Mean Sea Level Data Research Articles

Assessing vulnerability and enhancing resilience of port systems in southeast Texas facing sea-level rise

Climate change and the associated sea level rise (SLR) are presenting newfound challenges to the port systems and coastal transportation infrastructure of southeast Texas. This paper introduces a Geographic Information Systems (GIS) based model designed to simulate inundation scenarios under various sea-level projections, aiming to assess the vulnerabilities of both port facilities and road networks. The study area encompasses a specific region within Jefferson County, southeast Texas, encompassing three major ports: Port Arthur, Beaumont, and Orange. Utilizing a high-resolution (1-m) Digital Elevation Model (DEM) derived from the 2017 LiDAR dataset, this model is integrated with NASA’s sea-level rise projections to compute the extent and volume of inundation across low, medium, and high SLR scenarios. Drawing from monthly mean sea level data spanning from 1958 to 2020, the lowest SLR projections, derived from the relative sea-level trend measured at the Sabine Pass, TX gauge station, indicate a yearly increase of 6.16 mm, with a 95% confidence interval of +/- 0.74 mm. Projections for 2050 and 2,100 show the lowest SLR at 0.17 m and 0.48 m, respectively. In contrast, the medium to high RSLR projections under the IPCC SSP3-7.0 scenario for 2050 and 2,100 stand at 0.54 m and 1.34 m, respectively. The findings reveal that, under medium to high SLR scenarios, the extent of inundated areas in the study region is expected to expand by 12.4% in 2050 and 19.9% in 2,100, compared to the lowest SLR projection. Additionally, the length of submerged roadways is predicted to increase by 6.9% in 2050 and 13.3% in 2,100, in comparison to the lowest SLR projection. It is worth noting that some margin of error may be introduced due to factors such as the width of the port area and access roads, the high-resolution DEM, and the alignment of computed inundated areas with the existing topography. Overall, the manuscript highlights the urgency of proactive planning and underscores the importance of safeguarding critical infrastructure in the context of climate change and SLR.

Reducing the Uncertainty in the Satellite Altimetry Estimates of Global Mean Sea Level Trends Using Highly Stable Water Vapor Climate Data Records

AbstractThe global mean sea level (GMSL) has risen by 3.3 ± 0.2 mm.yr−1 (68% confidence level) over 1993–2021. The wet troposphere correction (WTC) used to compute the altimetry‐based mean sea level data is known to be a large source of error in the GMSL long‐term stability. The WTC is derived from the microwave radiometers (MWR) on board the altimetry missions. In order to improve the long‐term estimates of the GMSL, we propose an alternative WTC computation based on highly stable climate data records (CDRs) of water vapor derived from independent MWR measurements on board meteorological satellites. A polynomial model is applied to convert water vapor to WTC. The CDR‐derived WTC enables reducing the low frequency uncertainty of the WTC applied to the altimetry data, hence reducing the uncertainty of the GMSL trend estimate. Furthermore, over 2016–2021, the comparison of MWR‐based with CDR‐based WTC shows a likely drift of the Jason‐3 MWR WTC on the order of −0.5 mm.yr−1 that would lead to an overestimation of the GMSL trend from 2016.

Assessment and Prediction of Sea Level Trend in the South Pacific Region

Sea level rise is an important and topical issue in the South Pacific region and needs an urgent assessment of trends for informed decision making. This paper presents mean sea level trend assessment using harmonic analysis and a hybrid deep learning (DL) model based on the Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN) technique, Convolutional Neural Network (CNN), Gated Recurrent Unit (GRU) and Neighbourhood Component Analysis (NCA) to build a highly accurate sea level forecasting model for three small islands (Fiji, Marshall Island and Papua New Guinea (PNG)) in the South Pacific. For a 20-year period, the estimated mean sea level rise per year from the harmonic computation is obtained: 112 mm for PNG, 98 mm for Marshall Island and 52 mm for Fiji. The DL procedure uses climate and environment-based remote sensing satellite (MODIS, GLDAS-2.0, MODIS TERRA, MERRA-2) predictor variables with tide gauge base mean sea level (MSL) data for model training and development for forecasting. The developed CEEMDAN-CNN-GRU as the objective model is benchmarked by comparison to the hybrid model without data decomposition, CNN-GRU and standalone models, Decision Trees (DT) and Support Vector Regression (SVR). All model performances are evaluated using reliable statistical metrics. The CEEMDAN-CNN-GRU shows superior accuracy when compared with other standalone and hybrid models. It shows an accuracy of >96% for correlation coefficient and an error of <1% for all study sites.

