Extreme High Water Research Articles

Scale of temperature variability in the maritime Antarctic intertidal zone

The Antarctic Peninsula is currently considered as one of the fastest changing regions on Earth yet temperature variability in some of its environments and habitats is not well-documented. Given the increased glacier retreat, summer melts, sea level rise and ozone losses the intertidal zone is likely to be one of the most rapidly altering of environments but also one of the least investigated in polar waters. This study aims to quantify summer temperature variability in some habitats of the intertidal zone at King George Island. Three transects were selected across tidal flat. Four temperature loggers were deployed at each of them from extreme low water spring tide level to extreme high water spring tide level between 07.12.2010 and 18.03.2011. All the loggers were deployed at the rocky substratum. The temperature range across the study tidal flat was between −2.26°C and +21.18°C. The average (summer) temperature obtained from 12 loggers varied from +1.89 to +3.26°C. In all the three transects average temperature increased with tidal height. Much higher temperature variability was recorded at higher than at lower tide locations. Differences in temperature between the three study transects existed. Results obtained from the studied tidal flat show that several factors combined altogether, including: water movement by tidal forces, wave action, air temperature, sun light intensity, shore lithology and the presence of ice and snow in the area, seem to influence its temperature.

A nonstationary analysis for the Northern Adriatic extreme sea levels

The historical data from the Trieste, Venice, Porto Corsini, and Rimini tide gauges have been used to investigate the spatial and temporal changes in extreme high water levels in the Northern Adriatic. A detailed analysis of annual mean sea level evolution at the three longest operating stations shows a coherent behavior both on a regional and global scale. A slight increase in magnitude of extreme water elevations, after the removal of the regularized annual mean sea level necessary to eliminate the effect of local subsidence and sea level rise, is found at the Venice and Porto Corsini stations. It seems to be mainly associated with a wind regime change occurred in the 1990s, due to an intensification of Bora wind events after their decrease in frequency and intensity during the second half of the 20th century. The extreme values, adjusted for the annual mean sea level trend, are modeled using a time‐dependent GEV distribution. The inclusion of seasonality in the GEV parameters considerably improves the data fitting. The interannual fluctuations of the detrended monthly maxima exhibit a significant correlation with the variability of the large‐scale atmospheric circulation represented by the North Atlantic Oscillation and Arctic Oscillation indices. The different coast exposure to the Bora and Sirocco winds and their seasonal character explain the various seasonal patterns of extreme sea levels observed at the tide gauges considered in the present analysis.

Effects of sea level rise on frequency analysis of 1% annual maximum water levels in the coast of Florida

Traditionally, annual maximum water levels (AMWLs) data mixed with sea level rise (SLR) effects have been used in probability analysis of extreme values. However, considering that SLR can be described by a regression equation, the deterministic variables of SLR should be separated from the extreme value probability analysis. To account for the SLR impact on the extreme high water level in the Florida coastal waters, frequency analysis of AMWL in Pensacola and Fernandina Stations in Florida coast are investigated in this study. With the data for the past 89 and 100 years, regression equations have been derived to predict the SLR trends in Pensacola and Fernandina stations, respectively. Consider sea level rise is not a random variable, historic AMWLs are modified by removing SLR to provide SLR-removed AMWLs for frequency analysis. By comparison to SLR-removed AMWLs, the GEV (general extreme value) and Xu–Huang distributions are shown to provide reasonable predictions of AMWLs. After frequency analysis of SLR-removed AMWLs, SLR impacts are included by adding the SLR from the SLR regression equation in the future. AMWLs with SLR impacts for any return period up to year 2100, with tables for 100-year AMWLs, are provided to support coastal hazard mitigation planning.

