Several researchers have attempted to find a suitable spectrum model for Indonesian waters, but these references do not provide a common understanding of defining a spectrum model. This prompted the researcher to reas...
详细信息
Several researchers have attempted to find a suitable spectrum model for Indonesian waters, but these references do not provide a common understanding of defining a spectrum model. This prompted the researcher to reassess the applicability of the wave spectrum model in Indonesia based on more appropriate data sources and systematic work procedures. This research is based on time series wave profile measurement data, which are then transformed into power spectral density curves (referred to as spectrum curves). From a number of obtained spectrum curves, this study aims to recommend key parameter values that indicate the shape of the spectrum in the western java sea so that it can be applied to the needs of marine building design. The procedures carried out in this study include: adjustment of the values of the key parameters of the JONSWAP spectrum (alpha and gamma);matching against a number of spectrum models;evaluation of the distribution functions to define the values of alpha and gamma;as well sensitivity test. The results of this study recommend alpha 0.99 = 0.00943 and gamma 0.99 = 2.11 for application in marine building design, as well alpha 0.5 = 0.00163 and gamma 0.5 = 1.07 for application in operational studies.
We used about 2000 Sentinel-1 SAR-C images of the western java sea for statistical analyses of the marine oil pollution in that area. Our results demonstrate that most pollution was found along the main ship traffic r...
详细信息
ISBN:
(纸本)9781728163741
We used about 2000 Sentinel-1 SAR-C images of the western java sea for statistical analyses of the marine oil pollution in that area. Our results demonstrate that most pollution was found along the main ship traffic routes, and further hot spots of oil pollution were found in offshore oil fields. Although the mean wind speed in the area of interest is generally low enough to support the visibility of oil spills on SAR imagery, we found a reverse correlation with the number of oil spills per SAR image. About 50% of the oil spills covered a sea surface area up to 0.5 km(2), and another 50% had an axes ratio up to 10, i.e., they were elliptical or quasi-circular. Comparing results obtained by different operators we found that the absolute numbers of oil spills differed, but the qualitative conclusions, regarding the location of pollution hot spots, are the same.
暂无评论