scholarly journals Capturing Coastal Dune Natural Vegetation Types Using a Phenology-Based Mapping Approach: The Potential of Sentinel-2

2019 ◽  
Vol 11 (12) ◽  
pp. 1506 ◽  
Author(s):  
Flavio Marzialetti ◽  
Silvia Giulio ◽  
Marco Malavasi ◽  
Marta Gaia Sperandii ◽  
Alicia Teresa Rosario Acosta ◽  
...  
Keyword(s):  
Open Source ◽  
Sand Dunes ◽  
Cost Effective ◽  
Mediterranean Coast ◽  
Coastal Dune ◽  
Hierarchical Level ◽  
Remotely Sensed Data ◽  
Dune System ◽  
Lazio Region ◽  
Mapping Approach

Coastal areas harbor the most threatened ecosystems on Earth, and cost-effective ways to monitor and protect them are urgently needed, but they represent a challenge for habitat mapping and multi-temporal observations. The availability of open access, remotely sensed data with increasing spatial and spectral resolution is promising in this context. Thus, in a sector of the Mediterranean coast (Lazio region, Italy), we tested the strength of a phenology-based vegetation mapping approach and statistically compared results with previous studies, making use of open source products across all the processing chain. We identified five accurate land cover classes in three hierarchical levels, with good values of agreement with previous studies for the first and the second hierarchical level. The implemented procedure resulted as being effective for mapping a highly fragmented coastal dune system. This is encouraging to take advantage of the earth observation through remote sensing technology in an open source perspective, even at the fine scale of highly fragmented sand dunes landscapes.

No evidence for interspecific interactions between plants in the first stage of succession on coastal dunes in subarctic Quebec, Canada

1997 ◽  
Vol 75 (6) ◽  
pp. 902-915 ◽  
Author(s):  
Gilles Houle
Keyword(s):  
Plant Biomass ◽  
Interspecific Interactions ◽  
Regional Climate ◽  
Salt Spray ◽  
Coastal Dunes ◽  
Growing Season ◽  
Coastal Dune ◽  
Dune System ◽  
Abiotic Conditions ◽  
Herbaceous Perennials

Coastal dunes are very dynamic systems, particularly where the coast is rising as a result of isostatic rebound. In those environments, succession proceeds from plants highly tolerant to sand accumulation, salt spray, and low nutrient availability to less disturbance-tolerant and stress-tolerant, more nutrient-demanding, and supposedly more competitive species. In the subarctic, the regional climate exacerbates the stresses imposed by local abiotic conditions on the dunes. I hypothesized that facilitation would be particularly significant on the foredune of subarctic coastal dune systems because of intense stresses (local and regional) and frequent disturbance in the form of sand deposition. Belowground and aboveground plant biomass was sampled at three different periods during the 1990 growing season along transects perpendicular to the shoreline on a coastal dune system in subarctic Quebec (Canada). The three herbaceous perennials found on the foredune (Honckenya peploides, Elymus mollis, and Lathyrus japonicus) were segregated in time during the growing season and in space along the topographical gradient. The biomass of Honckenya, the first species encountered as one progresses from the upper part of the beach towards the foredune ridge, was not correlated to substrate physicochemistry. However, the biomass of Elymus and that of Lathyrus, the next two species to appear along the flank of the foredune, were related to pH, Mg, Na, and Cl (negatively), and to P and Ca (positively). These results suggest variable linkages between substrate physicochemistry and plant species along the foredune, possibly in relation to species-specific tolerance for abiotic conditions and requirements for substrate resources or to microscale influence of the plants themselves on substrate physicochemistry. Removal experiments carried out over 2 years revealed only one significant unidirectional interaction between these three species along the topographical gradient, and little plant control over abiotic variables (e.g., soil temperature, wind velocity, and photosynthetically active radiation). Early primary succession on subarctic coastal dunes (and elsewhere) appears to be under the control of strong limiting abiotic conditions. As plants slowly gain more control over the physical environment, interspecific interactions (positive and negative) may become more significant. Key words: Elymus mollis, facilitation, Honckenya peploides, inhibition, Lathyrus japonicus, removal experiment, succession, tolerance.

