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Author: search.filters.author.Weerasinghe, V.P.A.

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    A systematic literature review on integrating disaster risk reduction (DRR) in sustainable tourism (SusT): Conceptual framework for enhancing resilience and minimizing environmental impacts
    (Elsevier, 2024) Jayasinghe, G.Y.; Perera, T.A.N.T.; Perera, H.A.T.N.; Karunarathne, H.D.; Manawadu, L.; Weerasinghe, V.P.A.; Sewwandi, B.G.N.; Haroon, M.H.; Malalgoda, Chamindi; Amaratunga, Dilanthi; Haigh, Richard
    This literature review meticulously explores the integration of Disaster Risk Reduction (DRR) techniques into sustainable tourism (SusT), placing a focal point on enhancing resilience and mitigating environmental impacts. By examining several disciplines, including tourism management, disaster management, environmental science, green innovation, and sustainable development, this study recognizes major themes, research gaps, and best practices in this emerging subject. It underlines the importance of SusT and the need for effective DRR programs to alleviate the negative effects of catastrophes on tourism destinations and ensure their long-term sustainability and resilience. Science Direct, Springer, SAGE Publications, and Wiley's online library were the selected databases and the inclusion criteria were based on studies that looked at how DRR measures were implemented in SusT practices and how effective they were in increasing resilience and lowering environmental effects. The selected literature reveals many concepts and ways for integrating DRR in tourism, such as pre-disaster planning, risk assessment, capacity building, and stakeholder involvement. The assessment identifies the vital part played by government agencies, local entities, and tourist service providers in organizing and coordinating these programs. It points out potential obstacles to DRR integration within the tourism sector. The review emphasizes the importance of monitoring and measuring the outcomes of DRR programs in tourism, and it suggests the use of metrics and indicators to assess how well resilience-building and environmental impact reduction strategies are implemented. These insights may be utilized by policymakers, academics, and practitioners to design methods that enhnace the resilience of tourism destinations while minimizing environmental consequences.conditions in Sri Lankan marine waters, thus qualifying mangrove ecosystems in microtidal coasts as effective carbon sinks.
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    The spatial variability of physicochemical parameters of mangrove soil and mangrove species in Negombo Lagoon, Sri Lanka
    (Elsevier, 2024) Wickramasingha, W.S.B.; Weerasinghe, V.P.A.
    Mangrove forests are unique and invaluable ecosystems due to their role in biodiversity, coastal protection, and carbon sequestration. This study examined spatial variability of selected physicochemical parameters of mangrove soil and species distribution at the Negombo lagoon. Eighteen sampling sites were selected based on judgmental sampling techniques. A 10 m x 10 m area was selected within the 1 km x 1 km grid to get the replicate soil samples from 0 − 15, 15–30 and 30–45 cm depths from the surface. Further, a vegetation survey was conducted to identify mangrove species in the same 10 m x 10 m area. Soil temperature, pH, salinity, and soil organic matter (OM) were analyzed using standard laboratory methods. Results show that temperature varied spatially from 25.2 °C to 30.0 °C, with the highest temperature recorded in the topsoil layer. Soil pH and salinity spatially varied from 5.39 to 8.31 and 0.56 % to 8.83 %, respectively. Soil organic matter spatially varied from 2.56 % to 15.7 % and increased with the increasing depth. Soils with high salinity tend to reduce OM by accelerating the mineralization of OM. Correlation analysis showed a positive relationship between salinity and OM (r = 0.57; P < 0.05). Rhizophora apiculata, Rhizophora mucronate and Avicennia marina were associated more in soils with high salinity (3.72 % − 7.15 %) and neutral to weakly alkaline pH. Bruguiera gymnorrhiza was more prevalent in soils with higher salinity (7.69 % − 8.83 %) and lower pH, while Lumnitzera racemosa was found in acidic to slightly alkaline pH but with low salinity (1.35 % − 1.92 %) soils. Sonneratia caseolaris was recorded in soils with the lowest salinity (0.83 % − 1.04 %). The findings offer valuable insights for decision-making processes for conserving and restoring mangrove forests, providing effective and sustainable environmental management strategies.
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    Selecting suitable locations to establish a ground solar farm in Trincomalee District in Sri Lanka using GIS
    (Faculty of Science, University of Kelaniya Sri Lanka, 2023) Senadeera, T. S. M.; Bandara, W. M. J. Y.; Herath, H. M. A.; Ariyawansha, J. M. M. S.; Weerasinghe, V.P.A.
