scholarly journals Spatiotemporal Storm Impact on the Northern Yucatan Coast during Hurricanes and Central American Cold Surge Events

2019 ◽  
Vol 8 (1) ◽  
pp. 2 ◽  
Author(s):  
Wilmer Rey ◽  
Paulo Salles ◽  
Alec Torres-Freyermuth ◽  
Pablo Ruíz-Salcines ◽  
Yi-Cheng Teng ◽  
...  

We investigate the storm impact associated with historical events in the northern Yucatan Peninsula. The study area is prone to coastal flooding due to both its geographical location and low-lying areas. Extreme events associated with tropical cyclones and Central American cold surge (CACS; locally known as Nortes) are ubiquitous in this region, and coastal development in the study area has exacerbated the erosion of the sand beach-dune system. This study aims to assess the impact on the northern coast of Yucatan associated with different types of storms and to investigate the role of the dune in its spatial variability. Nearshore hydrodynamics, associated with hurricanes (Gilbert: 14 September 1988; Isidore: 22 September 2002) and energetic Nortes (Norte A: 12 March 1993; Norte B: 25 December 2004), were computed using a numerical model. The beach and dune characteristics were extracted from a LIDAR flight with a spatial resolution of 1 m conducted in 2011. Furthermore, the extreme water levels and the spatiotemporal variability of the storm-impact regime (swash, collision, overwash, or inundation), along a 41.5 km stretch of coast, were derived using both runup parametrizations and the modeling results. On the one hand, the predominant storm impact regimes for Hurricanes Gilbert and Isidore were inundation and overwash, respectively. The flood that propagated from east to west in the northern Yucatan was due to westerly-directed hurricane tracks. On the other hand, for the Norte events, the predominant impact regimes were collision and overwash for Nortes A and B, respectively. This difference in the impact regime between Norte events can be ascribed to tidal differences. Moreover, during the passages of Nortes A and B, the flood was propagated from west to east in the northern Yucatan, consistent with cold-front paths. The results suggest that the western part of the study area presented a stronger impact regime due to the dune degradation caused by coastal infrastructure and settlements established in those areas. This work highlights the important role of sand dunes in providing natural coastal protection during Norte events.

2018 ◽  
Vol 18 (4) ◽  
pp. 1247-1260 ◽  
Author(s):  
Gemma L. Franklin ◽  
Alec Torres-Freyermuth ◽  
Gabriela Medellin ◽  
María Eugenia Allende-Arandia ◽  
Christian M. Appendini

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.


Author(s):  
A.-L. Montreuil ◽  
M. Chen ◽  
A. Esquerré ◽  
R. Houthuys ◽  
R. Moelans ◽  
...  

<p><strong>Abstract.</strong> Sustainable management of the coastal resources requires a better understanding of the processes that drive coastline change. The coastline is a highly dynamic sea-terrestrial interface. It is affected by forcing factors such as water levels, waves, winds, and the highest and most severe changes occur during storm surges. Extreme storms are drivers responsible for rapid and sometimes dramatic changes of the coastline. The consequences of the impacts from these events entail a broad range of social, economic and natural resource considerations from threats to humans, infrastructure and habitats. This study investigates the impact of a severe storm on coastline response on a sandy multi-barred beach at the Belgian coast. Airborne LiDAR surveys acquired pre- and post-storm covering an area larger than 1 km<sup>2</sup> were analyzed and reproducible monitoring solutions adapted to assess beach morphological changes were applied. Results indicated that the coast retreated by a maximum of 14.7 m where the embryo dunes in front of the fixed dunes were vanished and the foredune undercut. Storm surge and wave attacks were probably the most energetic there. However, the response of the coastline proxies associated with the mean high water line (MHW) and dunetoe (DuneT) was spatially variable. Based on the extracted beach features, good correlations (r>0.73) were found between coastline, berm and inner intertidal bar morphology, while it was weak with the most seaward bars covered in the surveys. This highlights the role of the upper features on the beach to protect the coastline from storm erosion by reducing wave energy. The findings are of critical importance in improving our knowledge and forecasting of coastline response to storms, and also in its translation into management practices.</p>


Author(s):  
Yanira Oliveras-Ortiz ◽  
Wesley D. Hickey ◽  
Jennifer S. Jones

Educational leaders in rural schools across the world face distinctive challenges. In this chapter, the authors report the findings of two studies examined through narrative inquiry conducted in a Garifuna and Ketchi Mayan village in Central America. The case studies explore the role of the principal as a strategic leader to improve the education system, and the impact of these leaders in their communities. By sharing these stories, the authors illustrate the importance of strategic thinking, as well as both transformative and servant leadership to promote change.


