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Md Mahdi Hj Abd Latif and Gabriel Y.V. Yong
The coast at Berakas in the Brunei-Muara district of Brunei Darussalam suffers from erosion caused by a combination of fluvial and marine processes. This paper investigates the…
Abstract
The coast at Berakas in the Brunei-Muara district of Brunei Darussalam suffers from erosion caused by a combination of fluvial and marine processes. This paper investigates the rate and pattern of erosion along a 1.8-km stretch of coast to compare the difference between the unprotected and protected sections. We used (i) image and spatial analysis and (ii) field geomorphology. The Digital Shoreline Analysis System (DSAS) in ArcGIS was used to compare the study area using two Google Earth images. The study found that the unprotected section had receded by 4.6 m between 2009 and 2019, while the protected section had advanced by 8.0 m over the same period; intense gullying and slumping of cliff continued at both sections. The detached headland breakwaters in the protected section were effective in stabilizing the coast. A concrete drain installed parallel to the cliff edge appears to be capable of intercepting storm runoff, but its effectiveness was undermined by lack of maintenance. We conclude that terrestrial-fluvial processes continue to erode coastal land and cause slumping of the cliff face at Berakas. However, coastal protection structures that curb the marine process could stabilize the coastline, even where sediment transport is active.
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Pradeep K. Rawat, C.C. Pant, P.C. Tiwari, P.D. Pant and A.K. Sharma
The main objective of the study is to identify the vulnerable areas for river‐line and flash flood hazard and its mitigation through GIS Database Management System (DBMS) of…
Abstract
Purpose
The main objective of the study is to identify the vulnerable areas for river‐line and flash flood hazard and its mitigation through GIS Database Management System (DBMS) of geo‐hydrometeorological parameters. The Dabka watershed constitutes a part of the Kosi Basin in the Lesser Himalaya, India in district Nainital has been selected for the case illustration.
Design/methodology/approach
The Dabka DBMS is constituted of three GIS (Geographic Information System) modules, i.e. geo‐informatics (consists of geomorphology, soils, geology and land use pattern, slope analysis, drainage density and drainage frequency), weather informatics (consists of daily, monthly and annual weather data about temperature, rainfall, humidity and evaporation) and hydro‐informatics (consist of runoff, sediment delivery, and denudation). The geo‐informatics and weather informatics modules carried out by comprehensive field work and GIS mapping than both modules used to carry out hydro‐informatics module. Through the integration and superimposing of spatial data and attribute data with their GIS layers of all these modules prepared Flood Hazard Index (FHI) to identify the level of vulnerability for flood hazards and their socio‐economic and environmental risks.
Findings
The results suggest that geo‐environmentally most stressed areas of barren land (i.e. river‐beds, flood plain, denudational hills, sites of debris flow, gullies, landslide prone areas etc.) have extreme vulnerability for flood hazard due to high rate of runoff, sediment load delivery and denudation during rainy season (i.e. respectively 84.56 l/s/km2, 78.60 t/km2 and 1.21 mm/year) whereas in geo‐environmentally least stressed dense forest areas (i.e. oak, pine and mixed forests) have low vulnerability due to low rate of stream runoff, sediment load delivery and denudation (i.e. respectively 20.67 l/s/km2, 19.50 t/km2 and 0.20 mm/year). The other frazzled geo‐environment which also found high vulnerable for flood hazard and their risks is agricultural land areas due to high rate of stream runoff, sediment load delivery and denudation rates (i.e. respectively 53.15 l/s/km2, 90.00 t/km2 and 0.92 mm/year).
Research limitations/implications
For hydro‐informatics module it is quite difficult to monitor water and sediment discharge data from each and every stream of the Himalayan terrain due the steep and rugged topography. It requires strategic planning and trained man power as well as sufficient funds; therefore representative micro‐watershed approach of varied ecosystem followed for a three years (2006‐2008) period.
Practical implications
The study will have great scientific relevance in the field of river‐line flood and flash flood hazard and its socio‐economic and environmental risks prevention and management in Himalaya and other mountainous terrain of the world.
Originality/value
This study generated primary data on hydro‐informatics and weather informatics to integrate with geo‐informatics data for flood hazard assessment and mitigation as constitutes a part of multidisciplinary project, Department of Science and Technology (D.S.T.) Government of India.
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José Guilherme Moreira Simões Vieira, Joana Salgueiro, Amadeu Mortágua Velho da Maia Soares, Ulisses Azeiteiro and Fernando Morgado
The development of models that allows the evaluation and prediction of erosion processes is an important tool for the management and planning of coastal systems. Mangrove forests…
Abstract
Purpose
The development of models that allows the evaluation and prediction of erosion processes is an important tool for the management and planning of coastal systems. Mangrove forests systems are under threat by the impacts of erosion, which is also intensified by human activity (and aggravated in the scenarios of global warming and climate change). The purpose of this paper is to develop a model of geographic information systems (GIS) that can be used for any estuary area, but it can also be used for mangroves.