    Renewable energy is energy derived from natural sources that are regenerated at a higher rate than consumed. One of the examples of the most effective renewable energy sources is solar energy, which is derived from the sun. Solar energy can be extracted directly or indirectly for human use. With the rapid growth in energy demand, solar energy has led to an increased interest in power generation. In Sri Lanka, solar energy investments have developed rapidly in recent years. The ground solar farm is one of the solar energy harvesting types for electricity generation, especially at the industrial level. Our main focus is to provide an additional power supply to the National Grid of Sri Lanka, and this study focuses on utilising Geographic Information Systems (GIS) to identify suitable areas for establishing a ground solar farm in the Trincomalee District, Sri Lanka. Trincomalee District has a tropical wet and dry climate with high sunlight. According to that Trincomalee District was selected as the study area by considering solar irradiation and by focusing on the cumulative solar power plant capacity in Sri Lanka. According to the literature review, various factors can be useful for selecting locations for a ground solar farm. Land surface temperature, slope, land use, and proximity to roads were selected as criteria for this case study. The separate criterion maps were generated and they were reclassified according to the requirements, and those were used with Analytical Hierarchical Process (AHP) to find the weights for overlay analysis in GIS. The resulting final factor map shows a land area of 24.47 km2 for Trincomalee District as highly suitable for establishing a ground solar farm. This case study aims to reduce the overconsumption of natural resources that are used to produce energy and to ensure the protection of the environment through using renewable energy.
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    Statistical Tool to Address the Influence of Urbanization in Groundwater Quality in Colombo District, Sri Lanka
    (SAGE, 2022) Antalyn, Babu; Weerasinghe, V.P.A.
    Management of groundwater quality is becoming a key feature of a sustainable future while implementing sustainable development goals which are given by United Nations. During past decades, rapid land-use changes, urbanization, and population expansion are highly influenced the groundwater quality. To provide policymakers and water managers with reliable information on groundwater quality is a challenge to achieving sustainable development goals in developing countries. Therefore, this study intended to assess the spatial variability of groundwater quality using selected physicochemical parameters at the 39 available groundwater wells during the southwest monsoon period. Spatial variability is explained in 13 Divisional Secretariat Division (DSD) levels in Colombo district due to easier interpretation and management purposes. Afterward, groundwater quality was related to urbanization using population density and built-up density in 13 DSD levels in Colombo district, Sri Lanka. PCA (Principal Component Analysis) shows that 08 DSD levels are urban and 05 DSD levels are rural. pH (3.22–6.73), COD (8.91–52.9 mg/L), BOD5 (1.2–9.9 mg/L), and DO (2.17–5.05 mg/L) showed deviations from the given standards by local authorities in Sri Lanka. A significant relationship (p < .05) was found between urbanization and physicochemical parameters in regression analysis. The water quality index shows poor water quality indices in urban areas and vice versa in rural areas which is similar to the results obtained by statistical analysis. A sustainable urban development plan with continuous groundwater quality monitoring is necessary to protect groundwater resources in Sri Lanka.
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    Surface water quality assessment for the management of hydrological regimes: Kalu Oya and Mudun Ela catchment in Sri Lanka
    (Environmental Nanotechnology, Monitoring & Management, 2021) Thotagamuwa, H.T.B.N.; Weerasinghe, V.P.A.
    This study aims to assess the relationship between surface water quality and the land-use of an urban catchment named ‘Kalu Oya and Mudun Ela catchment’ located in the western province, Sri Lanka. Ten judgmental sampling locations of the streamflow were selected to measure water temperature, pH, salinity, conductivity, Total Dissolved Solids (TDS), Biological Oxygen Demand (BOD₅), Chemical Oxygen Demand (COD), oil & grease, nitrate and dissolved phosphorous levels, flow rates over five months of the period from June to October 2018. All these parameters varied independently with a significant difference from other sites (ANOVA, p < 0.05). Water temperature and nitrate levels showed a strong clustering pattern with positive Moran’s index values supported by higher Z-scores. (Moran’s index 0.557 and 0.5106, Z-score 2.773 and 2.419 respectively). Higher oil & grease levels exceeding the accepted levels were observed at all the sampling sites. Oil & grease values showed a strong positive correlation with the flow rate (Coefficient-0.807, P value-0.005) revealing that higher oil & grease levels in the stream may be resulted by subsurface flushing. Site 02 is affected by the effluent discharged by the Colombo fish market having higher phosphate and TDS levels. Clustering pattern of nitrate and dispersed pattern of oil & grease of the Kalu Oya and Mudun Ela catchment show evidence of the poor drainage system in the catchment. Improving the drainage system may enhance water infiltration by reducing the volume of runoff and improve the water quality by that it can be used as an effective urban storm water drainage system in the hydrologic water regime.
