scholarly journals The Spatiotemporal Characteristics and Dynamic Changes of Tidal Flats in Florida from 1984 to 2020

Geographies ◽  
2021 ◽  
Vol 1 (3) ◽  
pp. 292-314
Author(s):  
Chao Xu ◽  
Weibo Liu
Keyword(s):  
Tidal Flat ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
Critical Role ◽  
Kendall Test ◽  
Tidal Flats ◽  
Dynamic Changes ◽  
Spatiotemporal Characteristics ◽  
Spatiotemporal Scales ◽  
Slope Estimator

Tidal flats are playing a critical role in the coastal environment, which mainly rely on satellite images to map the distribution on large spatiotemporal scales. Much effort has been made to monitor and analyze the spatiotemporal dynamics of tidal flats in order to provide worthwhile references for scientists and lawmakers. Instead of considering the dynamics of tidal flats only, this study implemented a series of comprehensive analyses on the tidal flats along the coast of Florida during the period 1984–2020. First, the analyses on the pixel level examined the spatiotemporal characteristics of tidal flat dynamics and the interactions with lands and permanent water. Second, the contiguous pixels of tidal flats were assembled as objects, and two geometric attributes were calculated and used to track the temporal patterns of tidal flat dynamics on this level. Finally, the Mann–Kendall test and Sen’s slope estimator were applied to identify and quantify the significant trends of tidal flat dynamics on the two levels. The results highlighted the differences in tidal flat distributions and dynamics between the Gulf Coast and Atlantic Coast, which further verified effective GIS representations and analyses that could be applied to other coastal studies.

scholarly journals Simple Empirical Models for Estimating the Increase in the Central Pressure of Tropical Cyclones after Landfall along the Coastline of the United States

2005 ◽  
Vol 44 (12) ◽  
pp. 1807-1826 ◽  
Author(s):  
Peter J. Vickery
Keyword(s):  
United States ◽  
Tropical Cyclones ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
Critical Role ◽  
The United States ◽  
Empirical Models ◽  
Central Pressure ◽  
Translation Speed ◽  
Hurricane Wind

Abstract Modeling the increase in the central pressure of tropical cyclones following landfall plays a critical role in the estimation of the hurricane wind hazard at locations removed from the coastline. This paper describes the development of simple empirical models for estimating the rate at which tropical cyclones decay after making landfall. For storms making landfall along the Gulf of Mexico Coast and the coast of the Florida Peninsula, it is shown that the rate of storm filling is proportional to the central pressure difference and translation speed at the time of landfall and is inversely proportional to the radius to maximum winds. Along the Atlantic Coast the effect of radius to maximum winds does not play as significant a role in the rate of storm decay as compared with that seen in Florida and along the Gulf Coast. The models developed here can readily be included in any hurricane simulation model designed for estimating wind speeds in the United States.

scholarly journals Recent Evolution of Coastal Tidal Flats and the Impacts of Intensified Human Activities in the Modern Radial Sand Ridges, East China

2020 ◽  
Vol 17 (9) ◽  
pp. 3191 ◽  
Author(s):  
Yifei Zhao ◽  
Qing Liu ◽  
Runqiu Huang ◽  
Haichen Pan ◽  
Min Xu
Keyword(s):  
Tidal Flat ◽  
Human Activities ◽  
Land Reclamation ◽  
Critical Role ◽  
Tidal Flats ◽  
Sediment Supply ◽  
Flat Area ◽  
Sand Ridges ◽  
Gradual Process ◽  
Radial Sand Ridges

