Symposia & Conferences
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Item 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.Item 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.Item 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.Item 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.Item Investigation of water consumption pattern in University of Kelaniya(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Lekamge, M.L.D.; Dayananda, M.D.N.R.; Shanthamareen, M.; Weerasinghe, V.P.A.Water Consumption is an environmentally and socially concerned aspect. Close observation of the water consumption pattern, help to apply water conservation measures effectively. The main objective of this study is to investigate the water consumption pattern in University of Kelaniya during last thirty-one (31) months from January 2014 to September 2016. During this period, university has received four water bills each month. Water bills and student intake details were collected from the administration division. Data was analyzed using Microsoft Excel. This study also investigated students’ attitudinal changes in water consumption after the implementation of the polythene prevention policy. A questionnaire survey was conducted among randomly selected 200 students in the Faculty of Science, in order to assess the water consumption pattern in Science Faculty canteen before and after the implementation of polythene prevention policy. The data obtained from administration division shows and increase in annual water consumption. The average monthly water consumption is 18,551.32m3 and average monthly cost for water consumption is 821,870.90 LKR. The average daily water consumption per head in the University is 0.06342 m3 (63.42L). According to the WHO (World Health Organization) standards about 20 L water per capita per day should be assured to maintain basic personal and food hygiene. The highest water consumption has observed in the canteens and hostels whereas the lecture halls have the lowest water consumption. According to the results the monthly water consumption and monthly total charge shows an increasing trend with fluctuations. From January to February there is a sharp increase of the monthly water consumption as a result of the student intake. A peak water consumption is observed during the March – April in each year. As a tropical country Sri Lanka receives high amount of solar radiation during that period. Therefore, the water consumption increases due to the temperature increase. The depressions in the curve is observed in the vacation and study leave periods. University of Kelaniya has implemented a polythene prevention policy beginning from the 1st of September, 2016. As a result of that the use of polythene and lunch sheets have been banned within the university canteens. The highest percentage of students shifted from university dinner packets to outside is observed during the dinner time is 20.5%. The highest percentage of students shifted from lunch packets to plates is observed during the lunch time is 43%. This might be affected to the water consumption due to washing plates. This is a preliminary study to investigate the water consumption pattern in the University of Kelaniya. There should be a well maintained database for identifying water consumption and to have separate water meters for each Faculty to apply water conservation methods according to the cleaner production policy. It will help to reduce the water consumption in each Faculty. Using those information water conservation strategies such as introduction of push taps, sensory taps and rain water harvesting system can be implemented in order to save more water.Item Determination of an eligible location for installation of a solar panel system in the University of Kelaniya using GIS(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Heshani, A.L.S.; Athukorala, S.M.W.; Leelarathna, W.D.S.R.; Weerasinghe, V.P.A.According to the international energy agency, the role of renewables continue to increase in the electricity, heating and cooling and transport sectors. Newly develop technology in photovoltaic cells that have the potential to dramatically increase solar power generation in the next two decades. Being closer to the equator, Sri Lanka has a great opportunity to have solar energy throughout the year almost 5-6 hours per day. Sri Lankan power supply organizations are mainly depending on diesel, coal and hydro power. Still we do not have enough sources to supply electrical energy throughout the country. All the energy sources except hydro power are not considered as environmental friendly since they emit high amount of carbon to generate power. Being the first Green University in Sri Lanka, University of Kelaniya has initiated many approaches for energy conservation within the University. This study was carried out to find out the most suitable location within the University for installation of a solar panel system using ArcGIS software. For this, surface area of roof of buildings, height of buildings, elevation of the land, disturbance from other structures such as buildings and trees were selected. Map layers were created by using high resolution satellite image. Surface elevation profile was created by using available contour lines. Building layer was digitized from the satellite image using ArcGIS software. After overlaying all layers together suitable roofs were selected for the solar panels to install. In order to find possible energy in the area, meteorological data was collected including minimum and maximum atmospheric