Extreme Level Fluctuations in the Seas of the Russian Arctic in the Context of Global Climate Change

The presented article is devoted to the results of detailed studies of the features of extreme sea level fluctuations in the Russian Arctic under the conditions of global climate change. Estimates of the rate of mean sea level rise in the Arctic are obtained from the monthly mean sea level data at coastal tide gauges and satellite altimetry. It was found that for the Arctic Ocean coast from the Kara to the Chukchi Seas, the highest tides take place in the Khatan- ga Bay (Preobrazheniya Island), 131 cm. In the White, Kara, Laptev and Chukchi Seas, the seasonal variability of harmonic tidal constants was studied; it occurs due to changes in hydrometeorological conditions during the year. The ADCIRC hydrodynamic model was adapted for the conditions of the Laptev Sea. Numerical modeling of sea level oscillations from 1980 to 2000 was performed. According to the simulation results, the maximum ranges of residual sea level fluctuations are observed both for the total level and at the mouth of the Khatanga (489 cm) and Oleneksky Bay (444 cm). Based on the data of coastal observations and numerical modeling, the authors obtained estimates of extreme level fluctuations with different recurrence periods.

Analysis of vertical reference levels in the brazilian coast: comparing local and global approaches

There is a historical search for the unification of different geodetic reference systems in order to better integrate geodetic investigations. In particular, coastal zones pose the challenge of connecting terrestrial and oceanic references when working with different vertical reference levels. This study aims to investigate the goodness-of-fit of ocean models to local observations, as well as to update and improve reference levels (RL) in two tide gauges (TGs) in Brazil (Imbituba and Fortaleza). Local RLs were connected to a global reference system (GRS80), which allowed absolute analyses using the mean sea surface (MSS) and lowest astronomical tide (LAT) models MSS_CNES_ CLS15, DTU_15_MSS, DTU_18_MSS and DTU_15_LAT. In the selected TGs, the MSS models showed a difference of centimeters in regards to the local mean sea level (MSL) defined by the Directorate of Hydrography and Navigation (DHN). Sea Surface Topography (SSTop) values were estimated from Global Geopotential Models and MSL data. The results indicated possible inconsistencies in the global model of LAT when compared to local observations, likely due to the difficulty of modeling coastal zones.

Global Mean Sea Level. Time Trends and Persistence with Long Range Dependent Data

Global mean sea level data are examined in this work by looking at the presence of time trends in the context of long memory or long range dependent processes. By looking at both seasonal signals retained and seasonal signals removed data from 1992 to 2020, the results show that the two series display significant time trend coefficients and high levels of persistence.

Long-Term Community Dynamics Reveal Different Trajectories for Two Mid-Atlantic Maritime Forests

