geosciences Review Review of Local and Global Impacts of Volcanic Eruptions and Disaster Management Practices: The Indonesian Example Mukhamad N. Malawani 1,2, Franck Lavigne 1,3,* , Christopher Gomez 2,4 , Bachtiar W. Mutaqin 2 and Danang S. Hadmoko 2 1 Laboratoire de Géographie Physique, Université Paris 1 Panthéon-Sorbonne, UMR 8591, 92195 Meudon, France; [email protected] 2 Disaster and Risk Management Research Group, Faculty of Geography, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia; [email protected] (C.G.); [email protected] (B.W.M.); [email protected] (D.S.H.) 3 Institut Universitaire de France, 75005 Paris, France 4 Laboratory of Sediment Hazards and Disaster Risk, Kobe University, Kobe City 658-0022, Japan * Correspondence: [email protected] Abstract: This paper discusses the relations between the impacts of volcanic eruptions at multiple- scales and the related-issues of disaster-risk reduction (DRR). The review is structured around local and global impacts of volcanic eruptions, which have not been widely discussed in the literature, in terms of DRR issues. We classify the impacts at local scale on four different geographical features: impacts on the drainage system, on the structural morphology, on the water bodies, and the impact Citation: Malawani, M.N.; on societies and the environment. It has been demonstrated that information on local impacts can Lavigne, F.; Gomez, C.; be integrated into four phases of the DRR, i.e., monitoring, mapping, emergency, and recovery. In Mutaqin, B.W.; Hadmoko, D.S. contrast, information on the global impacts (e.g., global disruption on climate and air traffic) only fits Review of Local and Global Impacts the first DRR phase. We have emphasized the fact that global impacts are almost forgotten in the of Volcanic Eruptions and Disaster DRR programs. For this review, we have extracted case studies from Indonesia, and compared them Management Practices: The to those of other regions, because Indonesia is home to >130 volcanoes and experienced several latest Indonesian Example. Geosciences 2021, volcanic eruptions with VEI > 5. 11, 109. https://doi.org/ 10.3390/geosciences11030109 Keywords: volcanic eruption; disaster risk management; risk mitigation; local impact; global impact Academic Editors: Gianluca Groppelli and Jesus Martinez-Frias 1. Introduction Received: 27 December 2020 Volcanic eruptions are considered major (very large) when the Volcanic Explosivity Accepted: 24 February 2021 Index (VEI) ≥ 5 [1,2]. The nature of the impacts of a VEI ≥ 5 eruption ranges from the Published: 1 March 2021 destruction of a city, an entire region, climate disturbances as well as to air travel [3–5]. Even an eruption with VEI < 5 may also have the potential to modify the environment Publisher’s Note: MDPI stays neutral and landscape particularly in proximal and medial facies, as well as surrounding human with regard to jurisdictional claims in societies [2,6]. The variety of environmental destructions due to volcanic eruption differs published maps and institutional affil- from primary (e.g., summit collapse, vegetation burning, death), secondary (e.g., atmo- iations. spheric cooling, global warming), and tertiary (e.g., flood, famine, disease) effects [6]. It is mostly generated by gas emissions, ashes, lava flow, pyroclastic flow, lahar, debris flow, and landslide which results in local and global impacts [6]. The variety of impacts can be simplified at the local scale by their consequence in Copyright: © 2021 by the authors. various geographical features. Geographical features are any features on the Earth’s surface, Licensee MDPI, Basel, Switzerland. whether natural or not, which can be characterized spatially and temporally [7]. It may be This article is an open access article classified into four categories: (i) the drainage system, (ii) the structure morphology, (iii) distributed under the terms and the water bodies, and (iv) the society and environment (e.g., Refs. [2,8]). Several studies of conditions of the Creative Commons local impacts have helped to design the disaster risk reduction (DRR) program on volcanic Attribution (CC BY) license (https:// disasters, e.g., monitoring and evacuation [9], total vulnerability assessment [10], livelihood creativecommons.org/licenses/by/ and resettlement [11,12]. At the global scale, the DDR issues such as air traffic disruptions 4.0/). Geosciences 2021, 11, 109. https://doi.org/10.3390/geosciences11030109 https://www.mdpi.com/journal/geosciences Geosciences 2021, 11, x FOR PEER REVIEW 2 of 19 Geosciences 2021, 11, 109 2 of 18 [10], livelihood and resettlement [11,12]. At the global scale, the DDR issues such as air trafficor climate disruptions disturbance or climate are more disturbance complex are because more