Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Journal of Ecological Engineering

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Biak Island

Sortuj według:

Ogranicz wyniki do:

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

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.

The Impact of Tsunami on Mangrove Spatial Change in Eastern Coastal of Biak Island, Indonesia

Hamuna Baigo, Kalor John Dominggus, Tablaseray Vivia Elvanny

Journal of Ecological Engineering

2019

Vol. 20, nr 3

1--6

This study was conducted to find out how large was the impact of the tsunami incident of 1996 on the mangrove spatial change and also to understand the distribution and level of mangrove density before and after tsunami in Biak Island (Oridek District and East Biak District), Biak Numfor Regency, Indonesia. In order to determine the condition of mangrove before tsunami, landsat 5 TM satellite image acquisition of July 6, 1994 and landsat 7 ETM+ satellite image acquisition of August 31, 2000 were used. The information about the distribution and extent of mangroves was obtained by analyzing the spectral values based on color composite image (RGB 453) and NDVI analysis. Overlay map of the result satellite image interpretation was used to learn the change of mangrove spatial extent area due to tsunami. The result showed that the mangrove area before the tsunami was 286.83 Ha (high density 36.63 Ha, medium density 140.60 Ha and small density 109.60 Ha), meanwhile the mangrove extent area after the tsunami was 102.51 Ha (high density 24.39 Ha, medium density 22,86 Ha and small density 55.26 Ha). The mangrove conditions before tsunami were crucial to the impact of mangrove area degradation directly. The change of mangrove spatial extent into two districts after tsunami occurred in 1996 amounts to 184.32 Ha, which it approximately 202.50 Ha mangrove being lost and the addition of mangrove in the new area are 18.18 Ha. The tsunami that occurred in 1996 affected the coastal ecosystems, especially the mangrove ecosystems in Oridek District.