GIS-based risk assessment for the Nile Delta coastal zone under different sea level rise scenarios case study: Kafr EL Sheikh Governorate, Egypt

Sea level changes are caused by several natural phenomena, including mainly ocean thermal expansion, glacial melt from Greenland and Antarctica. It was estimated, in this respect, that global average sea level rose, during the 20th Century, by at least 10 cm. This trend is expected to continue and most likely accelerated during the 21st Century due to human-induced global warming. Global average sea level is expected to rise, by the year 2100, due to global warming between 0.18 and 0.59 cm. Such a rise in sea-level will significantly impact coastal areas due to the high concentration of natural and socioeconomic activities and assets located along the coast. The northern coastal zone of the Nile Delta is generally low land, and is consequently vulnerable to direct and indirect impacts of sea level rise (SLR) due to climate changes, particularly inundation. Despite the uncertainty associated with developed scenarios for climate change and expected SLR, there is a need, according to precautionary approach, to assess and analyze the impacts of SLR. Such an assessment, on one hand, can assist in formulating effective adaptation options to specific, sometimes localized, impacts of SLR. On the other hand, such an analysis can contribute significantly to the development of integrated approach to deal with the impacts of SLR. The objective of this paper is to assess and spatially analyze the risks of expected sea level rise (SLR), in particular inundation, and its implications up to the year 2100 in Kafr El Sheikh Governorate, Egypt, using GIS techniques. For that purpose, a GIS was developed for the study area and then utilized to identify the spatial extent of those areas that would be vulnerable to inundation by SLR. Moreover, various land uses/land covers susceptible to such inundation were identified. Results indicate that more than 22.59 % and 24.50 % of the total area of Kafr El Sheikh Governorate would be vulnerable to inundation under B1 and A1FI (IPCC most optimistic and pessimistic scenarios), respectively. No significant difference was noticed between the two scenarios in terms of spatial extent of SLR impacts. It was also found that a significant proportion of these areas were found to be currently either undeveloped or wetlands. Moreover, it was found that about 90.13 % of the vulnerable areas are actually less exposed to the risks of SLR due to the existence of a number of man-made features, not intended as protection measures, e.g. International Coastal Highway, that can be used to limit the areas vulnerable to inundations by SLR.     

Coastal inundation in the north-eastern mediterranean coastal zone due to storm surge events

Low-elevation coastal areas and their populations are at risk during and after the appearance of a storm surge event. Coastal flooding as a result of storm surge events is investigated in this paper for a number of areas around the north-eastern (NE) Mediterranean coastal zone (Adriatic, Aegean and north Levantine seas). The sea level rise (SLR) due to storm surge events is examined for the period 2000?C2004. Wind data, atmospheric pressure and wave data for this period as well as in situ sea elevation measurements (from stations around the Mediterranean coasts) were used. Potential inundation zones were then identified using a 90-m horizontal resolution digital elevation model (DEM). At these zones, the sea surface elevations were calculated for the study period, using the collected data and a 2D storm surge simulation model (1/10^o??1/10^o) output, examining the sea level alteration in specific coastal areas, where in situ measurements are absent and are characterised as ??risky?? in inundation areas, due to their topography. In order to determine the level of storm track implication on major SLR incidents, the trajectories of the respective storm events were computed. The aim of this paper is to investigate the major storm surge events that appeared during the study period, identify the major ??risky?? costal regions along the north-eastern Mediterranean coast and determine their hazard level due to inundation caused by storm surge phenomena. The combination of the risk level determination of an area and the calculation of sea level alteration is an important tool in terms of predicting and protecting the coastal area from extreme meteorological incidents.     