Effects of the North Atlantic Oscillation and wind waves on salt marsh dynamics in the Danish Wadden Sea: a quantitative model as proof of concept

Long-term eustatic sea-level variation has been recognized as a primary factor affecting the hydrological and geomorphic dynamics of salt marshes. However, recent studies suggest that wind waves influenced by atmospheric oscillations also may play an important role in many coastal areas. Although this notion has been conceptually introduced for the Wadden Sea, no modeling attempts have been made yet. As a proof of concept, this study developed a simulation model using the commercially available STELLA® software, based on long-term data on water level and sedimentation collected at a back-barrier marsh on the Skallingen peninsula in Denmark. In the model, the frequency (number year–1) of wind-driven extreme high water level (HWL) events (>130 cm Danish Ordnance Zero) was simulated in terms of the North Atlantic Oscillation (NAO) index. Then, surface accretion (cm year–1) and submergence duration (h year–1) were simulated for the period 1933–2007. The model showed good performances: simulated rates of surface accretion and simulated durations of submergence decreased from 1950 to 1980, the point at which the NAO shifted from its negative to its positive phase, and increased thereafter. Despite continuous increases in surface elevation, increases in simulated submergence duration were apparently due to wind-driven HWL events, which generally increased in frequency after 1980. These findings for the Danish Wadden Sea add to the growing body of evidence that the role of atmospheric oscillations—e.g., the NAO—as drivers of wind-generated water level variations merits more attention in assessing the impact of climate change on coastal marshes.

Extreme Waves and Wave Run-up in Halifax Harbour under Climate Change Scenarios

The tendency for rising sea levels, combined with changes in the frequency and intensity of extreme storm events raises the potential for flooding and inundation of coastal locations such as Halifax Harbour, in the context of climate change. In this study, we consider three scenarios for extreme high water levels based on climate change scenarios and estimates for land subsidence, rising mean sea levels, and return period analysis for extreme events (from previous studies). We also investigate the effect of ocean waves on these estimates for extreme high water levels. Because the most damaging storm to make landfall in Nova Scotia over the last century was Hurricane Juan (2003), it was chosen to simulate the extreme case of storm-generated waves and wave run-up in Halifax Harbour. To simulate waves generated by Hurricane Juan, a nested-grid system consisting of two modern state-of-the-art operational wave models was used. High quality winds were used to drive the wave models, and the simulations used recently updated high resolution coastal bathymetry. Observed water elevation changes in Halifax Harbour were used in wave model simulations of Hurricane Juan. The Federal Emergency Management Agency's (FEMA) run-up model is used to estimate wave run-up elevation, which is validated with recorded high water observations along the coastline. Simulated waves and wave run-up elevations for Hurricane Juan suggest that the maximum significant wave heights at the mouth of the Harbour were 9.0 m, and the wave run-up was as high as 2.0 m along the shoreline of Halifax Harbour. In this way, we estimated the impact of waves and wave run-up on extreme high water elevations for three climate change scenarios in Halifax Harbour, under worst-case conditions. The sensitivity of these estimates is analyzed for different water level variations, wave propagation directions and shore slope profiles. [Traduit par la rédaction] La tendance à la hausse du niveau de la mer de pair avec les changements dans la fréquence et l'intensité des événements de tempêtes extrêmes augmentent le risque d'inondation et de submersion à des emplacements côtiers comme le port d'Halifax dans le contexte du changement climatique. Dans cette étude, nous examinons trois scénarios de niveaux de hautes eaux extrêmes basés sur des scénarios de changement climatique et estimations de subsidence du terrain, l’élévation du niveau moyen de la mer ainsi que l'analyse de la période de retour d’événements extrêmes (faite lors d’études antérieures). Nous examinons aussi les effets des vagues de l'océan sur ces estimations de niveaux de hautes eaux extrêmes. Étant donné que la tempête la plus dévastatrice à avoir touché terre en Nouvelle–Écosse au cours du dernier siècle a été l'ouragan Juan (2003), c'est celle-ci que nous avons choisie pour simuler le cas extrême de vagues produites par une tempête et de remontée de vagues dans le port d'Halifax. Pour simuler les vagues produites par Juan, nous nous sommes servis d'un système à grilles imbriquées consistant en deux modèles de vagues opérationnels à la fine pointe de la technologie. Les modèles de vagues étaient pilotés par des données de vent de haute qualité et les simulations disposaient d'une bathymétrie côtière à haute résolution récemment mise à jour. Les changements observés d’élévation de l'eau dans le port d'Halifax ont été utilisés dans les simulations de l'ouragan Juan par les modèles de vagues. Nous utilisons le modèle de remontée des vagues de la Federal Emergency Management Agency (FEMA) pour estimer la hauteur des remontées, qui est validée par rapport aux observations de hautes eaux enregistrées le long de la côte. Les vagues et les hauteurs de remontée des vagues simulées pour l'ouragan Juan suggèrent que la hauteur significative maximale des vagues à l'entrée du port était de 9,0 m et la remontée des vagues atteignait 2,0 m le long de la côte du port d'Halifax. Nous avons de cette manière estimé l'impact des vagues et de la remontée des vagues sur l’élévation des hautes eaux extrêmes pour trois scénarios de changement climatique dans le port d'Halifax dans les conditions les plus défavorables. Nous analysons la sensibilité de ces estimations à divers changements de niveau d'eau, directions de propagation et profils de pente côtière.

