Evacuation Plan for Tsunami Disaster Response on the South Coast of Malang, Indonesia Usman Fadly1* & Shoimah Fadhilatus1 1

Evacuation Plan for Tsunami Disaster Response on the South Coast of Malang, Indonesia Usman Fadly1* & Shoimah Fadhilatus1 1. Department of Urban and Regional Planning, Brawijaya University, Malang, INDONESIA *[email protected], [email protected]

Abstract Fast and accurate initial evacuation is a very important variable in tsunami disaster response. Thus exact evacuation plan is required as part of the response efforts of disaster. However, evacuation planning is a complex problem that involves many aspects of behavior and management. Tamban Beach, Sendangbiru Beach, and Sempu Island are located in tsunami-prone areas. Sendangbiru area is a strategic area with the main function of national/international ports, industry, and other functions, namely settlements, fisheries, tourism, protected areas, religious rituals, as well as defense and security. The potential of the tsunami disaster could affect the safety of tourists and coastal communities in those areas. There are also no tsunami response plans in those coastal areas, such as shelter and evacuation route plan. The research aims to produce a map of the area affected by the tsunami disaster using numerical simulation and spatial analysis. The research also aims to produce a map of shelter and evacuation routes using weighting analysis and network analysis with ArcGIS by considering the characteristics of local wisdom of the community. The results of the analysis are affected areas map, evacuation points map, and evacuation routes map in Tamban Beach, Sendangbiru Beach, and Sempu Island.

Keywords: Tsunami, Evacuation Route, Shelter, Malang

Introduction Sendangbiru Beach, and Sempu Island are included Based on Malang Regency Regulation 3/2010 in tsunami-prone areas. Sendangbiru area is a concerning Spatial Planning for Malang Regency in strategic area with the main function of 2010-2030 states that tsunami-prone areas cover all national/international ports, industry, and other the beaches in the southern part of Malang functions, namely settlements, fisheries, tourism, Regency. The handling of tsunami-prone areas is protected areas, religious rituals, as well as defense done by avoiding tsunami-affected areas as a built and security. The potential of the tsunami disaster area and developing mangrove forests and buildings could affect the safety of tourists and coastal that can minimize tsunami disasters. Efforts to communities in Tamban Beach, Sendangbiru Beach, handle/ manage tsunami-prone areas include and Sempu Island. The location of community planting mangrove forests in potential settlements close to the beach and the knowledge of areas; development of protection functions in areas the community and tourists are still lacking in along the coastline; limiting urban and rural understanding the threat of the tsunami disaster, settlements and community activities in areas that are causing high vulnerability when tsunami disaster flat and close to the coast, and directing settlements occurs so that it can take lives and property losses as far as 1 km from the coastline; in areas that are that can affect the economy of the surrounding located or adjacent to the coast such as in community (Kusuma et al, 2017). There are no Sendangbiru, Tamban, Kondangmerak, must be tsunami response plans in the coastal areas of developed with building codes that can reduce and Tamban Beach, Sendangbiru Beach, and Sempu direct the water system when a tsunami occurs, Island, such as shelter plans and evacuation routes residential areas must also be equipped with areas for (Usman et al, 2019). evacuation in a short time; and the development and training or simulation of tsunami early warning Therefore, it is necessary to study the protection of system. the Coast of Tamban Beach, Sendangbiru Beach, and Sempu Island against the threat of a tsunami disaster. Sumbermanjing Wetan District is included in the This starts from mapping the tsunami-affected southern part of Malang Regency which is directly area then planning shelter and evacuation routes to bordered by the Indian Ocean. Tamban Beach, 휕훾 푢 휕훾 푣 휕훾 푤 reduce the number of losses and the number of 푥 + 푧 + 푧 = 푆 (1) 휕푥 휕푦 휕푧 푝 victims when a tsunami occurs. 휕푢 휕휆 푢푢 휕휆푦 푣푢 휕휆 푤푢 훾 휕푝 휕 휕푢 휆 + 푥 + + 푧 = − 푣 + 훾 푣 2 푣 휕푡 휕푥 휕푦 휕푧 휌 휕푥 휕푥 푥 푒 휕푥

