University of Sri Jayewardenepura: Journals & Proceedings
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Concept of Proportional Adjustment in Asset Value based on Ease of Accessibility
Full text linkDifferent approaches for asset valuation are often used based on understanding of the case specific requirements. These are based on fundamental principles that govern the rules and parameters that ensure the process, result is fair and valid. Although, some methods, are ambiguous and lack clarity. This paper intends to address ambiguity of one such method where the belting of land is used. The paper also gives logical reasoning and explanation of the concept of ease of accessibility and the proportional adjustment of value. This concept gives the criteria to test if a property is too narrow or too long along with the appropriate reduction applicable in both cases. If the property is too narrow, the reduction is computed directly from ease of accessibility. If the property is too long, the reduction is computed by Auxiliary Belting Method
Understanding Encroachments and their Effects on Quality of Life: Perspectives of Residents in the Western Coastal Zone
Full text linkMany encroachments, representing different activities have been notified along the western coastal belt of Sri Lanka. Residents along the encroachments have complained about several issues that disrupt their daily lives. While extensive research has been done on community attitudes towards encroachments there remains a critical gap regarding the influence of coastal encroachments on the quality of life of residents in Sri Lanka. This research examines the impact of coastal encroachments on residents' quality of life in Dehiwela, Sri Lanka, focusing on infrastructural, social, and ecological factors. A quantitative approach was utilized, with a structured questionnaire directed to 75 residents, and data was analyzed through mean value and correlation analyses. Results of correlation present a moderate positive correlation between infrastructural factors and quality of life, while social and ecological factors show strong positive correlations and confirm that encroachments affect the quality of life of people. This study highlights the need for targeted policy interventions to control encroachments and foster sustainable living conditions
සාහිත්යයේ නිරූපිත ශ්රී ලාංකේය බුද්ධ ප්රතිමා කලාවේ ප්රභවය හා පූර්ව අවදියේ බුද්ධ සංකේත වන්දනය
No full textFollowing the Mahindagamana, an intense reverence for Buddhism and the Buddha developed across the nation. Sri Lankan artists, in response, dedicated significant attention was directed to sculp the Buddha's form in statues, drawing inspiration from his spiritual essence. As time progressed, the art of crafting Buddha statues evolved, encouraging Buddhists who traditionally revered Buddhist symbols to begin worshiping through these statues. This study examines the origins of the Buddha image as depicted in literary texts and the shift from symbolic to statue worship using a qualitative research method. Based on evidence from primary sources like the Mahavamsa, Samanthapasadika, and Pujavaliya, and supplemented by othersecondary sources, it is evident that sculptors conceptualized and crafted Buddha's image in statues, capturing the character of Buddha as praised in the literature
Variation of Chlorophyll Content of Selected Mangroves from Diverse Salinity Environments on the East Coast of Sri Lanka
Full text linkMangroves are unique coastal plants subjected to salinity stress. Seasonal changes in water availability can affect leaf pigments such as chlorophyll and thereby influence physiological functions. Determining the response of chlorophyll content is crucial to assess the adaptability of mangroves to changing environments. The objective of the study was to investigate the response of chlorophyll content of three common mangrove species (Avicennia marina, Excoecaria agallocha, and Lumnitzera racemosa) from diverse salinity sites during wet (WS) and dry seasons (DS) in the Eastern Coast of Sri Lanka. The sites were Sathurukondan (water salinity -WS: 0.6±0.55 ppm; DS: 6.1±0.79 ppm), Thampalagamam (water salinity - WS: 2.9±0.15 ppm; DS: 15.2±0.84 ppm), and Panama (water salinity - WS: 9.6±0.55 ppm; DS: 32.8±0.84 ppm). Field measurements of chlorophyll content (SPAD-502plus) were taken on three plants per species, with fifteen leaves per plant (air temperature: WS 25°C-32°C and DS 32°C-37°C). Data analysis was performed using one-way ANOVA (MINITAB 18). Results revealed that chlorophyll content of E. agallocha was significantly higher (p<0.05) compared to other species during both seasons. A. marina exhibited significantly lower values at Sathurukondan and Thampalagamam during DS while L. racemosa showed the same trend during WS. During the WS, A. marina showed a significantly higher value (47.1) at the lowest salinity site while the other species showed similar values across all sites. In the DS, L. racemosa and E. agallocha showed significantly lower values (44.9 and 48.3) at the high salinity site while A. marina showed a similar value across the diverse salinity sites. Only L. racemosa showed a significantly higher chlorophyll content in DS than WS across all sites. Overall, E. agallocha showed the highest chlorophyll content amongst the species irrespective of season and showed a limited response to salinity variation amongst sites during the wet season. During the dry season it was more responsive while A. marina showed a limited response. Thus, the selected species showed distinct chlorophyll responses to salinity across different sites during the wet and dry seasons. This variability underpins the importance of species selection for restoration efforts as their physiological traits may influence their survival and productivity in response to stressors such as salinity. Further, it suggests that species level chlorophyll variability and responses should be considered when using spectral reflectance-based methods such as remote sensing to monitor mangrove health and productivity.
