
Ranjana U K PiyadasaUniversity of Colombo · Department of Environmental Technology
Ranjana U K Piyadasa
PhD
Professor, University of Colombo
About
141
Publications
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Introduction
Professor Ranjana U K Piyadasa currently works at University of Colombo as a Hydrogeologist. Their current project is 'Weather forecasting and Simulation of Flood for Sustainable Land Use Management of Bentota River Right Bank Basin in Sri Lanka' and many more research activities in Sri Lana and all over the world.
Publications
Publications (141)
Ground and surface waters can be contaminated by landfill leachate, which is considered a major environmental concern. The research aims to evaluate the chemical composition of the leachate produced at the Kerawalapitiya Waste Management Park (KWMP) and assess the surface water quality in its vicinity. Twelve sampling points were identified, and co...
Urban wetlands are essential ecosystems that play a pivotal role in advancing sustainable development within urban eco-environments. Understanding community perceptions is paramount to grasping urban residents' attitudes towards the benefits derived from these habitats, thus shaping effective wetland management strategies. This paper seeks to evalu...
Environmental impact of land use, land change, and climate change have been perilous around Sri Lanka during past few decades. SWAT is a small watershed to river basin-scale model used to simulate the quality and quantity of watersheds and the impacts of climate change. This study was carried out to (a) explore the performance of the SWAT in simula...
The Kelani River basin in Sri Lanka experienced frequent floods and inundations due to the unavoidable rapid population increase and land cover change, endangering the lives of the inhabitants and their ability to support themselves through agriculture. This study was conducted to ascertain changes in vegetation cover and population density in low...
Water is becoming contaminated as a result of the growing population, industrialization, the use of compost in agricultural production, and man-made activities Surface water and groundwater are the prime water source for household and drinking uses in coastal areas. The flow of seawater into freshwater aquifers is known as saltwater intrusion, and...
Flooding is an indivisible component of nature facing by the human across the world. It is proven that 'flood' is highly required to the cyclical process of river based ecosystems. During the last few centuries, the global urbanization has been severely affected by the phenomena of flood among all types of natural disasters which occur worldwide, a...
Rising sea levels, groundwater exploitation, and urbanization were the primary causes of seawater intrusion, exerting pressure on coastal aquifers. In Sri Lanka’s urban coastal region, a comprehensive physicochemical description of groundwater has yet to be identified. Therefore, the objectives of this research were to (a) use a Geographic Informat...
The primary focus of this assessment is to determine the current state of knowledge related to main irrigation and water management services felt by the related government stakeholders in the dry zone of Sri Lanka. Data were collected through focus group discussions using a pre-tested, well-structured interview questions in 2019. The respondents we...
Abstract. Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. Materials from the land's surface can move through the soil and end up in the groundwater. Ja-Ela Divisional Secretariat Division is one of most populated D...
The COVID 19 virus, has prompted people to utilize plastic protective equipment (PPE) more regularly. As the result, water bodies were highly polluted due to utilized PPE and wastewater discharge during the pandemic. This study was carried out to evaluate the immediate impact of PPE and municipal wastewater discharge on surface water bodies. The on...
Floods are known to be one of the most frequent natural disasters in Sri Lanka since years. The loss of natural land cover for human-modified land uses influences the occurrence, frequency and severity of floods. The Bolgoda River Basin which is located in Western Province of Sri Lanka has been identified as a highly vulnerable area for flash flood...
Urban home gardening combined with novel agricultural techniques is an emerging new trend that can help for urban sustainability. Sustainable home gardening may advance food security while strengthening the urban agro-ecosystem. Meanwhile it improves land utilization, household socioeconomic factors and human wellbeing. Moreover, to ensure food sec...
Evaluation of land suitability for agricultural development is a necessity of agro-ecosystem sustainability. Therefore, this study was conducted (a) to assess the agricultural LULC based on NDVI image analysis, and (b) to evaluate spatial variations of soil physico-chemical parameters in Western coastal region (Waikkala), Sri Lanka. The study ident...