휕 휕푢 휕푤 + 훾 푣 + − 훾 퐷 푢 − 푅 + 훾 푆 (2) 휕푧 푧 푒 휕푧 휕푥 푣 푥 푥 푣 푢

휕푣 휕휆 푢푣 휕휆푦 푣푣 휕휆 푤푣 훾 휕푝 휕 휕푣 휕푢 휆 + 푥 + + 푧 = − 푣 + 훾 푣 + 푣 휕푡 휕푥 휕푦 휕푧 휌 휕푥 휕푥 푥 푒 휕푥 휕푦

휕 휕푣 휕 휕푣 휕푤 + 훾 푣 2 + 훾 푣 + − 훾 퐷 푣 − 푅 + 훾 푆 휕푦 푦 푒 휕푦 휕푧 푧 푒 휕푧 휕푦 푣 푦 푦 푣 푢 (3)

휕푤 휕휆푥 푢푤 휕휆푦 푣푤 휕휆푧푤푤 훾푣 휕푝 휕 휕푤 휕푢 Figure 1. Tamban Beach, Sendangbiru Beach, & Sempu Island 휆 + + + = − + 훾 푣 + 푣 휕푡 휕푥 휕푦 휕푧 휌 휕푦 휕푥 푥 푒 휕푥 휕푧 Sumber: Google Maps, 2020

휕 휕푤 휕푧 휕 휕푤 훾푣휌 ∗ 푔 + 훾 푣 + + 훾 푣 2 − 훾 퐷 푤 − 푅 + 훾 푆 − 휕푦 푦 푒 휕푦 휕푧 휕푧 푧 푒 휕푧 푣 푧 푧 푣 푢 휌 Research Methods 휕퐹 휕훾 푢퐹 휕훾 푣퐹 휕훾 푤퐹 훾 + 푥 + 푥 + 푧 = 푆 (4) 푣 휕푡 휕푥 휕푦 휕푧 퐹 Research Background Note: t = time Research Objective x,y = horizontal coordinates z = vertical coordinate Tsunami Hazard Shelter and Evacuation u,v,w = velocity components in the x,y,z directions Affected Area Route Mapping Mapping ρ = relative density of the fluid p = pressure Weighting Analysis Network Analysis for Numerical Simulation ve = kinematic viscocity for Shelter Evacuation Route g = gravitional acceleration ɣv = porosity Tsunami Hazard Shelter Distribution Evacuation Route Affected Area Maps Maps Maps ɣx,, ɣy, ɣz = areal porosities in x, y, and z projections S = source of mass for wave generation Figure 2. Research Flow Chart SF,Su,Sw = wave generation source Dx,Dz = coefficient for sponge layer A. Numerical Simulation Rx,Rz = resistant components due to porosity in x and z axis Numerical simulations with software CADMAS- SURF/3D carried out to estimate the tsunami B. Weighting Analysis propagation (Usman, 2019; Wicaksono & Usman, Weighting analysis carried out to select a building 2020), make sure the behavior of a tsunami wave that could potentially be a shelter and not when it reaches the shore (Usman and Rahim, 2017; potentially based on parameters land use, number of Usman et al, 2019), as well as analyzing the several floors, capacity, area, distance from the road, types of topography and beach configurations distance from the beach (Suharyanto et al, 2012, (Usman et al, 2013). The basic equation in this Usman & Sari, 2019, Usman et al, 2020) numerical simulation is the continuity equation and the momentum equation known as the Navier-Stokes C. Network Analysis equation. The equation used in this study is the Network analysis using ArcGIS was conducted to continuity equation expressed in equation (1) and the choose evacuation routes that momentum equation from equations (2) to (4). The were fast, safe, and easily accessible to equation system proposed by Sakakiyama and the community based on the parameters road condition (hierarchy, intensity, width, pavement Kajima (1992), where the porosity of the regionx, type, and quality), distance, travel time, and river y, y, on the x, y, and z axis projection is used to investigate the interaction between existence (Suharyanto et al, 2012, Usman & Sari, waves and topographic modification. 2019, Usman et al, 2020).