INCREASED WATER LEVELS DUE TO MORPHODYNAMIC CHANGES; THE LIMFJORD, DENMARK

The Limfjord is an estuary in Denmark between The North Sea and Kattegat. The Thyboroen Channel connects the fjord with The North Sea. The water levels in the western part of the Limfjord are strongly correlated with the water level in the sea at Thyboroen. Analyses revealed a close to threefold increase in the channel cross section over the last 100 years. This has led to a detailed investigation into the effects of the channel cross section on the extreme high water levels in the Limfjord now and in the future. For Lemvig in the western part of the Limfjord the water level with a return period of 100 years would have been 1.73 m with the 1958 channel bathymetry throughout the whole period and 1.99 m with the 2005 channel bathymetry. With the extrapolated 2060-bathymetry the 100 years water level will be 2.38 m. A number of measures to counteract the consequences of this development have been evaluated.

Modelling ice cover formation of a lake–river system with exceptionally high flows (Lake St. Martin and Dauphin River, Manitoba)

Abstract In 2011, Manitoba experienced extreme flooding on a wide extended scale that affected many large watersheds, in particular the Upper Assiniboine, Qu'Appelle and Souris River watersheds. In order to protect Winnipeg from excessive flooding, some of the flood waters were diverted via the Portage Diversion into Lake Manitoba and Lake St. Martin, causing extreme high water levels and flooding of these lakes. The outlet of this entire drainage basin is the Dauphin River flowing from Lake St. Martin to Lake Winnipeg. The river's conveyance capacity was exceeded by the flood and the lakes could not be drained fast enough to avoid damage from high flood levels and shore line erosion and property damage from accentuated wind setup (seiche) and wave uprush (runup) of the lake water. An Emergency Channel was constructed to compensate for this constriction, which now conveys additional water from Lake St. Martin towards Lake Winnipeg. Due to the extreme flooding, the Dauphin River had unprecedented record flows in the autumn of 2011. Ice cover formation during winter freeze-up of these waters could potentially exacerbate the flooding situation for communities alongside Lake St. Martin and the Dauphin River. Hence, the river ice model RIVICE was implemented to determine flood protection elevations to which existing dikes needed to be raised and extended. The modelling takes into consideration the potential frazil ice generation that can raise water levels by up to 3 m from open water levels. High discharge and water level data was available to calibrate the model both for an open-water and an ice-covered case. Three scenarios were then simulated to determine ice-covered water levels of the river for early, best-estimate and late freeze-up events to determine flood protection levels along the Dauphin River and Lake St. Martin. The model was successfully validated using data collected during a freeze-up event in December 2011.

Modelling sea level rise impacts on storm surges along US coasts

Sound policies for protecting coastal communities and assets require good information about vulnerability to flooding. Here, we investigate the influence of sea level rise on expected storm surge-driven water levels and their frequencies along the contiguous United States. We use model output for global temperature changes, a semi-empirical model of global sea level rise, and long-term records from 55 nationally distributed tidal gauges to develop sea level rise projections at each gauge location. We employ more detailed records over the period 1979–2008 from the same gauges to elicit historic patterns of extreme high water events, and combine these statistics with anticipated relative sea level rise to project changing local extremes through 2050. We find that substantial changes in the frequency of what are now considered extreme water levels may occur even at locations with relatively slow local sea level rise, when the difference in height between presently common and rare water levels is small. We estimate that, by mid-century, some locations may experience high water levels annually that would qualify today as ‘century’ (i.e., having a chance of occurrence of 1% annually) extremes. Today’s century levels become ‘decade’ (having a chance of 10% annually) or more frequent events at about a third of the study gauges, and the majority of locations see substantially higher frequency of previously rare storm-driven water heights in the future. These results add support to the need for policy approaches that consider the non-stationarity of extreme events when evaluating risks of adverse climate impacts.

