TSUNAMI EVACUATION AND MITIGATION PLANNING FOR DETAIL SPATIAL PLAN BASED ON MULTI SCENARIO TSUNAMI HAZARD ASSESSMENT IN SIDAMULIH DISTRICT AND PANGANDARAN DISTRICT, PANGANDARAN REGENCY

• Main Author: Paramita Rattyananda, Nela
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/65276
• Institution: Institut Teknologi Bandung

The major tsunamis that occurred in Banyuwangi (1994), Aceh (2004), Pangandaran (2006) and Mentawai (2010) which originated in the subduction zone can serve as lessons and benchmarks for early warning systems, mitigation and community capacity in dealing with tsunami disasters. The South Coast of Java, which stands out for its coastal tourism, but was located in a subduction zone, makes it prone to earthquakes followed by a tsunami, including along the West Coast of Pangandaran. Today, the West Coast of Pangandaran which includes Sidamulih and Pangandaran sub-districts has developed into a bustling coastal tourism area, with potential and is included in the 19th regional development project of 50 National Tourism Destinations. The development of this area was marked by the construction of a coastal tourism area, a tourist village, the Paamprokan Square and the Grand Pangandaran Megaproject The evacuation plan owned by Pangandaran Regency made by Pusdalops Kab. Pangandaran (2017) not all areas on the west coast have evacuation signs and evacuation maps. Second, the maps and plans use the 2006 Pangandaran tsunami hazard scenario which was a single tsunami scenario. This research was conducted qualitatively, where the data generated was descriptive data which was then poured into a narrative statement. Data was collected through field observations, interviews with resource persons from government agencies and other agencies that play a role in disaster management, and secondary data from previous studies and from related agencies. Community preparedness, supported by infrastructure readiness and a well-thought-out evacuation plan, was important in dealing with tsunami disaster risks in the West Coast Region, so a study of tsunami evacuation and mitigation planning for the RDTR level is needed in Sidamulih and Pangandaran sub-districts, Pangandaran district. This study uses a multi scenario tsunami hazard assessment that was expected to produce a more detailed hazard map than a single-scenario tsunami hazars assessment because that combines several single scenarios earthquake that take into account various tsunami earthquake source points and produces a hazard map with the worst scenario. The Earthquake-Tsunami used as input for multi scenario tsunami hazard assessment in this study were existing tsunami events, historical events and study of tsunami prediction scenarios. The existing events used were the 2006 Pangandaran Tsunami, historical events sourced from paleotsunami research and tsunami prediction scenarios using the megathrust scenario south of Java Mw 8.7. All three were then integrated and simplified to produce an analysis of high, medium and low hazard zones. The high hazard zone was a zone that is exposed to at least 2 tsunami scenarios covering areas along the coast of Pangandaran District and Sidamulih District. The second was the moderate hazard zone, which was an area exposed to a tsunami scenario that covers an area of approximately 1 kilometer from the coast. The third is the low hazard zone, which is a zonevii not exposed to the tsunami, that was expected to be a horizontal evacuation destination for residents exposed to the tsunami. The hazard map generated from the multi scenario tsunami hazard assessment then becomes input for conducting risk studies, calculating tsunami evacuation plans, comparing single scenario and multi scenario tsunami hazard assessment, and planning spatial planning for tsunami disaster mitigation and evacuation. Disaster risk analysis was calculated using hazard analysis comes from the multi scenario tsunami hazard assessment, the vulnerability calculation is based on the disaster risk assessment guidelines in the Regulation of the Head of the National Disaster Management Agency (BNPB) No. 2 of 2012 and the capacity calculation comes from the head of BNPB regulation No. 3 of 2012. The risk analysis gets a very high-risk index in Indonesia. coastal areas and high index in villages located 1 kilometer from the coast. The analysis and calculation of tsunami evacuation and mitigation were divided into calculation of evacuation capacity and analysis of evacuation buildings for the placement of both existing and planned TES using the formula from the Guidelines for Planning for Tsunami Evacuation Paths and Signs. The Tsunami Evacuation Site then compares the results from the 2006 Pangandaran tsunami single scenario and the multi scenario tsunami hazard assessment. Evacuation analysis shows that there were five villages located in coastal areas that require additional TES, namely Cikembulan, Sukaresik, Pananjung, Pangandaran and Wonoharjo villages because the time of evacuation takes more time than the arrival time of the tsunami. The addition of TES in the form of vertical buildings will be more effective to accommodate a large number of residents and tourists. Meanwhile, the other five villages, namely Cikalong, Pajaten, Sidamulih, Purbahayu and Sidomulyo still have enough time to evacuate horizontally to higher ground. TES was planned to add 10 strategic locations and have a minimum floor height based on the calculations made. The number of TES is outside of the 4 existing TES locations that already exist in the research location. This study also carried out spatial planning for tsunami mitigation and evacuation which was assessed using the SWOT method and using the input of a multi scenario tsunami hazard assessment, analysis of coastal spatial planning based on morphology and analysis of coastal protection in the coastal area of the West Coast of Pangandaran. It will also recommend coastal spatial planning as mitigation and placement of TES for tsunami evacuation based on the model from Ihsan & Pramukanto (2017) and visualized by cross-section analysis. Considerations in spatial planning were tourism areas that have fast growth and development located in earthquake and tsunami-prone zones. Spatial planning at the research site requires a spatial planning synergy between tourism and disaster mitigation. Spatial planning in coastal areas based on a SWOT analysis needs to be done by dividing the mitigation zone and building coastal protection as a barrier to tsunami waves in the form of a greenbelt. The greenbelt pattern can be divided into several scenarios, namely integrating coastal forests as a tourist attraction, building greenbelts as a means of retaining building debris carried by the tsunami waves and planting greenbelts in coastal tourism areas and each empty side between buildings while still paying attention to the planning of making evacuation routes in the vacation area. While the division of mitigation zones, the research location can be divided into three zones, namely the Protection Zone with a minimum width of 300 meters from the coastline, the Limited Use Zone placed after the protection zone with a width of up to 1 km from the coastline and Development Zone with a width of 1 km from the coastline.