The coastal tidal flats of the modern Radial Sand Ridges (RSRs) are typical silt-muddy tidal flats in Central Jiangsu Province. These tidal flats play a critical role in coastline protection and biodiversity conservation, and against storm surges, but have recently been displaying drastic changes in geomorphic dynamics because of human activities. However, a comprehensive understanding of spatiotemporal changes in tidal flats in RSRs remains lacking. Hence, we employed a novel remote sensing method by obtaining the instantaneous high/low tide line positions from over 112 scenes of Landsat satellite images of the study area from 1975 to 2017, which were used to track the recent evolution of the coastal tidal flats in the modern RSRs over the past four decades. We found that the shoreline of the tidal flats showed an advanced seaward trend, and the waterline of the tidal flat presented a gradual process during different periods. The total tidal flat area in the study area showed an obviously decreasing trend overall, and approximately 992 km2 of the tidal flat was lost. We also found that the coastal tidal flats in the modern RSRs were generally undergoing erosion in the low tidal flats, especially in the Northern Swing and Southern Swing areas, while the high tidal flats showed a slowed accretionary change. Land reclamation was the main factor affecting the reduction in the tidal flat area, as the reclamation area has increased by 1300 km2, with an average of 35.14 km2/year. In addition, the erosion of the tidal flats was associated with a reduced sediment supply. Our findings will provide useful information for local managers and researchers to support future environmental management because increasing demand for land and rising sea levels are expected in the future.

scholarly journals Testing Possible Scenario-Based Responses of Vegetation Under Expected Climatic Changes in Khuzestan Province

2021 ◽  
Vol 14 ◽  
pp. 117862212110133
Author(s):  
Hadi Eskandari Damaneh ◽  
Meysam Jafari ◽  
Hamed Eskandari Damaneh ◽  
Marjan Behnia ◽  
Asadollah Khoorani ◽  
...  
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Kendall Test ◽  
Baseline Period ◽  
System Model ◽  
Future Period ◽  
Khuzestan Province ◽  
Ecosystem Planning ◽  
Slope Estimator ◽  
Precipitation And Temperature

Projections of future scenarios are scarce in developing countries where human activities are increasing and impacting land uses. We present a research based on the assessment of the baseline trends of normalized difference vegetation index (NDVI), precipitation, and temperature data for the Khuzestan Province, Iran, from 1984 to 2015 compiled from ground-based and remotely sensed sources. To achieve this goal, the Sen’s slope estimator, the Mann-Kendall test, and Pearson’s correlation test were used. After that, future trends in precipitation and temperature were estimated using the Canadian Earth System Model (CanESM2) model and were then used to estimate the NDVI trend for two future periods: from 2016 to 2046 and from 2046 to 2075. Our results showed that during the baseline period, precipitation decreased at all stations: 33.3% displayed a significant trend and the others were insignificant ones. Over the same period, the temperature increased at 66.7% of stations while NDVI decreased at all stations. The NDVI–precipitation relationship was positive while NDVI–temperature showed an inverse trend. During the first of the possible future periods and under the RCP2.6, RCP4.5, and RCP8.5 scenarios, NDVI and precipitation decreased, and temperatures significantly increased. In addition, the same trends were observed during the second future period; most of these were statistically significant. We conclude that much assessments are valuable and integral components of effective ecosystem planning and decisions.

scholarly journals Rainfall trend and variability over Opak River basin, Yogyakarta, Indonesia

2020 ◽  
Vol 1000 (1000) ◽  
Author(s):  
Wakhidatik Nurfaida ◽  
Hendra Ramdhani ◽  
Takenori Shimozono ◽  
Indri Triawati ◽  
Muhammad Sulaiman
Keyword(s):  
River Basin ◽  
Water Resource ◽  
Rainfall Intensity ◽  
Kendall Test ◽  
Rainfall Data ◽  
Positive Trend ◽  
Sen’S Slope Estimator ◽  
Sen’S Slope ◽  
Slope Estimator

Rainfall intensity seems to be increasing nowadays due to climate change as presented in many studies of both global and regional scale. Consequently, cities worldwide are now more vulnerable to flooding. In Indonesia, increasing frequency of floods was reported for the past decades by The National Agency for Disaster Countermeasure (BNPB). To understand the rainfall changes, long-term trend evaluation over a specific area is then crucial due to the large variability of spatial and temporal rainfall distribution. This study investigates the homogeneity and trend of rainfall data from 20 stations over the Opak River basin, Yogyakarta, Indonesia. A long-term ground observation rainfall data whose period varies from 1979 to 2019 were analyzed. Non-parametric Mann – Kendall test was applied to assess the trend, while the magnitude was calculated using the Sen’s slope estimator. An increasing annual maximum of daily rainfall intensity was observed at four stations on a 0.95 confidence level based on the Mann – Kendall test, while the Sen’s slope estimator shows a positive trend at almost all stations. The trend of heavy rainfall frequency was also found to be significantly increased, with only one station showed a decreasing trend. Furthermore, this paper also described the spatial and temporal rainfall variability. Positive trend was mostly found during the rainy season, while the negative trend occurred during the dry season. This could pose a challenge for water resource management engineering and design, such as water supply systems or reservoir management. Understanding this phenomena will benefit hydrologists in preparing future water resource engineering and management.