Awareness of sea-level response under climate change on the coast of Ghana

In response to climate change, coastal communities are expected to experience increasing coastal impacts of sea-level rise (SLR). Strategies formulated and implemented to curb these impacts can thus be more effective if scientific findings on the response to climate change and SLR impacts on coastal communities are taken into consideration and not based merely on the need for coastal protection due to physical coastal erosion. There is also the need to determine the level of awareness of sea-level rise and responses in coastal communities to improve adaptation planning. This study assesses the impact of future erosion on the coastal land cover of Ghana. This assessment estimates approximately 2.66 km², 2.77 km², and 3.24 km² of coastal settlements, 2.10 km², 2.20 km² and 2.58 km² of lagoons, 1.39 km², 1.46 km² and 1.71 km² of wetlands to be at risk of inundation by the year 2050 based on coastal erosion estimates for the 2.6, 4.5 and 8.5 Representative Concentration Pathways (RCPs) used in the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC). This study also assesses the level of awareness of respondents to SLR on the coast of Ghana and explores the availability and level of integration of scientific knowledge of SLR into coastal adaptation strategies in Ghana. Assessment of the awareness of SLR responses to the changing climate in Ghana is made through semi-structured interviews at national, municipal/district and coastal community scales. Although settlements may be inundated based on the coastal erosion estimates, coastal dwellers interviewed cherish their proximity to the sea and are determined to maintain their occupancy close to the sea as spatial location influences their source of livelihood (fishing). Respondents lack knowledge/understanding of SLR, as the majority of household interviewees attributed the rise or fall in sea level to God. Respondents from Ngiresia alleged that the ongoing coastal sea defence project in their community has led to increased malaria cases.     

Examining the potential impacts of sea level rise on coastal wetlands in north-eastern NSW,Australia

The coastal wetlands of north-eastern New South Wales (NSW) Australia are increasingly being affected by anthropogenic factors such as urbanisation, residential development and agricultural development. However, little is known about their vulnerability to sea level rise as a result of climate change. The aim of this research is to predict the potential impact of sea level rise (SLR) on the coastal wetland communities. Sea Level Affecting Marshes Model (SLAMM) was used to predict the potential impacts of sea level rise. Geographic Information System (GIS) was used for mapping and analysis. It was found that a meter rise in sea level could decrease coastal wetlands such as Inland fresh marshes from about 225.67 km² in February 2009 to about 168.04 km² by the end of the century in north-eastern NSW, Australia. The outcomes from this research can contribute to enhancing wetland conservation and management in NSW.     

National assessment of coastal vulnerability to sea-level rise for the Chinese coast

Sea-level rise as a result of climate change increases inundation and erosion, which are affected by a complex interplay of physical environmental parameters at the coast. China’s coast is vulnerable to accelerated sea-level rise and associated coastal flooding because of physical and socio-economical factors such as its low topography, highly developed economy, and highly dense population. To identify vulnerable sections of the coast, this paper presents a national assessment of the vulnerability of the Chinese coast using 8 physical variables: sea-level rise, coastal geomorphology, elevation, slope, shoreline erosion, land use, mean tide range, and mean wave height. A coastal vulnerability index was calculated by integrating the differentially weighted rank values of the 8 variables, based on which the coastline is segmented into 4 classes. The results show that 3% of the 18,000-km-long Chinese coast is very highly vulnerable, 29% is highly vulnerable, 58% is moderately vulnerable, and 10% is in the low-vulnerable class. Findings further reveal that large amounts of land and population will be vulnerable to inundation by coastal flooding from sea level rise and storm surge. Finally, some suggestions are presented for decision makers and other concerned stakeholders to develop appropriate coastal zone management and mitigation measures.     

As the world warms: rising seas, coastal archaeology, and the erosion of maritime history

The human history of coastal regions around the world has been under assault for decades, from forces that include dam building, coastal modifications, the destruction of wetlands, marine erosion, population growth and rampant development, looting, and other processes. Global warming will exacerbate the destruction of cultural resources in coastal zones through accelerated sea level rise, intensified storm cycles, and related coastal erosion. Although average global sea levels have been rising for ∼20,000 years, they slowed dramatically about 7,000 years ago. Rates of sea level rise now appear to be increasing rapidly due to growing anthropogenic emissions of carbon dioxide and other greenhouse gases. Global warming and rising seas, especially when combined with population growth and the implementation of measures designed to protect endangered coastal properties, threaten the deep maritime history of human migrations, settlement, and adaptations in coastal areas around the world. Ranging in age from the mid-Pleistocene to recent historic times, coastal archaeological sites contain invaluable data on ancient coastal societies, fisheries, and ecosystems. Archaeologists, historians, and other cultural resource managers must do more to anticipate, evaluate, and mitigate the effects of global warming, sea level rise, and coastal erosion on the long history of human maritime cultures.     