Facile fabrication of superhydrophobic ZnO surfaces from high to low water adhesion

Superhydrophobic surface is commonly fabricated by a combination of micro- and nano-scale structure and low surface energy materials. In this paper, superhydrophobic ZnO surfaces with controllable water adhesion have been fabricated by combining both a simple hydrothermal process and self-assembly of stearic acid. We regulate the hydrothermal process by using different zinc salt aqueous solution to control different morphologies of ZnO surfaces. After being modified with stearic acid, the as-prepared ZnO surfaces show an analogous extreme nonwetting property but high contrast water adhesion that ranges from very high to extremely low. This simple and practical method can provide an important strategy for the adhesion adjustment on superhydrophobic surfaces.

大流量ウォータージェットの流動構造とボイド率分布

In this study, the laser tomography method was applied to measure the void fraction distribution of the water jet in radial direction and axial direction. The continuous laser beam emitted by Nd:YAG green laser (wavelength=532nm, beam diameter=0.25mm) is introduced into the water jet in normal to the flow direction. The laser beam is emitted toward the photo detector, which is located at the opposite side. The photo detector can detect the transmissivity of the laser beam passing across the cross section of the jet. By detecting the laser at the photo detector, we can get the transmissivity distribution of the jet in radial direction. By using this measured transmissivity distribution data, we can reconstruct the void fraction distribution inside of the jet by using the tomography method. For the image reconstruction, we applied ML-EM method (Maximum Likelihood — Expectation Maximization) and assumed that the water jet droplet follows some specific distribution. By using these techniques, the void fraction distribution of the extreme high speed water jet can be successfully measured.

조석-해일 결합모형을 이용한 목포시 범람 모의

A coupled tide-surge model, which has been evaluated the utility in the previous study, is applied for simulating the inundation phenomena. The coupled model system adopts the hydrodynamic module of MIKE21 software, and the study area is identical to the previous study. The only difference is additional detailed areas for simulating inundation. An artificial scenario of a virtual typhoon striking Mokpo coastal zone at spring high tide is simulated. Then the calculated water level corresponds to the extreme high water level(556 cm) for 100 year return period. The result also shows the inundation depth is 50~100 cm not only near the Mokpo Inner Port but also near the Mokpo North Port. Finally, the coastal inundation prediction map is drawn on the basis of inundation simulation results.

Comparative gas exchange performance during the wet season of three Brazilian Styrax species under habitat conditions of cerrado vegetation types differing in soil water availability and crown density

We studied the influence of environmental conditions in different vegetation types of the Brazilian savanna (cerrado s.l.) on CO 2 assimilation and water use efficiency of Styrax ferrugineus, S. camporum and S. pohlii, which are morphologically similar but have distinct distribution patterns. We measured leaf gas exchange and water relations in adult and young plants. Adult plants of S. ferrugineus were measured in the cerrado s. str.; plants of S. camporum at the edge of cerradão, a woodland vegetation; and in a riparian forest those of S. pohlii. Eight-month-old young plants were planted in the cerrado s. str., at the edge and in the understory of the cerradão, and in the understory of the riparian forest. For young plants, the high light availability in the cerrado s. str. resulted in a threefold greater CO 2 assimilation rate ( A) compared to the other sites. A of adult plants under full irradiation (1800 μmol photons m −2 s −1) was significantly lower in S. pohlii compared to S. ferrugineus and S. camporum. Although sufficient soil water was available at every site at the end of the wet season, the extreme high water content in the riparian forest soil led to increased stomatal conductance ( gs) and transpiration rate ( E) for young plants of S. camporum and S. pohlii, but not of S. ferrugineus. However, the large gs in S. pohlii and S. camporum young plants did not result in higher A rates. The differences may indicate some specialization of S. ferrugineus to best growth in open savanna and of S. pohlii in riparian forest habitats. The high water use efficiency of S. camporum young plants in the understory of cerradão seems not yet sufficient to emphasize that this species benefits from this particular habitat. Because, while water supply during the wet season is quite sufficient, soil water deficits and frequent fires can occur during the dry season and might modify strongly the habitat conditions for the three Styrax species.

