Papers by Amila Buddhika Jayasinghe
PLOS ONE, Feb 6, 2023
Vegetation land fragmentation has had numerous negative repercussions on sustainable development ... more Vegetation land fragmentation has had numerous negative repercussions on sustainable development around the world. Urban planners are currently avidly investigating vegetation land fragmentation due to its effects on sustainable development. The literature has identified a research gap in the development of Artificial Intelligence [AI]-based models to simulate vegetation land fragmentation in urban contexts with multiple affecting elements. As a result, the primary aim of this research is to create an AI-based simulation framework to simulate vegetation land fragmentation in metropolitan settings. The main objective is to use non-linear analysis to identify the factors that contribute to vegetation land fragmentation. The proposed methodology is applied for Western Province, Sri Lanka. Accessibility growth, initial vegetation large patch size, initial vegetation land fragmentation, initial built-up land fragmentation, initial vegetation shape irregularity, initial vegetation circularity, initial building density, and initial vegetation patch association are the main variables used to frame the model among the 20 variables related to patches, corridors, matrix and other. This study created a feed-forward Artificial Neural Network [ANN] using R statistical software to analyze non-linear interactions and their magnitudes. The study likewise utilized WEKA software to create a Decision Tree [DT] modeling framework to explain the effect of variables. According to the ANN olden algorithm, accessibility growth has the maximum importance level [44] between-50 and 50, while DT reveals accessibility growth as the root of the Level of Vegetation Land Fragmentation [LVLF]. Small, irregular, and dispersed vegetation patches are especially vulnerable to fragmentation. As a result, study contributes detech and managing vegetation land fragmentation patterns in urban environments, while opening up vegetation land fragmentation research topics to AI applications.
Asian transport studies, 2018
Journal of south asian logistics and transport, Mar 1, 2021
This study presents a methodology to assess transport network resilience to urban flooding. The p... more This study presents a methodology to assess transport network resilience to urban flooding. The proposed methodology is developed based on the centrality measures and graph theory. The study utilises Open-Source GIS tools to compute betweenness and closeness centrality values. The case study was carried out in Greater Colombo-Sri Lanka, with reference to three significant urban flooding events in 2010, 2016, and 2017. The study assessed the resilience of road network in terms of topological impacts and accessibility changes. The results revealed three key findings. First, over 60% of road network revealed a significant change in its topological structural coherence during each flooding event. This was particularly pronounced in vehicular movements relative to pedestrian movements. Second, the study revealed a redundant depreciation of the transport accessibility as it shifted from city centre to peripheral areas creating temporary accessibility hotpots in the periphery. Third, a significant drawback of the resilience of road network was identified in terms of the deviation from the shortest path, increasing the travel time and trip length. In overall, the study concluded that the proposed methodology can be utilised as a planning and designing tool to assess road network`s resilience devising precautionary measures to mitigate disaster risk.
Journal of the Eastern Asia Society for Transportation Studies, 2019
FARU Journal, Nov 19, 2021
Muthurajawela Marsh and Negombo Lagoon have lost their marshland and mangroves from 41% and 21% a... more Muthurajawela Marsh and Negombo Lagoon have lost their marshland and mangroves from 41% and 21% accordingly from 1997 to 2017. Vegetation land fragmentation (VLF) is the foremost reason that accelerates the vegetation cover change. However, Sri Lanka has not been given sufficient attention to investigate VLF with case studies. Further, fragmentation patterns like dissecting, shrinking, and disappearing are still essential to investigate with empirical studies to comprehend the phases of VLF. Therefore, this study attempts to quantify the level of vegetation land fragmentation (LVLF) in the Western Province's Grama Niladhari Divisions (GNDs) from 2000 to 2020 by applying the Landscape Division Index (FRAGSTATS). It further analyses the patterns of VLF by using 200 fragmented locations. The key findings demonstrate that 54% of GNDs have more than 60% of the LVLF in the Gampaha District from 2000 to 2010. Although it has reduced up to 49% from 2010-2020, the Gampaha District remains in the highest position. It additionally discloses the significant increment in LVLF along the expressways from 2010 to 2020. 46% of fragmented patches indicate the mixed of dissecting, shrinking, and disappearing patterns. Therefore, the study provides methodological application and quantitative insights for planners to investigate VLF and its patterns.