Maritime forests are threatened by sea-level rise, storm surge and encroachment of salt-tolerant species. On barrier islands, these forested communities must withstand the full force of tropical storms, hurricanes and nor’easters while the impact is reduced for mainland forests protected by barrier islands. Geographic position may account for differences in maritime forest resilience to disturbance. In this study, we quantify two geographically distinct maritime forests protected by dunes on Virginia’s Eastern Shore (i.e., mainland and barrier island) at two time points (15 and 21 years apart, respectively) to determine whether the trajectory is successional or presenting evidence of disassembly with sea-level rise and storm exposure. We hypothesize that due to position on the landscape, forest disassembly will be higher on the barrier island than mainland as evidenced by reduction in tree basal area and decreased species richness. Rate of relative sea-level rise in the region was 5.9 ± 0.7 mm yr−1 based on monthly mean sea-level data from 1975 to 2017. Savage Neck Dunes Natural Area Preserve maritime forest was surveyed using the point quarter method in 2003 and 2018. Parramore Island maritime forest was surveyed in 1997 using 32 m diameter circular plots. As the island has been eroding over the past two decades, 2016 Landsat imagery was used to identify remaining forested plots prior to resurveying. In 2018, only plots that remained forested were resurveyed. Lidar was used to quantify elevation of each point/plot surveyed in 2018. Plot elevation at Savage Neck was 1.93 ± 0.02 m above sea level, whereas at Parramore Island, elevation was lower at 1.04 ± 0.08 m. Mainland dominant species, Acer rubrum, Pinus taeda, and Liquidambar styraciflua, remained dominant over the study period, with a 14% reduction in the total number of individuals recorded. Basal area increased by 11%. Conversely, on Parramore Island, 33% of the former forested plots converted to grassland and 33% were lost to erosion and occur as ghost forest on the shore or were lost to the ocean. Of the remaining forested plots surveyed in 2018, dominance switched from Persea palustris and Juniperus virginiana to the shrub Morella cerifera. Only 46% of trees/shrubs remained and basal area was reduced by 84%. Shrub basal area accounted for 66% of the total recorded in 2018. There are alternative paths to maritime forest trajectory which differ for barrier island and mainland. Geographic position relative to disturbance and elevation likely explain the changes in forest community composition over the timeframes studied. Protected mainland forest at Savage Neck occurs at higher mean elevation and indicates natural succession to larger and fewer individuals, with little change in mixed hardwood-pine dominance. The fronting barrier island maritime forest on Parramore Island has undergone rapid change in 21 years, with complete loss of forested communities to ocean or conversion to mesic grassland. Of the forests remaining, dominant evergreen trees are now being replaced with the expanding evergreen shrub, Morella cerifera. Loss of biomass and basal area has been documented in other low elevation coastal forests. Our results indicate that an intermediate shrub state may precede complete loss of woody communities in some coastal communities, providing an alternative mechanism of resilience.

Rising sea level and its implications on coastal tourism development in Cape Town, South Africa

While there is agreement among tourism role-players on tourism's potential to contribute to socio-economic and environmental development, the industry is under severe threat from the increased impact of climate variability and change. This study examines the implications of rising sea level on coastal tourism in Cape Town, South Africa. Making use of mean sea level data from permanent sea level markers, remote sensing and field observations, supported by key informant interviews, the study found that coastal tourism is under threat from rising sea level. Current and projected rising sea level, as well as other extreme weather events such as the increased storm intensity trigger massive waves and tides that result in storm surges, which overtop and encroach into the land surface area. At least 80% of the city's 2019/2020 Blue Flag beaches are now under threat from rising sea level and coastal erosion. The study also found that some of the iconic tourist attractions such as the Cape Point, V&A Waterfront, Robben Island and several beaches along the False Bay area are under the same threat. Other tourism facilities under threat of weather extremes from climate change include servitudes, coastal roads, railway facilities and tidal pools: all threatening the attractiveness of some resorts. Management implicationsRising sea level is a huge challenge that requires innovative solutions for the city of Cape Town. Given the threat that the industry is facing, there is a need for a public-private partnership aimed at ensuring that there are sufficient resources to help the tourism sector is capable of adapting to climate change. Increase insurance cover is a must to protect businesses from anticipated increased damage from rising sea levels and associated weather extreme events. Continued risk assessment is a must to ensure the industry is abreast with the continued changes which are threats to coastal tourism resorts and infrastructure.