Predicting the spatial distribution of mangroves in a South African estuary in response to sea level rise,substrate elevation change and a sea storm event

The spatial distribution of mangroves in the Mngazana Estuary under sea level rise induced by climate change, together with different substrate elevation change scenarios was predicted for 2020, 2050 and 2100. The present inundation frequency tolerance range was from 0.8 to 31.2 %, equivalent to substrate elevation thresholds of 1.1 and 1.7 m amsl. These thresholds were measured by field surveys and analysis of a gauge station situated near the mouth of the estuary. The predictions were based on the assumption that the inundation frequency tolerance range of mangrove stands remains constant in the future. Through the use of a digital elevation model an initial increase of 2.10 ha year^?1 was found in mangrove area between present and 2020 (from 122.6 to 143.6 ha). This was due to habitat becoming available that is currently too compacted for seedling establishment to occur. This compaction resulted from human and cattle traffic for grazing. Thereafter there would be a mean loss of 0.66 ha year^?1 from 2020 through 2100. Landward migration of mangroves would not take place due to the elevation limit of adjacent non-mangrove areas. In addition, the loss rate would increase to 1.01 ha year^?1 under insufficient sediment accretion, but would decrease to 0.18 ha year^?1 under thriving mangroves condition. The analysis of sea storm event in September 2008 showed that local water level increased by 28 cm and maximum affected area was 87.0 ha (about 71 % of mangrove stands). The inundation continued over 5 days. The results indicated that the combination impact of sea level rise, substrate elevation change and sea storm would possibly be a threat to tropical African estuaries with large flat intertidal areas and mangroves.     

The impact of sea-level rise along the Polish Baltic coast

A DTM (Digital Terrain Model) map and the analytical powers of GIS (Geographical Information System) were used in deterministic and probabilistic methods for analysis of inundation of a coastal area. These methods were applied to evaluate the effects of a rise in sea-level on the coastal zone of the Puck Lagoon (Poland) over a period of 100 years. The analysis evaluated the following aspects: the threat to man-made objects such as buildings and roads; changes in the impact of the sea on the coastal environment manifested as the frequency of flooding of grasslands and marshland in the coastal depression, and the formation of a dune embankment. The analysis covered a ca. 5 km stretch of low-lying coastline, in which there are two rapidly growing villages and a nature reserve. The study showed that a sealevel rise of 40 cm would increase the frequency of flooding in the area and would probably cause the dune ridge vegetation to deteriorate.     

Climate change impacts on a large-scale erosion coast of Hai Hau district,Vietnam and the adaptation

Among the effects of global warming, sea level rise (SLR) and severe typhoons pose the greatest threat to the stability of human settlements along coastlines. Therefore, countermeasures must be developed to mitigate the influences of strong typhoons and persistent SLR for coastal protection. This study assesses climate change impacts on coastal erosion, especially in two projected SLR scenarios of RCP2.6 and RCP8.5. The results show that SLR and severe typhoons lead to the increase of coastal erosion, beach lowering and scour. Moreover, as in projected SLR scenarios, average waves in high tide can cause severe soil erosion at inner slopes and lead to dyke failure by 2060. The paper highlights the need for additional countermeasures to protect the coast of Hai Hau district against SLR and severe typhoons. Among the alternatives available for countering these threats, applying soil stabilization and soil improvement combined with geosynthetics are promising strategies for coastal structures. Hybrid structures can be used with earth reinforcement and soil improvement. Additionally, the paper emphasizes the importance of multiple protective adaptations, including geosynthetics and ecological engineering measures against climate change-induced severe erosion on the coast of Hai Hau district.     

Interactions between water and land in The Netherlands

The Netherlands are one of the most densely populated coastal countries in the world and there is only limited space for living, working, transport and recreation, while there is also the need to preserve and expand valuable natural habitats. In order to solve many existing and future conflicts of interest, and in order to create ‘added value’, strategies are developed to optimize the use of water-land systems. The principle of ‘building with nature’ is applied in order to integrate land in sea and water in land in such a way that future generations will be able to use coastal resources in a sustainable way, including a minimal effort to maintain the coastline and the promotion of a multiple-use system. The concept of Integrated multifunctional sustainable coastal zone development is introduced. This concept deals with a balanced approach to the lack of space for present and future coastal uses in relation to each other, to the hinterland, and to the sea. Flexible master plans are developed, taking into account many functions of the coastal zone, and facilitating adaptation to future developments—e.g. impacts of climate change and relative sea level rise. In this regard increasing the flexibility of the coastal zone is of vital importance. Large-scale coastal land reclamations in The Netherlands are dealt with, based on two different principles: (1) polder systems (low lying land reclamations surrounded and protected by dikes), (2) systems of ‘building with nature’—land reclamation protected by man-made foreshores, beaches and dunes. In the latter type new flexible dynamic-equilibrium coasts are created for many functions, while coastal vulnerability is reduced and a flexible coast is developed.     

