The impact of climate change on small-scale fishermen in Malaysia

This study aims to conceptually discuss the impacts of climate change on small-scale fishermen in Malaysia. Based on the document analyses made, it was concluded that Malaysia is also experiencing the impacts of climate change similar to other countries in the world. This impact of climate change has brought negative implications towards several community groups and the small-scale fishermen are one of them. Climate change is found to have increased several risks associated with fishing activities, affect their productivity, health and damage to the public facilities. A number of adaptation strategies were recommended and it is hope to assist the related parties in constructing the best adaptation strategies to overcome the rising climate change in Malaysia

Numerical modelling on the performance of submerged breakwater using the SPH-based DualSPHysics model

Implementation of coastal structures are known to mitigate issues of coastal erosion and impacts of sea waves during storm events on coastal areas. Among the various coastal structures implemented in Malaysia, the submerged breakwater called as WABCORE is being studied. This structure was originally designed by the National Hydraulic Research Institute of Malaysia and has been implemented at the shores of Pulau Tinggi, Johor, Malaysia. The objective of this study is to identify the wave transmission coefficient of the improved WABCORE structure under a variety of wave conditions. The effect of wave steepness (Hi/L) parameter on the wave transmission coefficient would also be highlighted. The study also considers the arrangement of the WABCORE structures, whereby the structures are stacked in a 4:3:2 (broad) and 3:2:1 (narrow) manner. This study implements the use of an open-source code known as DualSPHysics to simulate the various conditions. The results signify that the WABCORE structure is capable of dissipating waves despite its various condition

Effets des moussons sur la morphodynamique des plages de la cote est de la malaisie peninsulaire : exemples du littoral de kuala terengganu

In Southeast Asia, coastal dynamics are governed by a special equilibrium between northeast an southwest monsoons. In the context of sea-level rise and climate change, the monsoon regimes create an adaptation of the coastal dynamics. This situation gives rise to erosion phenomena along the coastline. However, public authorities have attempted to mitigate the problems of erosion by the construction of coastal defence structures. However, artificial structures can affect the wave regime, hydrodynamic circulation and sediment transport, thus reducing the ability of the shoreline to respond to natural forcing factors (such as with double monsoon season regimes) and also fragmenting the coastal space. The present thesis explores the problems of erosional phenomena, shoreline evolution and beach morphodynamics along the Kuala Terengganu shoreline on the East Coast of Peninsular Malaysia, with the aim of understanding the natural versus anthropogenic factors. This study was conducted in three phases to address the following topics: i) shoreline evolution from 2006 to 2014; ii) mid-term surveys (bi-monthly) involving data collection from July 2013 until June 2015 and; iii) short-term surveys (twice daily) with data collection (Topographic, hydrodyanamic and sediment transport measurments) during northeast and southwest monsoons. Based on a morphodynamic model for simulating seasonal processes, erosion is found to dominate most of the stations during northeast monsoons, while accretion or beach recovery is observed during southwest monsoons.En Asie du Sud-Est, la dynamique côtière est régie par un équilibre spécial entre les moussons du nord-est et sud-ouest. Dans un contexte de l'élévation du niveau de la mer et d’un changement climatique avéré, les régimes de la mousson ont commencé à évoluer et à modifier les équilibres hydro-morpho-sédimentaires sensibles au niveau des espaces littoraux. Cette situation engendre des phénomènes d'érosion le long du littoral, notamment le littoral NE de la Malaisie. Cependant, les autorités publiques ont tenté d'atténuer les problèmes d'érosion par la construction d’ouvrages de défense côtière. Ces derniers peuvent affecter le régime des houles, la circulation hydrodynamique et le transport des sédiments, réduisant ainsi la capacité du rivage à répondre aux facteurs du forçage naturels (régime de la double saison de mousson) et à fragmenter l'espace côtier. La présente thèse explore les problèmes des phénomènes d'érosion, l'évolution du littoral et la morphodynamique des plages le long du rivage de Kuala Terengganu sur la côte Est de la Malaisie péninsulaire par rapport aux facteurs naturels et anthropiques. Cette étude a été menée en trois phases pour aborder les sujets suivants: i) évolution long terme du trait de côte du littoral NE de la Malaisie de 2006 à 2014; ii) évolution moyen terme du littoral (suivi mensuel) de juillet 2013 à juin 2015 et; iii) suivi court terme à travers des campagnes de mesures hautes fréquences (mesures topographiques, hydrodynamiques et de transport des sédiments) sur quelques sites du littoral NE de la Malaisie pendant les moussons nord-est et sud-ouest. Sur la base d'un modèle morphodynamique pour simuler les processus saisonniers, il est apparu que l'érosion domine la plupart des stations suivies sur le littoral pendant la période de la mousson du nord-est, tandis que l'accrétion ou la recouvrement sédimentaire des plages sont observés pendant les moussons du sud-ouest