temperature, rainfall, and sunshine hours from Welisara meteorological station which is the nearest meteorological station to the University. The mean values of meteorological parameters obtained for the past 8 months were as follows; maximum atmospheric temperature of 28.28 0C and minimum of 26.02 0C, rainfall of 171.92 mm and sunshine hours were 7.6 hours. After selecting suitable buildings from the map, visual observation was done to calculate roof area of each building manually. The building with the highest surface area and minimum disturbance from adjacent structures was selected as the best suited location. The best suited location was selected and also it shows the highest monthly average consumption of electricity among other university buildings. Apart from that suitable lands also can be considered. But as the availability of lands in the university premises is a limited factor, priority was given to the rooves of the buildings. It is easy to make 3D view of the University by using 3D Analyst, if there is a higher resolution Digital Elevation Model (DEM). Roof structure and the shape can be used to maximize the efficiency of solar panels. GIS can be used as a supportive tool in optimization of determining the best suited location for the solar panel installation.Item Selection of suitable site for establishing a biogas unit using GIS: Case study in University of Kelaniya(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Wadasinghe, L.G.Y.J.G.; Gnanasingha, S.M.; Weerasinghe, V.P.A.Bio degradable waste management is one of emerging environmental issues in Sri Lanka due to higher moisture levels. As a first green university of Sri Lanka, the University of Kelaniya implements their green policy towards sustainable environment. Bio degradable waste can be managed either by composting or bio gas generation since they are the currently available most cost-effective management methods. Composting alone it needs bigger land to manage all biodegradable waste within the university. Bio gas unit will helps to reduce the land usage for waste management in the University. Bio gas can be used as an alternative fuel source to reduce the consumption of LP gas within the university. Generated sludge can used as fertilizer to preserve the gardening. The main objective of this case study is to identify a suitable site to implement a bio gas unit in the University of Kelaniya by using ArcGIS 10.2 software. Three major criteria were selected namely generated waste amount, bare land, and road accessibility. If it is closer to higher waste generation places, it will save the energy in transportation. Road accessibility is needed to bring waste to the bio gas unit. By using higher resolution satellite image of university of Kelaniya, boundary of the university, building layer and road layer were digitized using ArcGIS software. Since there were no records of biodegradable waste generation in different buildings in the university premises, primary data collection was done. Student hostels and canteens were used to identify the amount of bio degradable waste since they are the identified highest bio degradable waste generation places. Waste was measured by using a spring weighing scale. For analysis, collected data was added to the new layer called waste generated places. Layers were converted into raster format and then reclassify all the layers. Majority amount of waste was generated in gymnasium student canteen and girls’ hostels which ranges from 300-340 kg per day. Buildings with higher waste generation was selected in separate layer. Bare lands were selected using higher resolution image classification and manually update it. Then selected building layer, road layer, and bare land layer were overlaid using weighted overlay method to find out the suitable sites for the bio gas unit. Map layout was developed to show the suitable sites for the bio gas unit in University of Kelaniya. The most suitable place was selected after visual observation. The proposed area for the bio gas unit should not be too closer to hostels, or lecture halls for safety purposes. This map could be used by any responsible party such as administration division or Green committee for their future waste management planning purposes. GIS is an important tool to identify suitable area maps to save time in decision making.Item Mapping and suitability study of existing locations of waste collection bins at University of Kelaniya(Faculty of Science, University of Kelaniya, Sri Lanka, 2016) Handapangoda, H.M.A.K.; Jayawardana, H.A.D.A.K.; Weerasinghe, V.P.A.Solid waste management is one of the major environmental and social problems in Sri Lanka. Waste without proper segregation is the one of the main roots of barrier to implement solid waste management systems. University of Kelaniya has established waste collecting bins in different locations in the university premises in order to facilitate waste management within the university premises. The main objective of this study is to map the existing locations of the waste collecting bins in the University using Geographical Information System (GIS). Other objective was to find out the suitability of the existing locations of the waste collecting bins. There are two types of waste collecting bins at University premises. Namely, waste separated bins; biodegradable waste (green), paper waste (blue), polythene and plastic waste (orange), glass (red) and non-separated bins. Locations of the both types of bins were recorded using GPS Garmin eTrex 10 model. GPS data was transferred to ArcGIS10.2 software to map the locations of