nan Syamsidik

Local and indigenous knowledge on climate-related hazards of coastal and small island communities in Southeast Asia

Coastal and small island communities in Southeast Asia face daily threats from the impacts of climate change and climate-related hazards. This paper describes and analyses local and indigenous knowledge and practices related to climate-related hazards identified and documented in Indonesia, the Philippines and Timor-Leste. These include observations of changes in the environment and celestial bodies to predict climate-related hazards. Communities use local materials and methods to prevent and/or mitigate such hazards, and adapt to and prepare for them. Rituals and ceremonies are based on traditional or religious beliefs. Together with customary laws that govern behaviour, these rituals engender and reinforce respect for the environment, strengthen social cohesion, and thus help communities to better face and respond to the impacts of climate change and climate-related hazards. After going through a process of documentation, analysis and validation, local and indigenous knowledge can be grouped and categorised, which helps us better understand how such knowledge can be integrated with science. This will then enable communities to develop strategies to cope with climate-related hazards and adapt to climate change. Scientists, practitioners and policy-makers can also harness this knowledge for further research, education, and policy. It is important to promote the transmission of local and indigenous knowledge to increase community resilience.

Numerical simulation of the impacts of reflected tsunami waves on Pulo Raya Island during the 2004 Indian Ocean tsunami

There are numerous small populated islands near western Sumatra in Indonesia. The Weh, Banyak, Mentawai, and Enggano islands are home to many Indonesians. These small islands have been found to be effective at reducing tsunami wave energy on several occasions. At the same time, they are situated around Sumatras active subduction zone and are often among the areas most affected by tsunamisas in the case of Pulo Raya Island, in the western Aceh Jaya district about 800 m from Sumatra. Pulo Raya was devastated by the 2004 Indian Ocean tsunami. This study investigates the hydrodynamic processes of reflected tsunami waves and their impact on Pulo Raya, using a Cornell Multi-grid COupled Tsunami (COMCOT) model to simulate the tsunami wave runup and subsequent hydrodynamic processes. The simulation confirms eyewitness accounts that it was not the initial runup, but the reflected waves that devastated the worst-hit areas of the island. As a result, we can recommend that governments and communities on small islands need to anticipate the impacts of reflected waves following a tsunami, especially at lee side of of the island that was perceived to be a safer place by the island community before the 2004 Indian Ocean tsunami.

Numerical Simulations of Impacts of the 2004 Indian Ocean Tsunami on Coastal Morphological Changes Around the Ulee Lheue Bay of Aceh, Indonesia

Wave forces during the 2004 Indian Ocean tsunami have caused morphological deformations of some coastal areas in Aceh, Indonesia. The sediment transport process during the tsunami wave propagation around near shore areas is a challenging numerical problem. To observe the coastal morphological changes after the Indian Ocean tsunami, this study numerically simulates the coastline changes, sedimentation and erosion areas, and seabed profiles changes around the Ulee Lheue Bay of Aceh, which was severely damaged by the tsunami. Two-dimensional horizontal areas were simulated by Cornell Multi-grid Coupled Tsunami (COMCOT) and Delft3D. Data of the nearshore area were collected from previous measurements acquired by the Indonesian Navy. According to the results, sediment in the sea area was deposited approximately 2.5km from the initial coastline, at the northern part of one small island occupying the Ulee Lheue Bay. This island reduced the energy of the tsunami waves during the backwash process, dumping a signif...

RECENT RESEARCH ON TSUNAMI HAZARDS FOR SUMATRA AND THE SOUTH CHINA SEA AREA

Some challenging issues in tsunami disaster mitigation and risk management are raised at the AIWEST-DR2011 in Conjunction with SCSTW-4. Currently there is no enough attention given to potential tsunamis in South China Sea due to the lack of data for historic tsunamis in the area, therefore there is a need to have a joint effort among the countries bordering the South China Sea to collect scientific evidence of historic tsunamis along the border of the South China Sea.

