DSpace Collection:

An Improved Method to Detect Shoreline Changes inSmall-Scale Beaches Using Google Earth Pro

2020-01-01T00:00:00Z

Title: An Improved Method to Detect Shoreline Changes inSmall-Scale Beaches Using Google Earth Pro Authors: Warnasuriyaa, T.W.S.; Kumara, M.P.; Gunasekara, S.S.; Gunaalan, K.; Jayathilaka, R.M.R.M. Abstract: Shoreline change studies in small-scale beaches require high-resolution satellite images. In this regard, high-resolution satel-lite images from Google Earth (GE) would be an alternativesource however novel studies are needed to verify the effective-ness and the efficiency of applying those images for shorelinechange detection in small-scale beaches. Addressing this gap,the current study attempts to develop a new method.Accuracies of delineated shorelines under different scenarioswere used to develop relationships with digitizing methods andused eye-altitude to estimate the most effective, efficient andproductive method. This was done using Digital ShorelineAnalysis System (DSAS) in ArcGIS software. It was found that theeye-altitude influences on digitizing accuracy and it could beimproved when increasing the zoom level of the image which isunder investigation. Maximum zoom level (50m) used in thisstudy showed the highest accuracy in shoreline digitizing whilethe most productive eye-altitude for shoreline delineation wasfound as 300m. The current study identified that GE coupledwith DSAS tool in ArcGIS software can be used as an effectiveand efficient method for small-scale shoreline change analysisand it is suggested that this methodology could be adopted forother similar studies

Floating Microplastics in Northern Coastal Waters of Sri Lanka: Quanti cation and Characterization by FTIR

2022-01-01T00:00:00Z

Title: Floating Microplastics in Northern Coastal Waters of Sri Lanka: Quanti cation and Characterization by FTIR Authors: Shobiya, G.; Sivashanthini, K.; Einar, G.B.; Deeptha, A. Abstract: Microplastic (MP) pollution is a growing issue in Sri Lanka. However, few ndings have been reported in the Northern coastal belt of Sri Lanka. This study provides the rst evidence of the prevalence and abundance of MPs in the Northern Sri Lankan coastal waters of Mathagal, Point Pedro and Charty Beach in Ja na. Floating MPs were collected using a plankton net with a mesh size of 153 m horizontally at the surface once a month from August 2020 to January 2022. The MPs were characterized based on their physical morphology; size, shape and colour by stereo microscope and chemical composition by Fourier transform infrared spectroscopy (FTIR). MPs (1-5 mm) were found in each site studied. The MP abundance was signi cantly varied both spatially and temporally (p< 0.05). The overall mean MP concentration was 1.40 1.12 items m-3 with values of 1.31 1.39 items m-3, 2.34 2.5 items m-3 and 0.56 0.81 items m-3, at Mathagal, Point Pedro and Charty Beach respectively. MPs with a diameter of 2-4 mm (64%) predominated. The investigation discovered that the three most prevalent shapes in the overall abundance were lms (31%), fragments (26%) and bers (16%). White MPs were shown to be the most widespread (47%), followed by blue (28%) and green (16%). The FTIR analysis revealed that polyethylene (59%) was the most abundant polymer type, followed by polypropylene (27%). Land based sources, including shing and recreational activities were identi ed as a major contributing source of pollution in the studied coastal environment.

A study on mass accumulation of macrophytes in Northern and Eastern coast of Srilanka

2022-01-01T00:00:00Z

Title: A study on mass accumulation of macrophytes in Northern and Eastern coast of Srilanka Authors: Thapeetha, Y.; Saruga, K.; Uventhikka, S.; Sivagini, K.; Ragavan, N.; Nahmagal, K.; Shobiya, P.; Khalingarajah, H.; Sivashanthini, K.; Sutharshiny, S. Abstract: The coastal areas in Northern and Eastern part of Srilanka became an eyesore on 8th November 2021 with unprecedented amount of macrophytes piled upon the beaches. A survey was carried out to identify and analyze the distribution of macrophytes accumulated along the coast. Morphometric analysis was performed based on shapes of leaves, leaf margins, vein structures, leaf and stalk textures and length of petiole to confirm the species. The leaves of the plants under the study were found as shiny, roughly round, ovoid or kidney-shaped, up to 15cm across in length with densely arranged longitudinal veins. Leaf stalks were bulbous and spongy. The petiole of the plant was about 50cm long often swollen and its base enclosed in a stipule. From the morphometric study, the plants accumulated was identified as water hyacinth(Eichhornia crassipes). Water hyacinth is one of the world’s most invasive aquatic plants that native to the Amazon basin, spread from South America to other parts of the world and is known to cause significant ecological and socio-economic effects. This plant was introduced as an ornamental plant into the state of West Bengal of India in the 18th century. Currently, India is severely infested by this weed. It is noteworthy that during the period of accumulation in Srilanka, the similar incident was also recorded in Kovalam Beach, India. Based on the meteorological data and the distribution of species, it was presumed that it had been followed by severe flood condition and also by high velocity water currents originated in the Bay of Bengal. As a follow up action, it is necessary to study the potential utilization of these accumulated plants in the future.

First Report of Leaf Spot Disease of Philodendron hastatum, an Ornamental Plant in SriLanka

2022-01-01T00:00:00Z

Title: First Report of Leaf Spot Disease of Philodendron hastatum, an Ornamental Plant in SriLanka Authors: Nawananda, P.H.R.S.; Mahendranathan, C.; Emmanuel, C. J.