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Journal : Ecotrophic, Journal of Environmental Science

PEMETAAN HABITAT PERAIRAN DANGKAL DI KAWASAN PADAT WISATA TANJUNG BENOA BALI MENGGUNAKAN DATA REMOTE SENSING I Wayan Gede Astawa Karang; I Wayan Matsya Deva Nagendra; I Dewa Made Khrisna Putra Astaman; I Gede Hendrawan
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 13 No 2 (2019)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (461.795 KB) | DOI: 10.24843/EJES.2019.v13.i02.p10

Abstract

Most of the tourism area are distributed along the coast that intersects directly with those that result in degradation of the ecosystem inside. The southern region of Bali is one region that have experienced rapid development of tourism activities. The expansion of the tourism area in Tanjung Benoa, Bali occurs to coastal areas and directly contact with underwater habitat such as coral reefs and seagrass beds which can damage the underwater ecosystem. The goal of this study is to map shallow water habitat in densely packed tourist areas Tanjung Benoa, Bali using remote sensing technique. Two satellites dataset (Sentinel-2A and Landsat 8) at different spatial and spectral resolutions were tested using Lyzenga algorithm. The maksimun likehood supervised classification is used to classify the underwater objects and accuracy test were then conducted to to evaluate the classification effectiveness. The results showed that there were three types of shallow water habitats in Tanjung Benoa coastal area, such as dead coral, seagrass, and sand. The accuracy test showed Sentinel-2A images with an overall accuracy of 80,00% and kappa accuracy of 59.27%. had higher accuracy than Landsat 8 images with an overall accuracy of 68,29% and kappa accuracy of 35,43%. Keywords: Remote Sensing; Shallow Water Habitat; Tanjung Benoa; Sentinel-2 A; Landsat 8
STUDY OF INTERNAL SOLITARY WAVES FEATURE EXTRACTION BASED ON STATIONARY WAVELET TRANSFORM BY SENTINEL-1A IMAGE IN LOMBOK STRAIT Chonnaniyah Chonnaniyah; Takahiro Osawa; I Wayan Gede Astawa Karang
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 13 No 1 (2019)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (368.693 KB) | DOI: 10.24843/EJES.2019.v13.i01.p04

Abstract

Stationary Wavelet Transform (SWT), mother function Symlet 4, shows an effective method for Internal Solitary Waves (ISW) feature extraction and four parameters (soliton numbers, first crest length, wavelength and propagation direction) estimation by Sentinel-1A C-band Synthetic Aperture Radar (SAR) imagery in Lombok Strait. The ISW feature can be distinguished from other features using the SWT noise reduction process and simple thresholding methods. ISW feature extraction results by SAR images can show ISW characteristics more clearly and can be used as a basis for obtaining ISW spatial-temporal distribution maps in the Lombok Strait. Our estimation results show that the arc-like type of ISW in the Lombok Strait propagated to the north of the sill with the detected soliton numbers are 2 solitons per packets with a wavelength about 3.20 km and the first crest length varies about 60.27 km near the Kangean Island with the propagation direction about 50.38 degree to the North.
SIMPANAN KARBON PADANG LAMUN DI KAWASAN PANTAI SANUR, KOTA DENPASAR Yoga Ibnu Graha; I Wayan Arthana; I Wayan Gede Astawa Karang
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 10 No 1 (2016)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (257.514 KB) | DOI: 10.24843/EJES.2016.v10.i01.p08

Abstract

Seagrass is one of the marine resources that considerably potential as a CO2 absorbent and functioned as carbon sinks in the oceans known as blue carbon. The result of carbon sequestration from the process of photosynthesis is stored as carbon stocks on seagrass tissue, or streamed to multiple compartments, such as sediment, herbivores and other ecosystems. This study aims to assess the potential for carbon stock storage in biomass on a tissue of seagrass in Sanur Beach coastal area. The observations of seagrass are included the seagrass type, seagrass stands, and measurement of environmental parameters. Then the sampling was conducted to obtain the value of seagrass biomass. The carbon stocks obtained through the conversion of biomass by using carbon concentration analysis of seagrass tissue and then carried a spatial distribution of carbon stocks. Types of seagrass found in Sanur Beach coastal area consist of eight species that are Enhalus acroides, Thalassia hemprichii, Halophila ovalis, Syringodium isoetifolium, Cymodocea serrulata, Cymodocea rotundata, Halodule uninervis and Halodule pinifolia. The result of the carbon stock seagrass in the bottom substrate is 60% greater than the carbon stock in the top substrate which is 40%. Seagrass covering 322 ha of Sanur Beach coastal area with a total potential carbon storage of 66.60 tons or 0.21 tons / ha. Seagrass key role as a carbon storage is on the bottom substrate tissue, and Enhalus acroides is a seagrass species that contributes the most to the carbon storage.
LAND SUBSIDENCE ANALYSIS OBSERVED BY PS-INSAR METHOD IN SOUTHERN PART OF BALI, INDONESIA (A CASE STUDY OF DENPASAR AND BADUNG AREA) Made Ryan Dwiputra; Takahiro Osawa; I Wayan Gede Astawa Karang
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 14 No 2 (2020)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2020.v14.i02.p11