The Impacts of ENSO and IOD on the MSL of The Arabian Gulf and The Arabian Sea by Using Satellite Altimetry Data

The main objective for the current research is to determine the linear trends of the mean sea level (MSL) resulting from the influence of the Southern Oscillation of El Niño (ENSO) and the Indian Ocean dipole (IOD), which have increased in recent times due to increased global warming using satellite altimetry of MSL data. Statistical time series technique has been used. The standard ordinary univariate and bivariate linear regression method as well as Pearson correlation were used. Linear trends for the positive phase of IOD were detected on mean sea level while no linear trends of ENSO were detected in the Arabian Gulf. On the other side, linear trends of the negative phases of IOD and ENSO were detected on mean sea level in the Arabian Sea over the period 1993-2013. It is most important for climate research to provide accurate predictions of sea level rise in the coming years and plan the activities to lessen the disasters before they happen.

Outliers and Level Shift Detection of the Mean-sea Level, Extreme Highest and Lowest Tide Level Data

부산, 목포 ì§€ì ì˜ í‰ê· í•´ìˆ˜ë©´(MSL)ê³¼ ê³ ê·¹ì¡°ìœ„, ì €ê·¹ì¡°ìœ„ 자료의 이상자료 시계열 모델링을 수행하였다. 시계열 모델은 ê³„ì ˆì„±ë¶„ì„ 포함하는 SARIMA 모형이며, ì¼ì‹œì ì¸ 변화에 해당하는 이상자료(Additive Outlier, AO)와 ì˜êµ¬ì ì¸ 변화를 의미하는 ê¸°ì¤€ê³ ë„ 변화(Level Shift, LS)를 모델에 포함하였으며, AIC 기준에 의거하여 ìµœì  모델을 ì„ ì •í•˜ì˜€ë‹¤. 이상자료 모형의 매개변수 ì¶”ì •ì€ R 프로그램 ‘tsoutliers’ 패키지(‘tso’ 함수)를 이용하였다. ì„ ì • 모형을 이용하여 이상자료와 ê¸°ì¤€ê³ ë„ 변화 진단에 ì ìš©í•œ ê²°ê³¼, 부산의 월 단위 ê³ ê·¹ì¡°ìœ„ 자료에서 2003, 2012ë „ 발생한 태풍 매미(MAEMI), 산바(SANBA)에 의한 ì¼ì‹œì ì¸ 수위상승을 65.5, 29.5 cm ì •ë„ë¡œ ì¶”ì •í•˜ì˜€ìœ¼ë©°, 목포의 월 단위 í‰ê· í•´ìˆ˜ë©´ 자료에서는 1 983ë „ì˜ 영산강 하굿둑 건설 ì‚¬ì— ì— 의한 ê¸°ì¤€ê³ ë„ 변화를 21.2 cm ì •ë„ë¡œ ì¶”ì •í•˜ì˜€ë‹¤. 한편 본 연구에서 구성한 모형은 모형의 편향을 ìœ ë°œí•˜ëŠ” 이상자료의 영향을 포함하며, 모형에 의한 RMS 오차는 연간 자료를 사용한 경우, 부산은 M SL 1 .95 cm, ê³ ê·¹ì¡°ìœ„, ì €ê·¹ì¡°ìœ„ 각각 5.11 cm, 6.50 cm이며, 목포의 경우에는 큰 조차의 영향으로 MSL 2.01 cm, ê³ ê·¹ì¡°ìœ„, ì €ê·¹ì¡°ìœ„ 각각 1 1 .80 cm, 9 .1 4 cm로 부산보다 다소 높게 나타났다. 핵심용어: 이상자료 모형, ì¼ì‹œì  이상자료, ê¸°ì¤€ê³ ë„ 변화, í‰ê· í•´ìˆ˜ë©´, ê³ ê·¹ì¡°ìœ„ì™€ ì €ê·¹ì¡°ìœ„

Climate change, mean sea levels, wetland decline and the survival of the critically endangered Capricorn Yellow Chat