Design/methodology/approach
This paper uses georeferentiation which is defined as a set of parameters that best characterize the mangrove areas: elevation (m); geomorphology; geology; land cover; anthropogenic activities; distance to the coastline (m) and maximum tidal range (m). Three different methods are used to combine the various vulnerability parameters, namely, DRASTIC index, analytical hierarchy process (AHP) and square root of the geometric mean.
Findings
The three approaches presented in this work show different types evaluating vulnerability to erosion, highlighting a stronger overvaluation of the areas presented with a high vulnerability, through the use of DRASTIC index when compared with two other approaches. The use of the AHP shows similarity to the square root of the geometric mean model, but the AHP also presents a higher percentage of vulnerable areas classified as having medium to very high vulnerability. On the other hand, the use of square root of the geometric mean led to a higher percentage of areas classified as having low and very low vulnerability.
Research limitations/implications
These three qualitative models, based on a cognitive approach, using the set of parameters defined in this research, are a good tool for the spatial distribution of erosion in different mangroves in the world.
Originality/value
Global warming and climate change scenarios require adaptation and mitigation options supported by science-based strategies and solutions.
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Identifying stone decay forms is an essential first step in stone conservation. In this study a visually based geomorphological approach was used to provide a rapid assessment of…
Abstract
Identifying stone decay forms is an essential first step in stone conservation. In this study a visually based geomorphological approach was used to provide a rapid assessment of the general weathering characteristics displayed by building sandstones in Stoke‐on‐Trent. Stone decay was found to be largely caused by the mechanical disruption of the sandstone and its occurrence was extremely variable in both space and time. The study demonstrates the close interrelationship between stone properties, environmental conditions, morphology of weathering features, and building characteristics. It is important that these close and dynamic interrelationships are recognised when seeking to explain or predict stone behaviour for management purposes.
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Ravindra K. Pande, Dhanjita Burman and Ravinder Singh
The purpose of this paper is to evaluate landslide hazard problems in Hanuman Chatti area of Uttarakhand, India. Every year NH 58 experiences landslide activities, which disrupts…
Abstract
Purpose
The purpose of this paper is to evaluate landslide hazard problems in Hanuman Chatti area of Uttarakhand, India. Every year NH 58 experiences landslide activities, which disrupts the tourist traffic to Badrinath shrine and higher Himalaya.
Design/methodology/approach
An urgent need is being felt to have a comprehensive landslide hazard evaluation factor (LHEF). The major causative factors that influence the slope stability are lithology, structure, soil depth, soil texture, geomorphology, slope morphology, slope dip, slope aspect, slope magnitude, weathering, land use and land cover and anthropogenic activities. The present analysis is based on the rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability.
Findings
In the study area, nine old landslides (0.238 sq.km) and five new landslides (0.086 sq.km) are recorded. On the basis of the various causative factors the study area is classified into five landslide hazard classes.
Research limitations/implications
The analysis is based on the experience gained for the last seven years (1999‐2007). The period is short for developing any hypothesis but sufficient care has been taken to consider vital factors.
Practical implications
With the help of LHEF appropriate landslide hazard management tools can be adopted. Once a LHEF rating scheme in which numerical ratings for different categories are determined on the basis of their estimated significance in causing instability, is standardized it can be applied to the entire Himalayan region, which is very prone to landslide hazard.
Originality/value
Although the paper is an attempt to evaluate the efficacy of landslide hazard zonation techniques developed by various agencies in the past, some modification as per the requirement has been made in various stages of investigation.
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Lara Bulcão, Luís Ribeiro, Pedro Arsénio and Maria Manuela Abreu
The evolution of the concept of landscape to incorporate components like cultural and socio‐economic factors, in addition to the natural and aesthetic features, influenced the…
Abstract
The evolution of the concept of landscape to incorporate components like cultural and socio‐economic factors, in addition to the natural and aesthetic features, influenced the perception of landscape as a resource. On the other hand, the relationships between territorial features as well as the understanding of their temporal dynamics determine the significance of these features for the quality of a landscape and, consequently, for its conservation. This implies that all components – natural and physical, but also cultural and visual – upon which landscape quality is assessed, ought to be considered and studied globally. Natural resources and cultural heritage, however, are usually considered independently when developing protected areas management plans. Here, we present a methodology developed for the Monte da Guia management plan, which allows the interrelated analysis of landscape factors such as geology, geomorphology, pedology, flora and vegetation cover as well as the cultural and visual characters. Using the concepts of biophysical sensitivity and visual quality, we evaluated the relevance of these various factors for the determination of the state of equilibrium/degradation of a landscape, and hence for its conservation value. This methodology may contribute to the development of improved zoning maps and management guidelines determining land use and management strategies for the conservation of individual resources that, together, determine landscape quality.