Responsiveness of Ada Sea Defence Project to salt water intrusion associated with sea level rise

The Ada peninsular in Ghana has suffered rapid coastal erosion and inundation for over half a century, accompanied by loss of property and livelihoods, economic stagnation and salt water intrusion. Government intervened to respond to these threats by implementing a sea defence project. A preliminary assessment indicates the project will deal with some urgent needs of property loss reduction and invigorate livelihood and economic opportunities. However, it will have minimal beneficial impacts on groundwater salinization, and may actually intensify salinity of surface water in the Volta River and adjoining water points by shifting salinity intrusion further upstream to affect hitherto salinity-free areas. The spatial reach of the salinity shift is uncertain. The potential for further sea level rise will aggravate and accentuate the region’s water scarcity dilemma if a coherent water management strategy is not sort sooner. The project demonstrates the limitations of employing static, narrow objectively designed sea defence project as a response to coastal erosion and inundation, because it lacks the capacity to deal with dynamism, complexity and multi-dimensional impacts associated with climate change related sea level rise.     

Land cover types and ecological conditions of the Estonian coast

Detailed analysis of the land cover of the Estonian coastal zone is presented based on Estonian laws on coastal zone management, the CORINE Land Cover (CLC) system, the status of protected areas, and administrative division data of Estonia. By law the coastal zone is defined as a 200-m wide zone landward from the mean sea level line. The length of the Estonian coastline (including the islands) is 3794 km. The 200-m zone of the Estonian coast is very diverse. Out of the 34 CORINE land cover types represented in Estonia 30 are found in the coastal zone. Three dominating land cover types in the coastal zone of Estonia are inland marshes, coniferous forest and semi-natural grassland. Their total share is 47%; the other 27 land cover types represented here cover 53% of the coastal zone. The Estonian coastal zone is generally in a good natural condition. The proportion of artificial surfaces throughout the zone is merely 4.7%, while agricultural landscapes cover only ca. 10%. Land cover data for the coastal zone are also presented by county. Of the 200-m coastal zone 24% is under protection, which is more than twice the value for Estonia as a whole (11%). Legislative protection of the coastal zone is presently satisfactory. The use of the CORINE Land Cover system enables comparisons with other European regions since CLC data have been compiled for most of Europe.     

Coastline management in The Netherlands: human use versus natural dynamics

The boundary between land and sea in The Netherlands changes continuously. Every kilometre of the present position of the Dutch sandy coastline is the result of the interface between natural dynamics initiated by the sea and man-made action on land. Before 1990, each year ca. 20 ha of dunes disappeared through coastal retreat. In 1990 the Dutch government decided to stop any further long-term coastal recession and chose for ‘dynamic preservation’, which primarily aims, at ensuring safety against flooding and sustainable preservation of the values and interests attached to the dunes and beaches. Five years later, a first review of the benefits and bottlenecks of the new coastal defence policy could be presented. The overall conclusion is that the 1990-choice for dynamic preservation was right. The considerable losses of dunes and beaches do not occur any longer. Sand nourishment is an effective method of coastline maintenance, which also serves the functions of the beach and dune area for human society. However, serious erosion of the deeper part of the shoreface threatens the coastline of the 21st century. Nearly a doubling of the nourishment volume is necessary to prevent a renewed landward shift of the coastline. An anticipated accelerated sea level rise (ca. 60 cm/century) will increase the sand losses by another 25%. Plans are being finalized for large-scale land reclamation in front of the coastline as an answer to growing spatial problems on land. In other plans polders, now safely protected by sea dikes, will be returned to the sea in order to restore ecologically valuable salt marshes and mud flats. The position of the coastline will continue to change in the coming decades. Besides natural dynamics, human use of the coastal zone will certainly affect this process: measures to maintain the coastline at its 1990 position need to be seen in perspective: the coastline as a part of the coastalzone.     

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.     