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    Vector Autoregressive (VAR) model for forecasting water level in Attanagalu Oya
    (Faculty of Science, University of Kelaniya, Sri Lanka, 2020) Anuruddhika, M.L.P.; Premarathna, L.P.N.D.,; Perera, K.K.K.R.,; Hansameenu, W.P.T.; Weerasinghe, V.P.A.
    Flood is one of the major natural hazards in the world. Sri Lanka also undergoes flooding incidents every year. Both natural and human-induced activities such as precipitation, unplanned infrastructures, water drainage, lack of vegetation cause floods. High precipitation is one of the main reasons for flooding. Generally, most flood incidents occur in monsoon periods and inter monsoon periods. Attanagalu Oya, one of the tributaries of Kelani river and downstream of Kelani river cause to flood in the Gampaha district, Sri Lanka. According to the literature, the water level in Attanagalu Oya has not been studied using the multivariate time series approach. Therefore, this study aims to develop a Vector Auto Regressive (VAR) model to forecast the water level in Attanagalu Oya. The fitted model might be useful to identify the flood incidents that occur due to overflowing Attanagalu Oya. The model is fitted for daily water level and rainfall data for ten years. Water level data at the Dunamale gauging station of Attanagalu Oya and rainfall data at the Henarathgoda station were obtained from the Irrigation Department and Meteorological Department respectively. The analysis was carried out using R statistical software. Missing and unusual values of rainfall data were cleaned using the average values. Cross-correlations were calculated to identify lags of the rainfall data that might be useful to predict the water level. Results indicated the significant correlations at lags 1,2 and 3 as expected in this context as it takes 1-2 days to raise the water level after rain. The best VAR model must be chosen by selecting the optimal autoregressive order which is selected based on the minimum Akaike's Information Criterion (AIC). The lowest AIC score was achieved at the order of 8. Hence, VAR (8) model was selected as the best model. Results indicated that the rainy season occurred in southwest monsoon (May-September) and second inter monsoon (October-November) periods. The water level is also increased in those periods. According to the observed values of 2019 significant increase in water level could be seen from mid-September to November and the beginning of December. Forecasted results also showed an increase in water level in those periods. Also, the model accuracy was examined using mean absolute percentage error (MAPE) and root mean squared error (RMSE). Accuracy test results showed that the MAPE and RMSE values for forecasted rainfall are 2.907063 and 16.13093 and the water levels are 0.7730767 and 0.9059733 respectively. Hence, those values indicated that the model is adequate for forecasting. Findings of this study are vital to Agricultural Department to plan their cropping calendar, and urban council to plan various development and construction activities and warn the community in Attanagalu Oya basin for staying alert in the periods in which the water level is increased. Besides, this study is continued to improve the accuracy of the existing VAR model and to advance the existing model by considering other factors such as temperature and humidity.
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    A potential habitat corridor for Western Purple-faced Langur between Forest Reserves in Sri Lanka: GIS as a tool in connectivity modelling
    (Acta Ecologica Sinica, 2019) Panagoda, P.A.B.G.; Weerasinghe, V.P.A.