Abstract

The utilization of groundwater unwise leads to problems for the life of sentient beings. The majority of environmental damage, mainly by groundwater utilization, is done or caused by human activities. The land subsidence, drought, seawater intrusion are some examples of damage caused by groundwater utilization unwise. This research aims to estimate land subsidence in southern Bali and analyze groundwater level reduction with land subsidence. The PS-InSAR technique to monitor land subsidence has been carried out in several regions in Indonesia and other countries. In this study, 38 images of Sentinel-1 taken from February 2015 to December 2018 are used to analyze the PS-InSAR technique. Land subsidence is found in Denpasar Utara district and Kerobokan district with deformation in -8 mm to -19 mm and velocity up to -5 mm/year. The utilization of groundwater causing land subsidence in Southern Bali is no significant relationship with coefficient correlation 0,16 and influenced only 2,7%. Limited groundwater data also influences the correlation between groundwater utilization and the occurrence of land subsidence. Keywords: Land Subsidence; Sentinel-1A; PS-InSAR; Southern Bali.
SHORELINE SENSITIVITY INDEX TO OIL SPILLS IN NUSA PENIDA MARINE PROTECTED AREA (MPA), BALI IPG Eka Handrayana Putra; Takahiro Osawa; I Wayan Gede Astawa Karang
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 15 No 1 (2021)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2021.v15.i01.p05

Abstract

The Shoreline Sensitivity Index(SSI) is one crucial aspect to know in protecting the coast from all threats, including oil spills. This study aims to determine the shoreline's sensitivity for oil spills based on several oceanographic parameters: shoreline type, tidal range, slope, and wave high in Nusa Penida, Map Protection Area (MPA). The weight overlay method was employed to apply the geographic information system (GIS). Each parameter component was scored as five categories before the weighted overlay. The shoreline sensitivity level of Nusa Penida island is divided into five categories: very low sensitive, low sensitive, medium sensitive, high sensitive, and very high sensitive. As the results, the SSI was categorized during the east monsoons (from June to August) and during the west monsoons (from December to February) is at a low sensitivity level to very high sensitivity. SSI during east monsoons there is about 60.05% (627.33 ha) in the medium, 9.39% (98.11 ha) in the high, and 2.39% (24.99 ha) in the very high sensitive. The SSI during the west season is about 78.16% (816.95 ha) with the medium, 19.43% (203.11 ha) with the high, and 2.39% (24.99 ha) with the very high sensitive. The difference in wave height during east and west monsoons greatly affects the sensitivity level of the Nusa Penida coastal area. However, sensitivity level in Jungutbatu and Lembongan Villages are not affected by the east or west monsoons.Keywords: Shoreline Sensitivity; GIS; Nusa Penida; Oil Spill.
ESTIMASI SIMPANAN KARBON PADA BIOMASSA MANGROVE DI TAHURA NGURAH RAI Ni Luh Putu Ratih Pravitha; I Wayan Gede Astawa Karang; Made Suartana
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 16 No 2 (2022)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2022.v16.i02.p08

Abstract

Mangroves contribute to mitigating climate change by storing carbon. As mangrove forests have a high rate of carbon sequestration and storage, carbon stock calculations are required to quantify the accumulation of carbon stored in a site to determine its involvement in decreasing greenhouse gas emissions. This study aims to estimate carbon storage at the Mangrove Information Center (MIC) by using an allometric calculation of the mangrove above-ground biomass data. Data collection was carried out on January 10-14, 2022 at the MIC, with an area of 322 ha. The method used is a 1000 meters line transect plot divided into 15 measuring plots in three mangrove ecological zones (front, middle, and back). Biomass data were taken in a non-destructive way based on measurements of the circumference girth at breast height (GBH) and the results were calculated using allometric. According to data analysis, the average total surface biomass of mangroves in MIC is 781.30 kg, with estimated carbon storage in MIC is 36,727 tons/ha. Overall, the total carbon stock in the stratum MIC is 11.826,253 tons. The highest estimated carbon storage is in Plot 9, which is 91,799 tons/ha, while the lowest estimated carbon storage is in Plot 2, which is 13,873 tons/ha. The high numbers of carbon storage from mangrove above-ground biomass are mostly found in the middle and front zones because of the very dense mangrove density. Keywords: mangrove; above-ground carbon estimation; climate change mitigation
RETRIEVAL OF SURFACE CURRENT FROM HIMAWARI-8 SEA SURFACE TEMPERATURE DATA AND PARTICLE IMAGE VELOCIMETRY METHOD Wati, Kadek Setiya; Osawa, Takahiro; Astawa Karang, I Wayan Gede
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 17 No 2 (2023)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2023.v17.i02.p08