scholarly journals The role of the reef–dune system in coastal protection in Puerto Morelos (Mexico)

2018 ◽  
Vol 18 (4) ◽  
pp. 1247-1260 ◽  
Author(s):  
Gemma L. Franklin ◽  
Alec Torres-Freyermuth ◽  
Gabriela Medellin ◽  
María Eugenia Allende-Arandia ◽  
Christian M. Appendini
Keyword(s):  
Sand Dunes ◽  
Coastal Flooding ◽  
Water Levels ◽  
Coastal Protection ◽  
Dune System ◽  
Fore Reef ◽  
Extreme Water Levels ◽  
Reef Environments ◽  
Storm Impact

Abstract. Reefs and sand dunes are critical morphological features providing natural coastal protection. Reefs dissipate around 90 % of the incident wave energy through wave breaking, whereas sand dunes provide the final natural barrier against coastal flooding. The storm impact on coastal areas with these features depends on the relative elevation of the extreme water levels with respect to the sand dune morphology. However, despite the importance of barrier reefs and dunes in coastal protection, poor management practices have degraded these ecosystems, increasing their vulnerability to coastal flooding. The present study aims to theoretically investigate the role of the reef–dune system in coastal protection under current climatic conditions at Puerto Morelos, located in the Mexican Caribbean Sea, using a widely validated nonlinear non-hydrostatic numerical model (SWASH). Wave hindcast information, tidal level, and a measured beach profile of the reef–dune system in Puerto Morelos are employed to estimate extreme runup and the storm impact scale for current and theoretical scenarios. The numerical results show the importance of including the storm surge when predicting extreme water levels and also show that ecosystem degradation has important implications for coastal protection against storms with return periods of less than 10 years. The latter highlights the importance of conservation of the system as a mitigation measure to decrease coastal vulnerability and infrastructure losses in coastal areas in the short to medium term. Furthermore, the results are used to evaluate the applicability of runup parameterisations for beaches to reef environments. Numerical analysis of runup dynamics suggests that runup parameterisations for reef environments can be improved by including the fore reef slope. Therefore, future research to develop runup parameterisations incorporating reef geometry features (e.g. reef crest elevation, reef lagoon width, fore reef slope) is warranted.

Geomophological and vulnerability analysis of a coastal delta under increased hydrological alteration over the past two centuries: Tana River delta, Kenya, East Africa.

2021 ◽  
Author(s):  
Peter Gitau ◽  
Stéphanie Duvail ◽  
Dirk Verschuren ◽  
Dominique Guillaud
Keyword(s):  
Sea Level Rise ◽  
East Africa ◽  
Sea Level ◽  
Coastal Dune ◽  
River Delta ◽  
River Channels ◽  
Dune System ◽  
The Past ◽  
Tana River ◽  
Coastal Dune System

<p>Coastal deltas worldwide are under risk of degradation due to the increasing impacts of sea-level rise, and continuous human alterations of river basin hydrology. This research highlights the geomorphological changes that have occurred within the Tana River delta in Kenya, an important deltaic ecosystem of high biodiversity value in East Africa.</p><p>The geomorphological features (river channels, floodplain, coastal dune system) and their evolution over the past two centuries were described. Aerial and satellite imagery was used to assess the magnitude and distribution of coastal changes from the 1960s to present.  Additionally, sediment cores recovered within the mangrove environment were analysed to establish the succession of sedimentation periods and patterns. Finally, we explored the response of the coastal processes of deposition and erosion under anthropogenic alterations of the hydrological system.</p><p>It was established that over the past two centuries Tana River has changed its main channel and outlet to the Indian Ocean on three occasions. A first river avulsion occurred in the 1860s, followed by a second avulsion in the late 1890s that was promoted by human interference through channel expansion and dyke construction. The third change in river course has occurred gradually over the past 20 years, amid human efforts to engineer the river channels.</p><p>From the sediment analysis and radiocarbon dating, it is ascertained that the lower deltaic region developed rapidly over the past ~180 years, facilitated by increased sedimentation from the main Tana River. On the other hand, analysis of the coastline changes indicate that there has been increased erosion of the coastal dune system and mangrove vegetation along the former river outlet, leading to rapid marine intrusion into local subsistence farming areas. By analysing the combined impacts of both natural river dynamics and human alteration we highlight how the integrity of the Tana River delta has increasingly become vulnerable under present sea level rise and continued upstream river alteration.</p>

