Browsing by Author Piyadasa, Ranjana U. K.

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Issue DateTitleAuthor(s)
2006After the Tsunami- Relief and Rehabilitation in Sri Lanka - restarting towards the futurePiyadasa, Ranjana U. K.
2014An Assessment of seasonal variation water quality in the inlets of Diyawannawa Lake, Sri LankaDharmasoma, U. Y. I. L.; Piyadasa, Ranjana U. K.
2008Developing a Model using GIS to identify Soil Erosion Potential Areas of Kukule ganga watershed, Sri LankaKarunaratne, A; Piyadasa, Ranjana U. K.
2010Environmental impacts due to river sand mining: A case studyPiyadasa, Ranjana U. K.
2009The GIS based Applications of interpolating of Rainfall within Kukule River in Sri Lanka.Karunaratne, A; Piyadasa, Ranjana U. K.
2013GIS based groundwater quality mapping and analysis in southern part of Anuradhapura DistrictWijeratne, V.P.I.S.; Piyadasa, Ranjana U. K.
2009GIS Techniques for the Tsunami Hazard Mapping and Identification of the Evacuation Sites; A Case Study in Devinuwra Area, Southern Sri LankaPiyadasa, Ranjana U. K.; Weerasinghe, K.D.N; Chandana, P.G
2008Groundwater for Sustainable Development - Problems, Perspectives and ChallengesPiyadasa, Ranjana U. K.
2010Groundwater Management study in confined and unconfined aquifers - Case study in Puttalam town areaPiyadasa, Ranjana U. K.
2006Groundwater Quality and It’s Distribution Features in the Right Bank of Nilwala Ganga- Sri Lanka (Badulla Oya and Kirama Oya Basins)Piyadasa, Ranjana U. K.; Weerasinghe, K.D.N; Kumara, P.W.H
2007Groundwater Quality assessment in agriculture dominant watershed of Southern Sri Lanka (Case study in Polwatumodera river basin water shed-Weligama, Denipitiya)Piyadasa, Ranjana U. K.
2013Groundwater Quality Distribution in Agro-Wells in Cascade Systems: A Case Study of Horivilla Cascade in Anuradhapura DistrictWijeratne, V.P.I.S.; Piyadasa, Ranjana U. K.; Weerasinghe, M.
2014Groundwater quality variation in Kalpitiya Peninsula- Sri LankaMathaeraarachchi, D. S.; Piyadasa, Ranjana U. K.; wickrmasinghe, D.
2014Heavy metal contamination of water in Negombo lagoon and interconnected water sourcesWater quality in natural lagoons that are located within close proximity to human settlements is generally at contamination risk due to increasing anthropogenic activities. The Negombo lagoon situated in the Gampaha District in Sri Lanka is a lagoonal estuary. It receives surface water runoff mainly from Dandugamoya, Ja-ela, Hamilton and Dutch canals. During the recent past, it has been noted by several researches that there is increasing evidence in anthropogenic activities in Negombo lagoon and surrounding areas. The present study was carried out to assess the contamination levels of heavy metals of water in the Negombo lagoon and interconnected water sources. Sampling was carried out in 19 locations; 6 in the Negombo lagoon and 13 from the interconnected sources (5 samples from Hamilton canal, 2 samples each from Dutch canal, Dandugamoya and Ja-Ela and one sample each from Kelani estuary and Ocean-Negombo). The data collection was conducted during relatively wet (May) and relatively dry (September) months in 2013. Water samples were analysed in the laboratory as per the standards methods of American Public Health Association (APHA manual) by using the Atomic Absorption Spectrophotometer. The tests were carried out to detect heavy metals: cadmium (Cd), chromium (Cr), copper (Cu), Lead (Pb), manganese (Mn), and zinc (Zn) in water. Data analysis was accomplished using ArcGIS (version 9.3) software package along with Microsoft Excel. Standards for inland water and drinking water of Sri Lanka were used to determine the threshold levels of heavy metals. The results show that concentrations of Cr, Cu, Mn and Zn of all water bodies were below the threshold level of human consumption and quality standards for inland waters in Sri Lanka. The Cd and Pb levels of water in Negombo lagoon and Hamilton canal were comparatively high. Furthermore the Cd and Pb levels of Dandugamoya, Ja-ela and Dutch canals were below the maximum permissible levels in both relatively wet and relatively dry periods. Concentration of Cd and Pb in Negombo lagoon and Hamilton canal showed seasonal oscillation with the rainfall. Both the parameters demonstrate a negative relationship with precipitation. Comparatively a high Cd and Pb concentrations was observed during the dry period. In conclusion, the Cd and Pb levels were high in the lagoon and Hamilton canal while the concentration of Cd and Pb were below the threshold level in Dandugamoya, Ja-ela and Dutch canal waters. The findings were important as the study indicates the spatial and seasonal variations of presence of heavy metals in the lagoonal water and which probably links to anthropogenic activities.; Chandrasekara, C.M.N.K.; Weerasinghe, K.D.N.; Pathirana, Sumith; Piyadasa, Ranjana U. K.
2014Identification of Spatial Distribution and Issues related to Groundwater Quality in Palugaswewa DS Division in Anuradhapura DistrictWijeratne, V.P.I.S.; Piyadasa, Ranjana U. K.
2009Observations of groundwater Quality Distribution in Tsunami affected areas using GIS (Case study in Weligama- Sri Lanka)Piyadasa, Ranjana U. K.
2012Spatial Variability of Soil Characteristics along a Landscape Gradient in Bellanwila-Attidiya AreaCooray, S. K.; Piyadasa, Ranjana U. K.; Wickramasinghe, D.
2012Variations in water quality in coastal regions of negomboChandrasekara, C.M.K.N.K.; Piyadasa, Ranjana U. K.; Weerasinghe, K.D.N; Pathirana, S.