TOWARDS A RESILIENT CITY Building Disaster Resilience: Infrastructure Optimization for Earthquake Evacuation in Lebak Siliwangi
CONTEXT
VULNERABILITY TO INFORMAL SETTLEMENTS
STRATEGY OF PUBLIC SPACE OPTIMIZATION
LEBAK SILIWANGI EXISTING CONDITION
Informal settlements are having characteristics such as high density for both people or buildings. It is contribute to increasing the vulnerability and risk to disaster. Holistic disaster management is a needs, not only in physical aspects but also in sosio-cultural dimension.
Considering natural characteristic of informal settlements which is resilient, self-organized, and incremental changes, the optimization of public space as basic infrastructure for facing earthquake have to suit it’s nature. There are also possible creating collaboration with government and private sector to increase the quality of space. The are two main strategies to optimize public space in Lebak Siliwangi such as:
Lebak Siliwangi is only 9 km apart from Lembang Fault. The scenario which developed by BMKG (2015) triggers MMI scale VII impact in Lebak Siliwangi, caused by Lembang Fault earthquake. MMI scale VII illustrates moderate damage impact such as crack of walls, broken glass of window, fall roof, and medium structural building damage. It will be huge losses if there is no real action to mitigate the disaster in such area of informal settlements.
Public Open Space • Turn unused space into public open space; • Optimize public open space in public area (school).
LEBAK SILIWANGI
City of BANDUNG
With that strategies, division of role from stakeholders are as follows:
Coblong, Bandung
Retrofits stateowned public building (school)
Government
Private Sector
Retrofits publicowned building and provide open space as part of CSR
People/ Community
Lebak Siliwangi location is in Coblong District, Bandung, the capital of West Java Province. It is sorrounded by high economic area (Cihampelas and Dago commercial area) and high education (ITB). It is also bordered by Cikapundung River. Lebak Siliwangi has been transformed into informal settlements from agricultural land post 1945.
Operational and maintenance for newly added public space
Population
Building
Area
4.291 people
822 units
8,35 ha
FURTHER STUDY AND DEVELOPMENT
(BPS, 2017)
There are 5 open spaces and 5 mosques identified in Lebak Siliwangi. The scale and typology of each space are vary. Most of open spaces are usually functioned as sport field, motorcycle communal park lot, or community hall. Mosque usually found in the middle of area, so people have to reach the alleyways further. Some area are still not covered by the existing public space. Therefore, current total area of public space is also still insufficient to fit all people when they are gather at same time.
Provision of public space must be accompanied by good and accessible circulation. Clear evacuation route is needed to make sure public space as evacuation destination is reachable. Optimizing the alleyways space, providing direction signage, is such strategies to implied in informal settlements. Therefore, choosing optimum and shortest route is have to be calculated in detail.
POTENTIAL IMPROVEMENT/OPTIMIZATION
Besides preparing structural mitigation, such as providing infrastructure, non-structural mitigation is also must be done. Building public awareness and capacity in facing the earthquake is one of the key to reduce the vulnerability and risk to disaster. However, good provided infrastructure will never be useful if there is no capacity and knowledge of people when the disaster occurs.
NATURAL DISASTER HAZARD Lebak Siliwangi is categorized as disaster-prone are for several hazard, such as: landslide (medium risk), fire, and earthquake (medium risk). (Bappelitbangda Bandung, 2019)
To optimize service area of infrastructure, improvement or adding another space is a need. There are 3 potential spots to improve service area of open space, optimizing school field and add 2 other open spaces in middle and northern of the site. Also there is public building that could optimized as evacuation destination, SDN (State Basic School) Pelesiran.
One of the triggers for an earthquake in Bandung is Lembang Fault. There is an active fault located in northern Bandung, with a length of 29 km across Cimeta (West Bandung Regency) - Batu Loceng (Bandung Regency). Geological characteristic and earthquake potential from Lembang Fault are as follows: Slip Rate
Potential Magnitude
1,95-3,45 mm/year
6,5-7,0 M
Last Massive Earthquake 15th Century
(Daryono, 2018)
(Daryono, 2018)
(Daryono, 2018)
6,5 M
Recurrence Period
(BMKG, 2015)
Public Building • Building retrofitting, make sure the building ready to face 7,0 M earthquake.
170-670 years (Daryono, 2018)
INFRASTRUCTURE FOR EARTHQUAKE MITIGATION Mitigation is a series of efforts to reduce disaster risk, both through physical development and raising awareness and capacity building to face the threat of disaster (Law 24/2007). There are vary infrastructure for mitigating earthquake in various area. It has to be suitable with unique feature and characteristic of location. Ye et. al. (2011) explain that basic infrastructure that has to be provided to ensure the evacuation against earthquake is public open space and evacuation route. Open space has to consider spatial distribution and distance, so it could meet the demand. Sagala and Saraswati (2013) defined optimum distance to reach in high density settlements when earthquake occurs is 60-80 meters. Regarding characteristic of informal settlements, there have to be clear direction to evacuate. The alleyways have to be free of obstacle to direct evacuee towards the destination/open space.
LEBAK SILIWANGI EXPERIENCE There are several moderate scale earthquake happened and felt in Lebak Siliwangi. In emergency situation people are trying to reach open space such as public open space, major alleyways, and main street. But also found that people are also trying to reach stronger building, such as mosque. So in this case, not only public open space that could be functioned as evacuation destination, but aslo public building which have stronger building structure that ordinary settlement.
With those additions, most of area of Lebak Siliwangi are served to public space for evacuation destination. Unless the southern area which left intentionally because having direct acces to major alleyway. And the formal office and commercial building which have direct access to main street.
REFERENCES Anhorn, J. & Khazai, B. (2015). Open space suitability analysis for emergency shelter after an earthquake. Natural Hazards Earth Syst. Sci., 15, 789–803. Central Bureau of Statistics. (2018). Coblong in Figures 2018. Bandung: BPS Daryono, M. R., Natawidjaja, D. H., Sapiie, B., & Cummins, P. (2018). Earthquake Geology of the Lembang Fault, West Java, Indonesia. Tectonophysics. doi:10.1016/j.tecto.2018.12.014 Hernandez-Garcia, Jaime. (2013). Public Space in Informal Settlements: The Barrios of Bogota. Newcastle: Cambridge Scholar Publishing Law No. 24/2007 regarding Disaster Management Sagala, Saut., & Saraswati, S. (2013). Spatial Analysis of Existing Public Open Space for Evacuation Area During Secondary Earthquake, A Case Study: Sukahaji Village, Bandung. Forum Geografi Vol. 27, No. 2, p. 123-134 Shah, Fatima & Ranghieri Federica. (2012). A Workbook on Planning for Urban Resilience in the Face of Disasters: Adapting Experiences from Vietnam’s Cities to other cities. Washington D.C: World Bank
SDN Pelesiran
Office and Commercial Area
sitaruna.cityplan.id Ye, M., Wang, J., Huang, J., Xu, S., & Chen, Z. (2011). Methodology and its application for community-scale evacuation planning against earthquake disaster. Natural Hazards, 61(3), 881–892.
Muhammad Rafialdy Janitra 25619007