The land use pattern, disaster scenarios, and the impact on human needs are different over the past decades. In this context, mainstreaming disaster risk reduction in ecosystem-based approaches requires multi-sector and multi-stakeholder engagement with a better conceptual model, improved understanding of ecosystems, effective community engagement,...
The scenario of home gardening during the period of the COVID-19 has been identified as a trending and important way of providing food security, economic relief, as well as mental and physical wellbeing to the people. Therefore, this study was conducted to assess the (a) women's participation in home gardening during the COVID-19 pandemic, and (b)...
The corona virus disease 2019 (COVID19) pandemic has changed how we work, learn and interact as social distancing guidelines have led to a more virtual existence, both personally and professionally.COVID19 has affected daily life in unprecended ways. The time spent at home significantly increased during the covid 19 pandemic and this change in resi...
This study used the groundwater quality index (GWQI) and Geographic Information System (GIS) techniques to examine groundwater quality in the western coastal region of Sri Lanka. The spatial and temporal variation of 18 groundwater samples' physiochemical parameters [pH, electrical conductivity (EC), turbidity, total dissolved solids (TDS), sodium...
Surface water pollution has many sources and it is generally induced by anthropogenic activities. This study revealed on industrial hazardous waste which is generated by Chromium based leather tanning industry in Colombo District. The research study was conducted to identify industrial hazardous wastes which are generated by Chromium base leather t...
Fifteen districts were affected by floods and landslides in Sri Lanka due to the heavy rains in southwest monsoon during May 2017. The floods in Baddegama DSD were severe than the previous years and affected the livelihood of the people. The objectives of this study were to evaluate the economic impact of 2017 floods in Baddegama divisional secreta...
Groundwater is a vital source of water for industrial, domestic and agricultural activities in Waikkala, Sri Lanka. Degradation of ground water is one of the major critical problems affecting the future economic development of Sri Lanka. The objective of this study was to analyse the underground water quality of the western coastal region, specific...
Fifteen districts were affected by floods and landslides in Sri Lanka due to the heavy rains in southwest monsoon during May 2017. The floods in Baddegama DSD were severe than the previous years and affected the livelihood of the people. The objectives of this study were to evaluate the economic impact of 2017 floods in Baddegama divisional secreta...
This study mainly bases on Middle Canal (Meda Ela) of Kandy city which is known as an affluent of Mahaweli river. It has a complex catchment area with diverse type of land uses including densely populated urban areas. Meda Ela is the main urban drain runs through Kandy city and it is one of the main storm water drainage canals which discharging sto...
Water is a scarce resource in the dry zone of Sri Lanka and it is a major problem faced by the cultivators in the area. Since their cultivations totally depend on irrigation water every possible effort should be put
in order to optimize the water usage to achieve increased crop production. Recent reports on water management activities of several ir...
Over the past few decades there has been developing interest to escalate local food production in order to obviate food insecurity and scarcity. In Sri Lanka peri – urban agriculture have been recognized as a significant complementary source contributing to food and nutritional security and livelihoods. Food production on small plots adjacent to hu...
Land degradation in coastal areas due to seawater
intrusion, and coastal salinity is one of the major critical
problems aff ecting the sustainable development of Sri Lanka.
Coastal salinity risk is increasing in the Bentota area while
diminishing land productivity which results in poor food
production and giving rise to several socio-economic
issue...
Climate-related extreme geophysical events are among critical global challenges, and Sri Lanka is the second most-affected nation. To minimize disaster impacts and enhance the livability of human settlements, the concept of building community resilience has become crucial in disaster management and preparedness. This paper presents key results and...
Seawater intrusion is increasing in Bentota area, Sri Lanka while diminishing the land productivity and yielding poor food production and making several socio economic issues for the community in the area. Key innovation of this study is to model coastal salinity susceptibility in Bentota area based on the future scenario of climate change to mitig...
In the contemporary context, ground water has become a diminishing resource in the dry zone coastal areas of the island due to the vast utilization and over exploitation. The study was conducted to identify the sea level rise and its impacts on coastal water in Kalpitiya Peninsula, west coast of the Sri Lanka, using geographical Information System...
