Browsing by Author "Warusavitharana, EJ"

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item: Conference-Full-text
4onse – 4 times open and non-conventional technology for sensing the environment: an integrated low-cost environmental monitoring system (ems) for developing countries
(Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa, Sri Lanka, 2017-12) Ratnayake, GR; Mahanama, PKS; Warusavitharana, EJ; Weerasinghe, SN; Warnakulasooriya, KMHK; Sudantha, BH; Jayasuriya, YP; Sudantha, BH
4 times Open & Non-conventional technologies for Sensing the Environment (4ONSE) is an ongoing joint research project between University of Moratuwa, Sri Lanka and University of Applied Sciences and Arts of Southern Switzerland. This project was initiated in a time where the necessity of a low-cost, non-conventional, and precise hydrometeorological monitoring system has been of great demand due to the increased number of weather-related environmental hazards and disasters in Sri Lanka. This work comprises an integrated approach to setting-up an experimental nonconventional Environment Monitoring System (EMS) based on open hardware, open software, open standards and open data which could measure the rainfall, wind speed, wind direction, relative humidity, air temperature, barometric pressure, soil moisture, light intensity, and the water level. With comparison to other available weather stations, this research argues the cost effectiveness of the 4ONSE system, in terms of its technology, hardware and software. Such a fully accessible, royalty-free and low cost system could provide developing countries with accessible technology for the so called ‘Internet of Things’ economy. Even though the use of technologically sound and low system is necessary to monitor the environmental data, less is known about use, validity, accuracy and cost effectiveness of such systems. This research explores the accuracy of 4ONSE’s measurements against those of a reference station and further explores and proves its effectiveness and suitability in terms of environmental monitoring in the context of developing countries.
item: Conference-Full-text
4onse as a complementary to conventional weather observation network
(2019-12) Sudantha, BH; Warusavitharana, EJ; Ratnayake, GR; Mahanama, PKS; Warusavitharana, RJ; Tasheema, RP; Cannata, M; Strigaro, D; Sudantha, BH
Over the centuries, sensing the weather has been important to mankind for decision making. Weather observations are important to better understand the climate variability and its consequences which ranges over different temporal and spatial scales such as localized rainfall and thunderstorms to large scale storms and droughts. Analysis of climate induced phenomenon is data intensive and the data collected from very sparse network of professional weather stations have become incapable to forecast magnitude of the climate induced events. In this research, we present a 4ONSE network as a complementary to professional, state-owned weather station network. This open network was built on 4 open pillars – open hardware, open software, open standards and open data. Credibility of the network was assessed by analyzing the reliability and accuracy of data, cost incurred in building the station and conformity of measured parameters with WMO standards. Even though the 4ONSE station is not a high tech, professional weather station, these mini stations can be used to filling the gaps left by professional weather stations. Thus, they can be used to improve the coverage of the existing weather network of the country and to obtain the observations at near real time for producing accurate weather and disaster forecasts.
item: Conference-Abstract
Application of ArcGIS model builder and Python Scripting for urban flood modeling
Bandara, DMPD; Mahanama, PKS; Warusavitharana, EJ
Accurate projection of flood extents in urban catchments has become a challenging task. Accurate data on inundation is useful for identifying flood risk areas and developing flood management strategies to mitigate the negative consequences. Owing to high costs of sophisticated flood simulation modeling software, currently, the required flood data for different studies and projects in Sri Lanka is collected through gauging stations, GPS devices and participatory based mapping approaches. However, these methods are highly time consuming and limited in accuracy. Hence, this paper presents an integrated model that simulates flood prone areas, flood levels and flood water accumulation time in urban areas using ArcGIS model builder and Python scripting. The model was calibrated and validated considering part of the urbanized area beside Kelani River. The results indicated that there is a high level of consistency between the observed and simulated results. Accordingly, the model presented in this paper can be used to simulate the flood inundation information in urban areas in a relatively fast, inexpensive and accurate manner.
