Coast Of Sumatra Research Articles

The 2004 Tsunami Impact on Andaman & Nicobar Islands: Consequences and Future Way Forward

The 2004 Indian Ocean tsunami, caused by a powerful undersea earthquake off the coast of Sumatra, resulted in unprecedented destruction across several coastal regions. The Andaman & Nicobar Islands, located near the epicenter, suffered significant loss of life, displacement, and environmental degradation. This paper provides a comprehensive analysis of the tsunami’s impact on the Andaman & Nicobar Islands, detailing the immediate effects, long-term consequences, and rehabilitation efforts. The paper also explores the economic, social, and psychological ramifications of the disaster, particularly on indigenous communities. Looking ahead, it emphasizes the importance of sustainable development, community-based disaster preparedness, and ecosystem restoration to build resilience in the region. The proposed way forward focuses on developing infrastructure that is disaster-resilient, improving disaster management systems, and empowering indigenous communities in rehabilitation efforts to ensure long-term recovery and resilience.

Analysis of Social Perspectives in Reconstructing the History of Urbanization in Medan City

Urbanization is considered to be an ingrained social phenomenon in various large Indonesian cities, characterized by rapid urban population growth and drastic changes in social, economic and environmental structures. Urbanization in Indonesia shows a rapid increasing trend over the last few decades. Medan City, as one of the main urban centers in North Sumatra, has not escaped the impact of significant urbanization. Along with rapid economic and demographic growth, the city has experienced a major transformation in various aspects of city life. This research aims to identify the history of urbanization in Medan City from a social perspective. The research method used is a qualitative descriptive method through literature study sourced from journals, scientific articles, books and other relevant sources. The results of this research show that urbanization in Medan City has been going on for a long time. Strategically located on the east coast of Sumatra and between the confluence of the Deli River and the Babura River, Medan has vital trade access to the Malacca Strait. Especially in the period 2012 to 2022, the increase in population in Medan City occurred in almost all sub-districts. Of the 21 sub-districts, 17 sub-districts experienced an increase in population of more than 10%. Only one sub-district experienced a decline in population, namely Medan Baru Sub-district by 7.89%. The high level of urbanization in the city of Medan is generally caused by several factors, such as strategic location, the presence of natural resources (SDA), and supporting natural conditions. Meanwhile, the impact on society's social life includes rapid population growth, changes in societal structure, and social and cultural dynamics.Keywords: History, Urbanization, Social, Medan City

The Development of Islamic Maritime Civilization on the East Coast of Sumatra during 17th-18th Centuries

The Development of Islamic Maritime Civilization on the East Coast of Sumatra during 17th-18th Centuries

Regional Lineament Pattern and Morphotectonic Analysis: The Investigation of Geological Structures and Present-Time Relative Tectonic Activity in the Tin Granite Area of Belitung Island, Indonesia

Belitung Island is located on the East Coast of Sumatra and is the southernmost extension of the Southeast Asian granite belt. Despite the flat terrain of the island, numerous granite outcrops provide insight into the past tectonic activities that caused the uplift in the region. This study analyzes the current state of Belitung's tectonic activity by examining its morphotectonic index and lineament pattern. A National Digital Elevation Model (DEMNAS) dataset with a resolution of up to 8.1 m will be used to assess the geological patterns and relative tectonic activity from the surface. The relationship between the regional lineament system and morphotectonic quantification throughout the landforms of Belitung Island will also be considered. The modified Segmented Tracing Algorithm (m-STA) technique extracted the lineament features. The Index of Relative Active Tectonic (IATR) was calculated by averaging several morphotectonic indices, such as asymmetry factors (AF), stream-length index (SL), mountain-front sinuosity (Smf), and valley floor width-height ratio (VF) factors, to quantify the relative tectonic activity of the area. The combination of the two methods shows that Belitung is currently experiencing relatively weak tectonic activity compared to the past. This is supported by the surface appearance, which is mainly composed of lowlands. Several granite outcrops and highlands are aligned along the NW-SE and NE-SW directions, corresponding to the main geological structures in the area.