Abstract

As human activity occurs at the surface, which is influenced by surface currents, understanding surface currents is crucial. Ocean currents are not solely caused by wind, but also of other factors, such as sea surface temperature. To obtain surface current data, BMKG used HF radar installed in several places, including Flores Sea. This location is significant because it has large ports and heavy crossing traffic. This study aims to analyse surface current data retrieve from Himawari-8 SST data by applied PIV algorithm. Using the PIV algorithm, a cross-correlation plane is generated by comparing two identically sized interrogation windows obtained from successive images. On 5 December 2022 in the Flores Sea, Himawari-8 SST data was employed to estimate sea surface currents every 10 minutes. Surface current motion varies widely from image to image. Western areas are dominated by westward currents, while central and eastern areas are dominated by eastward currents during daylight hours, and westward currents during the night. Synoptic wind affects surface current movement during those hours. Validation with observational data from the Labuan Bajo HF radar shows that the V component current estimation is better than the U component current estimation. This is particularly prevalent in the south and in areas close to the KAWA radar HF location. Keywords: Flores Sea; SST; Himawari-8; PIV; surface current
Co-Authors Abd. Rahman As-syakur Alexis Chappuis Anak Agung Istri Candra Kirana Anisa Dea Novianti Artha C. Rosevina Anak Ampun Astaman, I Dewa Made Khrisna Putra Astiti Ratnasari Astiti Ratnasari Azhar Muhammad Hanisa Brasika, Ida Bagus Mandhara Chonnaniyah Chonnaniyah Chonnaniyah, Chonnaniyah Cindi Ayu Lestari Cornelia Coraima Lazaren Dian Novianto Dwi Budi Wiyanto Dwi Nindra Saputra Eka Andiani, Anak Agung Elok Faiqoh Elvita Rahmani Fitra Cahya Prima Fumihiko Nishio Gede Dicky Pradipta Wedayana Gede Indra Putra Pratama Gede Surya Indrawan Gilang Pratama I Dewa Ayu Ratna Raksa Eka Putri I Dewa Nym. Nurweda P., I Gede Andika Wijantara I Gede Hendrawan I Gede Merta Yoga Pratama I Gede Mita Anjas Swara I Gusti Agung Bagus Wisesa Sastra I Gusti Agung Indah Mahasani I Gusti Bagus Sila Dharma I Gusti Bagus Sila Dharma I Kadek Dedy Antara Putra I Ketut Suta Negara I Made Ekayana I Nengah Jaya Nugraha I Nyoman Januarta Triska Putra I Putu Trisna Buana Putra I Wayan Arthana I Wayan Eka Dharmawan I Wayan Krisna Eka Putra I Wayan Krisna Eka Putra I Wayan Matsya Deva Nagendra I Wayan Matsya Deva Nagendra I Wayan Nuarsa I Wayan Nurjaya IDA AYU ASTARINI IPG Eka Handrayana Putra Irwan Jatmiko Jero Ketut Tri Ayu Lestari Kadek Bagus Padmaningrat Kadek Dwi Artama Kadek Setiya Wati Kholifatul Aziz Kuncoro Teguh Setiawan Kuncoro Teguh Setiawan Luh Made Chandra Luh Made Chandra Luh Putu Ayu Depi Nurcahyani Made Narayana Adibhusana Made Ryan Dwiputra Made Suartana Naila Makfiya Ni Kadek Martini Ni Luh Kade Paramita Kusuma Ni Luh Putu Ayu Sumarni Ni Luh Putu Ratih Pravitha Ni Luh Putu Ria Puspitha Ni Putu Eva Damayanti Nidzar Muhammad Rafly Nikmah Fitria Nuraini Nuryani Widagti Pande Ketut Cahya Krisnanta Arioka Putra Bagus Panji Pamungkas Putra, I Nyoman Giri Putu Bagus Angga Utama Putu Eka Tulistiawan Rony Clinton Sabil Al Alif Siti Rohani Syifa’ul Qolbiyatun Nisa Takahiro Osawa Takahiro Osawa Takahiro Osawa Takahiro Osawa Takahiro Osawa Takahiro Osawa Takahiro Osawa Takahiro Osawa Tulistiawan, Putu Eka Valenthio Sidauruk Wati, Kadek Setiya Widiastuti Karim Widiastuti Karim Widiastuti Widiastuti Widiastuti Widiastuti Yasa, Putu Kumara YASUHIRO SUGIMORI Yasuhiro Sugimori Yoga Ibnu Graha Yuli Naulita Yulianto Suteja