Abstract. In this paper we investigate the question not of how, but why people actively choose to live with continued exposure to considerable hazard. A field survey of the human–volcano interaction at Bromo Volcano was based on semi-structured interviews and focus group discussions. The recorded interviews were transcribed and analysed according to recurrent themes in the answers. Findings from field investigation were then confronted with previous existing concepts of human exposure to natural hazards. The result shows that the interaction between humans and the volcanic environment at Bromo volcano is multifaceted and complex. The Tengger people choose – rather than being forced – to live with volcanic hazards. They are not only exposed to its negative consequence, but also enjoy benefits and opportunities of physical, spiritual and socio-cultural nature that arise within the human–volcanic system. Following this perspective, the concept of risk itself must be revisited and expanded from a one-sided focus on hazardous processes to a more holistic view of risk that includes the various positive aspects that pertain to the entire system. The development of a generic human–volcanic system model could provide the basis for the development of an open-risk concept.
Penelitian ini bertujuan untuk: (1) menganalisis karakieristik geomorfologi dan satuan-saiuan beniuklahan di daeran peneliiian, (2) menganalisis karakteristik bawah permukaan (subsurface) di daerah peneliiian, dan (3) mengkaji hubungan aniara karakteristik geomorfologi dengan karakieristik bawah permukaan (subsurface) di daerah penelitian. Kajian karakteristik geomorfologi dan. saiuan-saiuan bentuklahan di daerah penelitian dilakukan berdasarkan interpretasi citra sate/it multi resolusi, interpretasi peta RBI, dan survei lapangan. Berbagai teknik penajaman citra diterapkan untuk memperjelas kenampakart geomorfologikal pada citra sate/it. Delineasi satuan bentuklahan dilakukan secara on-screen dengan menggunakan Sistem Informasi Geografi (SIG). Proses penghalusan delineasi satuan bentuklahan dilakukan dengan mempertimbangkan analisis pola kelurusan, pola aliran, dan pola penggunaan lahan yang ada pada citra sate/it dan analisis pola kontur pada peta RBI digital. Informasi mengenai materi penyusun bentuklahan beseria struktur geologi yang menyertainya diperoleh dari pembacaan peta geologi. Kajian karakteristik bawah permukaan (subsurface) dilakukan dengan analisis geofisika, analisis data bor dan survei lapangan. Analisis hasil penelitian dilakukan. secara deskriptif dan secara spasial atas obyek yang diteliti. Hasil 'peneliiian menunjukkan bahwa morfologi daerah Bantu! dapai diklasifikasikan sebagai dataran, perbukiian, dan pegunungan. Bentuklahaii secara umum di Bantu/ terdiri dari 6 bentukiahan berdasarkan genesisnya, yaitu: jluoial, marine, aeolian, solusional, denudasional, dan struktural. Selain itu, struktur bawah permukaan daiaran rendah Bantu/ berupa asimetris graben. Kedalaman basemen graben bervariasi hingga 1,6 km. Kedalaman sedimen bervariasi antara 3 - 150 m. Sedimen alluvium tebal yang tidak terkonsolidasikan menempati bagian timur dataran aluvial yang dekat gawir dan. Pegunungan Baturagung. Sedimen alluvium dangkal yang tidak terkonsolidasikan menempati bagian bagian barat daiaran aluvial dekat bukit sisa dan perbukitan denudasional. Kedalaman muka airtanah dangkal menempati beniuklahan. fluvial, marine, dan aeolian. Sebaliknya, Kedalaman muka airtanah dalam menempaii bentuklahan denudasional, sirukiural, dan solusional. Selain itu, bentuklahan fluvial, marine, dan aeolian memiliki nilai kerapatan (densitas) batuan rendah, yang menunjukkan material penyusun tebal yang tidak terkonsolidasikan berupa alluvium Kuarter ..