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Julia Rey-Perez and María Eugenia Siguencia Ávila
The purpose of this paper is to present a methodology developed on the basis of the Historic Urban Landscape (HUL) notion applied for the city of Cuenca in Ecuador. The…
Abstract
Purpose
The purpose of this paper is to present a methodology developed on the basis of the Historic Urban Landscape (HUL) notion applied for the city of Cuenca in Ecuador. The identification of cultural values – among all the actors involved in the city – draws up a series of sustainable urban development strategies.
Design/methodology/approach
This methodology is based on the city analysis from the local community and multiple disciplines such as geomorphology, environment, urban planning, historic cartography, architecture, archaeology, anthropology, and economy. Further qualitative data collection methods included 16 workshops with 168 citizens, specific surveys, mapping, and on-site observations. The challenge of this methodology is not only its implementation in the world heritage city of Cuenca in Ecuador, but also the integration of the management of the historic centre within the overall city development plan.
Findings
The application of the HUL concept has allowed the identification of a series of strategies for the urban development where the points of view coming from different stakeholders were gathered. The project reveals the existence of values and attributes, so far overlooked in the actual heritage management system. In addition, a Geographic Information System database has been created with all the information related to Cuenca with the possibility of making it available for the community in the future.
Research limitations/implications
The project has been developed within one year with scarce economic resources: that is the reason why the planned activities took longer than expected.
Social implications
Social participation has played a key role in the development of the project.
Originality/value
This research process in Cuenca has led to its incorporation as a Latin-American pilot city for a programme developed by the World Heritage Institute of Training and Research for the Asia and the Pacific Region.
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L. Schulte, R. Julià, H. Veit and F. Carvalho
The multidisciplinary Fluvalps‐3000 research project focuses on the variability of the Late Holocene and historical fluvial dynamics in alpine catchments. The purpose of this…
Abstract
Purpose
The multidisciplinary Fluvalps‐3000 research project focuses on the variability of the Late Holocene and historical fluvial dynamics in alpine catchments. The purpose of this paper is to examine the potential of a 3,600 year‐long record composed from fluvial deposits for flood hazard assessment.
Design/methodology/approach
The research is based on a multi‐proxy approach integrating methods of various disciplines as sedimentology, geochronology, pedology, geomorphology, palynology, history, and archaeology. This paper considers particularly the sedimentological and geocronological methods applied to the fluvial records of several key sections of the Lütschine and Lombach fan deltas.
Findings
The sedimentary data of the high‐resolution fan delta record show up to seven major aggradation pulses from 3,600 cal yr BP to present. Furthermore, 19 minor burial episodes occur between 3,600 and 1,050 cal yr BP at average intervals between 113 years (Lütschine) and 105 years (Lombach) suggesting that aggradation during the focused period was triggered by centennial flood events. Nine coarse‐grained flood layers of the Lütschine record, deposited during the last 3,350 years by catastrophic flood events at a recurrence interval of 370 years, coincide with positive radiocarbon anomalies and cold phases in the Alps. The solar influence on regional hydrological regime is proposed as the main factor triggering the flooding events. However, the impact of land‐use changes in the region since 2,300 cal yr BP was detected by pollen and geochemical proxy data from fluvial deposits.
Originality/value
According to the results, the 2005 flood may not be considered as one of these mayor catastrophic events, thus providing useful data for future risk assessment by regional and local authorities. The 3,600 year flood history derived from fan delta proxies, presented in this paper, is unique in the European Alps.
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The purpose of this paper is to reassess Chiswell's vulnerability to storm and sea flooding since an analysis made in 1979 and to identify characteristics of resilience, a more…
Abstract
Purpose
The purpose of this paper is to reassess Chiswell's vulnerability to storm and sea flooding since an analysis made in 1979 and to identify characteristics of resilience, a more recent item of disaster studies terminology.
Design/methodology/approach
Chiswell's geography, geomorphology and changes affecting its vulnerability up to 1979, are described against its history of storms. Two serious storms in 1978 and 1979 drew attention to Chiswell's need of improved protection and a flood alleviation scheme was completed. Some consequences for Chiswell of the completed scheme are described and considered in relation to climate change, Chiswell's inclusion in the UNESCO Jurassic Coast and its expression of human ecology in a context of natural hazards of the sea.
Findings
Resilience existed before its inclusion in the terminology of disaster studies. The role of a community pressure group and of local and national administrations are considered against the timescale of protection provision. The essential requirement of external inputs before community resilience became evident is highlighted, together with additional observed and itemised characteristics of resilience.
Research limitations/implications
Updated research is based upon the results of rapid field observation and extensive use of internet sources, not available in 1979.
Practical implications
Realities of resilience may assist interpretation of its theoretical evaluations and expectations.
Originality/value
As yet, there are few field evaluations of resilience.
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