The Indian Ocean Tsunami and Land Use Changes in Indonesia

Several tsunamis generated in the Indian Ocean have delivered impacts on land use and spatial planning for the affected areas. New regulations for city planning have also been introduced as part of mitigation efforts and to control land use in Indonesia. This chapter is aimed at elaborating the land use changes at several selected areas in Indonesia, those were motivated by tsunamis in the Indian Ocean. Three tsunami-affected areas will be taken into consideration in this chapter, namely, Banda Aceh and Meulaboh (after the 2004 Indian Ocean tsunami) and the Mentawai Islands (after the 2010 Mentawai tsunami). Policy change analysis was done, and it is coupled with spatial analysis using previous published data and images. Banda Aceh and Meulaboh were the most affected cities due to the Indian Ocean tsunami in 2004. Meanwhile, land use changes at Mentawai Islands are analyzed based on the latest interventions made around their areas. Three major units of land use were classified in this chapter. Relocation programs made at the three selected locations faced difficulties due to the land price hikes, and there are some coastal communities who work as fishermen, and this made them difficult to be relocated far away from coastal area. To prevent further uncontrollable land use changes at coastal area, the local Government of Banda Aceh and Meulaboh puts a strict regulation for the coastal area. Meanwhile, the disaster mitigation-based spatial planning in the Mentawai Islands is still in the process of formulation.

Progress of Coastal Line Rehabilitation After the Indian Ocean Tsunami Around Banda Aceh Coasts

Coastal recovery at tsunami affected areas is another challenging work for practitioners. Pressures from demand to acquire ample and suitable land to restart economy activities and from harmonizing nature with the development are among the reasons why the coastal recovery may enter into complicated decision process. This chapter elaborates lessons learned from coastal recovery process around Banda Aceh to restore coastal lines around this area after severely damaged by the Indian Ocean Tsunami waves in 2004. A time series of maps to show the coastal morphological dynamics around Banda Aceh was used to compare the coastal features between 2004 and 2011 conditions. Other similar studies focusing on the coastal recovery around this area were also included to strengthen the lessons of the coastal recovery process orchestrated after the tsunami. Four coastal locations around Banda Aceh were selected to show the different approaches used to recover the coasts and impacts on the area after the efforts.

Numerical simulation for estimating of sediment transport due layouts of port

The need for a new and improved fisheries port has significantly increased in the Bireuen District of Aceh, particularly in Peudada due to several factors presented in this paper. During this time the fishing port used by the communities located in the river channel makes it difficult for the fishermen to get into the port area due to the shallowness of the mouth of the estuary. Port master plan study is required to examine several possible locations for the proposed port. In planning the hydro-oceanographic aspects of the port is an essential requirement to determine the layout of a port. Several factors that need to be reviewed relating to the layout of the ports include sedimentation, waves, and currents. These factors affect the movement of the ship, tranquility waves in the port basin, and for the maintenance dredging of the harbor due to sedimentation. This study is aimed at estimating the best layout of the port basin between two scenarios due to the sedimentation process, waves propagation, and cu...

Preliminary study on performance of a coupled hydrodynamic and sediment transport model on small domain

Numerical simulation is one of the useful tools to analyze natural phenomena in the earth such as the tsunami disaster. Several numerical models can simulate the tsunami wave from its generation, propagation, and inundation. However, most tsunami models do not include the sediment transport module. The tsunami wave actually induces a lot of sediment during the propagation in the coastal area. In the case of Indian Ocean Tsunami in 2004, massive morphological changes were caused by the tsunami waves around Sumatra coast. In Aceh, some areas eroded by the tsunami wave were living place for a local community. It is indispensable for the resident in the coastal area to estimate the risk of morphological changes due to a tsunami wave. Therefore, a model that can investigate the morphological changes due tsunami wave is necessary. The result of this model can be used to consider a countermeasure for tsunami wave impact in the coastal area, such as land-use management and planning. The COMCOT-SED model had been developed by several researchers. This model combines the hydrodynamic module and the sediment module. The aim of this study is to get general information about performance of the COMCOT-SED model and to modify the model for more accurate results. Firstly, the model was demonstrated in the ideal condition to confirm the model validity. Then, we evaluated the model performance comparing the model results and the laboratory experiment data which was conducted by other researcher. The authors found that the results of water level and bottom profile by the original model in the ideal condition are not suitable. The model modification will give us more suitable results. The modified model will be applied to simulate the tsunami wave and sediment transport in the small area.Numerical simulation is one of the useful tools to analyze natural phenomena in the earth such as the tsunami disaster. Several numerical models can simulate the tsunami wave from its generation, propagation, and inundation. However, most tsunami models do not include the sediment transport module. The tsunami wave actually induces a lot of sediment during the propagation in the coastal area. In the case of Indian Ocean Tsunami in 2004, massive morphological changes were caused by the tsunami waves around Sumatra coast. In Aceh, some areas eroded by the tsunami wave were living place for a local community. It is indispensable for the resident in the coastal area to estimate the risk of morphological changes due to a tsunami wave. Therefore, a model that can investigate the morphological changes due tsunami wave is necessary. The result of this model can be used to consider a countermeasure for tsunami wave impact in the coastal area, such as land-use management and planning. The COMCOT-SED model had been ...