Epigenetic reprogramming of host and viral genes by Human Cytomegalovirus infection in Kasumi-3 myeloid progenitor cells at early times post-infection

2021 ◽  
Author(s):  
Eleonora Forte ◽  
Fatma Ayaloglu Butun ◽  
Christian Marinaccio ◽  
Matthew J. Schipma ◽  
Andrea Piunti ◽  
...  
Keyword(s):  
Gene Expression ◽  
Post Infection ◽  
De Novo ◽  
Critical Role ◽  
Myeloid Cells ◽  
Viral Gene Expression ◽  
Chromatin Accessibility ◽  
Viral Gene ◽  
Dynamic Changes ◽  
Pol Ii

HCMV establishes latency in myeloid cells. Using the Kasumi-3 latency model, we previously showed that lytic gene expression is activated prior to establishment of latency in these cells. The early events in infection may have a critical role in shaping establishment of latency. Here, we have used an integrative multi-omics approach to investigate dynamic changes in host and HCMV gene expression and epigenomes at early times post infection. Our results show dynamic changes in viral gene expression and viral chromatin. Analyses of Pol II, H3K27Ac and H3K27me3 occupancy of the viral genome showed that 1) Pol II occupancy was highest at the MIEP at 4 hours post infection. However, it was observed throughout the genome; 2) At 24 hours, H3K27Ac was localized to the major immediate early promoter/enhancer and to a possible second enhancer in the origin of replication OriLyt; 3) viral chromatin was broadly accessible at 24 hpi. In addition, although HCMV infection activated expression of some host genes, we observed an overall loss of de novo transcription. This was associated with loss of promoter-proximal Pol II and H3K27Ac, but not with changes in chromatin accessibility or a switch in modification of H3K27. Importance. HCMV is an important human pathogen in immunocompromised hosts and developing fetuses. Current anti-viral therapies are limited by toxicity and emergence of resistant strains. Our studies highlight emerging concepts that challenge current paradigms of regulation of HCMV gene expression in myeloid cells. In addition, our studies show that HCMV has a profound effect on de novo transcription and the cellular epigenome. These results may have implications for mechanisms of viral pathogenesis.

Shark Nursery Grounds of the Gulf of Mexico and the East Coast Waters of the United States

2007 ◽  
Keyword(s):  
United States ◽  
Gulf Of Mexico ◽  
East Coast ◽  
Gulf Coast ◽  
Atlantic Coast ◽  
The United States ◽  
Shark Species ◽  
Carcharhinus Plumbeus ◽  
Nursery Areas ◽  
Pesticide Metabolites

<em>Abstract.</em>—Because of their tendency to accumulate in estuaries and coastal regions, organochlorine (OC) contaminants such as pesticides and polychlorinated biphenyls (PCBs) represent potential threats to the quality of essential fish habitat for many shark species. These compounds pose special risks to immature sharks in particular because of their ability to impair growth and sexual maturation in juvenile fish at environmentally relevant levels of exposure. In order to assess the extent of these risks in shark populations on the East Coast of the United States, the present study examined concentrations of 30 OC pesticides/pesticide metabolites and total PCBs in juvenile sandbar <em>Carcharhinus plumbeus </em>and blacktip <em>C. limbatus </em>sharks from seven major nursery areas in the western Atlantic Ocean and eastern Gulf of Mexico. Quantifiable levels of PCBs and 13 OC pesticides/ pesticide metabolites were detected via gas chromatography and mass spectrometry in liver of 25 young-of-the-year blacktip sharks from the southeastern U.S. Atlantic coast and three regions on Florida’s gulf coast: Cedar Key, Tampa Bay, and Charlotte Harbor. Similarly, quantifiable levels of PCBs and 14 OC pesticides/metabolites were detected in 23 juvenile <em>C. plumbeus </em>from three sites on the northeastern U.S. coast: middle Delaware Bay, lower Chesapeake Bay, and Virginia’s eastern shore. Liver OC concentrations in Atlantic sandbar and blacktip sharks were higher than expected and, in some cases, comparable with elevated levels observed in deep-sea and pelagic sharks. Although significantly lower than those observed in Atlantic sharks, pesticide and PCB levels in Florida blacktip sharks were similar to, if not greater than, OC concentrations reported in adults of other coastal shark species. Based on these data, OC contamination appears to pose significant threats to habitat quality in sandbar and blacktip shark nursery areas on the U.S. Atlantic coast.