Abstract Small island ecosystems and their inhabitants face a significant threat from global warming, which jeopardizes their sustainability. These communities are particularly vulnerable to the impact of climate change, as they heavily rely on natural resources for their livelihoods and are more vulnerable than mainland regions. Additionally, the effects of global warming on oceanographic conditions will disproportionately affect these communities. Therefore, it is essential to take urgent action to address the challenges small island states face and promote their resilience in the face of climate change. To preserve the coastal ecosystems in Karimunjawa, Indonesia, this study proposes an alternative spatial plan through micro-zonation analysis. The study conducted literature reviews and field surveys to collect data and developed recommendations for the current spatial plans through spatially, descriptive statistics, and comparative analysis. The findings show that sea surface temperatures in Karimunjawa and Kemujan Island have increased by 1–2 ℃. Stress levels were found for coral reefs at the bleaching warning position for all Karimunjawa Island marine areas, including Kemujan Island. Legon Lele and Tanjung Gelam were found to have suspended sediment traces and indications of heavy metal contamination, making them the research focus. The Karimunjawa micro-zonation boundaries were obtained, especially in the Legon Lele and Tanjung Gelam areas, with an area of 640.63 and 817.45 ha, respectively. The proposed micro-zonation for Karimunjawa National Park zoning refers to watersheds-sedimentary cells, making it an example of implementing integrated coastal management (ICM) spatial boundaries in Karimunjawa and other nations.
This research was carried out in Lampuuk District, Nanggroe Aceh Darussalam Province. The main aims of this research are to analyze the impacts of the tsunami on landforms, especially their morphological aspects, to analyze the change of water quality and to predict the time required to recover the water quality to initial condition. Pedo-geomorphological approach has been applied in this research in order to evaluate the impacts of tsunamis to each geomorphological unit. Geo-electrical sounding and groundwater flow mapping have been conducted to understanding groundwater depth and potential water contaminant flow. Results show that tsunami caused high impacts to water quality and soil. The salinity of soil reached to > 3000 μohms/cm. Time required to recover soil quality into initial condition is approximately 2 years. We estimated that the time needed for water quality recovering is approximately 5 years.
Indonesia is exposed to earthquakes, volcanic activities, and associated tsunamis. This is particularly the case for Lombok and Sumbawa Islands in West Nusa Tenggara, where evidence of tsunamis is frequently observed in its coastal sedimentary record. If the 1815 CE Tambora eruption on Sumbawa Island generated a tsunami with well-identified traces on the surrounding islands, little is known about the consequences of the 1257 CE tremendous eruption of Samalas on the neighboring islands, and especially about the possible tsunamis generated in reason of a paucity of research on coastal sedimentary records in this area. However, on Lombok Island, the eruption of the Samalas volcano produced significant volumes of pyroclastic flows that entered the sea in the North and East of the island. These phenomena must have produced a tsunami that left their traces, especially on Sumbawa Island, whose western coastline is only 14 km away from Lombok’s eastern shore. Therefore, the main goal of this study is to investigate, find evidence, and determine the age of marine-origin sediments along the shore of the Alas Strait, Indonesia. We collected and analyzed samples of coral and seashells from marine deposits identified along the west coast of Sumbawa, i.e., in Belang Island and abandoned fishponds in Kiantar Village, in order to identify the sources and the occurrence period of these deposits events. Based on the radiocarbon dating of coral and seashell samples, we concluded that none of the identified marine deposits along the western coast of Sumbawa could be related chronologically to the 1257 CE eruption of Samalas. However, possible tsunami deposits located in Belang Island and abandoned fishponds in Kiantar Village yielded 4th century CE, 9th century CE, and 17th century CE. We also conclude that past large earthquakes triggered these tsunamis since no known volcanic eruption occurred near the Alas Strait at that time that may have triggered a tsunami.
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The district of Kajhu Perumnas, located north-east of Banda Aceh, is a flat area that allowed wave penetration far inland, until 5 km in some places. The topography was locally modified by the turbulent wave front and then buried by a layer of sediment translocated from the beaches and seafront dunes. In order to better understand the link between wave dynamics and sediment facies in that particular setting, the tsunami deposits were studied in the light of direct and indirect evidence concerning the number and behaviour of the waves involved. The respective roles of run up and backwash on the sedimentary signature were also studied. Near the sea, the deposits were found to be coarse and ungraded, whereas inland the frequency of stratified normally graded sequences increases. Once the water had completely retreated, the entire area affected by the tsunami, which is covered by unconsolidated sands, became prone to active wind deflation caused by an increase in wind speed. On flat zones located inland, the deflation caused an accumulation of sand, which now forms fields of small dunes that are rapidly growing in size Measurements carried out in August 2005 have estimated that ~1100 m3·ha– 1 of coastal sediment was transported and deposited inland.During the year following the event, the displacement by runoff back towards the sea of sediment that was initially spread inland by the tsunami wave train has been feeding the longshore drift. It contributed to beach progradation and the displacement of the coastline towards the sea (Fig. 1) at a rate of 150 m to 500 m during the year following the event.
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