Results and Discussion 40% of the slope. In the middle, north, and east are A. Overview of Sumbermanjing Wetan the valleys, while the southernmost area is the sea, District coast and coral islands. 11 village is located on the Sumbermanjing Wetan District is one of the 33 slopes and 4 villages located on the coastal beach districts in the Malang Regency. Sumbermanjing they are Sitiarjo Village, Tambakrejo Village, Wetan District is about 30 km from the capital of Tambaksari Village, and Sidoasri Village. The 4 Malang Regency to the southeast. The administrative villages were prioritized in the study because center of Sumbermanjing Wetan District is in settlements located on the coast with a height of 1-50 Argotirto Village, but the economic center is in meters above sea level will be directly affected when Sumbermanjing Wetan Village. Astronomically, a tsunami disaster occurs. Sumbermanjing Wetan District has located between 112.4031 to 122.4634 East Longitude and 8.2411 to Based on the year-end population registration 8.1443 South Latitude. The administrative area of results, the demographics condition of the coastal Sumbermanjing Wetan District consists of 15 village of Sumbermanjing Wetan District in 2018 villages, 40 hamlets, 113 RW (Citizen Associations), recorded 9293 households and 3,204 populations and 514 RT (Neighborhood Associations). The total consist of 16,126 males and 15,888 females. area of Sumbermanjing Wetan District is around 259.25 km2 which is the widest District or around Table 2. Demographics Condition of Each Coastal Village in 8.04% of the total area of Malang Regency. The Sumbermanjing Wetan District in 2018 boundaries of the Sumbermanjing Wetan District are No. Village Male Female Populations Household 1 Sitiarjo 4.281 4.360 8.641 2.924 as follows: 2 Tambakrejo 3.947 3.867 7.814 2.100 North: Turen District and Dampit District 3 Tambakasri 5.281 5.143 10.424 2.699 East: Dampit District and Tirtoyudo District 4 Sidoasri 2.617 2.518 5.135 1.570 South: Indian Ocean Source: Sumbermanjing Wetan District in Figures, 2019 West: Gedangan District Education facilities in the coastal village of Table 1. The Area of Each Coastal Village in Sumbermanjing Sumbermanjing Wetan District in 2018 consisted of Wetan District 18 Elementary School, 7 Junior High School, and 2 No. Village Area (ha) Percentage (%) Senior High School. Health facilities in the coastal 1 Sitiarjo 3,439 22.79 village of Sumbermanjing Wetan District in 2018 2 Tambakrejo 2,738 28.36 3 Tambakasri 2,170 30.61 consisted of 1 health center, 3 secondary health 4 Sidoasri 1,941 18.24 centers, 28 posyandu, 4 village polyclinic, and 1 Source: Sumbermanjing Wetan District in Figures, 2019 pharmacy. Worship facilities in the coastal village of Sumbermanjing Wetan District in 2018 consisted of In general, the soil conditions in the 35 protestant churches, 19 mosques, and 112 prayer Sumbermanjing Wetan District is a latosol type with rooms. mostly grayish colored. The type of soil makes the soil structure in the Sumbermanjing Wetan District Table 3. Education Facilities of Each Coastal Village in into fertile so perfect used for agriculture and Sumbermanjing Wetan District plantations. The land is widely used by residents as No. Village ES JHS SHS 1 Sitiarjo 5 1 1 paddy land with an area of 912.81 ha, dry land which 2 Tambakrejo 3 2 - is used for settlements, gardens, and 3 Tambakasri 7 3 1 fields with an area of 4,872.89 ha. A large number 4 Sidoasri 3 1 - of land uses affects the vulnerability of disasters, the Source: Sumbermanjing Wetan District in Figures, 2019 land use of paddy fields, gardens, fields also affects the vulnerability of disasters, because most villagers work in agriculture.

