International Research Symposium on Pure and Applied Sciences (IRSPAS)
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Item GIS as a tool to find the suitable place for construction of water tanks in Karuwalabadda, Puttalam District, Sri Lanka(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Vaigunthan, T.; Lansakara, L. M. A. P.; Weerasinghe, V. P. A.The United Nations has long been addressing the global water crisis caused by insufficient water supply to satisfy basic human needs and growing demands on the world's water resources to meet human, commercial and agricultural needs. Although there are lots of water bodies in Sri Lanka some parts of the country suffer with a severe water crisis. Karuwalabadda is a Grama Niladari Division (GND) in Puttalam district in Sri Lanka which has 135 houses and more than 245 families and there are no any surface water bodies observed in the area. The most considerable problem in that area is the lack of drinking water due to longer period of drought except 4 -5 months. Many organizations and students from different universities tried to help them as short term solutions by distributing water in bowsers and bottles. There were several drawbacks of these solutions such as water distribution coverage is changing, water distribution does not occur throughout the day, higher fuel waste for water bowsers, there is no specific route for distribution of water and plastic bottles make environmental problem etc. Hence previous solutions are not sustainable, it is proposed to construct tanks permanently in different locations of the area. The suitable locations to construct water tanks were found out using ArcGIS software for the construction of tanks with minimum environmental impacts. From the GND map of Sri Lanka, Karuwalabadda study area was extracted and digitized with houses and main roads. Buffer was done 500m away from houses and 75m away from roads and then reclassified. Land use map of Karuwalabadda was converted from vector to raster. Surface water layer was not considered because there are no any surface water body in Karuwalabadda GND. Criteria for the suitable locations were bare land, 500 m away from houses and 75 m away from main roads. The final suitable area to construct water tanks map was prepared by assigning weightage to different thematic maps as 60% to land use map, 20% to houses and 20% to roads and then they were superimposed by weighted overlay tool. Final map was classified into 03 classes as suitable, moderately suitable and not suitable area. From suitable area 07 locations were selected to construct the water tanks. It was observed that constructing seven tanks of capacity 3000 L in the selected areas the water need of the whole village can be fulfilled. Proposed number of families for one tank can be approximately 22 families. Society based maintenance can be an effective way to maintain these tanks and by handing over these tanks to Preadeshiya Sabha water can be filled once a week. GIS technology is an effective and efficient tool for solving any location based environmental problems in the world and it has more potential to be used further to overcome many environmental challenges.Item Mapping the land use land cover impacts by the war using remote sensing and GIS in Maritimepattu division, Sri Lanka in 1979, 2010 and 2018(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Sandamali, K. U. J.Land cover is defined as the layer of soil and biomass, including regular vegetation, harvests, and human structures, that involves the land surface. Land use refers to the reasons for which people activity in the land cover. Land cover and land use (land use/cover) are firmly related and reliant, and much of the time treated conversely. Land use/cover change is the impact of many collaborating forms that are dynamic over a wide scope of scales in reality. Advances in remote detecting and spatial examination methods have profited specialists of incredible assets for mapping and distinguishing changes in land use/cover. Recent investigations have utilized these advanced strategies for the study of land use/cover changes. The Mullaitivu town of Maritimepattu division has been the point of convergence of the armed conflict between the administration of Sri Lanka and the Liberation Tigers of Tamil Eelam (LTTE) for more than two decades. Consequently, the Mullaitivu zone has been influenced seriously in contrast with different regions of Sri Lanka. Landsat satellite images were used due to freely available, reliable data source with longer time coverage. In this study, Landsat 2, 5 and 8 images of 1979, 2010 and 2018 were used as the data sources respectively. Digital image processing used to get ready land use/cover maps from satellite images contained various advances including digital image preprocessing for removal of errors in atmospherically and geometrically, image enhancement for increasing the accuracy of images, and image classification for identify relevant land use/cover classes. All these steps were done with the use of ENVI and ArcGIS 10.1 software. Supervised image classification of maximum likelihood classification was used for preparing land use/cover maps and the training samples of accuracy assessment and signature collection for classification done with historical maps, historical records, Google earth images, pan-sharpening technique, and false color and true color composite images. In addition the statistical analysis was performed to calculate the land use/cover variation within the period. Rendering to the study, it reveals that vegetation and settlements were getting highly decreased in the war period by 11.97% and 5.54% respectively and on the other hand forest area get increased by 2.86 %. Furthermore, according to the 2018 image (nearly after 10 years from the war), there were 10.52% and 13.10% of the increase in settlements and vegetation in the Mullaitivu area respectively.Item Land Subsidence Susceptibility Mapping in Bandarawela & Ella DS Divisions in Sri Lanka, using GIS(4th International Research Symposium on Pure and Applied Sciences, Faculty of Science, University of Kelaniya, Sri Lanka, 2019) Kangana, U. S.; Illeperuma, I. A. K. S.Land subsidence is gradual settling or sudden sinking of the earth's surface owing of subsurface movement of earth materials; most of the identified subsidence were caused by server withdrawal of underground water and increasing development of land and water resources. Land subsidence at Bandarawela is a controversial topic, because of environmental issues caused by Uma oya multipurpose development project. Villages of the Ella and Bandarawela divisional secretariats face that hazard. The main objective of the study was to identify land subsidence susceptibility areas in Bandarawela and Ella DS divisions using Geographic Information System (GIS) techniques. Recorded data of subsidence areas, which were reported as coordinates, were collected by National Building Research Organization. Nine land subsidence conditioning factors were considered such as altitude, slope, aspect, distance from fault, distance from river, Normalized Difference Vegetation Index (NDVI), Stream Power Index (SPI), Topographic Wetness Index (TWI) and land use to generate land subsidence index maps. Altitude, Slope, Aspect, SPI and TWI data layers were generated by height data from survey department. Distance from faults layer derived by faults coordinators buffering and similarly distance from river layer was derived by river map buffering. NDVI layer was derived by Landsat-8 images. Spatial data layers for each of these factors were created in raster mode and classified layers into classes. Land Subsidence Susceptibility Map was created using Frequency ratio (FR) model and Analytic Hierarchy process (AHP) method. In FR analysis, each individual considering factor is compared to the land subsidence inventory map and assigned weighted value for each class. AHP is pair wise comparison method and to apply this approach, select conditioning factors; arrange these factors in a hierarchic order; assign numerical values to subjective judgments on the relative importance of each factor and synthesize by generating map. Those two models were compared. Result shows that 16.99% and 6.92% of the total area were in high and very high susceptibility prone area in FR model. But AHP model shows that those values are 8.42% and 3.99% respectively. Result also stresses that high susceptibility prone areas lie closer to the tunnel axis. Theses result can obtain an understanding of the nature of land subsidence and promulgate public awareness of such geo hazard to decrease human and economic losses. The advantages of using statistical modeling is easiness and the convenience of handling the inputs, outputs, and the hierarchy of the whole calculation process. It can process large amount of data in the GIS environment within a short period of time. In statistical models, conditioning factors must have normal distribution, which is considered as a deficiency in this type of modeling processItem 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.