Genetic diversity and structure of Hopea bilitonensis, an endemic Dipterocarp from Belitung Island, Indonesia

Hopea bilitonensis Ashton (Dipterocarpaceae) is a small tree endemic to some islands on the east coast of Sumatra, particularly Belitung Island, Indonesia, and the northwest of Malaysia. Forest fragmentation and degradation in Belitung Island could affect population and genetic diversity of this species. The main objectives of this study are to examine genetic diversity and structure of H. bilitonensis on Belitung Island, Sumatra. Multiplexed ISSR genotyping by sequencing (MIG-seq) is used for genotyping and SNP detection. Genetic diversity and structure were determined using STRUCTURE analysis. We found that genetic diversity of H. bilitonensis is lower in seedlings than in juvenile and mature individuals. In contrast, inbreeding coefficient is lower in mature individuals than in the seedlings and juveniles. Genetic clusters (K=3) are detected in the early regeneration stages. These genetic structure separates the population of seedling and juvenile stages more clearly than in the mature individuals. Representation of these genetic clusters is essential when collecting propagation material for ex-situ conservation and establishing new populations of this threatened species to ensure its sustainability.

Integrated water management practice in tropical peatland agriculture has low carbon emissions and subsidence rates

Hydrological management in the use of peatland for agriculture is the backbone of its sustainability and a critical factor in climate change mitigation. This study evaluates the application of an integrated water management practice known as the “Water Management Trinity” (WMT), implemented since 1986 on a coconut plantation on the eastern coast of Sumatra, in relation to CO2 emissions and subsidence rates. The WMT integrates canals, dikes, and dams with water gates to regulate water levels for both coconut agronomy and the preservation of the peat soil. The WMT has successfully regulated and maintained an average yearly water table depth of −45 to −51 cm below the surface. The methodology involved a closed chamber method for measuring soil CO2 flux using a portable Infrared Gas Analyzer, conducted weekly over a six-month period to cover dry and rainy season at bi-modal climate condition. Subsidence measurements have been ongoing from 1986 to 2022. The results show bare peat soil has heterotrophic respiration CO2 emissions of 7.77 t C–CO2 ha−1 yr−1, while in coconut plantations 7.99 t C–CO2 ha−1 yr−1, similar to emissions in mineral soils. Autotrophic respiration leads to the overestimation of CO2 emissions on peatland and accounts for 212–424% of the total emissions. The cumulative subsidence from 1986 to 2022 is −56.3 cm, with a soil rise of +0.8 cm in 2022, indicating a flattening rate of subsidence. This is characterized by an increase in bulk density at the surface from 0.072 to 0.144 gr/cm3, with approximately 81% of the subsidence being due to compaction. The statistical analysis found no relationship between water table depth and CO2 emissions, indicating that water table depth cannot be used as a predictor for CO2 emissions. In summary, peatland agriculture has a promising future when managed sustainably using an integrated hydrological management system.

A negative biological Indian Ocean dipole event in 2022

The biological dipole mode index (BDMI) showed a negative biological Indian Ocean dipole (BIOD) event occurred in the Equatorial Indian Ocean with the corresponding BIOD index BDMI(Ratio) at − 0.31 in October 2022. The chlorophyll-a (Chl-a) ratio (or Chl-a anomaly) between Chl-a in October 2022 and October Chl-a climatology from the Visible Infrared Imaging Radiometer Suite (VIIRS) showed negative dipolar features with the depressed and enhanced Chl-a in the east and west IOD zones, respectively. During this negative BIOD event, Chl-a ratio dropped to ~ 0.4–0.5 in the offshore region of the west Sumatra Coast in the east IOD zone, while it increased to ~ 1.5–1.6 in the northern west IOD zone. Temporal variations of the longitudinal averaged Chl-a ratio and the 20 °C isothermal (ISO20) depth anomaly generally coincided and collocated with each other. The positive and negative BIOD events in 2019 and 2022, respectively, were attributed to the nutrient dynamics driven by the physical dynamics in these two phases of IOD events. In the negative BIOD event in 2022, the depressed Chl-a in the east IOD zone was attributed to low sea surface nutrient levels due to dampened upwelling and deepened thermocline, while anomalously high Chl-a in the west IOD zone were driven by higher sea surface nutrient concentrations caused by the surface water divergence and shoaling thermocline.

Sistem Mitigasi Dan Adaptasi Bencana Dalam Menghadapi Potensi Acaman Mentawai Megathrust Sebagai Inovasi Teknologi Edukasi Kebencanaan

The urgency of this research is to provide an understanding and education system for disaster adaptation mitigation to communities living on the coast of West Sumatra and outside West Sumatra so that people are smarter and ready to face situations that occur when a disaster strikes. In this way the risk of greater loss of life can be avoided. The aim of this research is to produce a geographic educational information system for disaster adaptation mitigation in dealing with the potential threat of the Mentawai Megathrust based on WebGIS. The method used is four-D, namely Define, Design, Development, and Disseminate. The process of presenting the model is carried out through the define stage, namely finding data about predicted locations and impacts of disasters. The second stage of design is creating a geographic mitigation and disaster adaptation educational information system application design which contains evacuation route map designs, shelter location map designs and independent evacuation animations. The third stage of development is developing the system after testing and implementing the system, the disseminate stage is socializing the use of the application to people living on the coast of West Sumatra and disseminating research results through research results books.