Most of the topography in Sumbermanjing Wetan District has a form of highland hills with elevations between 0-650 meters above sea level and less than Table 4. Health Facilities of Each Coastal Village in Sumbermanjing Wetan District Hea Second Villa Pos Pha lth ary ge No. Village yan rm Cen Health Polyc du acy ter Center linic 1 Sitiarjo 1 - 10 1 1 2 Tambakrejo - 1 8 1 - 3 Tambakasri - 1 5 1 - 4 Sidoasri - 1 5 1 - Source: Sumbermanjing Wetan District in Figures, 2019

Table 5. Worship Facilities of Each Coastal Village in Sumbermanjing Wetan District Prayer Protestant No. Village Mosque Room Church Figure 3. Tsunami Hazard Affected Areas on Tamban Beach, 1 Sitiarjo 5 2 18 Sendangbiru Beach, & Sempu Island Area 2 Tambakrejo 2 11 7 3 Tambakasri 11 99 1 C. Shelter Plan and Evacuation Route 4 Sidoasri 1 - 9 The evacuation route can be planned according to the Source: Sumbermanjing Wetan District in Figures, 2019 principle of the collector, local, and environment

road hierarchy. In this case, roads that have primary Sumbermanjing Wetan District has a lot of beach access, namely primary collectors and secondary tourism potential because of its location which is collectors, are roads that have a relatively high directly adjacent to the Indian Ocean. Among them intensity that can be used to reach the shelter. The are Tamban Beach, Sendangbiru Beach, and Sempu road network in the study area consists of a road Island. The number of attractions in the coastal network with a hierarchy of primary collectors, village of Sumbermanjing Wetan District in 2019 secondary locales, primary locales, and consisted of 12 beaches and 1 forest tourism. neighborhood roads. The main road network

Table 6. Number of Attractions of Each Coastal Village in connects Sumbermanjing Wetan District with other Sumbermanjing Wetan District Districts such as Turen District, Gedangan District, No. Village Beach Forest Tourism and Dampit District. The main road network to 1 Sitiarjo 3 - Sendang Biru Beach and Sendang Biru TPI is 2 Tambakrejo 7 1 included in the primary collector road hierarchy. The 3 Tambakasri - - local road conditions in the study area generally use 4 Sidoasri 2 - asphalt pavements with a width of 4-6 m. However, Sumber: Sumbermanjing Wetan District in Figures, 2019 the condition of the secondary collector road network B. Tsunami Hazard Affected Areas leading to the beach location in Sumbermanjing Figure 3 is an overlay of numerical simulation results Wetan District is still a lot of holes and is not yet and spatial analysis using ArcGIS with topographic equipped with road markings and street lighting. data based on SRTM data to predict areas affected by Besides, the road hierarchy leading to the beach in the tsunami disaster in the areas of Tamban Beach, the Sumbermanjing Wetan area is a hierarchy of Sendangbiru Beach, and Sempu Island. The red color environmental roads. Where the road network is in indicates the height of the tsunami inundation >2 m, the form of pavement types of asphalt, macadam, and the orange color indicates the height of the tsunami rocky and sandy macadam roads with a width of inundation 1.5-2 m, the yellow color indicates the about 3 m. Land disaster evacuation routes are height of the tsunami inundation 1-1.5 m, the light carried out by considering the width of the road green color indicates the height of the tsunami according to the road hierarchy. The evacuation route inundation 0.5-1 m, and dark green indicates the consists of a primary route and a secondary route. height of a tsunami inundation <0.5 m. The primary evacuation route uses the southern ring path with a width of 8 m with a hierarchy of collector roads, while the secondary evacuation route uses local roads and neighborhood roads with a width of Table 7. Evacuation Location Estimated Shelter 2-6 m. Space Village Amount of Location Area Need Impact (m2) Sitiarjo ± 1,710 Sitiarjo 306 505 Village Field m² Al-Falah ± 805 Mosque m² Jawi Wetan Tambakrejo ± 946 Tambakr Christian m² 2,184 3,604 ejo Church Baiturrahim ± 1,010 Mosque m² Tambakrejo ± 1,886 Village Field m²