Keywords: Chlorophyll, Mangroves, Salinity, Season, Physiolog
Understanding the Rising Threat to Sri Lankan Leopards in Central Hills; A Causation Analysis
No full textThe Sri Lankan Leopard (Panthera pardus kotiya) is the only big cat species found in Sri Lanka which is an endemic subspecies to the island. Due to rapid population decline and habitat loss, the IUCN has categorized the species as Vulnerable (VU). Over the past two decades, these apex predators have faced severe threats from anthropogenic activities, particularly in the central highlands’ tea cultivation landscapes. Despite being a protected species in Sri Lanka, the leopard death toll in the central highlands continues to rise at an alarming rate. To understand the existing threats and the demographics of leopard deaths, data on leopard mortality in the central hills from September 2018 to September 2024 were gathered from records maintained by the respective regional offices of the Department of Wildlife Conservation (DWC) and other related institutions. Additionally, semi-structured interviews were conducted at the ground level with various stakeholders, including officers of law enforcement institutions and community members, to verify causation. The spatial distribution of death records was analyzed using ArcGIS Pro 3.0 software package. A total of 54 leopard deaths were recorded in the central highlands during the study period. According to the records 30 were male and 18 were female, including one pregnant female while gender was not recorded in 6 instances. Regarding the causes of death, 66.7% of the animals were killed by humans, while 20.4% of the deaths were of unknown cause. Only 12.9% of the deaths were attributed to natural causes. Among human-caused deaths, 29 (80.6%) were due to snare traps, one was poisoned, and three each were caused by shooting and vehicle accidents. In five cases, individuals were found in possession of poached leopard skins and body parts. Although most leopard deaths were due to anthropogenic causes, most were accidental killings, where locals had set snares targeting other animals for bushmeat. However, the possession of leopard body parts by certain individuals suggests the existence of a black market for body parts of leopards, likely driven by poverty and local myths. These findings highlight the urgent need for an effective leopard conservation program in the central hills. Such programs must include strategies to communicate and educate the local community about the species and its ecological importance, initiatives to reduce poverty-driven bushmeat dependency, well-trained and equipped wildlife rescue teams, and robust law enforcement systems to combat illegal hunting and illegal trade.
Keywords: Sri Lankan leopards, Central hills, Threats, Deaths, Black marke
A Comparative Study of Essential Oil and Oleoresin Extraction from Different Ceylon Cinnamon Bark Grades: Process Optimization, Antioxidant Activity, and Chemical Composition
Full text linkSri Lankan cinnamon (Cinnamomum zeylanicum Blume) is the world's premier cinnamon, prized for its delicate flavour and potent health benefits. It is increasingly recognized as a key ingredient in healthy diets. This study was conducted to optimize the hydro-distillation extraction process of essential oil and solvent extraction process of oleoresin from the nine grades of true cinnamon bark mentioned in the Department of Cinnamon Development. This study underscores the significance of preserving the genetic diversity within Ceylon cinnamon. By optimizing extraction processes, we can minimize the amount of plant material needed to produce desired products. This, in turn, reduces pressure on wild populations and promotes sustainable harvesting practices. Recognizing the immense value of cinnamon can drive efforts to protect its natural habitats. The residue part of the grading process, commercially known as cinnamon offcuts yielded the highest sieved percentage (95.39±0.29%), making it the most viable grade for large-scale processing. The highest essential oil yield of the cinnamon offcuts (1.38±0.01 ml/g) was achieved at 100°C and 4h of extraction. While H2 (2.36±0.18%), H3 (2.30±0.07%), and Special (2.36±0.12%) grades exhibited the highest oil contents. Moreover, the cinnamon offcuts (1.36±0.03%) were the most strategic choice due to their lower raw material cost among all the grades. The highest cinnamaldehyde content was observed in H3 (72.31±0.30%) grade. The highest eugenol content (5.27±0.02%) was in the H3 grade and the highest linalool content (2.63±0.002%) was in the cinnamon offcuts. The highest safrole content was in C4 (0.62±0.007%), C5 (0.61±0.005%), and M4 (0.61±0.002%) grades. The Special grade had the highest cinnamyl acetate content (3.37±0.02%). In addition, the cinnamon offcuts had the highest DPPH radical scavenging activity (3.53±0.01 TE mg/g) among H3 and cinnamon offcuts. This study recognized Cinnamon offcuts as the most profitable and strategically sound option for the large-scale production of essential oil, due to its high oleoresin yield, lower production cost, availability, and favorable chemical profile.
