Wyniki wyszukiwania - BazTech

1

Spatial Analysis of Coastal Vulnerability Index to Sea Level Rise in Biak Numfor Regency (Indonesia)

Rumahorbo Basa T., Warpur Maklon, Tanjung Rosye H. R., Hamuna Baigo

Journal of Ecological Engineering

|

2023

|

Vol. 24, nr 3

113--125

EN

Assessing the vulnerability of coastal areas is important in evaluating impact of sea level rise due to global climate change. This study aimed to spatially analyze and map the vulnerability level of the Biak Numfor Regency’s coastal area on Biak Island to the threat of sea level rise. The study area is limited to 500 m from the coastline and is divided into 383 grid cells. The Coastal Vulnerability Index (CVI) method was used to map the level of vulnerability of coastal areas based on four coastal geological variables (coastal elevation, coastal slope, geomorphology, and shoreline change) and three ocean physical process variables (tidal range, average significant wave height, and relative sea level rise). The results showed that the coastal areas of Biak Numfor Regency, belonging to the low, medium and high-risk vulnerability categories, were 77,685.63 km (32.18%), 159,084.38 km (65.74%), and 5,024.96 km (2.08%), respectively. The variables that contribute significantly to the level of vulnerability are coastal elevation, coastal slope, coastal geomorphology, and shoreline changes due to abrasion compared to tidal range, significant wave heights, and sea level rise rates. Vulnerability studies of other variables that can contribute to the vulnerability of coastal areas are needed, such as socio-economic variables and the impact of human activities on changes in the coastal environment, to obtain a comprehensive CVI value in supporting coastal mitigation planning efforts against sea level rise disasters so that they are more focused.

2

Detection of Shoreline Changes due to Abrasion and Accretion Using Landsat Imagery – A Case Study in the Coastal Areas of Supiori Regency, Indonesia

Rumahorbo Basa T., Warpur Maklon, Hamuna Baigo

Ecological Engineering & Environmental Technology

|

2023

|

Vol. 24, iss. 7

161--171

EN

Shoreline changes have become a serious problem in all coastal areas worldwide. This study aimed to detect shoreline changes and analyze the shoreline change rate caused by abrasion and accretion in the coastal area of Supiori Regency, Indonesia. Landsat 8/9 imagery was used to determine the position of the coastline in 2013 and 2023. The shoreline movement (Net Shoreline Movement) and the shoreline change rate (End Point Rate) were analyzed using the Digital Shoreline Analysis System installed on ArcMap software. The results of this study indicate that there has been abrasion and accretion where there are several very significant locations. The maximum distance of the shoreline movements due to abrasion and accretion occurred in the Supiori Selatan District as far as -67.15 and 92.86 m, respectively. The average shoreline movement caused by abrasion ranges from -11.37 to -13.59 m and from 9.75 to 15.64 m in the case of accretion. From the comparison of abrasion and accretion, only the Kepulauan Aruri District has a positive value (dominant accretion), while the other four districts have a negative value (dominant abrasion). The shoreline changes rates in the study area caused by abrasion and accretion ranged from -1.22 to -1.46 m/yr and 1.05 to 1.68 m/yr, respectively. Abrasion and accretion in the study area are predominantly caused by natural factors such as waves, currents, and river flows, as well as caused by non-natural factors mainly due to human activities. Information on shoreline changes in the study area is an important aid for stakeholders involved in coastal area management. Therefore, planning, strategies, and mitigation efforts are urgently needed to anticipate increased coastal erosion and possible negative impacts.

3

Using Allometric Equations to Estimate Mangrove Biomass and Carbon Stock in Demta Bay, Papua Province, Indonesia

Indrayani Ervina, Kalor John Dominggus, Warpur Maklon, Hamuna Baigo

Journal of Ecological Engineering

|

2021

|

Vol. 22, nr 5

263--271

EN

The mangrove ecological services as carbon sinks and storage are very useful in the efforts to mitigate global warming and climate change. In this study, the above and below-ground biomass, carbon stock, as well as carbon sequestration by the mangroves in Demta Bay, Papua Province, Indonesia were estimated. Allometric equations were used to determine the mangrove biomass in 36 observation plots. The biomass value was used to determine carbon stock and estimate carbon sequestration. Nine mangrove species were found in Demta Bay, with the contribution of mangrove species to biomass (AGB and BGB) in the following order: Rhizophora apiculata > Rhizophora mucronata > Bruguiera gymnorhiza > Bruguiera cylindrica > Heritiera Littoralis > Xylocarpus molucensis > Rhizophora stylosa > Avicennia marina > Sonneratia caseolaris. The average mangrove biomass was estimated at 174.20 ± 68.14 t/ha (AGB = 117.62 ± 45.68 t/ha and BGB = 56.58 ± 22.49 t/ha). The carbon stocks in mangroves at the Ambora site were higher than the Tarfia and Yougapsa sites, averaging 123.57 ± 30.49 t C/ha, 81.64 ± 25.29 t C/ha, and 56.09 ± 39.03 t C/ha, respectively. The average carbon stock in the mangrove ecosystem of Demta Bay is estimated at 87.10 ± 34.07 t C/ha or equivalent to 319.37 ± 124.92 t CO2 e/ha. The results of this study indicate that the mangrove ecosystem in Demta Bay stores quite high carbon stocks, so it is necessary to maintain it with sustainable management. Therefore, climate change mitigation is not only done by reducing the carbon emission levels but also needs to be balanced by maintaining the mangrove ecosystem services as carbon sinks and sequestration.