item: Article-Full-text
Application of ArcGIS Model Builder and Python Scripting for urban Flood Modeling
(Faculty of Architecture University of Moratuwa, 2014-12) Bandara, DMPD; Mahanama, PKS; Warusavitharana, EJ
Accurate projection of flood extents in urban catchments has become a challenging task. Accurate data on inundation is useful for identifying flood risk areas and developing flood management strategies to mitigate the negative consequences. Owing to high costs of sophisticated flood simulation modeling software, currently, the required flood data for different studies and projects in Sri Lanka is collected through gauging stations, GPS devices and participatory based mapping approaches. However, these methods are highly time consuming and limited in accuracy. Hence, this paper presents an integrated model that simulates flood prone areas, flood levels and flood water accumulation time in urban areas using ArcGIS model builder and Python scripting. The model was calibrated and validated considering part of the urbanized area beside Kelani River. The results indicated that there is a high level of consistency between the observed and simulated results. Accordingly, the model presented in this paper can be used to simulate the flood inundation information in urban areas in a relatively fast, inexpensive and accurate manner
item: Conference-Abstract
Application of open source hardware and software in assessing the varying levels of perceived safety in cities
De Silva, CS; Warusavitharana, EJ; Ratnayake, R
Although planning is said to be done targeting the people, plan-making processes in most instances are dominated by top-down approaches, giving very little regard to how people perceive or feel about the cities they live in. The perceptions or ‗emotions‘ urban areas trigger, and how these cause behavioural changes reflect the implications of planning and decision making upon them. Prior studies indicate that environmental factors are capable of triggering affective reactions in people. Thus, throughout the course of this study, it was attempted to understand how environmental factors affected University students‘ perceptions of safety, which were quantified on the basis of emotions, i.e. the calmness or stress felt, and walking speeds. Data on emotional states were captured in real-time by a technically-sound, low-cost device assembled using Free and Open Source Software and hardware. The study demarcated the areas perceived to be ‗safe‘ and ‗un-safe‘ by people, and ranked them based on their perceived safety. The reasons for this classification were then identified. The results concluded that the factors in the environment affected people‘s emotional states and walking speeds, as people walked faster in areas regarded as ‗unsafe‘ and slower in areas regarded as ‗safe‘. The data also explained the difference between the behaviour of males and females, when perceived safety was concerned, during different times of the day. This study introduced the chance to identify unconscious emotional reactions of people, which can be served as useful inputs for urban planning. Furthermore, the study will confirm the value of the real-time sensing device as a tool beyond traditional methods in
item: Conference-Full-text
Building an open-source environmental monitoring system - a review of state-of-the-art and directions for future research
(Information Technology Research Unit, Faculty of Information Technology, University of Moratuwa, Sri Lanka, 2018) Sudantha, BH; Warusavitharana, EJ; Ratnayake, GR; Mahanama, PKS; Cannata, M; Strigaro, D; Wijesiriwardana, CP
The massive development take place in the field of IoT (Internet of Things) has enabled generation of large set of real time environmental data from low cost sensor networks. This has enabled developing nations to monitor their environments with more economical options. The environmental monitoring network of Sri Lanka is mainly handled by the government bodies such as Meteorological Department, Irrigation Department and Central Environmental Authority. Most of the systems are manually operated and sparsely distributed. The automated systems are restricted to certain main cities of the country. Thus, the data provided by the existing network not capable enough to generate reliable climate or disaster specific forecasts. The available data is mostly retained as hard copies and they are not freely and publicly available. Hence, every time, the researchers and decision makers need to purchase data and required to undergo redundant data collection procedures. In this context, the 4ONSE research project on developing an experimental, open-source, low cost and non-conventional Environmental Monitoring System (EMS) can be considered as the 1st initiative in Sri Lanka which creates a new revolution in the country for environmental data viewing and sharing without any charge. 4ONSE is the acronym for 4 times Open and Non-Conventional technology for Sensing the Environment, which is a joint research between University of Moratuwa and University of Applied Sciences and Arts of Southern Switzerland (SUPSI). Deduru Oya river basin area is the selected study area to deploy the 4ONSE systems. The Deduru Oya is 115km long and covers 2687km2 of catchment area. It carries flash floods during rainy seasons and very low flow during the dry seasons. Hence, the selected case study area is ideal for developing any forecasting application based on the real time environmental data. The project team has already deployed 27 systems in the basin. Temperature, rainfall, atmospheric pressure, solar radiation, relative humidity, soil moisture, wind speed and direction are the parameters measured by the system. In this research we attempt to present the state of the art of open source based environmental monitoring, architecture of the 4ONSE system, motivations behind deployment of the 4ONSE system and finally the lessons for the future research and development.
