MAPPING OIL SPILLS ON SEA SURFACE FROM SENTINEL 2 IMAGES USING PRINCIPAL COMPONENTS AND CATEGORICAL BOOSTING

A large oil spill in Iloilo Straight that occurred on July 3, 2020, as well as a possible deliberate, small but frequent oil spill and surfactant contamination in Manila Bay, were mapped. The method employs the Sentinel 2-1C image, which is transformed into principal components to reveal the presence of oil spills and possibly surfactants. Additionally, a gradient boosting algorithm was trained to discriminate between pixels that were contaminated with oil and those that were not. The multi-band image with three principal components with a 99% cumulative explained variance ratio highlights the occurrence of an oil spill in Iloilo Straight. Further, the classified image produced by pixel-based classification clearly distinguishes between water and oil pixels in the said area. The methodology was applied to a Sentinel 2-1C image of Manila Bay, with pixels observed/identified as oil and classified as well. The highest density of supposedly oil-contaminated pixels (large or small but frequent) was observed on the eastern side of Manila Bay (Bataan). While there were no documented oil spills concurrent to the satellite image used, historical reports on the area indicate that the likelihood of an oil spill is extremely high due to the massive amount of shipping activity. Pixels supposedly contaminated by oil spills also occur in areas near ports where oil spills could occur as a result of ship operations. Pixels with the same properties as oil contamination are also visible in areas adjacent to fishponds and aquaculture, where phytoplankton and fish contribute to surfactant contamination.

Measuring the Systematic Risk of Sectors within the US Market Via Principal Components Analysis: Before and during the COVID-19 Pandemic

This research measures the systematic risk of 10 sectors in the American Stock Market, discerning the COVID-19 pandemic period. The novelty of this study is the use of the Principal Component Analysis (PCA) technique to measure the systematic risk of each sector, selecting five stocks per sector with the greatest market capitalization. The results show that the sectors that have the greatest increase in exposure to systematic risk during the pandemic are restaurants, clothing, and insurance, whereas the sectors that show the greatest decrease in terms of exposure to systematic risk are automakers and tobacco. Due to the results of this study, it seems advisable for practitioners to select stocks that belong to either the automakers or tobacco sector to get protection from health crises, such as COVID-19.

Effect of uncontrolled fermentation and soaking on antinutrients of Tacca leontopetaloides (L) Kuntze (Taccaceae) tuber flour

Soaking and fermentation are two food technologies that are used by households or agro-industrial establishments. These practices aim at improving food nutritional acceptability and sensorial parameters. Tacca leontopetaloides tuber was used to study alleviation of antinutrients by solubilization and leaching through soaking, or by enzymatic degradation through fermentation. Soaking has lasted 72 hrs, and fermentation 48 hrs. Chemical methods have been used to determinate antinutrient levels in processed and unprocessed T. leontopetaloides tubers slices. A statistical analysis by means of XLSTAT was purchased for principal components and correlations between variables. Results show that the major antinutrients have exhibited resistance to microbial enzymes during fermentation or to solubilization in water. Levels of most antinutrients have increased instead of lowering when tacca tuber slices were soaked or fermented. The increase of components during soaking and fermentation is linked to the decrease of soluble components in T. leontopetaloides slices. Phytate is an antinutrient which resists to both food technologies, and saponins can be leached by 43.4 % through soaking or by 50.7 % during fermentation. These powerful antinutrients in T. leontopetaloides tuber necessitate food technologies combinations to eliminate them. Further investigations are necessary to succeed in antinutrient levels alleviation in T. leontopetaloides tuber.

Spatial Distribution and Landscape Characteristics of Flores Hawk-Eagle (Nisaetus Floris) Habitat in Flores Island

Flores Hawk-Eagle (FHE, Nisaetus floris) is one of the endemic and keystone species that was rarely studied among other eagles. The study on the FHE is currently experiencing limited information for estimating their distribution area. Therefore, the FHE habitat distribution is required as the essential information for developing the strategies and conservation action. The objectives of this study were to identify the spatial habitat distribution and analyze the characteristics of the habitat. Minimum convex polygon (MCP) and kernel-density estimation (KDE) 95% was combined with the land cover map for delineating the patch habitat of FHE. Slope, elevation, and land cover were used as environmental variables. Principal Component Analysis (PCA) combine with GIS were used for characterizing the landscape habitat. The results showed that there were eight habitat patches with a total area of 1.132 km2. Six principal components were retained from PCA analysis which explained 71.96% of data variance. Habitat characteristics of FHE describe its requirement for nesting and hunting activities for principal components 1 to 4, while for flight activity related to principal components 5 and 6. Forests and savannahs become the main habitat preference for both nesting and hunting activities. Results of this study will be supported as baseline information for developing conservation strategies and action for FHE.

STATISTICAL AND MULTIVARIATE TECHNIQUES TO TRACE THE SOURCES OF GROUND WATER CONTAMINANTS AND AFFECTING FACTORS OF GROUNDWATER POLLUTION IN AN OIL AND GAS PRODUCING WETLAND IN RIVERS STATE, NIGERIA.

Background: Groundwater is an important source of drinking water for the indigenous communities of Ebocha-Obrikom. Access to safe drinking water, in particular, is critical to one's health and, by extension, one's income and well-being. Underground wells are the primary supply of drinking water in the Niger Delta, and the groundwater is not always treated before consumption. As a result, water continues to be a vital environmental component that affects both humans and other life forms. Objectives: The aims of the research is to trace the sources and affecting factors of groundwater pollution via statistical and multivariate statistical techniques. Method: The investigation made use of standard analytical procedures. All sampling, conservation, transportation and analysis followed standard procedures described in APHA (2012). To prevent degradation of the organic substances, all obtained samples were transferred to the laboratory, while keeping in an icebox. Results: The study reveals that the greater the number of principal components extracted the greater variation in geochemical composition of the ground waters. It indicated that 34 parameters were distributed into six (6) and nine (9) principal components (PCs) extracted for groundwater samples for both rainy and dry seasons, potentially suggesting the input of different pollutants from different sources. Gas flaring, mineral dissolution/precipitation and anthropogenic input are the main sources of the physicochemical indices and trace elements in the groundwater. Groundwater chemistry is predominantly regulated by natural processes such as dissolution of carbonates, silicates, and evaporates and soil leaching, followed by human activities. Climatic factors and land use types are also important in affecting groundwater chemistry. Conclusion: Greater efforts should be made to safeguard groundwater, which is hampered by geogenic and anthropogenic activities, in order to achieve sustainable groundwater development. As a result, communities are recommended to maintain a groundwater management policy to ensure long-term sustainability. The study is useful for understanding groundwater trace sources in Rivers State's Ebocha-Obrikom districts. Such understanding would enable informed mitigation or eradication of the possible detrimental health consequences of this groundwater, whether through its use as drinking water or indirectly through consumption of groundwater-irrigated crops. As a result, determining its primary probable source of pollution (MPSP) is critical since it provides a clearer and more immediate interpretation. Furthermore, the research findings can be used as a reference for groundwater pollution prevention and water resource protection in the Niger Delta region of Nigeria.