complex a major eruptionbecause a maymajor impact eruption anyone may impactregardless anyone of their regardless geographic of their position geographic [13]. Unfortunately, position [13]. the Unfortunately, interaction of the both interaction local and ofglobal both impact local and with global DRR impact is undeveloped. with DRR DRRis undeveloped. is describe asDRR a systematic is describe effort as a systematic to reduce effortthe various to reduce types the of various causative types factors of causativ of disasterse factors by using of disasters various techniquesby using various or scientific tech- niquesapproaches or scientific [14]. approaches [14]. In thisthis study,study, we we present present Indonesian Indonesian cases cases both both of localof local and and global global impacts impacts along along with volcanoeswith volcanoes around around the world the world as a comparison. as a comparison. We also We describe also describe how they how relate they to relate disaster to disastermanagement management practices practices in order to in provide order to informed provide data informed for decision data for making. decision Indonesia making. is Indonesiaan archipelago is an archipelago country with country the highest with numberthe highest and number highest and density highest of activedensity volcanoes of active volcanoesin the world. in the Several world. active Several volcanoes active havevolcanoes become have open-laboratories become open-laboratories such as Merapi such inas MerapiCentral Java,in Central Agung Java, in Bali, Agung and in Sinabung Bali, and in Sinabung Sumatra (Figurein Sumatra1). Among (Figure 130 1). volcanoes Among 130 at present,volcanoes major at present, eruptions major have eruptions also repeatedly have also occurred repeatedly during occurred the historical during the period: historical e.g., period:Samalas e.g., (1257 Samalas CE), Tambora (1257 CE), (1815 Tambora CE), and (1815 Krakatoa CE), and (1883 Krakatoa CE) [5, 15(1883,16]. CE) [5,15,16]. Figure 1.1. DistributionDistribution of of active active volcanoes volcanoes in in Indonesia. Indonesia. Several Several volcanoes volcanoes create create remarkable remarkable eruption eruption by the by therange range of VEI of VEI3–7 (list 3–7 (listof VEI of VEIdata data Ref.: Refs.: [17,18]). [17 ,18]). 2. Local Impacts of Volcanic Eruptions 2.1. Impacts on the Drainage Systems Volcanic eruptions can lead to geomorphologicalgeomorphological transformations in valleys, talweg, and the hydrographic network due to erosion and sedimentation processes. For example, at Merapi volcano, the sediment supply from pyroclastic density currents into the river network leads leads to to riverbed riverbed aggradation aggradation and and subs subsequentlyequently riverbed riverbed incision incision [19]. [ 19The]. river The valleyriver valley morphology morphology has changed has changed from the from old the Me oldrapi Merapi (before (before 4.8 ka BP) 4.8 to ka the BP) new to the Merapi new (afterMerapi 4.8 (after ka BP) 4.8 edifice ka BP) by edifice detrital by fan detrital deposits, fan andesitic deposits, lava andesitic flows, lavatephra, flows, lapilli, tephra, and ashlapilli, layers and [20]. ash layersThese [materials20]. These buried materials the buriedeastern the drainage eastern system drainage of systemMerapi of during Merapi a majorduring flank a major collapse. flank During collapse. the During2006 CE theeruption, 2006 CE Merapi’s eruption, block-and-ash Merapi’s block-and-ash flow covered theflow interfluve covered theregion interfluve and the region main andvalley the on main the southern valley on flank the southern as long as flank ~7 km as long [21]. asIt ~7indicates km [21 ].that It indicatesthe materials that theproduced materials by produced volcanic byeruptions volcanic are eruptions substantial are substantialin shaping morphologyin shaping morphology and channel and stability. channel In the stability. case of In lahar/pyroclastic the case of lahar/pyroclastic input, the most input, hazard- the most hazardous location along a drainage system is river confluence. For instance, the ous location along a drainage system is river confluence. For instance, the Mapanuepe and Mapanuepe and Marella rivers’ confluence widened up to 1.3 km after lahar input from Marella rivers’ confluence widened up to 1.3 km after lahar input from the 1991 CE the 1991 CE Pinatubo eruption in Philippines [22]. Pinatubo eruption in Philippines [22]. In the tropics, sediment-discharge in volcanic rivers increases during and after erup- tions due to lahars, which can be either eruption-induced or rain-triggered during the Geosciences 2021, 11, x FOR PEER REVIEW 3 of 19 Geosciences 2021, 11, 109 3 of 18 In the tropics, sediment-discharge in