Understanding sea wave height conditions in sumatra waters

Ocean waves play a crucial role in influencing a wide range of marine and fisheries activities. In this research study, we aim to analyze the climatological conditions of sea wave heights in Sumatran waters over a span of 83 years (1940-2022). We utilize three-dimensional Copernicus numerical model simulations to examine seasonal patterns of sea wave heights and assess the likelihood of extreme wave events. Our findings reveal that high waves, reaching heights of 4-5 meters, are predominantly observed in the western and southern zones off the coast of Sumatra, particularly in the vicinity of smaller islands. Conversely, in enclosed or semi-enclosed waters, such as the lee side of Sumatra and the Malacca Strait, sea wave heights tend to be relatively lower. Seasonally, our study indicates that extreme wave heights are more likely to occur during the west season as opposed to the east season. This research provides valuable insights into the dynamic ocean wave conditions in Sumatran waters, which can have significant implications for various sectors reliant on the ocean environment.

Geological Science and the Making of Colonial Oil Frontiers on the East Coast of Sumatra, 1890-1930

In the early 20th century, the Dutch Empire emerged as a prominent oil producer internationally, with the Netherlands East Indies leading the way in petroleum production. The colonial petroleum industry’s success was bolstered by scientific and technological advancements that streamlined the oil exploitation process. Geology played a critical role as a scientific tool that facilitated the conquest of landscapes and crude oil control along Sumatra’s east coast. The study of geology supported the colonial oil politics, leading to a new era of oil mining exploitation through robust economic partnerships between the Dutch colonial government and private oil companies. This paper aims to explore the link between Dutch colonial scientific agency and the establishment of an oil extraction territory that transformed the natural environment and social conditions on the east coast of Sumatra, from Aceh to Palembang.

The dynamic economic landscape of Bengkulu: A comprehensive analysis and its implications for sustainable growth across sectors

This research presents a comprehensive examination of the economic climate of Bengkulu, a province on the southwest coast of Sumatra, Indonesia. Utilizing a mixed-methods approach, this study combined qualitative and quantitative data collected from a purposive sample of 135 participants, including local business owners, government officials, economic analysts, and residents. This study investigates various economic indicators such as income levels, employment statistics, and sectoral contributions to the regional economy. Employing a hypothetical regression analysis, this study explores the connections between sectoral contributions, employment rates, growth rates, and consumer spending in key sectors such as agriculture, services, mining, and retail and their impact on regional Gross Domestic Product (GDP) growth. The findings reveal a dynamic economic landscape with significant growth observed in certain sectors while also highlighting challenges such as economic inequality and the need for diversified economic strategies. This study not only offers insights into the current economic status and trends in Bengkulu, but also provides critical information for policy-making and strategic planning aimed at promoting sustainable and inclusive economic growth in the region.

Diurnal cycle of precipitation over coastal sea and small islands in the eastern region of Sumatra including season and Madden Julian Oscillation signatures

The Barisan Mountains influence atmospheric circulation in Sumatra and surrounding areas. Yet, precipitation patterns in eastern Sumatra, especially along the coast, are poorly understood. This study examines diurnal precipitation cycles in coastal seas and small islands of eastern Sumatra, utilizing 2015–2021 IMERG Version 06 rainfall data, data from 21 island rain gauges, and ERA5 reanalysis data to assess precipitation through three parameters: precipitation amount (PA), precipitation frequency (PF), and precipitation intensity (PI). The diurnal cycle of PA and PF is more pronounced than PI. Distinct diurnal precipitation patterns emerge between coastal seas and small islands despite their shared east coast location on Sumatra. Coastal seas exhibit early morning precipitation peaks forming Sumatras squall, influenced by offshore Sumatra and Malay Peninsula propagations, accentuated by high wind speeds. Coastal shape, land topography, and Sumatra's island size also impact coastal sea precipitation. On small islands, rainfall peaks earlier (12:00–15:00 LT) with gentle winds, indicating local convection due to land heating dominance. In addition, the low-amplitude topography of Bangka and Belitung islands also increase rainfall, so PA and PF are higher on these islands than on other small islands. Seasonal analysis reveals rising PA and PF near the equator during the dry southeast monsoon (SEM), linked to the dominant Inter-Tropical Convergence Zone (ITCZ). Conversely, areas like Bangka, Belitung, and the South Coast of Sumatra, farther from the equator, witness higher PA and PF during the wet northwest monsoon (NWM). The South Coast of Sumatra saw a substantial PA increase during NWM, about 60% higher than the southeast dry period. Despite varying cycle amplitudes, peak times for PA and PF remain consistent across seasons. MJO analysis during NWM highlights heightened PA and PF amplitudes across eastern Sumatra, especially over equator-adjacent coastal regions and small islands, reaching 40–70% above non-active MJO phases. In summary, this research examines diurnal precipitation variations in coastal seas and small islands of eastern Sumatra, enhancing understanding of regional climate patterns and factors impacting precipitation cycles in the area.

