventional analysis

Remote Sensing of Arctic Landscape Dynamics

Thesis (Ph.D.) University of Alaska Fairbanks, 2013Amplified warming in the Arctic has likely increased the rate of landscape change and disturbances in northern high latitude regions. Remote sensing provides a valuable tool for assessing the spatial and temporal patterns associated with arctic landscape dynamics over annual, decadal, and centennial time scales. In this dissertation, I focused on remote sensing studies associated with four primary components of arctic landscape change and disturbance: (1) permafrost coastline erosion, (2) thermokarst lake dynamics, (3) tundra fires, and (4) using repeat airborne LiDAR for the measurement of vertical deformation in an arctic coastal lowland landscape. By combining observations from several high resolution satellite images for a 9 km segment of the Beaufort Sea Coast between 2008 and 2012, I demonstrated that the report of heightened erosion at the beginning of the 2000s was equaled or exceeded in every year except 2010 and that the mean annual erosion rate was tightly coupled to the number of open water days and the number of storms. By combining historical aerial photographs from the 1950s and 1980s with recent high-resolution satellite imagery from the mid-2000s, I assessed the expansion and drainage of thermokarst lakes on the northern Seward Peninsula. I found that more than half of the lakes in the study area were expanding as a result of permafrost degradation along their margins but that the rate of expansion was fairly consistent (0.35 and 0.39 m/yr) between the 1950s and 1980s and 1980s and mid-2000s, respectively. However, it appeared that in a number of instances that expansion of lakes led to the lateral drainage and that over the 55-year study period the total lake area decreased by 24%. While these studies highlight the utility of quantifying disturbance during the remotely sensed image archive period (~1950s to present) they are inherently limited temporally. Thus, I also demonstrated techniques in which field studies and remote sensing data could be combined to extend the identification of landscape disturbance events that occurred prior to the remote sensing archive. I identified two large regions indicative of past disturbance caused by tundra fires on the North Slope of Alaska, which doubled the delineated area of tundra fire disturbance on the North Slope over the last 100 to 130 years. I conclude the dissertation by demonstrating the utility of repeat airborne light detection and ranging (LiDAR) data for arctic landscape change studies, in particular vertical surface deformation, and provide momentum for going forward with this emerging technology for remote sensing of arctic landscape dynamics. The quantification of arctic landscape dynamics during and prior to the remote sensing archive is important for ongoing monitoring and modeling efforts of the positive and negative feedbacks associated with amplified Arctic climate change

Combined flooding and water quality monitoring during short extreme events using Sentinel 2: the case study of Gloria storm in Ebro delta

Short extreme events have significant impact on landscape and ecosystems in low-lying and exposed areas such as deltaic systems. In this context, this paper proposes a combined methodology for the mapping and monitoring of the flooding and water quality dynamics of coastal areas under extreme storms from Sentinel 2 imagery. The proposed methodology has been applied in a coastal bay of the Ebro Delta (Catalonia, NE Spain) to evaluate jointly the impact of Gloria storm (January 2020) in land-flooding and water quality. The experimental results show that the Gloria storm had a strong morphological impact and altered the water quality (chl-a) dynamics. The results show a recovery in terms of water quality after some weeks but in contrast the coastal morphology did not show the same degree of resilience. This paper is the first step of an overall goal that is to set the bases in a long term, for a workflow for rapid response and continuous monitoring of storm effects in coastal areas and/or highly valuable ecosystems such as the Ebro Delta.This research was partially funded by the project New-TechAqua (European Union's Programme H2020, GA 862658). J. Soriano-González held a pre-doctoral grant funded by by Agència de Gestió d’Ajuts Universitaris I de Recerca (2020FI_B2 00148)Peer ReviewedObjectius de Desenvolupament Sostenible::14 - Vida SubmarinaObjectius de Desenvolupament Sostenible::13 - Acció per al ClimaPostprint (published version

Estuarine geomorphodynamic assessment of environmental change and stressor impacts: a geographic information systems and remote sensing (geoinformatic) modelling approach for sustainable management of southeast Australian coastal ecosystems

