Analisis Geomorfologi dan Oseanografi untuk Identifikasi Tipologi Pulau Kecil: Studi Kasus di Kepulauan Maluku Utara dan Karimunjawa

Abstract

Small islands in Indonesia have a vital role in developing social, economic, cultural, environmental, and national sovereignty. On the other hand, small islands are also very vulnerable to natural disasters and dynamics and/or human activities. Threats and disasters that exist on small islands can vary according to the characteristics and typology of the island. This study aims to identify the typology of small islands by utilizing geospatial data to analyze geomorphological parameters, including morphology, materials, processes, and oceanographic parameters such as the presence of coral reef ecosystems. The method in this research is divided into three stages, namely pre-field, field measurement, and post-field. Pre-field activities include formulating the characteristics of each island typology through literature studies and geospatial processing data, such as DEM and SPOT 7 satellite imagery, for the preparation of thematic maps. The field stage includes terrestrial surveys in the form of aerial photography, profiling, validation of interpretation results, and diving. The post-field step is carried out to process and analyze the results of the terrestrial survey conducted at the field stage. The analysis was carried out descriptively based on the results of data processing to determine the typology of the islands studied in this research case study. Based on the parameters that have been set and the results of field measurements, the islands of Mare and Tidore in the North Maluku Islands and Karimunjawa and Kemujan islands in the Karimunjawa Islands are categorized as small volcanic islands. Meanwhile, Cemara Besar Island in the Karimunjawa Islands is a small atoll island. Threats to small volcanic islands can be in the form of geological disasters such as earthquakes, volcanic eruptions, and tsunamis. On small atoll islands, the threat that lurks is related to the lack of freshwater and the physical-morphological dynamics of the island, which is strongly controlled by hydro-oceanographic characteristics.Keywords: geospatial, small volcanic island, small atoll island, morphology, disaster. AbstrakPulau-pulau kecil di Indonesia memiliki peranan vital dalam pengembangan sosial, ekonomi, budaya, lingkungan, dan kedaulatan bangsa. Di sisi lain, pulau kecil juga sangat rentan terhadap bencana maupun perubahan alam dan/atau aktivitas manusia. Ancaman dan bencana yang ada di pulau kecil dapat berbeda-beda mengikuti karakteristik dan tipologi pulau tersebut. Penelitian ini bertujuan untuk melakukan identifikasi tipologi pulau kecil dengan memanfaatkan data geospasial dalam analisis parameter geomorfologi yang meliputi morfologi, material, proses, serta parameter oseanografi seperti keberadaan ekosistem terumbu karang. Metode dalam penelitian ini dibagi menjadi tiga tahapan, yaitu pra lapangan, pengukuran lapangan, dan pasca lapangan. Kegiatan pra lapangan meliputi perumusan karaketristik masing-masing tipologi pulau melalui studi literatur serta pengolahan data geospasial, seperti DEM dan citra satelit SPOT 7, untuk penyusunan peta tematik. Tahap lapangan meliputi survei terestris berupa pengambilan foto udara, profiling, validasi hasil interpretasi, dan penyelaman. Tahap pasca-lapangan dilakukan untuk mengolah dan menganalisis hasil survei terestris yang dilakukan pada tahap lapangan. Analisis dilakukan secara deskriptif berdasarkan hasil pengolahan data untuk menentukan tipologi pulau-pulau yang dikaji dalam studi kasus penelitian ini. Berdasarkan pada parameter yang telah ditetapkan dan hasil pengukuran lapangan, maka Pulau Mare dan Tidore di Kepulauan Maluku Utara serta Pulau Karimunjawa dan Kemujan di Kepulauan Karimunjawa dikategorikan sebagai pulau kecil vulkan. Sedangkan Pulau Cemara Besar di Kepulauan Karimunjawa merupakan pulau kecil atol. Ancaman bagi pulau kecil vulkan dapat berupa bencana geologi seperi gempabumi, erupsi gunungapi, dan tsunami. Pada pulau kecil atol, ancaman yang mengintai berkaitan dengan minimnya sumberdaya air tawar dan dinamika fisik-morfologi pulau yang sangat dikontrol oleh karakteristik hidro-oseanografi.Kata kunci: geospasial, pulau kecil vulkan, pulau kecil atol, morfologi, kebencanaan.

Shoreline Dynamics in the Very Small Islands of Karimunjawa – Indonesia: A Preliminary Study

“…Based on the formation process, the Karimunjawa Islands have several geological formations, namely the Karimunjawa Formation (pTk), Parang (Tmpv), alluvium; coastal deposits (Qa), and marl, clay, and limestone deposits (Tmpg) (Mutaqin et al, 2022). The research location, i.e., Cemara Kecil, Cemara Besar, Menjangan Kecil, and Menjangan Besar, comprises the Parang Formation with material in the form of tuffs, volcanic breccias, and lava deposits, as well as formations of a younger age composed of alluvium material and coastal deposits (Mutaqin et al, 2022). The dominant very small islands material consists of alluvium material and coastal deposits may increase the possibility of coastal erosion (Förster et al, 2019;Giardino et al, 2018;Muhammad & Mardiatno, 2022;Mutaqin, 2017).…”

“…Indonesia is one of the largest archipelagic countries in the world, with a total of 17,000 islands. Most of the islands in Indonesia have an area of less than 2,000 km 2 or can be classified as small islands and less than 100 km 2 , which are called very small islands (BIG, 2022;Mutaqin et al, 2022). Furthermore, very small islands are more vulnerable to disasters due to climate change (Koroy et al, 2017;Miller et al, 2020;Mutaqin et al, 2022;Mutaqin, Handayani, et al, 2021).…”

“…Most of the islands in Indonesia have an area of less than 2,000 km 2 or can be classified as small islands and less than 100 km 2 , which are called very small islands (BIG, 2022;Mutaqin et al, 2022). Furthermore, very small islands are more vulnerable to disasters due to climate change (Koroy et al, 2017;Miller et al, 2020;Mutaqin et al, 2022;Mutaqin, Handayani, et al, 2021). This is due to the condition of very small islands, which tend to have narrow, isolated landmasses and relatively limited resources (Hidayat et al, 2023;Wilkinson et al, 2016).…”

“…This is due to the condition of very small islands, which tend to have narrow, isolated landmasses and relatively limited resources (Hidayat et al, 2023;Wilkinson et al, 2016). In addition, the relatively flat topography of the very small islands also makes this area somewhat prone to disasters (Handayani et al, 2022;Hidayat et al, 2023;Mutaqin et al, 2022;Mutaqin, Handayani, et al, 2021).…”

“…Small and very small islands have great potential to be utilized for various purposes such as tourism, economic zone, and conservation (Miller et al, 2020;Mutaqin et al, 2022;Wisha et al, 2022;Yulianda et al, 2010). For example, the very small islands in the Karimunjawa Islands are essential tourist destinations in Jepara Regency (Fafurida et al, 2020;Pribadi et al, 2020).…”