waste collecting bins. Base map was created by using high resolution satellite image. Building layer, road layer including foot path were digitized using ArcGIS 10.2 software and vector map was developed. Digitized vector layers and transferred GPS points layer were overlayed using overlay function in ArcGIS 10.2 software. Map layout was prepared to show the locations of waste collecting bins. Suitability of the existing locations of the waste collecting bins were studied according to the waste generation amounts in different places. Students canteens, staff canteens, student hostels, student recreational areas were identified as the main waste generation places at Dalugama premises in University of Kelaniya. Amount of waste generated was measured by using a spring weighing scale. Frequency of data collection was once a week. Microsoft Excel was used to analyze the data. The minimum and maximum range of bio degradable waste generation in Dalugama premises was 580-610 kg and non-bio degradable amount was 250-300 kg. Results show that the majority of separated bins are located in high waste generation places. Also it was clear that the generation amount of each type of waste depend on the type of the building, size of the building, amount of staff and students visited or worked and accessibility to bins. Further improvements are recommended in waste collection methods such as not to use separated bins to collect non separated waste and not to use non separated bins to collect separated waste. This will mislead the user when disposing garbage. Existing location of waste bins map can be used as a guide to the administration work as well as visitors and workers in the university.Item Agricultural drought assessment using MODIS satellite data in Kurunegala District(Department of Zoology and Environmental Management, University of Kelaniya, Kelaniya, Sri Lanka., 2016) Gamanayake, B.G.N.N.; Kadupitiya, H.K.; Weerasinghe, V.P.A.Drought is a climatic anomaly characterized by long spell scarcity of water. Agricultural drought is usually defined by less availability of soil water to maintain crop and forage growth by the deficiency of normal precipitation over an identified period of time. Since drought is a creeping phenomenon which appears slowly and resulting web of impacts not only to agriculture but also for all other aspects, monitoring, forecasting, evaluating impact and proposing solutions to drought hit areas are challenging than other disasters. Distinct to point observations of ground data, remote sensing provides direct spatial information on vegetation stress that occur due to drought conditions. This facilitates the utilization of time series Vegetation Indices derived using time series satellite data for continuous monitoring of vegetation conditions and tracking drought occurrences. MOD13Q1 (250m, 16-day) satellite images, which contain NDVI (Normalized Difference Vegetation Index), were used in this study and Vegetation Condition Index (VCI) was calculated using ENVI 4.5 Remote Sensing software for agricultural drought monitoring in Kurunegala District during the year 2000-2015. Spatial variability of drought frequencies was evaluated and mapped using ILWIS 3.4 free software. Map accuracy was assessed using actual drought data available for Kurunegala district in the database of Disaster Management Center. According to the results, North and North-West parts of Kurunegala District were identified as severe agricultural drought prone areas. In order to enhance the accuracy, water mask was recommended.Item Rainfall-Runoff-Inundation (RRI) model for flood analysis in Attanagalu Oya basin, Sri Lanka(Department of Zoology and Environmental Management, University of Kelaniya, Kelaniya, Sri Lanka., 2016) Dikkumbura, H.K.U.S.; Weerasinghe, V.P.A.Floods are one of the most critical forms of natural hazard in global and local context. In the case of large scale flooding, it is important to identify the flood inundation areas and map the areas that undergo flooding for future flood management plans. This study analyzed rainfall-runoff and inundation in the Attanagalu Oya basin with the Rainfall-Runoff-Inundation (RRI) model that simulates the rainfall-runoff and inundation processes simultaneously based on two-dimensional diffusion wave equations. The applicability of RRI model to simulate flood inundation areas over the Attanagalu Oya basin was also investigated. RRI model simulation was conducted with satellite-based topographical data and daily satellite-based rainfalls for the period of 15th to 18th May of 2010 which was the most recent destructive flood occurred in Sri Lanka.Water depths on slope, water depths on river and river discharges at a specific time step were obtained as output. The model performance was evaluated using satellite-based vector flood map in 2010 obtained from the Disaster Management Centre and river discharge data at Dunamale obtained from the Department of Irrigation, Sri Lanka. The simulation results showed 74.31 % accuracy in downstream flood inundation extent with vector flood map. The simulation under-predicted the flood inundation in upstream areas and tributaries due to the coarse resolution of digital elevation model. The relative error of river discharge data shows some underestimation of simulated flow discharges as it is -20.17 %. The model simulation was found to be capable of obtaining the peak flood inundation extent in downstream of basin due to its flat topography. RRI model can be used for the ungauged basins with no flow data available as its simplicity, requiring only rainfall input.