Keywords: Cinnamomum zeylanicum, Essential oil, Oleoresin, Cinnamaldehyde, Eugenol
 
Exploring the Impact of Diverse Herbal Mixtures on the Quality and Bioactive Attributes of 'Kithul' Treacle in the Sinharaja Forest Region
Full text linkSinharaja forest reserve is renowned for the practice of 'Kithul' tapping among traditional people. They collect sap from the young inflorescence of the Caryota urens palm by tapping young inflorescence. This study investigates sustainable tapping techniques for enhancing health influencing properties of ‘kithul’ treacle which produced from sap. This study explores the bioactive properties and quality of ‘kithul’ treacle where the ‘kithul’ palm is treated with four distinct tapping mixtures, each utilizing a unique blend of local herbal ingredients found from wilds. Tapping procedures were conducted on four ‘kithul’ trees, selected to ensure uniformity in environmental conditions and tapping age, facilitating a controlled analysis of treacle properties. Different traditional herbal tapping mixtures are used by villagers to tap kithul palm. The ingredients are secrets and vary from each individual. The antioxidant contents were assessed using DPPH and ABTS assays, while total polyphenol and flavonoid contents were measured using Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. Treacle from mixture 04 showed the highest antioxidant activity with DPPH and ABTS values of 63.84 ± 0.39 mg GAE/100g and 377.85 ± 3.76 mg TE/100g, respectively. Mixtures 01 and 03 had significantly higher polyphenol content (P<0.05), and mixture 03 exhibited the highest flavonoid content (39.79 ± 0.86 mg QE/100g). pH values of the kithul treacle ranged from 5.12 to 7.19. Notably, treacle from tapping mixture 02 had the highest Brix value at 70.5. Kithul treacle samples were analyzed to determine the proximate composition. Treacle from mixtures 04 exhibited relatively higher fat content, with water content consistently around 30 %. The ash content across all samples remained below 1.5%. High-Performance Liquid Chromatography (HPLC) analysis revealed the highest sucrose content in treacle from tapping mixture 04 (52.4%). Results demonstrated significant differences (P<0.05) in bioactive compounds among the tapping mixtures. The quality and the bioactive properties of kithul treacle was observed to vary depending on the composition of the tapping mixture used, highlighting the impact of mixture composition on the final product's characteristics. This research provides valuable insights into enhancing the nutritional and medicinal properties of 'kithul' treacle through optimized traditional tapping practices.
Keywords: Caryota urens, Antioxidants, Total flavonoids, Total polyphenol
Developing a Model to Predict the Abundance and Distribution of Sharks in Southern Sri Lanka
Full text linkSharks play a crucial role ecologically and economically. The distribution and abundance of marine sharks are highly influenced by natural environmental factors. This research identified the key environmental variables affecting the distribution and abundance of sharks along the southern coast of Sri Lanka. The study area covered the 0°N–6.5°N and 76°E–85.6°E tropical marine region. Monsoonal cycles significantly influence this region, producing rich upwelling that serves as a productive fishing zone. Catch data from gillnets and longlines, were obtained from the Department of Fisheries and Aquatic Resources, focused on the Silky shark, blue shark, Mako shark and Oceanic whitetip shark. Oceanographic variables, including Sea Surface Temperature (SST), Sea Surface Salinity (SSS), Sea Surface Height (SSH), and Mixed Layer Depth (MLD), derived from the remote sensing satellites (RSS), were extracted from Copernicus Marine Service for 2019, and converted into 1/30 spatial resolution to align with shark catch data. By using special python codes, processed satellite data and catch data were merged together. The effect of the oceanographic variable for distribution and abundance of sharks were analyzed using histogram analysis. Developed Generalized Additive Models (GAM), and Empirical Cumulative Distribution Function (ECDF) models were used to identify nonlinear relationships between environmental variables and shark Catch Per Unit Effort (CPUE). According to the results of Histogram analysis, GAM and ECDF model analysis status shows that high CPUE values were observed from July to December with corresponded to SST ranges of 28.5–28.9 °C, SSS level range of 34–35 practical salinity unit, SSH range of 0.42–0.46 m, and MLD depths range of 18–22 m. These favorable values in oceanographic variables were obtained during the southwest monsoon and second inter monsoon period from July to December 2019. This suggests that these oceanographic variables changers with monsoonal currents and upwellings may play a critical role in sustaining shark population and increased shark distribution in southern areas. At last, these findings explain how oceanographic variables shape shark ecology and distribution in this region.