AbstractAn isolated population of ~30 Capricorn Yellow Chats (Epthianura crocea macgregori) (Aves: Meliphagidae) occurs on a grassy marine plain (~4000 ha) with complex fresh to hypersaline wetlands bordering unvegetated salt flats and mangroves, the majority less than 2 m above mean sea level (MSL). While there are several species of sedge on the marine plain, only one, a tall salt‐tolerant sedge, Schoenoplectus subulatus, regularly provides tall cover and nesting habitat on the marine plain. Comparison of vegetation data between 2002 and 2018 at four breeding sites showed a loss of S. subulatus at two of the sites in conjunction with persistent extreme hypersalinity. In contrast, sites where S. subulatus recovered had elevated salinity levels coinciding with a drought in 2005–2008, but subsequently returning to pre‐drought levels. Concomitant with the loss of S. subulatus was a substantial decline in Capricorn Yellow Chat abundance. Possible drivers of persistent hypersalinity were an increase in sea level and consequent greater tidal ingress. The two most severely affected sites were relatively close to tidal influence and low points in the landscape. Evaluation of MSL data showed that habitat decline from 2002 to 2018 occurred over a period in which sea level rose by ~80 mm. While it is recognised that other variables are important, this study indicates that if sea‐level rise continues at the 2011–2017 rate of ~8.3 mm per annum, the Curtis Island marine plain will become unsuitable for Capricorn Yellow Chats in the next 60 years or less. Sixty years is likely to be a conservative estimate given that sea‐level rise rates are projected to increase further, as are the influence of more extreme weather events such as drought and storm surges on persistence of key vegetation. Ramifications for other Capricorn Yellow Chat sites and marine plain‐dependent fauna such as shorebirds also need consideration.

Spatial Correlation Analysis of the Mean Sea Level Data Sets in the Coastal Seas, Korea

Spatial Correlation Analysis of the Mean Sea Level Data Sets in the Coastal Seas, Korea

Investigation of Black Sea mean sea level variability by singular spectrum analysis

The mean sea level has been continuously increasing since the end of the 19th century and will continue to increase in the 21st century. The Intergovernmental Panel on Climate Change (IPCC) states that the sea level will rise by 40-60 cm until 2100. This situation will lead to social and economic problems, especially in coastal areas. For this reason, studies on sea level determination have great importance in our country. In this paper, we used the singular spectrum analysis (SSA) to investigate mean sea level variability along the coasts of the Black Sea, which is an intercontinental inland sea. This study aimed to determine the trend in sea level change along the coasts of the Black Sea over time. The mean sea level data from 10 tide gauge stations (Amasra, Batumi, Bourgas, Constantza, Igneada, Poti, Sevastapol, Trabzon II, Tuapse and Varna) are analyzed in this study. The mean sea level data were obtained from the Permanent Service for Mean Sea Level (PSMSL). SSA was applied to the mean sea level observations at tide gauges stations, and the results were interpreted. According to the analysis results, there are increasing trends at the Batumi, Poti, Tuapse, Constantza, Sevastopol and Varna stations. The obtained trend of Bourgas station is not significant. There is The results of the Amasra, Igneada and Trabzon II tide gauge stations were inadequate in interpreting any change. There were no trends at these stations. Close eigenvalues were computed from the mean sea level at the tide gauge stations. This situation shows that there is a dominant seasonal component in the time series.