    Endemic Western purple-faced langur (Semnophithecus vetulus nestor) of Sri Lanka, is an exclusively arboreal, critically endangered primate whose habitats are severely fragmented with the human population expansion. Labugama-Kalatuwawa Forest Reserve (LKFR) which is identified as the last strongholds for maintaining viable populations of the species over the long-run and Indikada Mukalana Forest Reserve (IMFR) which is located in a closer proximity to LKFR have no connection with each other at the current status. As there is no assertion of regional habitat connectivity at a metapopulation context, the study aimed to identify a potential habitat corridor for S. v. nestor between LKFR and IMFR by using GIS as a tool in connectivity modelling. Study area was first divided into 0.04 km2 grids using ‘fishnet’ tool. Fivemain resistance criteria for S. v. nestor movementwere selected namely; land use, road density, canopy cover, human tolerance and Feeding Plant Species Richness and Density (FPSRD). Each grid was assigned with resistance values for above criteria ranging from 1 to 6. Overall resistance layer for S. v. nestor movement was created using ‘weighted overlay’ in GIS environment. The best potential habitat corridorwas identified via least-costmodelling. The resultant corridor fallswithin an areawhichmainly comprises of forest and rubber (Hevea brasiliensis) monoculture. It further accounts for the highest human tolerance, canopy continuity, FPSRD and least road density. Resultant corridor can be improved by bridging existing gaps and enriching the corridor habitatswhichwould play an important role in conservation of S. v. nestor by minimizing the isolation of local populations, ensuring the gene flow and maintaining the minimum viable metapopulation in the long run. This study further demonstrates that GIS can be used as an effective tool for least-cost modelling which helps to identify potential wildlife movement corridors at minimum cost.
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    A census of diurnal primates in the villages located between Labugama-Kalatuwawa and Indikada forest reserves in Colombo District of Sri Lanka.
    (International Research Symposium on Pure and Applied Sciences, 2017 Faculty of Science, University of Kelaniya, Sri Lanka., 2017) Panagoda, P.A.B.G.; Weerasinghe, V.P.A.
    The diurnal primate populations which inhabit the villages, located between Labugama-Kalatuwawa and Indikada Forest Reserves in Colombo District of Sri Lanka, has a high conservation value due to the presence of critically endangered Semnophithecus vetulus nestor (Western purple-faced langur). In addition, these diurnal primate populations consisting of S. vetulus nestor and Macaca sinica (Toque macaque have caused many human-monkey conflict incidents within the area. No studies have assessed the local populations of diurnal primates within this area in spite of its importance in both above perspectives: conservation and conflict. Therefore, this study was aimed to assess the relative density and group size of diurnal primates and to statistically compare above two estimations between the two primate species. The census was carried out within a selected stripe of villages located between the two forests. Using reconnaissance walks, five trails (2 km each) were established to represent the study area, with a systematic sampling design. The trails were walked simultaneously, by five independent trained teams each consisting of five persons, in the morning and afternoon on 3rd of December, 2016. In addition, group counts of monkeys were made during 10 opportunistic field visits, from April to December 2016. For each species, the average group size and group and individual encounter rates (as a measure of relative density) were calculated. The group sizes and encounter rates of the two species were then statistically compared using Mann-Whitney U test. Group size of S. vetulus nestor (mean ± SE) was lower (4.46 ± 0.40 individuals) than that of M. sinica (8.29 ± 2.19 individuals), even though the median group sizes of the two species were not significantly different (p=0.1893). On the other hand, S. vetulus nestor was found to be more abundant in the area compared to M. sinica. The number of encounters of S. vetulus nestor and M. sinica during the census was 10 and 4 respectively. Further, the average group encounter rates (mean ± SE) of S. vetulus nestor and M. sinica, were 0.95 ± 0.31 and 0.33 ± 0.23 respectively (no. of groups/km) whereas the average individual encounter rates (mean ± SE) of S. vetulus nestor and M. sinica, were 4.23 ± 1.38 and 2.71 ± 1.89 (no. of individuals/km) respectively. However, no significant difference was found between the median group (p=0.470) and individual (p=0.4647) encounter rates of the two species. Yet, the higher abundance of S. vetulus nestor over M. sinica, could also be observed during the opportunistic observations made throughout the whole study period (opportunistic group encounters; 22 for S. vetulus nestor and 9 for M. sinica). The reliability of the results can further be improved by censusing at different times of the year. As this study sets a baseline, future studies are recommended to identify any growth or decline of this crucial population of primates.
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    Catchment based water quality evaluation of Pugoda Ela in Gampaha district, Sri Lanka
    (Sri Lanka Association for Fisheries and Aquatic Resources, 2012) Samadaree, A.D.S.; Weerasinghe, V.P.A.