ARTICLE DETAILS ABSTRACT Article History Published Online: 16Aug 2019 Surface water pollution has been increased due to various activities such as urbanization industrialization, agricultural activities and various anthropogenic activities. Standardized limitations in the water quality parameters for irrigation and drinking purposes such as pH, Ele...
This study was conducted to measure the impact of a municipal solid waste landfill on groundwater quality and Surface water quality around Karadiyana, a solid waste dumping site in Western Province Sri Lanka. One of the main complications related with dumping of municipal solid waste in a landfill site is the leachate release and its impact on the...
Due to the vast utilization and over exploitation, ground water has become a diminishing
resource evident from the recent past in the dry zone coastal areas of the world. Forceful
powers of both natural and anthropogenic directives have resulted accelerated ground water quality degradation causing fatal diseases and ground water stress as well. On...
The main urban centers of Colombo region are built on and around wetlands which are spatially distributed along the tributaries of Kelani River basin and has been facing numerous disturbances due to the escalating population growth (Abeysinghe & Samarakoon, 2017). Western Region Development initiatives started during the recent years are focused on...
The initiatives taken for disaster relief in Sri Lanka has been recurrently proven in vain due to the repeated disaster exposure which has increased the vulnerability of human beings living in the disaster prone regions poorly addressing the disaster risk reduction. This paper investigates the potential risks confronted by flood disaster prone popu...
Climate change is a causative factor of profound series of changers including sea level rising, increasing of sea surface temperature, storm surge condition during a cyclone and, extreme tide event along the coastal area around the world. Sea level rising is a major threat to the living right of 200 million of coastal communities in low lying coast...
Salt water intrusion (SWI) and coastal salinity are major causes for abandoning the paddy lands in Sri Lanka. More than 80% of paddy lands in left bank of Bentota River basin have been progressively abandoned due to contrasting degrees of saltwater intrusion by intimidating for agriculture, fishery, tourism and ground water in the area. This study...
Materials and Methods Eighty percent of land in the left bank of Bentota river basin has been abandoned and the present study was conducted to determine coastal salinity risk in the river basin. Groundwater (GW), surface water (SW) and soil was analyzed during August to October 2016. The pH, EC, TDS, Cl-and SO 4 2-in GW were 9.2, 2.6 dS/m, 2760 mg/...
Muthurajawela is one of the famous marshy wetlands in Sri Lanka with a high diverse ecosystem. In present context, detrimental environmental issues have been alarmed in Muthurajawela wetland due to improper waste disposal. As Muthurajawela consist of many distinct water bodies there is a high possibility of groundwater contamination through the lec...
Lunawa lagoon is situated about 19Km from Colombo city. It is about 2500m in length and about 100-250m in width.
The lagoon is one of small wetlands site in Sri Lanka. In present the lagoon environment has become deteriorated by
human and natural phenomena. The Lunawa lagoon and its catchment area in Rathmalana are compacted with various
industrial...
Water being the key element of life’s existence, essentially retain social, economic and environmental values, and is crucial for the sustainable development. It is evident that most of the future settlements will be located along the Coastal Belt of Sri Lanka while the global warming tempted Sea Level rise in the Indian Ocean could have a number o...
This document had been prepared by means of the outcome of the project
“Establishment of a Systematic Data Collection and Reporting mechanisms for Post
Disaster Housing Damage and Needs Assessment” which had been developed by the
Faculty of Technology, University of Colombo and funded by United Nations
Development Programme.
Purpose
The Hamilton canal in the western province of Sri Lanka is a man made canal situated in an area with immense anthropogenic pressures. The present study has been carried out to identify the quality variations of the water in Hamilton canal, and human perception about the present status of the water of the canal.
Design/methodology/approach...
The coastal dry zone areas of Sri Lanka mostly rely on ground water as the potable drinking water source because pipe born water is rarely provided. Most of the domestic units construct dug wells adjacent to houses where the ground water is exposed to fecal contamination due to pit – latrines. There available standards and commonly accepted factors...