What ecological role do soft-substrate tide pools play for fishes? Difference in community structures between estuarine and coastal tidal flats in subtropical Japan

2020 ◽  
Vol 71 (7) ◽  
pp. 737
Author(s):  
Taiga Kunishima ◽  
Katsunori Tachihara
Keyword(s):  
Tidal Flat ◽  
High Tide ◽  
Tidal Flats ◽  
Individual Species ◽  
Nursery Ground ◽  
Ecological Role ◽  
Soft Substrate ◽  
Use Patterns ◽  
Habitat Value ◽  
Ecological Roles

Soft-substrate tide pools are considered important habitats for fishes from an ecological perspective. However, the ecological roles of such pools and use patterns by fish remain unclear, especially regarding differences between estuarine and coastal tidal flats. In this study, quantitative sampling using the quadrat method was performed in the estuarine and coastal tidal flats on Okinawa-jima Island of subtropical Japan during four seasons. Ecological roles of soft-substrate tide pools were classified as follows: (1) permanent habitat for residents; (2) nursery ground for transients; and (3) waiting area until high tide for accidental species. Within these classifications, the ecological role and value of tide pools for transient fishes varied between the tidal flat types. The habitat value of tide pools is higher for residents than for transient species because the habitat is not replaceable for residents because of their specific ability to survive there. By contrast, transient and accidental species use the tide pools as temporary habitats; however, their high diversity affects the variation in community structure on Okinawa-jima Island. Our results suggest that we should consider not only species diversity, but also habitat use patterns of individual species, together with their life history, when evaluating habitat value with regard to conservation and management of each tidal flat.

Drivers of nano- and microplanktonic community structure in a Patagonian tidal flat ecosystem

2019 ◽  
Vol 41 (5) ◽  
pp. 621-639
Author(s):  
Juan F Saad ◽  
Maite A Narvarte ◽  
Mariza A Abrameto ◽  
Viviana A Alder
Keyword(s):  
Tidal Flat ◽  
Tidal Flats ◽  
Size Spectrum ◽  
Spatial Gradient ◽  
Total Biomass ◽  
Total Density ◽  
Phytoplankton Structure ◽  
Tidal Transport ◽  
Sw Atlantic ◽  
Inshore Waters

ABSTRACT Tidal flats are exceptionally dynamic coastal ecosystems. Tides are their main source of energy, whose influence decreases landwards (as land elevation increases), thus shaping physical, chemical and biological gradients. In this study, we assess whether the structure of nano- and microplankton varies along a spatial gradient in San Antonio Bay (SAB, SW Atlantic), a semi-desert coastal ecosystem with a wide tidal flat and a macrotidal regime. We hypothesize that the tidal effect shapes SAB’s both taxonomical groups and size spectrum. The seasonal sampling of 9 sites revealed that diatoms and small flagellates were the most abundant groups, together accounting for over 75% of total density in practically all sites and seasons. High densities of meroplanktonic stages of Ulva lactuca were recorded in spring at the innermost sites, accounting for over 95% of all planktonic cells. Slopes of the size spectrum analysis were in line with highly productive inshore waters (mean, −0.64) and showed that larger phytoplankton was the main contributor to total biomass, despite its decreasing importance toward inner sites. The spatial and seasonal variations found for lower trophic web compartments provide evidence of the importance of tidal transport in ruling phytoplankton structure in tidal flats under strong macrotidal regimes.

Sign in / Sign up

Export Citation Format

Share Document