Changes in extreme high water levels based on a quasi‐global tide‐gauge data set

A quasi‐global sea level data set from tide gauges has been used to investigate extreme sea level events and their spatial and temporal variabilities. Modern methods based on a nonstationary extreme value analysis have been applied to the maxima of the total elevations and surges for the period of 1970 and onward. A subset of the data was used to study changes over the 20th century. The analyses demonstrate the magnitude and timing of the seasonal cycle of extreme sea level occurrence, the magnitude of long‐term trends in extreme sea levels, the evidence for perigean and nodal astronomical tidal components in the extremes, and the relationship of the interannual variability in high water levels to other ocean and atmosphere variations as represented by climate indices. The subtraction from the extreme sea levels of the corresponding annual median sea level results in a reduction in the magnitude of trends at most stations, leading to the conclusion that much of the change in the extremes is due to change in the mean values.

Reducing negative flood impacts in 'Apatinski rit': Part of special nature reserve 'Gornje Pondunavlje' (Vojvodina, Serbia) using GIS

During the history, the Danube valley was often devastated the northwest part of Bačka. However, the Danube river created also one of the most rich full wetland complexes in Serbia, Special Nature Reserve 'Gornje Pondunavlje' (Upper Danube). Hunting-ground 'Apatinski rit' is located within borders of SNR 'Gornje Podunavlje'. The people from this region constructed river embankments and other fortification objects to protect themselves from the floods, but still there are spacious areas that are not protected. In those areas, many floral and animal species (including game) face floods every year. High water level of the Danube River is the most dominant factor of change of habitat conditions in hunting ground 'Apatinski rit'. About 60% of the territory of 'Apatinski rit' are in the zone of floods. During the extreme high water level, game animals suffer serious losses. The purpose of this paper is to present possible application of geographic information system (GIS) in flood prediction in hunting-ground 'Apatinski rit' in order to reduce negative flood impacts. GIS technologies are used in many aspects of flood identification, prediction, and hazard mitigation. In this paper a 3D model is introduced to realize the flooded areas. The flooded areas are estimated based on the Danube water levels and topography of the surrounding terrain. The estimated flooded areas based on several water levels are shown in the paper. During the flood some parts of hunting ground are under water, and some higher courts remain dry. By using 3D model, all the isolated 'islands' with trapped game can be located during the floods, which is crucial for rescue intervention priorities and decision making during the flood.

Biology of the endangered cyprinodontid Aphanius iberus in a saline wetland (SE Iberian Peninsula)

For the last few decades, Aphanius iberus, an endemic cyprinodontid from the Iberian Peninsula and included in international red lists, has been declining despite several management efforts. In this study we present the biology of the species in an isolated wetland managed for salt exploitation (its most common habitat type in the southeastern Iberian Peninsula). The population studied is found under conditions of extreme high salinity and water temperature. We have examined the effects of extractive management on catchability, population structure, growth and reproduction traits. The stock was characterized by significant differences in abundance between seasons (higher values: end of summer and early autumn). Drastic changes in salinity and water level have negatively affected the species abundance. The population structure was characterized by three age groups (0+, 1+ and 2+ in both sexes), a high degree of group‐size overlapping into the 0+ (>2 groups), a short life span and a long reproductive period (April/May to September). Gonadal mass represented a maximum of 19.6±0.5% of the total mass in females. We detected changes in life‐history traits which could be related to the management of the salt extraction, variations in water level that increase the salinity should be indirect effects on fish population by reducing vegetation mats.