item: Article-Full-text
An examination of the temporal effects of environmental cues on pedestrians’ feelings of safety
(Elsevier, 2017) De Silva, CS; Warusavitharana, EJ; Ratnayake, R
Although plans are made with people as the target, plan-making processes in most instances are dominated by top-down approaches, giving very little regard to how people perceive or feel about the cities they live in. The perceptions urban areas trigger and how these cause behavioural changes reflect the implications of planning and decision-making upon them. Prior studies indicate that environmental factors can trigger affective reactions in people. Thus, throughout this study, itwas attempted to understand howenvironmental factors affect University students' perceptions of safety,which were quantified on the basis of their arousal, i.e. the calmness or stress felt, and walking speeds. Data on arousal were captured in real-time by a technically-sound, low-cost device assembled using free and open source software and hardware. The study could demarcate and rank the areas perceived to be “safe” and “unsafe” by the University students in real-time using the assembled device and identify which environmental factors have the most significant influence on their perception of safety. This study introduces the chance to determine unconscious reactions of people by triangulating data gathered by several measurement techniques that are directly measured in the field, which can be served as useful inputs for urban planning. Furthermore, the study confirms the value of the real-time sensing device as a tool beyond traditional methods in understanding feelings of safety in environmental settings.
item: Article-Full-text
A model for evacuation risk assessment on transportation networks
(2014-04-09) Warusavitharana, EJ; Bandara, JMSJ
Cities around the uorld are vulnerable to ma'!Y kinds of disasters. Although the disaster risk reduction is widelY spoken and attempted, the complex layout of cities makes the risk reduction impossible most of the times. The rescuers cannot allvays reach out the victims during emergenciesdue to the congested and concentrated network of city systems. This leads to greater vulnerability of cities and the potential increase of casualties as the hazardous consequences
item: Thesis-Abstract
A Model for evacuation risk assessment on transportation networks
(2015-06-30) Warusavitharana, EJ; Bandara, JMSJ
Cities are areas where hazards are more likely to escalate into disasters due to the large and highly concentrated populations and infrastructure that are likely to be affected. The complex layout of urban transportation networks and multi-story buildings make it even more challenging for rescuers to reach victims, which leads to greater vulnerability of cities and the potential increase of casualties as the hazardous consequences would be exacerbated (Kwan & Lee, 2005). Traditional transportation demand analysis focuses on analyzing peak travel demands on weekday morning journey to work and evening journey from work trips and providing solutions to have acceptable level of service. However, it is important to give special consideration on analyzing demand and assessing transportation system capabilities during the special events or circumstances as well. One of these special event circumstances involves emergency evacuation. Emergency evacuation can be a life or death situation, where the lack of safe exit routes and the time that it might take to safely exit can be directly related to lives lost. The main objective of this research is to identify spatial distribution of transportation difficulties that might arise during an urgent evacuation. The research has used Geographical Information System based Network based approaches to model the evacuation risk of road segments in small areas or neighborhoods under the pre-disaster conditions. Using the network based approaches it is possible to model risk scenarios by considering pre-disaster factors, rather than largely depending on post-disaster factors which sometimes unreliable to collect. However the evacuation risk assessment model presented in this research is not applicable for certain events like seasonal floods, in which the evacuation paths of the road network cannot be justified when the roads get flooded and when the community takes adaptation measures to live with the flood. The spatial distribution of transportation difficulties was assessed by taking Galle city as the case study area and the uncertain event as the Tsunami disaster.
item: Article-Full-text
A Model for Evacuation Risk Assessment on Transportation Networks
(Faculty of Architecture University of Moratuwa, 2013-12) Warusavitharana, EJ; Bandara, JMSJ
Cities around the world are vulnerable to many kinds of disasters. Although the disaster risk reduction is widely spoken and attempted, the complex layout of cities makes the risk reduction impossible most of the times. The cannot always reach out the victims during emergencies due to the congested and concentrated network of city systems. This leads to greater vulnerability of cities and the potential increase of casualties as the hazardous consequences. The traditional transportation demand related analyses generally focus on analyzing peak travel demands on weekday morning journey to work and evening journey from work trips and provide solutions for acceptable level of service. However, it is also important to give special consideration on analyzing demand and assessing transportation system capabilities during the special events or circumstances. One of these special circumstances involves emergency evacuation. Modeling the complex spatial interactions between people and the environment that occur during an evacuation is an important need in developing a successful emergency plan. Tsunami is one of the major uncertain disasters which created a severe loss to Sri. Lanka in terms of loss of life, damages to infrastructure, and decline to the economic assets in year 2004. When the Tsunami wanting is given, the road network has to play a crucial role in responding to city's emergency evacuation. Therefore, it is essential to determine the spatial distribution of transportation difficulties and the most critical locations during the Tsunami pre-disaster situation. Hence, the evacuation risk assessment model presented in this research helps the city emergency planners to identify the most critical road segments and nodes that may hinder the efficient evaluation process because of their deficient configuration.