FARU Journal, Dec 31, 2020
Community resilience assessments and minimizing the anticipated disruptions to vulnerable communi... more Community resilience assessments and minimizing the anticipated disruptions to vulnerable communities, is a broad topic in disaster studies. In common practice, most of the indicator-based resilience assessment studies rely on statistical aggregation methods of tabular data collected for macro administrative units, as it is readily available in most of the countries. However, this method confronts severe drawbacks in converting such data into micro-scale geospatial units. To address those issues, this study proposes to utilize the Dasymetric Mapping Technique in the geospatial population resilience assessments, as it is capable of identifying the micro level impact to the population distribution as a pixel representation. In order to geospatially demonstrate the population exposure, the study has selected three major flooding events occurred in Colombo, Sri Lanka. The results revealed a great applicability of the proposed method as a statistical approach which estimates the exposed population by over 90% accuracy. Therefore, the proposed method is recommended to be utilized as an efficient tool of community resilience assessment as it is highly accurate in downscaling the spatial distribution of population data.
Transportation Research Board 96th Annual MeetingTransportation Research Board, 2017
Journal of Traffic and Transportation Engineering, Oct 1, 2017
A network centrality-based trip attraction estimation method is proposed. The accuracy of the mod... more A network centrality-based trip attraction estimation method is proposed. The accuracy of the model is more than 75%. Space syntax and spatial analysis tools are used. Land use data is not required to estimate trip attraction in the proposed model. Effective tool for developing countries.
Urban Science
Assessing the influence of urban density on surface runoff volume is vital for guiding the built-... more Assessing the influence of urban density on surface runoff volume is vital for guiding the built-form expansions toward flood-resilient cities. This paper attempts to develop a spatial simulation framework to assess the impact of urban density on the level of surface runoff (SR), at the scale of the micro-watershed. This paper proposes a spatial simulation framework that comprehensively captures the influence of urban density dynamics over surface runoff. The simulation model consists of 13 proxies of urban density that are identified through a systematic literature review. The model is formulated through three case applications in Colombo, Sri Lanka; and validated statistically and empirically with reference to flooding events that occurred in 2021–2022. The possible planning interventions for reducing urban flooding are analyzed through an AI-based application of Decision Tree Analysis. The model results indicated that impervious coverage, open space ratio, and road density have t...
Transactions of the Institute of British Geographers
International trade and material mobility are both growing aspects of the global economy. Global ... more International trade and material mobility are both growing aspects of the global economy. Global material use has tripled since the 1980s, with global consumption of raw materials forecast to double again by 2050 (UNEP, 2016). As the globalisation of production and consumption continues to deepen, a third of this material volume is now traded across international borders (UNEP, 2020). As 'international commodity trade is becoming the mainstay of many of the world's
National Science Foundation of Sri Lanka, Sep 29, 2021
The book is published under the Creative Commons license: CC BY-NC-ND (Attribution-NonCommercial-... more The book is published under the Creative Commons license: CC BY-NC-ND (Attribution-NonCommercial-NoDerivs). CC BY-NC-ND includes the following elements: BY-Credit must be given to the creator; NC-Only non-commercial uses of the work are permitted; ND-No derivatives or adaptations of the work are permitted. Under this license, others may download this work and share it as long as they credit the creators, but they can't change it in any way or use it commercially. The license also allows for text-and data-mining.
10th International conference on Structural Engineering and Construction Management: Special Session on Disaster Risk Reduction, Oct 17, 2020
FARU Journal, 2020
Simulation of flood inundation in urban areas longer important, given the magnitude of potential ... more Simulation of flood inundation in urban areas longer important, given the magnitude of potential loss and disruption associated with non-river based, urban flooding. The complexity of the urban environment and lack of high-resolution topographic and hydrologic data compromise the development and implementation of models. Low impact development (LID) is technical know-how on a collection of sustainable practices that mimic natural hydrological functions including infiltration, evapotranspiration or use of surface runoff. Several studies have been carried out to discuss the impact of urbanization scenarios in reducing the urban flood risk in watershed scale in Sri Lanka. Yet, there is a gap remains in simulating the effectiveness of LID-based planning practices to reduce flood risk with the complex built form scenarios. In such a situation, this study attempts to make a significant contribution to simulate the variations of flood regulation functions under different high-intensive urb...