In the present paper an appropriate model for Sri Lanka to build Disaster resilience nation, by participatory approach introducing evacuation zones through Eco-technological integration is discussed. The study was conducted in Gandara and Devinuwara area which underwent the Tsunami tragedy in 2004. A field survey was conducted through a structured...
Land degradation in coastal area is one of the major critical problems affecting the future economic development of Sri Lanka. Eighty percent of land in Bentota river basin has been abandoned and 25km distance along the Bentota river has already been affected by the seawater intrusion. Temporal and spatial variation of physicochemical parameters of...
Flood simulation modeling related to land use management is very important for mitigation and integration of disaster risk reduction in the development process. Flood estimation data obtained through gauging stations, Geographic Position System (GPS) devices and participatory-based mapping are poor in accuracy, and current software for flood simula...
Land is one of the most important natural resources for the survival and prosperity of humankind, and it is the platform on which human activities take place. The terms land use and land cover are not synonymous and the literature draws attention to their differences so that they are used properly in studies of land use and land cover change. Howev...
Paddy cultivation in Asia has evolved through generations with more than 2500 years old history. It was the main agricultural activity in many parts of this continent including Sri Lanka, which is known as the “Eastern granary”. Rice in the country is harvested from an area of approximately 158 million hectares producing more than 700 million tons...
ABSTRACT
Climate change has raised much concern regarding its impacts on future land use planning, varying by
region, time, and socio-economic development path. The principle purpose of land suitability evaluation
is to predict the potential and limitation of the land for crop production and other land uses. This study
was carried out to predict th...
Climate change has raised much concern regarding its impacts on future land use planning, varying by region, time, and socio-economic development path. The principle purpose of land suitability evaluation is to predict the potential and limitation of the land for crop production and other land uses. This study was carried out to predict the tempera...
Seawater intrusion and coastal salinity are major problems that affect the quality of inland water bodies and groundwater aquifers. This study analysed groundwater(GW) samples and surface water (SW) samples from the left bank of Bentota river basin to determine the coastal salinity effect and physicochemical parameters (Temperature, pH, Electrical...
Groundwater nitrate levels in the Jaffna peninsula of Sri Lanka are well above the World Health Organization limit of 10 mg/L as NO3 as N. As per collected data, well water from Inuvill exceeds 27.65 mg/L as NO3 as N this is where tobacco cultivation is found with the maximum expected nitrogen loading 322 kg/ha/crop, whereas in Pavisaarupoonganicho...
Paddy cultivation in Asia has evolved through generations with more than 2500 years old history. It was the main agricultural activity in many parts of the Asia and it is equally important today since most people in Asia are still engaged in the paddy cultivation. Over the centuries, most of our occupations relate with agriculture. That " s why, Sr...
Abstract
Strengthening Community Based Organizations (CBOs) must be accompanied with targeted actions to build the capacity of community structures to address identified issues. Mechanisms of strengthening and capacity building programs could include funding, providing training and organizational development programs, networking and exchange progra...
Over the past decades, the wetlands in Metropolitan Colombo have been influenced by a number of
anthropogenic impacts and unauthorized activities. Many of these activities have altered the soil
properties and consequently changed the overall functioning of many wetland systems. This study
analysed 200 soil samples to identify the similarities and d...
Rapid urbanization among cities is a global phenomenon that leads to greenhouse gas emissions and waste at its peak. Significantly, the land cover changes imposed by urbanization create urban heat islands (UHI). Colombo, the primate city of Sri Lanka, is also showing signs of UHI. As a developing city under rapid urbanization is experiencing land c...
The study was conducted in the Negombo estuarine lagoon locates in the Gampaha District of Sri Lanka. In this research, an investigation was carried out to identify and assess the distribution pattern of mangrove diversity across salinity gradient in the lagoon. A field survey was performed to collect primary data and vegetation sampling was carrie...
This study presents an evaluation of ground water quality in a unique coastal ecosystem Kalpitiya, which is a low-lying peninsula in North-Western coast of Sri Lanka. In this study we assessed the physical quality of ground water in the peninsula and developed GIS maps. It was evident that pH, EC and salinity were unable to meet standards of water...