Impact of 2019 Tropical Storm (Pabuk) on Beach Morphology, Terengganu Coast (Malaysia)

International audienc

Assessment of the impact of artificial coastal structure on shoreline evolution along a monsoon dominated coast : Kuala Terengganu, Malaysia

International audienc

Landslide Susceptibility Mapping in a Mountainous Area Using Machine Learning Algorithms

Landslides are a dangerous natural hazard that can critically harm road infrastructure in mountainous places, resulting in significant damage and fatalities. The primary purpose of this study was to assess the efficacy of three machine learning algorithms (MLAs) for landslide susceptibility mapping including random forest (RF), decision tree (DT), and support vector machine (SVM). We selected a case study region that is frequently affected by landslides, the important Kamyaran–Sarvabad road in the Kurdistan province of Iran. Altogether, 14 landslide evaluation factors were input into the MLAs including slope, aspect, elevation, river density, distance to river, distance to fault, fault density, distance to road, road density, land use, slope curvature, lithology, stream power index (SPI), and topographic wetness index (TWI). We identified 64 locations of landslides by field survey of which 70% were randomly employed for building and training the three MLAs while the remaining locations were used for validation. The area under the receiver operating characteristics (AUC) reached a value of 0.94 for the decision tree compared to 0.82 for the random forest, and 0.75 for support vector machines model. Thus, the decision tree model was most accurate in identifying the areas at risk for future landslides. The obtained results may inform geoscientists and those in decision-making roles for landslide management

Beach morphodynamic classification in different monsoon seasons at Terengganu beaches, Malaysia

International audienceWave climate, topography and sediments are the main forcing factors that influence beach morphodynamics. This paper characterise beach morphodynamic classification along the Terengganu coast during seasonal monsoons (the onset of southwest monsoon in June 2009 as calm conditions and northeast monsoon in December 2009 as storm conditions). Two main morphodynamic characteristics are used to define a reflective, intermediate and dissipative beaches such as the surf similarity index (ξb) and the dimensionless fall velocity (Ω). In order to estimate morphological changes, repetitive beach profiles were acquired and averaged. The morphodynamic characteristics are also supported with wave data collected from the European Centre for Medium-Range Weather Forecasts (ECMWF) database and modeled in Spectral Wave Flexible Mesh of Mike-21 module, in order to investigate the wave propagation along the Terengganu coast. According to the beach morphodynamic classification scheme, the southern Terengganu coast showed a reflective beach state with high wave energy and coarser sand. In contrast the northern part with low wave energy, due to sheltering by many islands, demonstrated an intermediate beach state and finer sediment. However, the trend of sediment mean grain size (D50) reveal finer to coarser during southwest and northeast monsoons respectively. The results of this study are helpful in formulating and preliminary observation on effective coastal zone management plan for monsoon-dominated coast especially in sandy beach

Spatial Prediction of Landslides Using Hybrid Multi-Criteria Decision-Making Methods: A Case Study of the Saqqez-Marivan Mountain Road in Iran