Spatial assessment of sea level rise on Martinique’s coastal zone and analysis of planning frameworks for adaptation

Accelerated sea level rise and hurricanes are increasingly influencing human coastal activities. With respect to the projected continuation of accelerated sea level rise and global warming one must count with additional expenses for adaptation strategies along the coasts. On the mountainous island Martinique the majority of settlements are situated along the coast almost at sea level. But potential rises in sea level and its impacts are not addressed in coastal management, even though saltwater intrusion and coastal erosion with increasing offshore loss of sediment are locally already a severe problem. At a sea level rise of 50 cm, one fourth of Martinique’s coastline will be affected by erosion and one fifth of the islands surface will have high probability to get flooded during coastal hazards. This is a growth of 5% of the impact area in comparison to present conditions. This article analyses potential adaptation strategies and argues that the development of a coastal zone management plan considering sea level rise and its impact area is of utmost importance. Empirical assessment models in combination with spatial analysis are useful in obtaining statements about coastal impacts concerning sea level rise. This paper sees itself as recommendation of action not only for Martinique.

上海滨岸带生态环境问题及调控对策

结合长江口上海滨岸带资源与环境现状,重点分析了上海滨岸地区在经济快速发展过程中面临的主要生态环境问题;指出上海滨岸地区面临风暴潮、海平面上升、地面沉降等主要自然灾害;滨岸水环境质量恶化,重金属等污染物的生态风险不容忽视;潮滩过渡围垦导致湿地生态系统破坏严重。探讨了污水排放等人类活动对滨岸带生态环境的影响。此外,从战略环境评价、污染控制、生态恢复、行政法规和管理等方面,提出了相应的调控对策。     

江苏沿海地区海洋灾害类型及其防治探讨

根据江苏沿海地区的地质地貌及气候的特点,综合分析了危害江苏沿海的海洋灾害类型,主要有海洋地质灾害、气候灾害和生物灾害等三种类型。地质灾害主要包括海岸侵蚀、海岸坍塌、和海平面上升;气候灾害主要包括台风风暴潮;生物灾害主要包括赤潮、湿地滩涂面积缩小等。提出相应的防治措施:(1)加强对海岸带地质背景和地质灾害研究,应用GIS和RS等先进技术建立海洋灾害信息系统;(2)加强海防工程建设,加高海堤提高质量,以防御灾害性海浪、风暴潮等侵袭;(3)应用生态学原理,建立沿海生态防护网,增强对风暴潮抵御能力保护沿海湿地资源;(4)加强对海洋灾害及防御知识的教育和对防灾减灾的管理等。     

Predicted effects of climate change,vegetation and tree cover on dune slack habitats at Ainsdale on the Sefton Coast,UK

Dune slack habitats are highly dependent on the availability of water to support flora and fauna. Typically this is provided by shallow groundwater. This paper describes the seasonal and long term variation in groundwater levels in part of the Sefton coastline between 1972 and 2007. The effects of climate change, vegetation management and coastline realignment on groundwater levels are modelled. The observed annual water table levels rise and fall with an amplitude of 1.5 m, but longer term variations and trends are apparent. A stochastic water balance model was used to describe the changes in water table levels in slack floors in the open dunes and also in areas afforested with pine trees. It was found that the pine trees evaporated 214 mm/year more than open dunes vegetation, resulting in the water table being 0.5–1.0 m lower under the trees than under the open dunes. The effects of climate change on the ground water was simulated using predictions of future climate conditions based on the UKCIP02 medium high emissions scenario. The increase in temperature and change in rainfall patterns will result in a decrease in mean ground water levels by 1.0–1.5 mm in the next 90 years. Typical patterns consist of sequences of 5–10 years of low water table levels interspersed by infrequent sequences consisting of 2–5 years of relatively high or “normal” levels. These results indicate that that flora and fauna that cannot survive a 5–10 year period of water table levels >2.5 m below ground level are unlikely to survive or persist in many slack areas and a change in the ecology of these slack may become inevitable. Other effects of climate change include sea level rise which will result in a gradual rise in water table levels. Coastal erosion will increase the water table gradient to the sea and result in a slight lowering of the ground water levels. Conversely coastal accretion will reverse this process. The spatial distribution of coastal erosion and accretion along the Sefton coastline and its likely impacts on groundwater levels are discussed. The modelling work described in this paper has identified the factors which have the largest effect on groundwater levels in temperate coastal dune systems.