Keywords: Abundance, Distribution, Oceanographic variables, Model, Monsoon patterns. 
Levels of Naphthalene and Phenanthrene Concentrations in Meandering Part of the Kelani River Basin, Sri Lanka
No full textPolycyclic Aromatic Hydrocarbons (PAHs) are diverse and ubiquitous organic pollutants which daily leach into the water bodies. Naphthalene (NAP) and Phenanthrene (PHE) are recognized as priority pollutants by the United States Environmental Protection Agency. The present study was carried out to evaluate the levels of NAP and PHE in water and biological samples collected from the meandering part of the Kelani River basin. Water fish samples were samples collected from 13 distinct locations (n=3 each) within two seasons, along the selected area underwent High-Performance Liquid Chromatography analysis, followed by rotary evaporation, organic solvent extraction and filtration. The results of the study provide valuable insights into the water quality of the studied area, indicating variations in NAP and PHE contamination. The concentrations of NAP in water ranging from 2.499-8.414 (mg/L) in wet season and 0.005-9.658 (mg/L) in dry season, where PHE concentrations vary from undetectable to 0.248 (mg/L) during the wet season and undetectable to 0.329 (mg/L) in dry season. The highest PHE concentration in water was recorded in Mattakkuliya in both seasons (wet-5.36±0.55(mg/L), dry 0.284±0.045 (mg/L). However, PHE was not detected in Talduwa, Kudagama, Kelaniya and Ambathale locations. Paliyagoda was heavily polluted, having the highest NAP concentrations in both seasons (wet-8.420±0.006 (mg/L), dry-9.648±0.010 (mg/L). The high concentrations of PAHs might be due to high oil and grease content caused by infrequent oil and sludge spills from nearby industries and tributary inflows. Since NAP has a higher solubility in water, the concentration of NAP in both water and fish samples was higher than that of PHE. This study provides valuable information for EIA programs and contributes to developing effective strategies to mitigate PAH pollution in the meandering part of the Kelani River.
Keywords: Polycyclic Aromatic Hydrocarbons, Naphthalene, Phenanthrene, HPLC, Kelani River basi
Application of HEC-HMS Model on Event-Based Simulation in Kalu Ganga for Flood Prediction
No full textRainfall-runoff modeling is crucial for managing flood risks, particularly in rivers like the Kalu Ganga in Sri Lanka, which frequently experiences flooding. The Hydrologic Engineering Center's Hydrologic Modeling System (HEC-HMS 4.10) provides an effective tool for simulating and analyzing rainfall-runoff dynamics. Event-based modeling is vital for understanding how a basin responds to specific rainfall events, aiding in accurate flood prediction and water resource management. This study tested six rainfall-runoff model combinations to determine the most effective configuration for the Kalu Ganga Upper catchment up to Ellagawa, focusing on simulating and predicting runoff accurately for flood events. Criteria such as rainfall type (event-based), spatial process (semi-lumped), model type (empirical), and fitted parameters were considered to select the best model combinations. Rainfall data from four gauging stations in the Ratnapura district and discharge data from the Ellagawa station (2018–2021) were used for calibration and validation, providing real-world input for the model. GIS tools were employed to delineate sub-basins and calculate catchment rainfall using Thiessen polygons, ensuring precise spatial representation of rainfall across the watershed. Calibration involved optimizing model parameters, and the results showed variation in performance across different events, highlighting the model's sensitivity to rainfall intensity and distribution. Among the six tested combinations, the Initial Constant method paired with the Clark Unit Hydrograph, the Recession base flow method, and the Muskingum routing method performed best, achieving a Nash-Sutcliffe Efficiency (NSE) of 0.98, Root Mean Square Error (RMSE) of 0.1, and Percent Bias (PBIAS) of 0.16. These results demonstrate the model’s high accuracy in simulating runoff and replicating observed discharge hydrographs. The findings emphasize the effectiveness of semi-lumped hydrological modeling in tropical basins influenced by varying rainfall patterns, forest cover, and land use. The SCS Unit Hydrograph transformation method was particularly suited for the study area’s tropical characteristics. However, the model's performance was affected by the quality of input data and the relatively short study period. Future studies should incorporate continuous rainfall simulations, additional gauging stations, and advanced methods like Green-Ampt and Mod Clark to further refine model accuracy. Integrating land-use changes, expanding the dataset, and considering longer simulation periods would enhance the model’s utility for water resource management and flood forecasting. This study demonstrates the potential of HEC-HMS as a reliable tool for event-based flood prediction in the Kalu Ganga basin, providing accurate forecasts of flood peaks and timing, and offering broader applications for similar tropical river basins.
Keywords: HEC-HMS, Rainfall-runoff model, Event-based rainfall, Calibration and Validation