Mapping and Index Vegetation Analyses of Mangrove in Saparua Island, Central Moluccas

2TMapping and index vegetation analyses of mangrove in coastal areas of Saparua Island, Central Moluccas was conducted using Landsat 7/ETM+ satellite data acquired in April to May 2007. The results showed that the distributions of mangrove vegetation were concentrated in the north, south, and west of the region with the area of 218.88 ha (38.26%), 105.12 ha (18.38%), and 248.04 ha (43.36%), respectively. Total area of mangrove vegetation in this island was about 572.04 ha (5.72 kmP2P), or 3.49% of the island area. Vegetation indexes (NDVI) in the north, south, and west of the region were dominated by values of >0.7 (very high density)

Seasonal Variability of Light Absorption Coefficient of Surface Water

Absorption coefficient measurement can be used in estimating water quality, optical characteristic of water column, and marine bio-optical models. The purposes of this research were to determine values and variability of sea surface absorption coefficient in the northeastern Gulf of Mexico (NEGOM) based on various seasons. The data were collected in spring, summer, and fall seasons in 1999-2000 with AC-9 instrument. The spatial distribution of absorption coefficient showed that relatively high values were generally found along the run off Missisippi, Mobile, Chochawati, Escambia, Apalachicola, and Suwannee rivers, as well as Tampa Bay. Meanwhile, relatively low values were found in offshore region. This pattern followed the distribution pattern of chlorophyll and CDOM. Based on the local region comparison of spectral average value of absorption coefficient, we found a significant difference (α = 95%) among regions with the highest value in the run off of the Mississippi and Mobile rivers, and the lowest value in the offshore region. Comparison of spectral average value of absorption coefficient among seasons at the three primary wavelengths (blue=440 nm, green=510 nm, and red=676 nm) also showed a significant difference (α = 95%) with the highest value during the summer 1999 (Su-99) and the lowest value during the spring of 2000 (Sp-00). Absorption coefficient values were influenced by oceanographic factors that varied in every season such as wind, surface currents, upwelling, the location and speed of the Loop Current, and the river discharge of fresh water into the NEGOM

Dynamic of Sea Level Anomaly of Indonesian Waters

A trend in sea level rise as a result of global warming could be a threat to small islands and coastal areas in Indonesia. The objective of this study was to determine the trend and variability of mean sea level anomaly (MSLA) in Indonesian waters during the 20 years of observation. The data used in this study were monthly MSLA data obtained from the AVISO website (ftp://ftp.aviso.oceanobs.com). Supporting data were the Southern Oscillation Index (SOI) (http://www.gom.gov.au/climate/enso), Dipole Indian Mode (DIM) index (http://gcmd.nasa.gov/records/GCMD_Indian_Ocean_Dipole.html), and the Pacific Decadal Oscillation (PDO) index (http://research.jisao.washington.edu/pdo/). Eigth stations of Indonesian waters were selected to study the variability of MSLA. In general, MSLA variabilities of Indonesian waters had a seasonal pattern, positively correlated with the SOI index, and negatively correlated with DIM and PDO indexes. The partial correlation of DIM was more dominant in west of Sumatra (r=-0.52) and south of Java (r=-0.44), PDO was more dominant in the northern waters of Papua (r=-0.37) and Makassar Strait (r=-0.33), and SOI was more dominant in northern Papua (r=0.52) and less toward the west of Indonesian waters. Overall, the MSLA variability of Indonesian waters can be explained by the variabilities of SOI, DIM, and PDO indexes with the lowest value in Natuna waters by 12% (R2=0.12) and the highest value in the northern waters of Papua by 54% (R2=0.54). Interannual variabilities were observed during ENSO events (SOI<-10) along with the maximum value of DIM index resulted in the lowest value of MSLA. Meanwhile, the highest value of MSLA was found during La Nina events (SOI>10) in conjunction with a minimum value of DIM and PDO indexes. The average rate of sea level rise in Indonesian waters was 5.84 mm/yr, almost two times higher than the average rate of global sea level rise (3.2 mm/yr)