2020 ◽  
Vol 17 (10) ◽  
pp. 2369-2386
Author(s):  
Maksymilian Solarski ◽  
Mirosław Szumny

Abstract This research aimed to identify the impact of local climatic and topographic conditions on the formation and development of the ice cover in high-mountain lakes and the representativeness assessment of periodic point measurements of the ice cover thickness by taking into consideration the role of the avalanches on the icing of the lakes. Field works included measurement of the ice and snow cover thickness of seven lakes situated in the Tatra Mountains (UNESCO biosphere reserve) at the beginning and the end of the 2017/2018 winter season. In addition, morphometric, topographic and daily meteorological data of lakes from local IMGW (Polish Institute of Meteorology and Water Management) stations and satellite images were used. The obtained results enabled us to quantify the impact of the winter eolian snow accumulation on the variation in ice thickness. This variation was ranging from several centimetres up to about 2 meters and had a tendency to increase during the winter season. The thickest ice covers occurred in the most shaded places in the direct vicinity of rock walls. The obtained results confirm a dominating role of the snow cover in the variation of the ice thickness within individual lakes.


2015 ◽  
Vol 15 (7) ◽  
pp. 1533-1543 ◽  
Author(s):  
P. Dissanayake ◽  
J. Brown ◽  
H. Karunarathna

Abstract. Impacts of storm chronology within a storm cluster on beach/dune erosion are investigated by applying the state-of-the-art numerical model XBeach to the Sefton coast, northwest England. Six temporal storm clusters of different storm chronologies were formulated using three storms observed during the 2013/2014 winter. The storm power values of these three events nearly halve from the first to second event and from the second to third event. Cross-shore profile evolution was simulated in response to the tide, surge and wave forcing during these storms. The model was first calibrated against the available post-storm survey profiles. Cumulative impacts of beach/dune erosion during each storm cluster were simulated by using the post-storm profile of an event as the pre-storm profile for each subsequent event. For the largest event the water levels caused noticeable retreat of the dune toe due to the high water elevation. For the other events the greatest evolution occurs over the bar formations (erosion) and within the corresponding troughs (deposition) of the upper-beach profile. The sequence of events impacting the size of this ridge–runnel feature is important as it consequently changes the resilience of the system to the most extreme event that causes dune retreat. The highest erosion during each single storm event was always observed when that storm initialised the storm cluster. The most severe storm always resulted in the most erosion during each cluster, no matter when it occurred within the chronology, although the erosion volume due to this storm was reduced when it was not the primary event. The greatest cumulative cluster erosion occurred with increasing storm severity; however, the variability in cumulative cluster impact over a beach/dune cross section due to storm chronology is minimal. Initial storm impact can act to enhance or reduce the system resilience to subsequent impact, but overall the cumulative impact is controlled by the magnitude and number of the storms. This model application provides inter-survey information about morphological response to repeated storm impact. This will inform local managers of the potential beach response and dune vulnerability to variable storm configurations.


2010 ◽  
pp. 103-108
Author(s):  
Leonardo Bichara Rocha

This paper reviews the major changes and trends in the raw and white sugar trade flows involving Latin American exporters and their partners. The paper assesses the recent absolute and relative growth in the volume of sugar exports from Brazil (the region’s and the world’s dominant exporter) and other major regional exporters such as Guatemala, Cuba, Colombia, Mexico and Argentina. Latin America has emerged as the world’s largest net sugar exporting region. Significant volumes of raw sugar of Latin American origin are now used by a large number of new destination refineries which have been set up in the Middle East and Asia. Indeed, the share of Latin America in global raw sugar exports has increased from 62.8% on average between 2002 and 2004 to 67.3% on average between 2006 and 2008. This paper also evaluates the impact of preferential trade agreements, including the CAFTA and the EPA, for Central American and Caribbean sugar exporters, as well as the implications of NAFTA for Mexico’s sugar. Finally, the paper discusses the potential gains and benefits that diversification into ethanol and cogeneration have provided to the major Latin American sugarcane industries.