Urban areas in most of the developing countries, particularly in South Asia, have faced major cha... more Urban areas in most of the developing countries, particularly in South Asia, have faced major challenges in traffic management and control in recent decades. Cities in those countries have recently been witnessed a rapid economic growth and urban sprawl, resulting an accelerated increase of vehicle movements which create several problems such as traffic congestion, road accidents and air pollutions. Therefore, it is important to formulate urban transport strategies and identify strategic transportation infrastructure projects for investment, before reaching the critical situation (Nishimiya, Koizumi, & Shimada, 2012). However, most of the transport planning efforts in developing countries have been based on the conventional transport planning process (Hamad & Faghri, 2003) which is difficult to be adopted for forecasting traffic in developing countries (Jayasinghe, Sano, & Nishiuchi, 2015). The difficulties of adopting conventional multi-step modeling in developing countries includes inadequate database for planning especially on land-uses, inadequate technical expertise in local level planning and implementing agencies, lack of funds to collect data and use sophisticated software applications, etc. (Paul, 2009), (TRL report cited in Cairns, 2011), (Hamad, Faghri, & Li, 2015). We have developed a new method based on graph theory and centrality to simulate traffic volume, which can effectively works to overcome the above-mentioned difficulties. Accordingly, this paper introduces the developed method, i.e. ‘Network Centrality Assessment’-NCA, and application possibilities based on five case studies in selected Sri Lankan and Indian cities
Bhumi, The Planning Research Journal, 2020
Rapid urbanization and land cover changes have increased the quantity of storm water flow in urba... more Rapid urbanization and land cover changes have increased the quantity of storm water flow in urban areas. In Sri Lanka, local authorities generally prefer conventional drainage solutions rather than providing innovative sustainable solutions in storm water management (SWM). Due to the lack of technological innovations and required standards, development plans prepared by local authorities have not been able to identify alternative practices for storm water management. Hence, this study focuses on the identification of effective and sustainable urban storm water management alternatives in the context of developing countries. Sustainable SWM alternatives that are identified through the literature have been classified under four main sectors i.e. Buildings, Open Spaces, Roads and Sideways. Evaluation is based on the comparative analysis between the existing SWM strategy and alternative SWM strategies under qualitative and quantitative criteria. Analytical Hierarchical Process (AHP) was...
Social Sciences, 2021
During the last two decades, determining the urban boundaries of cities has become one of the maj... more During the last two decades, determining the urban boundaries of cities has become one of the major concerns in the urban and regional planning subject domains. Many scholars have tried to model the change of urban boundaries as it helps with sustainable development, population projections and social policy making, but such efforts have been futile, owing to the complex nature of urbanization and the theoretical and technical limitations of the proposed applications. Hence, many countries continue to rely on the administrative boundary demarcation, which rarely represent the actual urbanizing pattern. In such context, this study utilized the “Intersection-Based Clustered Network Model—(iCN Model)” to determine the urban boundaries of cities and selected Sri Lanka as the study area and considered few cities to test the model empirically, with satellite imagery classified urban boundaries. The findings of the study depict that the iCN Model is capable of capturing the complex and dyna...
Demand fluctuation, known as demand uncertainty, usually occurs under several circumstances not o... more Demand fluctuation, known as demand uncertainty, usually occurs under several circumstances not only in ordinary logistics firm but also humanitarian logistics. An objective of this study is to tackle the facility locations and allocations under demand uncertainty in a case study for a relief distribution. The demand uncertainty is handled by robust counterpart in Robust Optimization (RO) called an ellipsoidal uncertainty set, which is a novel approach that has never been fully applied so far solving on a multi-facility location network. Herein, we analyze and compare three distinct network designs to find the most cost efficient and robust network. The best model is selected through continuous improvement by routing optimization, leading to delivery cost reduction.
International Journal of Sustainable Development and Planning, 2021
The configuration of urban areas depicts the pattern of urban agglomeration that drives a country... more The configuration of urban areas depicts the pattern of urban agglomeration that drives a country's economy. Since the era of the early-industrial revolution, many scholars have been continuingly attempted to recognize the pattern of urban agglomeration in cities and regions. Nevertheless, such efforts had been in completed in capturing the complex nature of the agglomerations in modern cities. In such context, this study proposes a novel modeling approach to capture the pattern of urban agglomeration of a given region. In the proposed model, which is named as the intersection based clustered network model (iCN Model), the centrality of the road network is considered as the primary indicator in capturing the urban agglomeration pattern. The model was developed on the basis of the percolation theory and fractal geometry. The model distinguishes the agglomerated urban clusters and measures the self-similarity of the clusters of urban agglomeration. The results revealed that the urban agglomeration pattern derived from the iCN model corresponds with the satellite imagery derived the urban agglomeration pattern with an acceptable level of accuracy (> 71% of KAPPA) and it is proposed to be applied in spatial planning and transport planning practice.
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Papers by Amila Buddhika Jayasinghe
limits to adaptation. In recognition, there are number
of knowledge - transferring and awareness-building programmes
undertaken in developing countries. While many
of such programmes are focused on ‘introducing knowledge
into local systems’ this research emphasizes the ‘existences
of knowledge within local systems’ on climate change. The
study aimed to explore the level of awareness on local rainfall
and temperature variations among the different societal
groups referring to two selected case studies in coastal Sri
Lanka.