Sensitivity analysis of the physical dynamics of the Fly River plume in Torres Strait

The intrusion in the Torres Strait of the Fly River plume polluted by mine tailings is an international water issue. To investigate the physical mechanisms involved in the intrusion process, numerical simulations were conducted to assess the relative influence of the bathymetry and the external forcing, namely the tides, the mean sea level slope across the strait, river runoff and wind forcing. The wind data from Horn Island, the only long-term wind station in the Torres Strait, is shown to be unreliable due to orographic effects. Mean sea level data from altimetry compare well with those from tide gauges in these shallow, reef-studded waters. The wind has a dominant effect on the mean sea level at seasonal and inter-annual periods. The resulting mean sea level difference across the strait fluctuated seasonally and strongly influenced the intrusion of the Fly River plume in the Torres Strait. The 3D finite-volume MOHID model reproduced the observation that the river plume starts by being stratified in the Gulf of Papua where it originates, and it mixes vertically when it enters the Torres Strait. The MOHID and the SLIM models were applied with different resolution to the Torres Strait and responded similarly to the external forcings. The predicted and observed Fly River plume intrusion in the eastern Torres Strait agreed well with each other, including the formation of patches due to flow reversals. However, the two models predicted a widely different Fly River plume in its far field in the western Torres Strait, the differences were attributed to the different bathymetry in the Australian and British-US bathymetry data for these poorly charted waters, which demonstrated the importance of the details of the bathymetry in controlling the extent of plume intrusion.

THE IMPACT OF SEA LEVEL RISE ON GEODETIC VERTICAL DATUM OF PENINSULAR MALAYSIA

Abstract. Sea level rise is rapidly turning into major issues among our community and all levels of the government are working to develop responses to ensure these matters are given the uttermost attention in all facets of planning. It is more interesting to understand and investigate the present day sea level variation due its potential impact, particularly on our national geodetic vertical datum. To determine present day sea level variation, it is vital to consider both in-situ tide gauge and remote sensing measurements. This study presents an effort to quantify the sea level rise rate and magnitude over Peninsular Malaysia using tide gauge and multi-mission satellite altimeter. The time periods taken for both techniques are 32 years (from 1984 to 2015) for tidal data and 23 years (from 1993 to 2015) for altimetry data. Subsequently, the impact of sea level rise on Peninsular Malaysia Geodetic Vertical Datum (PMGVD) is evaluated in this study. the difference between MSL computed from 10 years (1984 – 1993) and 32 years (1984 – 2015) tidal data at Port Kelang showed that the increment of sea level is about 27mm. The computed magnitude showed an estimate of the long-term effect a change in MSL has on the geodetic vertical datum of Port Kelang tide gauge station. This will help give a new insight on the establishment of national geodetic vertical datum based on mean sea level data. Besides, this information can be used for a wide variety of climatic applications to study environmental issues related to flood and global warming in Malaysia.

Discussion of: Boon, J.D. and Mitchell, M., 2015. Nonlinear Change in Sea Level Observed at North American Tide Stations.Journal of Coastal Research, 31(6), 1295–1305.

ABSTRACT Houston, J.R., 2016. Discussion of: Boon, J.D. and Mitchell, M., 2015. Nonlinear change in sea level observed at North American tide stations. Journal of Coastal Research, 31(6), 1295–1305. Boon and Mitchell determined sea-level acceleration using monthly averaged relative mean sea-level data from 45 U.S. tide stations and 1 Canadian station for 1969–2014. Their methods of analyzing tide gauge data are interesting and useful. However, they then projected sea-level change for 58 years from 1992–2050 based on constant accelerations calculated from these 46-year records. Calculations of acceleration based on records as short as 40–50 years are well known to be heavily corrupted by decadal variations in sea level. For example, Boon and Mitchell showed that 3–6 year variations in record length or time period resulted in what they said were “dramatic change” in calculated acceleration. Therefore, the accelerations they calculated did not even remain constant for a few years, making long-term projection...