Figure 4. Photo Mapping of Road Network Table 8. Estimated Travel Time Estim Dista Travel The determination of travel time to the shelter based Land Area ated Village nce Time on the average speed of walking during disaster Use (m2) Capac (km) (Minutes) evacuation using a speed of 1.07 m/s (assumed to be ity 1 m/s or 3.6 km/h) and the distance to the shelter. The Sitiarjo ± determination of evacuation route and shelter plan to Sitiarjo Village 1,710 1.2 18 1,334 adjust the distance as well as shelter width using Field m² Al-Falah ± 805 0.8 13 628 ArcGIS application. The shelter to be Mosque m² determined must be able to serve and accommodate Jawi according to the needs of the space for refugees. The Wetan Tambakr ± 946 needs of the space for refugees is obtained from the 1.5 24 738 affected population approximate amount multiplied ejo m² Christian 2 Tamba by the minimum space requirements per 1.65 m . Church krejo Baiturrah ± Based on the results of the analysis of the affected im 1,010 1.3 20 788 area, it was concluded that the coastal areas of the Mosque m² Tambakr Sumbermanjing Wetan District are necessary to have ± ejo a disaster evacuation plan especially for highly 1,886 1.7 27 1,437 Village m² affected areas with the densely populated area, that Field is Sitiarjo Village and Tambakrejo Village. Evacuation routes are divided according to Evacuation routes in Sitiarjo Villages and the village according to the estimated capacity Tambakrejo Villages pass-through the neighborhood needs. The purpose of each village evacuation route and local roads. The shelter location in Tambakrejo was made so that it would not fall into a mass buildup village is the Al-Falah Mosque area of 805 m2, Jawi when evacuating residents during a disaster to make Wetan Tambakrejo Christian Church area of 738 m2, it faster and more efficient. Baiturrahim Mosque area of 1,010 m2 and Tambakrejo Fields Village area of 1,886 m2 (Figure 4). The total area of land used as a shelter in Tambakrejo Village area of 3,604 m2, with an estimated refugee is 2,184 population, so the shelter area for Tambakrejo Village can be sufficient for space need of estimated refugee.

be used as evacuation routes, so that the road is always in good condition.

Acknowledgment The authors would like to express their gratitude towards the Faculty of Engineering, Brawijaya University, Research and Community Service (BPP FT- UB) through the Doctoral Grant scheme for funding this research.

References Figure 4. Photo Mapping of Shelter dan Evacuation Route in Central Statistics Agency of Malang Regency. 2019. Sitiarjo Village Sumbermanjing Wetan District in Figures 2019. Malang: Central Statistics Agency of Whereas for Sitiarjo Village the shelter is located in Malang Regency (Badan Pusat Statistik the Sitiarjo Village Field area Kabupaten Malang. 2019. Kecamatan of 1,710 m2 (Figure 5). The estimated disaster Sumbermanjing Wetan dalam Angka 2019. population of the high affected tsunami is 306 Malang: Badan Pusat Statistik Kabupaten population with the needs of space of 505 m2, so the Malang) shelter area for Sitiarjo Village can be sufficient for Kusuma, M.I, Rachmawati T.A, & Sari, N. 2017. space needs of an estimated number of victims. Coastal Tsunami Disaster Risk Reduction Case Study: Puger Beach Jember. Journal of Social and Cultural Space Studies. I (1): 107- 125 (Kusuma, M.I., Rachmawati T.A., & Sari, N. 2017. Pengurangan Risiko Bencana Tsunam Pesisir Pantai Studi Kasus: Pantai Puger Jember. Jurnal Kajian Ruang Sosial Budaya. I (1): 107-125) Malang Regency Regulation 3/2010 concerning Spatial Planning for Malang Regency in 2010-2030 (Peraturan Daerah Kabupaten Malang Nomor 3 Tahun 2010 tentang Rencana Tata Ruang Wilayah Kabupaten