Landslides along the main roads in the mountains cause fatalities, ecosystem damage, and land degradation. This study mapped the susceptibility to landslides along the Saqqez-Marivan main road located in Kurdistan province, Iran, comparing an ensemble fuzzy logic with analytic network process (fuzzy logic-ANP; FLANP) and TOPSIS (fuzzy logic-TOPSIS; FLTOPSIS) in terms of their prediction capacity. First, 100 landslides identified through field surveys were randomly allocated to a 70% dataset and a 30% dataset, respectively, for training and validating the methods. Eleven landslide conditioning factors, including slope, aspect, elevation, lithology, land use, distance to fault, distance to a river, distance to road, soil type, curvature, and precipitation were considered. The performance of the methods was evaluated by inspecting the areas under the receiver operating curve (AUCROC). The prediction accuracies were 0.983 and 0.938, respectively, for the FLTOPSIS and FLANP methods. Our findings demonstrate that although both models are known to be promising, the FLTOPSIS method had a better capacity for predicting the susceptibility of landslides in the study area. Therefore, the susceptibility map developed through the FLTOPSIS method is suitable to inform management and planning of areas prone to landslides for land allocation and development purposes, especially in mountainous areas

Total vulnerability of the littoral zone to climate change-driven natural hazards in north Brittany, France

International audienceCurrent worldwide projections of sea-level rise show a staggering increase in water level of up to 2 m by 2100 owing to global warming exacerbated by anthropogenically induced climate change. While amplified rates of sea-level rise is an immense hazard to coastal communities, storm surges are expected to increase in intensity and frequency making it an equally significant threat to coastal populations. In France, these hazards are not uncommon with records of extreme tempests every thousand years in the Holocene. Despite these recurring devastating events, in the Bay of Saint-Brieuc, Brittany, legislated laws for coastal management do not entirely focus on protecting littoral zones from such calamities. 130,739 people are concentrated in 21 municipalities with major cities located at close proximity to the shoreline with numerous socio-economic activities, which increases the vulnerability of the coastal population and infrastructures; thus, affirming the indispensable need of a thorough vulnerability assessment. Here, we conduct a mechanistic appraisal of the vulnerability of the bay considering thirteen parameters within three governing sub-systems that demonstrate the multidimensional dynamics in these municipalities. In the occasion of an extreme climatic event, our results of total vulnerability show risks in the sub-systems highlighting erosional processes due to augmented hydrodynamics, socio-economic and administrative vulnerabilities associated with anthropogenic development. Eight municipalities of the bay portray moderate to very high vulnerability and the remaining exhibits a lower risk; however, not devoid of high vulnerabilities for certain sub-systems. We posit that a more accurate fit for predicting the total vulnerability of the region can be achieved by exclusively integrating physical-natural and administrative sub-system vulnerabilities. We propose generic but requisite recommendations for Integrated Coastal Zone Management such as surveillance of urban development along the coast, implementation of coastal defense systems and appropriate industrial corridors to attenuate and dispose hazardous refuse

Rigid‑body analysis of a beveled shape structure in regular waves using the weakly compressible smoothed particle hydrodynamics (WCSPH) method

In many cases of wave structure interactions, three-dimensional models are used to demonstrate real-life complex environments in large domain scales. In the seakeeping context, predicting the motion responses in the interaction of a long body resembling a ship structure with regular waves is crucial and can be challenging. In this work, regular waves interacting with a rigid foating structure were simulated using the open-source code based on the weakly compressible smoothed particle hydrodynamics (WCSPH) method, and optimal parameters were suggested for diferent wave environments. Vertical displacements were computed, and their response amplitude operators (RAOs) were found to be in good agreement with experimental, numerical, and analytical results. Discrepancies of numerical and experimental RAOs tended to increase at low wave frequencies, particularly at amidships and near the bow. In addition, the instantaneous wave contours of the surrounding model were examined to reveal the efects of localized waves along the structure and wave dissipation. The results indicated that the motion response from the WCSPH responds well at the highest frequency range (ω>5.235 rad/s)