Analyzing sea level rise and tide characteristics change driven by coastal construction at Mokpo Coastal Zone in Korea

This study investigates a construction-induced sea level rise and tide characteristics change, using a regression analysis to separate the local construction effect such as sea-dike/seawalls and global warming from total sea level change. The study also makes it clear why and how the extreme high water level has risen just after constructions at Mokpo harbor in Korea. As a result of the regression analysis, it is found that the high water level rise for the period of 1960–2006 is ∼60 cm, which is summation of four components: ∼23 cm for Youngsan River sea-dike (1981), ∼15 cm for Youngam seawall (1991), ∼8 cm for Geumho seawall (1994), and ∼14 cm for gradual rise (due mainly to global warming). Then, a numerical simulation at Mokpo coastal zone is performed to identify each component, and the results support the premise that the tidal amplification caused by constructions is due mainly to the extinguishment of the tidal choking effect at outer Mokpogu. The tidal flat effect makes the amplification greater at spring tide or extraordinary high tide, which would result in the increase of inundation risk at the Mokpo coastal zone. Frequency distribution of observed high water level data shows increasing trend for both maximum value of astronomical tide component (simulated high water level) and meteorological tide component (surge height) after the coastal constructions. A frequency analysis presents that the high water level for 50 year return period, which is often used for design in practice, is 474 cm before the construction, and while that is 553 cm after the construction. Furthermore, design height might steadily be elevated considering future global sea level rise.

Water-yield estimates for critical loadings assessment: comparisons of gauging methods versus an isotopic approach

An isotope mass balance technique is applied to quantify water yield and refine a steady-state critical acid loadings assessment for 49 lakes in hydrologically complex, wetland-rich terrain of northeastern Alberta. The approach uses physical and climatological data combined with site-specific measurements of evaporative isotopic enrichment of 2H and 18O in lake water to measure lake residency and ungauged runoff to lakes. Mean water yields to individual lakes across the region over a 3-year period are estimated to range from 5 to 395 mm·year–1, with a standard deviation of two times the predicted estimates based on interpolation of gauged stream flow from broad-scale watersheds in the area. Comparison of the method with longer-term Water Survey of Canada hydrometric data suggests very similar average water yields for moderate- to large-sized watersheds. However, the isotope-based estimates appear to capture extreme low water yields in flat, disconnected areas and extreme high water yields in other areas thought to be related to stronger connections to regional groundwater flow systems. For aquatic ecosystems of northeastern Alberta, an area expected to be affected by acid deposition from regional oil sands development, continued refinement of the technique is important to accurately assess critical loads for ungauged systems, particularly those in low-yield settings.

Adapting to Pacific Island mangrove responses to sea level rise and climate change