Variability and Spatial Distribution of Total Scattering Coefficients of Surface Water in Various Seasons

Variability and spatial distribution data of the total scattering coefficients ares useful in the development of bio-optical algorithms of ocean color satellite. The purpose of this study was to determine the variability and spatial distribution of the total scattering coefficient at 9 wavelengths (λ) in different seasons. Field data collection were conducted in the Northeastern Gulf of Mexico (NEGOM) of the spring , summer, and fall in 1999-2000 by using the ac-9 in-situ Spectrophotometer and restricted to coastal waters of 10 m isobath and offshore of 1000 m isobath. The data were filtered using the moving average method and tested with the Kruskal-Wallis. The results showed that the average value of the total scattering coefficients were significantly different among spring, summer, and fall. In general, the total scattering coefficients were relatively high, especially in the coastal waters near the mouth of the river each season and relatively low in offshore waters except during the summer that the total scattering coefficients were also relatively high in offshore watersdue to the intrusion of the Mississippi river flow toward offshore containing high nutrients that can promote the growth of phytoplankton in the offshore, suspended material and lower salinity jointly to increase the total scattering coefficients

Change Detection of Coral Reef Habitat Using Landsat Imagery in Morotai Island North Maluku Province

Scientific information on coral reef habitat changes of Morotai island is very limited to none. This study aimed to detect the change of coral reef habitats between 1996 and 2013, using Landsat imagery integrated with field data in 2012. The research was conducted in the coral reef ecosystem of Morotai Island in North Maluku province. Change detection analyses were conducted using supervised classifications and transformation depth invariant index (DII), with five habitat classes i.e., mixed-habitat, coral, seagrass, sand, and rubble. The result showed that in 1996-2002 there was a significant increase in the mix-habitat and rubble classes (11.3% and 32.5%), however, there was a siginifcant decrease in the sand, seagrass, and coral classes of -14.1%, -14.9%, and -16.6%, respectively. In 2002-2013, mixed-habitat, sand, and seagrass classes were increase by 1.1%, 13.3%, and 24.78%, respectively. Meanwhile, coral and rubble classes were decrease by -22.7% and -27.0%, respectively. Within the period of 1996-2013, there was about 43.6% loss of coral reef of Morotai island. This was probably caused by the increase of seas surface temperature nad and the increase of human activities in the region

Spectral of Remote Sensing Reflectance of Surface Waters

Spectral measurements of remote sensing reflectance (Rrs) of surface waters in the northeastern Gulf of Mexico were conducted in various seasons in 1999-2000 using Fieldspec Analytical Spectral Devices (ASD) Spectroradiometer. Filtering process was performed on the data to eliminate invalid data. In general, in coastal waters particularly near rivers mouth (water type-2) the Rrs spectrals were relatively low at blue, maximum at green, and decreased to a minimum value at the red wavelength. In offshore waters (type-1), the general pattern of Rrs spectrals were maximum at the blue wavelength and then continued to decline at the green wavelength until the minimum value at the red wavelength except during summer where Rrs spectrals in most offshore area having the maximum value at the green wavelength due to the phytoplankton bloom as a result of freshwater intrusion from the Mississippi river. In general, the patterns and values of Rrs ​​were significantly different among seasons and locations. Results showed that Rrs values ​​at the blue wavelength (λ=400 nm) were generally higher in the spring than in other seasons ranging of 0.007-0.018 sr-1 in offshore waters and 0.004-0.015 sr-1 in coastal waters. During spring, Rrs values at the green ​​wavelength (λ=500 nm) were also higher than in other seasons ​​ranging of 0.005-0.013 sr-1 found in coastal waters. However, during summer in coastal waters, the maximum values of Rrs spectrals were found in different green wavelength on different locations showed the differences in the type and composition of phytoplankton, organic materials, and suspension matters at those locations