Figure 5. Photo Mapping of Shelter dan Evacuation Route in Malang Tahun 2010-2030 Tambakrejo Village Sakakiyama, T. dan Kajima, R. 1992. Numerical Simulation Nonlinear Waves Interacting with Conclusion Permeable Breakwaters. Proceedings of the There are five shelters in Sumbermanjing Wetan 23rd International Conference on Coastal District are Al-Falah Mosque area of 805 Engineering, ASCE: 1517-1530 m2, Jawi Wetan Tambakrejo Christian Church area Suharyanto, A., Pujiraharjo, A., Usman, F., of 946 m2, Baiturrahim Mosque area of 1,010 m2, and Murakami, K. & Deguchi C. 2012. Predicting Tambakrejo Fields Village area of 1,886 m2 which Tsunami Inundated Area and Evacuation is located in Tambakrejo Village, and Sitiarjo Road based on Local Condition Using GIS. Village Field an area of 1,710 m2 in Sitiarjo Village. IOSR Journal of Environmental Science, Evacuation routes that can be used in Toxicology and Food Technology, 1 (4): pp Sumbermanjing Wetan District are existing 5-11 roads. However, road repair needs to be done on Usman F., Murakami, K., Hariyani, S., Kurniawan, damaged/perforated road conditions, road widening, E.B., & Shoimah, F. 2019. Tsunami Disaster the addition of new roads to facilitate the evacuation Mitigation Analysis on the Shore of Java of disaster victims to the shelter. As well as carrying Island using CADMAS/Surf Numerical out road routine maintenance on the roads that will Simulations. Disaster Advances, 12 (2): pp 1- 5 Usman, F. & Rahim, S.E. 2017. Investigate the Effectiveness of Seawall Construction using CADMAS Surf 2D. Matec Web of Conferences, 97 (165): pp 1-8 Usman, F. & Sari, I.C. 2019. Determining the Location of Shelters for Tsunami Evacuation Based on Service Area Analysis in Paseban Village, Kencong Sub-District, Jember District. IOP Conf. Series: Earth and Environmental Science: pp 1-8 Usman, F. 2019. Predicting the Vulnerable Area of Tsunami Hazard Using CADMAS Surf 3D Case Study: Kolaka City, Southern Sulawesi, Indonesia. IOP Conf. Series: Materials Science and Engineering: pp 1-8 Usman, F., Anwar, M.R., Murakami, K., Shoimah, F., & Sari, I.C. 2020. Evacuation Road, Shelter Plan, and Preparedness for Tsunami Disaster Mitigation in Watulimo District, Trenggalek Regency, Indonesia. Disaster Advances, 13 (4): pp 1-9 Usman, F., Murakami, K., & Kurniawan, E.B. 2013. Study on Reducing Tsunami Inundation Energy by the Modification of Topography based on Local Wisdom. Procedia Environmental Sciences: pp 643-650 Usman, F., Suharyanto, A., & Murakami, K. 2013. Pacitan: City Without Local Wisdom fot Tsunami Hazard. A Indigenous Architectur as Basic Architectural Design, pp A-142 – A- 150 Wicaksono, A.D. & Usman, F. 2020. Investigation of Tsunami Impacted Area from Anak Krakatoa Volcanic Eruption. International Journal of Geomate, 19 (71): pp 235-241