Socio-Economic Changes in Coastal Fishermen of West Sumatra as the Impact of Coastal Abrasion

This study is about the socio-economic changes of fishermen on the west coast of Sumatra as a result of coastal abrasion. The purpose of this study is to explain the fishermen's struggle in dealing with abrasion and rebuilding the economy back to normal. The area on the west coast of Minangkabau facing the Indian Ocean is inhabited by people living on the coast. The west coast of Sumatra is very prone to coastal abrasion, because it faces the Indian Ocean which has high waves and big waves, so that coastal erosion always occurs in several areas, including Agam Regency, Padang Pariaman Regency, Padang City, and Pesisir Selatan Regency. In general, the west coast of Sumatra is a maritime-oriented residential area, both fishermen and other maritime cultural-oriented people. The nuances of their economic life are very dependent on the sea, such as fishing, processing of dried fish, sea transportation, port activities, shipping and trade. Ideally, all activities of fishing communities run smoothly according to the available natural and human resources. The method used is the historical research method, which includes heuristic (data collection), criticism, interpretation, and historiography. Several fishing settlements on the west coast of West Sumatra experienced coastal abrasion. As a result, they were forced to be moved to other settlements, so they could avoid the beach abrasion disaster. Automatically their livelihood changes and income also changes, resulting in social change. Those who initially worked as fishermen were forced to switch to the agricultural economy, because their settlement was far from the coast.

Diversity of brachyuran crab (Crustacea: Decapoda) in West Coast of North Sumatra, Indonesia

The west coast of Sumatra is a water area with a high potential for fishery products. One of the areas, (i.e., Sibolga City) is a national fishery center in Indonesia. The high productivity of these waters is supported by the presence of keystone species in nature, one of which is the crab (infraorder Brachyura). This study aims to record brachyuran species on the west coast of Sumatra that are still unknown. Sampling was conducted in Central Tapanuli Regency and Sibolga City using convenience sampling. The samples obtained were 50 individuals. Based on the identification, the sample consisted of 22 species belong to 6 families. Fourteen species is first recorded in this region, and five species are new records in Indonesia.

Local Wisdom of Nias Island Community Facing the Earthquake and Tsunami

This article describes the forms of local wisdom of the people of Nias Island in dealing with the natural disasters of the earthquake and tsunami. Nias Island, which is located on the west coast of Sumatra, is one of the islands included in the Eurasian plate fault in the Indian Ocean, which has periodically shaken due to earthquake shocks, which are sometimes accompanied by tsunami waves. To anticipate the impact of the earthquake and tsunami, the Nias community has several of local wisdom by building traditional houses to live in hilly areas that are located far from the seaside.

Socio-Economic History of the Mentawai Islands in West Sumatra Province

This study describes the socio-economic history of the population in the Mentawai Islands Regency, West Sumatra, Indonesia. Residents of the area engage in different socio-economic activities. The purpose of this study is to explain the socio-economic life of the majority in agriculture. The research methods used are historical methods, for example, heuristics, criticism, interpretation, and historiography. Mentawai Island residents have been active in the world of agriculture and plantations since the 16th century. At the time when Dutch traders arrived there, the Mentawai Islands were already in contact with ethnic groups who came from the west coast of Sumatra and the surrounding islands.

The Atmospheric and Oceanic Processes on Thermal Front Variability over the Java Sea