The research has built on three phases to (a)explain the
local climate variability over recent decades in Batticaloa;
(b)compare the identified most significant trends in rainfall
and temperature conditions with the level of awareness of
community on the trends to verify whether the local
knowledge exists within the system; (c)investigate whether
there are distinguishable differences among the societal
groups in terms of the level of awareness on climatic variations
as who aware better and worse respectively. The research
findings stressed the existence of strong observations
and memories on climate variations among local societal
groups at different degrees. Amongst, elderly people,
out-door workers who face difficulties as their livelihood
activities get frequently interrupted or rescheduled due to
weather changes and who depend on natural resources for
livelihoods are more aware on climatic variations while the
story of fracturing know-how among resettled communities
were emphasized. Findings urge strengthening the
knowledge sharing mechanisms within the local systems to
learn from each other in order to expand the limits to adaptation
and be more resilient to the emerging threats of climate
change.
most frequent climate change induced disaster in Asia, especially
in Sri Lanka. Meteorological records reveal that the
extreme rainfall events and frequency of occurrence of
floods is on increase over recent decades in most of the
cities in Sri Lanka. The assessment of vulnerability in terms
of temporal and spatial has been identified as a prerequisite
for adaptation planning, to make cities more resilient to climate
change. The current information base related to flood
hazard, which is produced by national agencies, is appropriate
for decision-making at national and provincial levels but
not at local level. Non-availability of reliable and reasonably
accurate flow of information among all stakeholders at local
level has hampered the formulation of ‘sustainable flood risk
adaptation strategies’ and the development of cities as climate
resilient. The production of flood hazard database for
a city using conventional tools (engineering and surveying)
is a very expensive and time consuming task. In this context,
the research has been carried out to test the applicability
of Participatory GIS (PGIS) as an alternative tool to
produce acceptable and realistic flood maps for the city in
shortest time period based on evidenced risk. This paper demonstrates the methodology adapted for PGIS
to collect and integrate the community knowledge and the
capability to develop reliable and realistic flood mapping
database for their own city. The overall contribution of this
work lies in demonstrating a grass-root level participatory
approach to collect, analyze and demonstrate flood records
for the development of sustainable flood risk adaptation
strategies in the process of making climate resilient cities.
study concluded that centrality measures are useful to measure transit demand of transit stops of Ahmedabad city with referring to both AMTS and BRTS.
As aimed in first sub objective this research, local closeness, Local Straightness, Global Closeness, Global Straightness, Betweenness A and Betweenness B were identified as appropriate centrality parameters that can use to measure street and transit network centrality of transit stops. The second sub objective was aimed to study the relationship between network centrality values and transit demand. In general, all three parameters revealed a significant correlation with transit demand. Specifically, BeB resulted significant relationship with transit demand of all types PT stops while LC, LS with small size PT stops and GC, GS with main transit hubs at city level. On that basis, four regression models (more than 80% accuracy) were developed to explain transit demand of different types of stops based on centrality values.
Aim of the third sub objective was to assess how centrality measures can be used to help the urban and transport planning process in Indian context. This research demonstrated three possible applications as planning and policy tool to identify the impact from network augmentation to transit demand of existing stops; to identify the impact from proposed land use plans to transit demand of existing stops; and to select location for transit stops or to plan multimodal system. Following the demonstrations, few transport design guidelines has been listed to increase transit demand of stops. Those applications have encouraged by comparing relative advantage of network centrality parameters in comparison to traditional transit demand modeling process.
Though this research successfully achieved desired objectives yet this can be developed into much advance analysis by doing further studies in relation to network centrality and passenger transfers, temporal change in transit demand and impact of city from on network centrality of PT systems. The methods developed in this research offers promise for transport planning applications in Indian context that it is urgently called for. This research has contributed to with a robust, dynamic planning tool that will guide transport planners in justifying their planning decisions in designing transportation policies for urban development’s Indian cities. Further, this is a positive contribution of emerging literature in spatial applications of network centrality parameters with a case of emerging Asian city.
On this background there is a need to introduce effective spatial analysis methods and promote their application in decision making process in Sri Lankan context. Therefore the main objective of this study is “test the applicability of connectivity analysis as a method to explain the pattern of urbanization (in Locations) of a selected region in Sri Lanka”.
For the purpose of testing the method, Kegalle district have selected as the study area. Relative connectivity values of each node in the study area were derived from the connectivity analysis technique. Then values are correlated with the existing urbanization level of the node, existing urbanization is measured by considering the number and scale of existing urban economic activities.
Since this is very first attempt in Sri Lankan context, in this study measured relative connectivity applying simple connectivity analysis method. Also study will be limited into one region in Sri Lanka.
The result reveals a significant correlation between the level of connectivity and the level of urbanization. It indicates that connectivity analysis method is capable enough to explain the pattern of urbanization in a region which is very difficult to extract and to analyze from the conventional approaches.