CR Climate Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials CR 32:161-176 (2006) - doi:10.3354/cr032161 Adapting to Pacific Island mangrove responses to sea level rise and climate change Eric L. Gilman1,15,*, Joanna Ellison1, Vainuupo Jungblut2, Hanneke Van Lavieren3, Lisette Wilson4, Francis Areki5, Genevieve Brighouse6, John Bungitak7, Eunice Dus8, Marion Henry9, Mandes Kilman10, Elizabeth Matthews11, Ierupaala Sauni Jr.6, Nenenteiti Teariki-Ruatu12, Sione Tukia13, Kathy Yuknavage14 1University of Tasmania, School of Geography and Environmental Studies, Locked Bag 1-376 Launceston, Tasmania 7250, Australia 2Secretariat of the Pacific Regional Environment Programme, PO Box 240, Apia, Samoa 3United Nations Environment Programme, Regional Seas Programme, PO Box 30552 Room T-232, Nairobi, Kenya 4WWF-South Pacific, PO Box 8280, Boroko, NCD, Papua New Guinea 5WWF-Fiji, 4 Ma’afu Street, Private Mail Bag, Suva, Fiji 6Coastal Management Program, Utulei Executive Office Building, Pago Pago, American Samoa 96799, USA 7Environmental Protection Authority, PO Box 1322, Majuro, MH 96960, Republic of the Marshall Islands 8Wildlife Conservation Society, PO Box 277, Goroka, Eastern Highlands Province, Papua New Guinea 9Department of Economic Affairs, PO Box PS12, Palikir, Pohnpei, FM 96941, Federated States of Micronesia 10Primary Resources Consulting Company, PO Box 1691, Port Vila, Vanuatu 11Palau Conservation Society, Box 1811, Koror, PW 96940, Palau 12Ministry of Environment, Land, and Agricultural Development, PO Box 234, Bikenibeu, Tarawa, Kiribati 13Department of Environment, PO Box 917, Nuku’alofa, Tonga 14Commonwealth of the Northern Mariana Islands Coastal Resources Management Office, Box 10007, Saipan MP 96950, USA 15Present address: 2718 Napuaa Place, Honolulu, Hawaii 96822, USA *Email: egilman@utas.edu.au ABSTRACT: Stresses associated with effects of climate change, including rise in relative mean sea level, present one set of threats to mangroves. Coastal development and ecosystems in the Pacific Islands region are particularly vulnerable to climate change effects. We investigated the capacity of Pacific Island countries and territories to assess mangrove vulnerability to the effects of climate change, and their capacity to adapt to mangrove responses to these forces. Technical and institutional capacity-building priorities include: (1) strengthening management frameworks to conduct site-specific assessment of mangrove vulnerability and incorporate resulting information into land-use plans to prepare for any landward mangrove migration and offsetting anticipated losses; (2) reducing and eliminating stresses on and rehabilitating mangroves, in part, to increase mangrove resilience to climate change effects; and (3) augmenting abilities to establish mangrove baselines, and monitor gradual changes using standardized techniques through a regional network to distinguish local and climate change effects on mangroves. Other priorities are to: (4) assess how mangrove margins have changed over recent decades; (5) determine projections of trends in mean relative sea level and trends in the frequency and elevation of extreme high water events; (6) measure trends in changes in elevations of mangrove surfaces; and (7) incorporate this information into land-use planning processes. Also in (8) some locations require spatial imagery showing topography and locations of mangroves and coastal development. Land-use planners can use information from assessments predicting shoreline responses to projected sea level rise and other climate change effects to reduce risks to coastal development, human safety, and coastal ecosystems. This advanced planning enables coastal managers to minimize social disruption and cost, minimize losses of valued coastal ecosystems, and maximize available options. KEY WORDS: Mangrove · Sea level rise · Climate change · Land-use planning · Pacific Islands Full text in pdf format NextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in CR Vol. 32, No. 3. Online publication date: October 26, 2006 Print ISSN: 0936-577X; Online ISSN: 1616-1572 Copyright © 2006 Inter-Research.

Extreme low and high water levels

A methodology for the prediction of low end and high end extremes in sustained water level is established. The observational data base is a long-duration sequence of monthly high and low extremes. The data identifies a deterministic trend attributable to Mean Sea Level rise and the nominal 19-year forcing in the astronomical tide. The data is pre-conditioned to remove these trends, defining a net data series suitable for extreme value analysis. Context-specific issues in the extreme value analysis are identified and resolved. These include probability model compatibility with elevation datums, rational estimation of the distribution parameters, and the estimation of confidence limits. The predictions for extreme low and high water levels are both real time and return period dependent.

강화도 갯벌 천해의 건간망 어획 어류의 계절 변동

Seasonal variation of the fishery resource in the shallow waters of Ganghwado tidal flat was investigated using monthly collected samples with a fence net from June 1998 to May 1999. Thirty-six species were found including 27 fish species, 6 crustaceans, and 3 molluscs. Of the fish, Konosirus punctatus, Sardinella zunasi Liza haematocheila and Synechogobius hasta dominated in the number of individuals <TEX>$(92.1\%)$</TEX> and in biomass <TEX>$(94.5\%).$</TEX> A few number of resident species, such as L. haematocheila and S. hasta, were collected only during the cold months. As the water temperature increased in the spring, the adult migratory fish such as K. punctatus and S. zunasi, were collected. In the summer, the juvenile fish recruited in the shallow water showing a peak in fish abundance. The data suggested that they grew until late autumn before moving to deeper waters for over-wintering. The principal component analysis showed that the seasonal variation in species composition was principally determined by water temperature and/or water temperature related factors. The species composition of the fish assemblage in the study area suggested that these species are highly adapted to extreme seasonal temperature variation and high water turbidity.