An Open Source e-Procurement Application Framework for B2B and G2B

2011 ◽  
pp. 76-97 ◽  
Author(s):  
Georgousopoulos Christos ◽  
Xenia Ziouvelou ◽  
Gregory Yovanof ◽  
Antonis Ramfos
Keyword(s):  
Open Source ◽  
Business Processes ◽  
Service Oriented Architecture ◽  
Cost Effective ◽  
Assessment Process ◽  
Application Framework ◽  
Two Phase ◽  
Model Driven ◽  
Service Oriented ◽  
The Cost

Since the early 1980s, Open Source Software (OSS) has gained a strong interest and an increased acceptance in the software industry that has to date initiated a “paradigm shift” (O’Reilly, 2004). The Open Source paradigm has introduced wholly new means of software development and distribution, creating a significant impact on the evolution of numerous business processes. In this chapter we examine the impact of the open source paradigm in the e-Procurement evolution and identify a trend towards Open Source e-Procurement Application Frameworks (AFs) which enable the development of tailored e-Procurement Solutions. Anchored in this notion, we present an Open-Source e-Procurement AF with a two-phase generation procedure. The innovative aspect of the proposed model relates to the combination of the Model Driven Engineering (MDE) approach with the Service-Oriented Architecture (SOA) paradigm for enabling the cost-effective production of e-Procurement Solutions by facilitating integration, interoperability, easy maintenance, and management of possible changes in the European e-Procurement environment. The assessment process of the proposed AF and its resulting e-Procurement Solutions occurs in the context of G2B in the Western-Balkan European region. Our evaluation yields positive results and further enhancing opportunities for the proposed Open Source e-Procurement AF and its resulting e-Procurement Solutions.

scholarly journals Towards improved, cost-effective surveillance of Ixodes ricinus ticks and associated pathogens using species distribution modelling

2019 ◽  
Vol 14 (1) ◽  
Author(s):  
Manuela Signorini ◽  
Anna-Sofie Stensgaard ◽  
Michele Drigo ◽  
Giulia Simonato ◽  
Federica Marcer ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Habitat Suitability ◽  
Pathogen Detection ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Cost Effective ◽  
Limiting Factor ◽  
Sampling Effort ◽  
Remotely Sensed Data ◽  
Ecological Requirements

Various ticks exist in the temperate hilly and pre-alpine areas of Northern Italy, where Ixodes ricinus is the more important. In this area different tick-borne pathogen monitoring projects have recently been implemented; we present here the results of a twoyear field survey of ticks and associated pathogens, conducted 2009-2010 in North-eastern Italy. The cost-effectiveness of different sampling strategies, hypothesized a posteriori based on two sub-sets of data, were compared and analysed. The same two subsets were also used to develop models of habitat suitability, using a maximum entropy algorithm based on remotely sensed data. Comparison of the two strategies (in terms of number of ticks collected, rates of pathogen detection and model accuracy) indicated that monitoring at many temporary sites was more cost-effective than monthly samplings at a few permanent sites. The two model predictions were similar and provided a greater understanding of ecological requirements of I. ricinus in the study area. Dense vegetation cover, as measured by the normalized difference vegetation index, was identified as a good predictor of tick presence, whereas high summer temperatures appeared to be a limiting factor. The study suggests that it is possible to obtain realistic results (in terms of pathogens detection and development of habitat suitability maps) with a relatively limited sampling effort and a wellplanned monitoring strategy.