Projections of tsunami inundation area coupled with impacts of sea level rise in Banda Aceh, Indonesia

In a long term, sea level rise is anticipated to give devastating effects on Banda Aceh, as one of the coastal cities in the northern tip of Sumatra. The growth of the population and buildings in the city has come to the stage where the coastal area is vulnerable to any coastal hazard. Some public facilities and settlements have been constructed and keep expanding in the future. According to TOPEX/POSEIDON satellite images, 7 mm/year the sea level has been risen between 1992 and 2015 in this area. It is estimated that in the next 100 years, there will be 700 mm additional sea level rise which will give a setback more over to a rather flat area around the coast. This research is aim at investigating the influence of sea level rise toward the tsunami inundation on the land area particularly the impacts on Banda Aceh city. Cornell Multigrid Coupled Tsunami Model (COMCOT) simulation numerically generated tsunami propagation. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Geological movement of the underwater fault was generated using Piatanesi and Lorito of 9.15 Mw 2004 multi-fault scenario. The inundation area produced by COMCOT revealed that the inundation area was expanded to several hundred meters from the shoreline. To investigate the impacts of tsunami wave on Banda Aceh, the inundation area were digitized and analyzed with Quantum GIS spatial tools. The Quantum GIS analyzed inundations area affected by the projected tsunami. It will give a new tsunami-prone coastal area map induced by sea level rise in 100 years.In a long term, sea level rise is anticipated to give devastating effects on Banda Aceh, as one of the coastal cities in the northern tip of Sumatra. The growth of the population and buildings in the city has come to the stage where the coastal area is vulnerable to any coastal hazard. Some public facilities and settlements have been constructed and keep expanding in the future. According to TOPEX/POSEIDON satellite images, 7 mm/year the sea level has been risen between 1992 and 2015 in this area. It is estimated that in the next 100 years, there will be 700 mm additional sea level rise which will give a setback more over to a rather flat area around the coast. This research is aim at investigating the influence of sea level rise toward the tsunami inundation on the land area particularly the impacts on Banda Aceh city. Cornell Multigrid Coupled Tsunami Model (COMCOT) simulation numerically generated tsunami propagation. Topography and bathymetry data were collected from GEBCO and updated with the availab...

Predicting impact of SLR on coastal flooding in Banda Aceh coastal defences

Banda Aceh is a low-lying city located at the northern tip of Sumatra Island and situated at the conjuncture of Malacca Strait and the Andaman Sea. A Sea Level Rise (SLR) rate at 7 mm/year has been observed around this region. In the next 50 years, this city will face a serious challenge to encounter impacts of the sea level rise, such as frequent coastal floodings. This study is aimed at estimating impacts of the sea level rise induced coastal floodings on several types of coastal structures and city drainage system. Numerical simulations of Delft3D were applied to investigate the influence of the gradual sea level rise in 50 years. The hydrodynamic process of coastal flooding and sediment transport were simulated by Delft3D-Flow. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Hydrodynamic process gains the flow process revealing the level of the sea water intrusion also observed in the model. Main rivers (Krueng Aceh, Krueng Neng, and Alue Naga Flood Canal) and the drainage system were observed to see the tides effects on coastal structures and drainage system. The impact on coastal community focusing on affected area, shoreline retreat, the rate of sea intrusion was analyzed with spatial tools. New coastal line, coastal flooding vulnerable area, and the community susceptibility properties map influenced by 50 years sea level rise is produced. This research found that the city needs to address strategies to anticipate the exacerbating impacts of the sea level rise by managing its coastal spatial planning and modify its drainage system, especially at the drainage outlets.Banda Aceh is a low-lying city located at the northern tip of Sumatra Island and situated at the conjuncture of Malacca Strait and the Andaman Sea. A Sea Level Rise (SLR) rate at 7 mm/year has been observed around this region. In the next 50 years, this city will face a serious challenge to encounter impacts of the sea level rise, such as frequent coastal floodings. This study is aimed at estimating impacts of the sea level rise induced coastal floodings on several types of coastal structures and city drainage system. Numerical simulations of Delft3D were applied to investigate the influence of the gradual sea level rise in 50 years. The hydrodynamic process of coastal flooding and sediment transport were simulated by Delft3D-Flow. Topography and bathymetry data were collected from GEBCO and updated with the available nautical chart (DISHIDROS, JICA, and field measurements). Hydrodynamic process gains the flow process revealing the level of the sea water intrusion also observed in the model. Main rivers (...