Investigation of sea level trends and the effect of the north atlantic oscillation (NAO) on the black sea and the eastern mediterranean sea

The North Atlantic Oscillation (NAO) has significant effects on sea levels, weather, and climate. In this study, the sea level trends and the effects of the North Atlantic Oscillation Indices (NAOI) on annual mean sea level data were assessed for the Black Sea and the Eastern Mediterranean Sea. The trends of sea level and NAOI were determined using Mann-Kendall dimensionless z statistics. Generally, upward sea level trends were detected for the Black Sea and the Eastern Mediterranean Sea. In the Black Sea, significant and continuous upward trends were detected after the year 1950. Weaker trends were detected for the Eastern part of the Mediterranean Sea. Sea level trends were correlated with trends in NAO indices; negative correlations were detected for the Black Sea, whereas positive correlations were found for the Eastern Mediterranean Sea. Paired t tests were performed to determine the turning points for all sea level data sets. The value of t was positive for all data sets, which means that the mean value of the data set before the turning point was smaller than the mean value of the data set after the turning point.

Seasonal fluctuations of the Baltic Sea level

Seasonal annual (Sa) and seasonal semiannual (Ssa) fluctuations are the dominant feature of long-period sea level variability in the Baltic Sea. Long-term series of observations (monthly mean sea level data) from the PSMSL database are used to estimate amplitudes and phases and to reveal spatial and temporal variations. It was found that the variations of seasonal amplitudes were quite significant from year to year and synchronous both within the Baltic Sea and in the Kattegat and Skagerrak straits. Climatologically averaged amplitudes and phases were calculated from 74 tide gauges, and the maps of spatial variability of seasonal constituents are plotted. The annual harmonic of the sea level gradually increases from the entrance (Danish Straits) to the heads of gulfs. The maximum amplitude of 12.7 cm is observed in the heads of the Gulf of Finland and Gulf of Bothnia. It is revealed that seasonal fluctuations in the Baltic Sea are caused by the zonal wind component.

Mean sea level changes near Weizhou island from 1969 to 2010

Tidal data from Weizhou, Zhapo, and Shanwei stations between 1969 and 2010 and from five gauging stations in the western Pacific Ocean provided by PSMSL, and the global mean sea level data recorded between December 1992 and December 2010 by TOPEX and Jason satellites were compiled and analyzed. The results show that the perennial mean sea level near Weizhou Island is 211.7 cm (relative to the water gauge zero), and the relative mean sea level rising rate is 2.2 mm yr−1 from 1969 to 2010, which is consistent with the relative mean sea level rising rate recorded at other gauging stations in the western Pacific regions and with the global mean sea level rising rate. The absolute mean sea level rising rate at Weizhou Island is 3.0 mm yr−1 from 1993 to 2010, also conforming with the global mean sea level rising rate (3.1±0.4 mm yr−1) during the same time period. The highest annual tide level at Weizhou Island has a rising rate of 4.6 mm yr−1 and shows a 20-year quasi-periodic variation from 1966 to 2010. The primary cause of the mean sea level rising is global warming.

Shoreline changes in response to sea level rise along Digha Coast, Eastern India: an analytical approach of remote sensing, GIS and statistical techniques

Shoreline is one of the rapidly changing linear features of the coastal zone which is dynamic in nature. The issue of shoreline changes due to sea level rise over the next century has increasingly become a major social, economic and environmental concern to a large number of countries along the coast, where it poses a serious problem to the environment and human settlements. As a consequence, some coastal scientists have advocated analyzing and predicting coastal changes on a more local scale. The present study demonstrates the potential of remote sensing, geospatial and statistical techniques for monitoring the shoreline changes and sea level rise along Digha coast, the eastern India. In the present study, multi-resolution and multi temporal satellite images of Landsat have been utilized to demarcate shoreline positions during 1972, 1980, 1990, 2000, and 2010. The statistical techniques, linear regression, end-point rate and regression coefficient (R2) have been used to find out the shoreline change rates and sea level change during the periods of 1972–2010. Monthly and annual mean sea level data for three nearby station viz., Haldia, Paradip and Gangra from 1972 to 2006 have been used to this study. Finally, an attempt has been made to find out interactive relationship between the sea level rise and shoreline change of the study area. The results of the present study show that combined use of satellite imagery, sea level data and statistical methods can be a reliable method in correlating shoreline changes with sea level rise.