scholarly journals Offline Next Generation Metagenomics Sequence Analysis Using MinION Detection Software (MINDS)

Genes ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 578 ◽  
Author(s):  
Deshpande ◽  
Reed ◽  
Sullivan ◽  
Kerkhof ◽  
Beigel ◽  
...  
Keyword(s):  
Open Source ◽  
Cost Effective ◽  
Ease Of Use ◽  
Remote Locations ◽  
Resource Limited ◽  
Field Samples ◽  
Sample Characterization ◽  
Internet Availability ◽  
Detection Software ◽  
Downstream Analysis

Field laboratories interested in using the MinION often need the internet to perform sample analysis. Thus, the lack of internet connectivity in resource-limited or remote locations renders downstream analysis problematic, resulting in a lack of sample identification in the field. Due to this dependency, field samples are generally transported back to the lab for analysis where internet availability for downstream analysis is available. These logistics problems and the time lost in sample characterization and identification, pose a significant problem for field scientists. To address this limitation, we have developed a stand-alone data analysis packet using open source tools developed by the Nanopore community that does not depend on internet availability. Like Oxford Nanopore Technologies’ (ONT) cloud-based What’s In My Pot (WIMP) software, we developed the offline MinION Detection Software (MINDS) based on the Centrifuge classification engine for rapid species identification. Several online bioinformatics applications have been developed surrounding ONT’s framework for analysis of long reads. We have developed and evaluated an offline real time classification application pipeline using open source tools developed by the Nanopore community that does not depend on internet availability. Our application has been tested on ATCC’s 20 strain even mix whole cell (ATCC MSA-2002) sample. Using the Rapid Sequencing Kit (SQK-RAD004), we were able to identify all 20 organisms at species level. The analysis was performed in 15 min using a Dell Precision 7720 laptop. Our offline downstream bioinformatics application provides a cost-effective option as well as quick turn-around time when analyzing samples in the field, thus enabling researchers to fully utilize ONT’s MinION portability, ease-of-use, and identification capability in remote locations.

scholarly journals A Multi-Scale Mapping Approach Based on a Deep Learning CNN Model for Reconstructing High-Resolution Urban DEMs

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1369
Author(s):  
Ling Jiang ◽  
Yang Hu ◽  
Xilin Xia ◽  
Qiuhua Liang ◽  
Andrea Soltoggio ◽  
...  
Keyword(s):  
High Resolution ◽  
Accuracy Assessment ◽  
Cost Effective ◽  
Reconstruction Method ◽  
Low Resolution ◽  
Multi Scale ◽  
Mapping Approach ◽  
Assessment Approach ◽  
Urban Topography ◽  
Complex Features

The scarcity of high-resolution urban digital elevation model (DEM) datasets, particularly in certain developing countries, has posed a challenge for many water-related applications such as flood risk management. A solution to address this is to develop effective approaches to reconstruct high-resolution DEMs from their low-resolution equivalents that are more widely available. However, the current high-resolution DEM reconstruction approaches mainly focus on natural topography. Few attempts have been made for urban topography, which is typically an integration of complex artificial and natural features. This study proposed a novel multi-scale mapping approach based on convolutional neural network (CNN) to deal with the complex features of urban topography and to reconstruct high-resolution urban DEMs. The proposed multi-scale CNN model was firstly trained using urban DEMs that contained topographic features at different resolutions, and then used to reconstruct the urban DEM at a specified (high) resolution from a low-resolution equivalent. A two-level accuracy assessment approach was also designed to evaluate the performance of the proposed urban DEM reconstruction method, in terms of numerical accuracy and morphological accuracy. The proposed DEM reconstruction approach was applied to a 121 km2 urbanized area in London, United Kingdom. Compared with other commonly used methods, the current CNN-based approach produced superior results, providing a cost-effective innovative method to acquire high-resolution DEMs in other data-scarce regions.

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