item: Article-Full-text
A model for evacuation risk assessment on transportation networks
(2014-04-09) Warusavitharana, EJ; Bandara, JMSJ
Cities around the uorld are vulnerable to ma'!Y kinds of disasters. Although the disaster risk reduction is widelY spoken and attempted, the complex layout of cities makes the risk reduction impossible most of the times. The rescuers cannot allvays reach out the victims during emergenciesdue to the congested and concentrated network of city systems. This leads to greater vulnerability of cities and the potential increase of casualties as the hazardous consequence
item: Article-Full-text
Stakeholder perception based approach to vulnerability assessment - case of Ratnapura municipal council area
(2014-04-09) Mahanama, PKS; Ranasinghe, TKGP; Warusavitharana, EJ
The intention of this paper is toprooide an alternative approach to thevulnerability assessment. Most of the present approaches that are involved in the vulnerability assessment process have been identified with various weaknesses. Most of the weaknesses are related to the elements that are considered in the approaches. Identifying the most suitable elements, when peiforming the vulnerability assessment, is crucial to the creation of disaster resilient cities. Stakeholder perceptions are vital to identify the site specific and disaster specific elements. This research develops an approach that is stakeholder perception based and mostlY relevant to the site specificities. Through the literature revielJ!, thirty three elements were identified lvith riference to flood and landslide. Factor anaiysis method was applied to identify the most influential elements among them through the stakeholder perception. The Vulnerability Assessment n/asperformed by applYing the identified elements, taking Rathnapura as the case study area.
item: Article-Full-text
Stakeholder Perception Based Approach To Vulnerability Assessment: Case Of Ratnapura Municipal Council Area
(Faculty of Architecture University of Moratuwa, 2013-12) Mahanama, PKS; Ranasinghe, TKGP; Warusavitharana, EJ
The intention of this paper is to provide an alternative approach to thevulnerability assessment. Most of the present approaches that are involved in the vulnerability assessment process have been identified with various weaknesses, l lost 0 the weaknesses are related to the elements that are considered in the approaches. Identifying the most suitable elements, when performing the vulnerability assessment is crucial to the creation of disaster resilient cities. Stakeholder Perceptions are vital to identify the site specific and disaster specific elements. This research develops an approach that is stakeholder perception based and mostly relevant to the site specificities. Through the literature review, thirty three elements were identified with reference to flood and landslide. Factor analysis method applied to identify the most influential elements among them through the stakeholder perception. The V ulnerability Assessment was performed by applying the identified elements, taking Rathnapura as the case study area.
item: Conference-Full-text
Use of mathematical modelling for planning municipal solid waste collection
(2014-01-10) Warusavitharana, EJ; Ranasinghe, TKGP
When people hear the term "Solid waste management" thry immediatelY think oj rerycling. But it is not the aspect that requires the greatest expenditure, or has the greatest impact on the urban environment and public health. It is the "collection" oj municipal solid waste that has a significant impact on both municipal expenditure and public health
item: Article-Full-text
Use of Mathematical Modelling for Planning Municipal Solid Waste Collection
(Faculty of Architecture University of Moratuwa, 2013-03) Warusavitharana, EJ; Ranasinghe, TKGP
When people hear the term “Solid waste management” they immediately think of recycling. But it is not the aspect that requires the greatest expenditure, or has the greatest impact on the urban environment and public health. It is the “collection” of municipal solid waste that has a significant impact on both municipal expenditure and public health. The decisions pertaining to solid waste collection and transportation are basically based on the perception and experience of drivers and other minor staff working at the municipalities. The optimum utilization of available resources within the municipalities for day to day collection of waste is essential as it makes the biggest demand on the Municipal budget. Therefore the main objective of this research is to develop a mathematical model as a tool for decision making in municipal solid waste collection. This research has utilized two mathematical models known as “Network Analysis” and “Transportation problem method” to achieve the aforementioned objective. The case study of this research is based on the proposed project of implementing three Integrated Resource Recovery Centres (IRRC) in the Matale Municipal Council (MC) to manage the solid waste by means of producing compost and recycling. By applying the two mathematical models, the research has shown the possibility of reducing the daily solid waste collection cost within the Matale MC Area.