The Java Sea is influenced by various atmospheric and oceanographic factors such as monsoon winds and the inflow of water from adjacent seas, thus leading to the formation of thermal fronts. In this research, the atmospheric process over the thermal front was estimated by using sea surface temperature (SST) gradient and crosswind-SST gradient calculation based on the GLORYS12V1 monthly SST data from Copernicus Marine Service (CMEMS) and the ERA5 monthly surface wind data from European Centre for Medium-Range Weather Forecasts (ECMWF) for 27 years (from 1993 to 2019). Moreover, the oceanic process was determined from the volume transports of three major channels surrounding the Java Sea, which are Karimata Strait, Sunda Strait, and the eastern boundary of the Java Sea. Based on the annual variance analysis, there are four main thermal front areas, such as Northern Java Coast (NJC), Eastern Sumatra Coast (ESC), Western Borneo Coast (WBC), and Eastern Borneo Coast (EBC). The annual variation of the thermal front over the ESC, WBC, and ESC has two peaks in March and October, while the NJC thermal front area has three peaks in March, July, and November. This study results that the thermal front activities over the NJC, WBC, and EBC are significantly correlated to the wind stress curl over those areas, with a coefficient correlation of about 0.62, -0.92, and -0.73, respectively. In addition, the increase in thermal front activity over the NJC area is controlled by negative wind stress curl with no lag time, while the WBC and EBC areas are controlled by positive wind stress curl with a lag time of 1 month (wind stress leads). On the other hand, the thermal front activity over the ESC area is closely related to southward volume transport from the Karimata Strait, with a correlation coefficient of -0.74 and a lag time of 2 months (volume transport leads).

The Diurnal Cycle of Rainfall and Deep Convective Clouds Around Sumatra and the Associated MJO‐Induced Variability During Austral Summer in Himawari‐8

AbstractThe effects of the diurnal cycle and large‐scale atmospheric disturbances dominate rainfall and cloud variability in the Maritime Continent. This study examines the modulation of the Austral Summer diurnal cycle by the Madden–Julian Oscillation (MJO) using cloud populations through precipitation and deep convective cloud derived from satellite measurements. Using Rainfall Potential Areas from Himawari‐8 Advanced Himawari Imager as a proxy for deep convection, our analysis shows that convective clouds are present ∼55% of the time over land in Sumatra during the afternoon and night. Cloud signatures reveal semi‐diurnal structures of deep convective clouds off the West Coast of Sumatra. In contrast, the East Coast exhibits explicit sea‐ward propagation patterns of deep convective controlled by the coastal effects around the Strait of Malacca and Java Sea, together with the influence of synchronized diurnal forcing between islands. We show that the MJO drives the enhanced convective phases, changing the cloud top type distribution, moisture convergence, and moisture transport over the equatorial Indian Ocean. The cold cloud area also increases during the MJO active phases, which is linked to frequent deep convective cloud development near the mountain ranges of Sumatra and the adjacent ocean. The analyses of cloud variations based on the rainfall potential areas and cloud top type provide evidence of the effects of convective processes on the diurnal cycle of ice and water vapor distribution in the troposphere.

Machine learning-based spatial data development for optimizing astronomical observatory sites in Indonesia.

Astronomical observatory construction plays an essential role in astronomy research, education, and tourism development worldwide. This study develops siting distribution scenarios for astronomical observatory locations in Indonesia using a suitability analysis by integrating the physical and atmospheric observatory suitability indexes, machine learning models, and long-term climate models. Subsequently, potential sites are equalized based on longitude and latitude zonal divisions considering air pollution disturbance risks. The study novelty comes from the integrated model development of physical and socio-economic factors, dynamic spatiotemporal analysis of atmospheric factors, and the consideration of equitable low air-pollution-disturbance-risk distribution in optimal country-level observatory construction scenarios. Generally, Indonesia comprises high suitability index and low multi-source air pollution risk areas, although some area has high astronomical suitability and high-medium air pollution risk. Most of Java, the east coast of Sumatra, and the west and south coasts of Kalimantan demonstrate "low astronomical suitability-high air pollution risk." A total of eighteen locations are recommended for new observatories, of which five, one, three, four, two, and three are on Sumatra, Java, Kalimantan, Nusa Tenggara, Sulawesi, and Papua, respectively. This study provides a comprehensive approach to determine the optimal observatory construction site to optimize the potential of astronomical activities.

Multi-metals analysis in sediment of the North Sumatra coast, Indonesia: The environmental status

This study aims to analyze multi-metals in marine sediment to provide the relative nature of metal concentrations. Sediment samples were collected in representative coasts of natural and more developing zones. The Sequential Extraction method was used to treat four metal associated hosts determined using the ICP-OES. Geo-accumulation index, Enrichment Factor and Principal Component analysis were used to evaluate. The metal concentrations varied and most of them appeared to show a gradual decrease from east, west to the isle coasts. The coastal environment has been recognized to contain non-residual associated metals suggesting the influence of anthropogenic metal input. These bioavailable fractions also show gradual decrease from the East coast to West and Isle coast. The environmental assessment reveals that most of these areas were categorized as unpolluted and concentration of some elements west and isle coast are relatively close to those of nature sediment.