Increased habitation and global warming is posing growing threats to the coastal zone and estuarine settings through direct and indirect environmental and anthropogenic modification of sensitive coastal systems and their relevant catchments. It is essential to understand the impact of the different stressors on the coastal environment under current conditions and within the historical record in order to predict future responses of estuaries and coastal wetlands. Short-term remote sensing and GIS modelling and field assessment have made a significant contribution to our knowledge on estuarine and coastal wetland dynamism within the last few decades. This thesis assesses the potential impacts of anthropogenic modifications, climatic factors and sea level rise on estuarine eco-geomorphic intertidal sedimentary landforms and their associated coastal wetlands in southeastern Australia based on three estuarine systems on the south coast of NSW: the estuarine Comerong Island, Wandandian deltaic estuary, and Towamba estuary. The thesis’ short-term evaluation approach shows that the degradation levels on estuarine platforms are dependent on catchment development, sediment characteristics, ecosystem stability and sea level rise inundation. During anticipated climate change and rising sea level conditions, estuaries depend on their sediment source areas, especially on modifications to their river catchment. Catchments with high anthropogenic modification levels, like the dam infrastructure in the Shoalhaven River catchment, influence sediment availability and transportation with clear impacts on eco-geomorphic coastal platform losses. In contrast, mostly unmodified but high-sloped catchments, such as the Towamba example, may have other negative effects on the estuary since the sediments are poorly sorted and coarser noncohesive quartz-dominated particles cause the geomorphic landforms and associated ecosystems to be more vulnerable to erosion and lead to less stable vegetation. Regions with small moderately modified catchments, such as the Wandandian site, allow ideal geomorphic processes to occur. Here, sediment is weathered slowly and moved downstream naturally to a secure inner estuarine deltaic setting where fine sandy/silty particles accumulate and provide more geomorphic stability. Associated vegetation assemblages ensure the progradation and steady growth of the deltaic eco-geomorphic system. The thesis assessment shows the eco-geomorphic-dynamism of the Towamba estuary, which has a mostly unmodified catchment surface (only 14% anthropogenic modifications), has grown a total of 0.17 km2 since 1949. This growth rate indicates that the Towamba estuary future scenarios will mostly be filled at the completion of the 21st Century. In comparison, the partially modified (22.1%) catchment has prograded the Wandandian deltaic shorelines resulting in the total growth of 0.24 km2 during the study period (1949-2016). However, results on Comerong Island show significant changes in the spatial extent, elevation, and shorelines with total net losses of 0.3 km2 over the investigated timespan (1949-2014). Changes included northern accretion (0.4 km2), and western, middle and southern erosion (0.7 km2) of the island. The thesis emphasises the dynamic character of the estuarine eco-geomorphic system, particularly using Normalised Difference Vegetation Index (NDVI) as a vegetation canopy assessment approach. This approach illustrates the significant correlations between vegetation and climatic and geomorphic influences at the study sites, indicating that these factors are the main drivers of vegetation canopy disturbance on intertidal sedimentary landforms during the 21st Century. Locally, map-algebra expression shows the spatial distribution of the NDVI identifies areas that need to be managed in relation to the causes and drivers. This modelling confirms the LiDAR-DEMs-driven character of the existing situations to their influencing factors, which also control the estimated future-scenarios and illustrate clear inundatable landform zones at the study sites by 2100. Results indicate that the rise of sea level will have tremendous effects on the coastal eco-geomorphic systems, particularly wetlands, throughout southeastern Australia and equivalent systems overseas by the end of this century. This thesis develops possible mitigation and adaptation strategies and sustainable solutions that might be utilized to minimize the indirect devastating consequences of climate change and anthropogenic modifications, particularly damming rivers, which cause direct sedimentation problems as implied by the Tallowa Dam case study. The thesis shows that intertidal sedimentary landforms will have a future negative or positive vegetarian response according to their evolving morphological character. Within a short-term timescale, the whole eco-geomorphic system will interact with many environmental and anthropogenic variables (particularly sedimentation rates) to evolve its own character over a longer timescale. Therefore, the long term assessment approach can be directed by having a better understanding of the existing situation and accurately identifying the past drivers. Future projections indicate that indirect anthropogenic-induced global warming will have a great effect on estuaries and coastal wetlands in the 21st Century. This research helps to provide an important framework for quantifying the current situation, future stressors and vulnerability responses during any intensification of natural and artificial coastal hazards, which may be of concern to the general public and environmental scientists who are currently focusing their attention on the best way to preserve estuaries and their wetland ecosystems at the current stage of global warming and human settlement

Late Quaternary Evolution of Western Australian Continental Shelf Sediment Systems

This thesis shows how Western Australian coast and continental shelf evolved into their present form, in response to changes in sea-level and climate, during the last Glacial Age. I have focused on four contrasting marine environments: the Kimberley coast and offshore islands, Shark Bay, the Swan River estuary and Geographe Bay. In each area, I took a multidisciplinary approach to my data collection and analysis utilising remote sensing, marine geophysics, sedimentological and geochronological methodologies