Browsing by Author Piyadasa, Ranjana U. K.
Showing results 1 to 18 of 18
| Issue Date | Title | Author(s) |
| 2006 | After the Tsunami- Relief and Rehabilitation in Sri Lanka - restarting towards the future | Piyadasa, Ranjana U. K. |
| 2014 | An Assessment of seasonal variation water quality in the inlets of Diyawannawa Lake, Sri Lanka | Dharmasoma, U. Y. I. L.; Piyadasa, Ranjana U. K. |
| 2008 | Developing a Model using GIS to identify Soil Erosion Potential Areas of Kukule ganga watershed, Sri Lanka | Karunaratne, A; Piyadasa, Ranjana U. K. |
| 2010 | Environmental impacts due to river sand mining: A case study | Piyadasa, Ranjana U. K. |
| 2009 | The GIS based Applications of interpolating of Rainfall within Kukule River in Sri Lanka. | Karunaratne, A; Piyadasa, Ranjana U. K. |
| 2013 | GIS based groundwater quality mapping and analysis in southern part of Anuradhapura District | Wijeratne, V.P.I.S.; Piyadasa, Ranjana U. K. |
| 2009 | GIS Techniques for the Tsunami Hazard Mapping and Identification of the Evacuation Sites; A Case Study in Devinuwra Area, Southern Sri Lanka | Piyadasa, Ranjana U. K.; Weerasinghe, K.D.N; Chandana, P.G |
| 2008 | Groundwater for Sustainable Development - Problems, Perspectives and Challenges | Piyadasa, Ranjana U. K. |
| 2010 | Groundwater Management study in confined and unconfined aquifers - Case study in Puttalam town area | Piyadasa, Ranjana U. K. |
| 2006 | Groundwater 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 |
| 2007 | Groundwater Quality assessment in agriculture dominant watershed of Southern Sri Lanka (Case study in Polwatumodera river basin water shed-Weligama, Denipitiya) | Piyadasa, Ranjana U. K. |
| 2013 | Groundwater Quality Distribution in Agro-Wells in Cascade Systems: A Case Study of Horivilla Cascade in Anuradhapura District | Wijeratne, V.P.I.S.; Piyadasa, Ranjana U. K.; Weerasinghe, M. |
| 2014 | Groundwater quality variation in Kalpitiya Peninsula- Sri Lanka | Mathaeraarachchi, D. S.; Piyadasa, Ranjana U. K.; wickrmasinghe, D. |
| 2014 | Heavy metal contamination of water in Negombo lagoon and interconnected water sources | Water 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. |
| 2014 | Identification of Spatial Distribution and Issues related to Groundwater Quality in Palugaswewa DS Division in Anuradhapura District | Wijeratne, V.P.I.S.; Piyadasa, Ranjana U. K. |
| 2009 | Observations of groundwater Quality Distribution in Tsunami affected areas using GIS (Case study in Weligama- Sri Lanka) | Piyadasa, Ranjana U. K. |
| 2012 | Spatial Variability of Soil Characteristics along a Landscape Gradient in Bellanwila-Attidiya Area | Cooray, S. K.; Piyadasa, Ranjana U. K.; Wickramasinghe, D. |
| 2012 | Variations in water quality in coastal regions of negombo | Chandrasekara, C.M.K.N.K.; Piyadasa, Ranjana U. K.; Weerasinghe, K.D.N; Pathirana, S. |