    Pugoda Ela is one of the main tributaries of Kelani River which is used for water supply to Colombo and Gampaha districts by National Water Supply and Drainage Board (NWSDB) in Sri Lanka. Limited recent studies are available on water quality of the catchment of this import tributary. Therefore Pugoda catchment was selected as the study area and was divided into four sub catchments defined as Sub catchment A, B, C, and D. Main objectives of the study were to identify the point and non- point sources of pollution and evaluate each source by comparing water quality parameters such as temperature, pH, TDS, conductivity, BOD5, COD, DO, NO',-N and total Coliform. Sample collection was carried out twice a month from February to July 2011 to study the water quality including wet and dry period of the 'Vala' season. The only identified point source was South Asia Textile Industry. Agricultural lands and animal husbandry were the major non-point sources of pollution in the area. The study was also planned to investigate the contribution of inorganic fertilizer application of paddy cultivation on the water quality of Pugoda Ela, on sub catchment basis. BODs values in all sub catchments were significantly different from each other in wet and dry seasons (P < 0.05) and ranged from 6.9 :t 0.147 to 10.578 :to.513 mg/I in dry season and from 4.778:t0.368 to 8.233:t0.261 mg/I in wet season .COD values in sub catchment A, Band D were not significantly different from each other in dry season (P > 0.05) and catchments ranged from 8.032 :t 0.679 to 9.617 :to.346 mg/I in dry season and 8.517:t0.679 - 1O.000:t0.318 mg/I in wet season. COD in sub catchment D was significantly the highest (P < 0.05) in both seasons of all sub catchments.NO-3-N concentration values in outlets of sub catchments ranged from 2.863:t0.721 to 7.969:t0.755 mg/I in dry season and ranged from 4.09:tl.160 to 7.5l4:t0.559 mg/I in wet season over the study period. NO-3-N concentration values in catchment A, Band C were not significantly different from each other in dry season (P > 0.05) and ranged from 2.863:t0.72l to 7.969:t0.755 mg/I in dry season and ranged from 4.09:tl.160 to 7.5l4:t0.559 mg/I in wet season. NO-3-N concentration values in sub catchment D was significantly highest (P < 0.05) in both seasons of all sub catchments. Total Coliform (MPN/ lOOm!) values in outlets of sub catchments ranged from 220.8:t1O.000 to 245.0:t17.l00 (MPN/ lOOm I) in dry season and ranged from l29.2:t13.600 to 258.3:t45.300 (MPN/ 100ml) in wet season over the study period. Total Coliform (MPN/ 100ml) values in all sub catchments were not significantly different from each other in dry season over the study period (P > 0.05). The highest amount of urea application 2050 tons per month was observed in sub catchment 0 where the highest extent of paddy cultivation occurs. The highest average load of total Coliform 450000 (MPN) was found in sub catchment B which had the highest population density. Although average level of COO of point source was high, the other measured water quality parameters were at permissible level of Sri Lankan inland surface water standards established by CEA. It is concluded that according to the CEA standards, Pugoda Ela consisted bathing quality water or with complete treatment it can be used as a source of drinking water.
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    Water audit in Yakkaduwa Pangnasara boy’s hostel, University of Kelaniya
    (Department of Zoology and Environmental Management, University of Kelaniya, Sri Lanka, 2017) Mudannayaka, M.M.M.K.; Pathum, B.A.V.J.; Mathithipan, S.; Jeyasri, N.; Weerasinghe, V.P.A.
    Water audit is a systematic approach of identifying, measuring, monitoring and reducing the water consumption by various activities in a building/institution/industry. This water audit was done for the Yakkaduwa Pangnasara hostel building in the University of Kelaniya. To achieve the main objective of water budget in the hostel building, there were sub objectives namely; identifying water uses, measuring actual water consumption, identifying water wastage and leakages and giving suggestions for water reduction of wastage and leakages carried out. Water usage volumes were identified using visual observations. Actual water consumption was estimated using a questionnaire survey and flow rate measurements. The questionnaire survey was based on the water usage data of students, non-academic and canteen staff. Visually observed leakages were measured. Using observations and flow rate measurements data, the actual consumption was estimated. Total input was calculated using water bills. Finally, the unaccounted water loss was calculated using total input and estimated consumption. The unaccounted water loss should be equal or less than 5% in well managed water system, but in this water audit the unaccounted water loss is 8.52 %. Unaccounted water losses should be reduced by decreasing water losses and applying more water conservation practices in the hostel. Awareness programs also will help to reduce the water losses in the hostel.