Author(s):  
Ming-liang Chen ◽  
Xing-guo Yang ◽  
Shun-chao Qi ◽  
Hai-bo Li ◽  
Jia-wen Zhou

Occurrence of a reservoir landslide and its potential secondary hazards near a dam can result in significant losses and casualties, such as those that resulted from the Vajont landslide. In this study, a cataclinal rock slope in the Maoergai reservoir was taken as a case to study the characteristics of the gravitational deformation process and to analyze the potential threat. The stability of rock slope is analyzed by the limit equilibrium method, and the potential landslide movement and subsequent waves are also simulated. Results indicate that lithology, geological structure, reservoir water level changes and artificial activities all play an important role for the large deformation of rock slope deformation, which is characterized by a combination of bending-toppling and principally shear-slip. Pre-calculations of potential threats indicated that the impact of a landslide wave would be greater at dead water levels than at the normal water level and could result in blockage of the inlet to the water diversion structure on the opposite right bank. These findings provide implication for the control of reservoir rock slopes: (i) serious attention should be paid to the influence of water on rock strength in early and (ii) infiltration must be prevented during water level rise.Thematic collection: This article is part of the Role of water in destabilizing slopes collection available at: https://www.lyellcollection.org/cc/Role-of-water-in-destabilizing-slopes


2017 ◽  
Author(s):  
Gemma L. Franklin ◽  
Alec Torres-Freyermuth ◽  
Gabriela Medellín ◽  
María Eugenia Allende-Arandia ◽  
Bernabé Gómez ◽  
...  

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 the 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 investigate the role of the reef-dune system in coastal protection under current climatic conditions at Puerto Morelos, located in the Mexican Caribbean Sea. Firstly, a nonlinear non-hydrostatic numerical model (SWASH) is validated with experimental data from a physical model of a fringing reef. The numerical model predicts both energy transformation and runup statistics as compared with experimental results for two different reef crest geometries conducted in a physical model. Thus, the numerical model is further used to investigate the role of the reef-dune degradation in coastal vulnerability. Wave hindcast information, tidal level, and a measured beach profile of the reef-dune system in Puerto Morelos are employed to predict extreme runup and estimate the storm impact scale for different scenarios. The numerical results show that ecosystem degradation has important implications for coastal protection against storms with return periods of less than 10 years. This 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.


2021 ◽  
Vol 9 (5) ◽  
pp. 518
Author(s):  
Gabriela Medellín ◽  
Martí Mayor ◽  
Christian M. Appendini ◽  
Ruth Cerezo-Mota ◽  
José A. Jiménez

Wave runup is a relevant parameter to determine the storm impact on barrier islands. Here, the role of the beach morphology on wave runup and storm impact was investigated at four coastal communities located on the northern Yucatan coast. Current wave conditions based on regional wind simulations, topo-bathymetric transects measured at each location, and a nonlinear wave transformation model were employed to reconstruct multi-year runup time series. Dune morphology features and extreme water levels (excluding storm surge contributions) were further employed to determine the storm impact at each site for different return periods. Despite the similar offshore conditions along the coast, extreme water levels (i.e., runup and setup) showed intersite differences that were mainly ascribed to subaerial and submerged morphological features. Numerical results showed that the average surf zone beach slope, sandbars, berm, and dune elevation played an important role in controlling extreme water levels and storm impact at the study sites under the present climate. Moreover, in order to assess the potential effect of climate change on coastal flooding, we analyzed wave runup and storm impact in the best-preserved site by considering wave conditions and sea level rise (SLR) projections under the RCP 8.5 scenario. Modelling results suggest no significant increase in the storm impact regime between the present and future conditions in the study area unless SLR is considered. It was found that to accurately estimate SLR contribution, it should be incorporated into mean sea level prior to performing numerical wave runup simulations, rather than simply adding it to the resulting wave-induced water levels.


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