Faculty of Engineering

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Start date: 2022Subject: search.filters.subject.Sri Lanka

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Now showing 1 - 5 of 5
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    PublicationOpen Access
    SUCCESSFUL DELIVERY OF PUBLICPRIVATE PARTNERSHIP (PPP) IN THE CONSTRUCTION PROJECTS OF SRI LANKAN HIGHER EDUCATION SECTOR
    (https://ciobwcs.com, 2022-06-24) Kandawinna, N; Mallawaarachchi, H; Vijerathne, D
    To gain economic advantages in the competitive world, governments tend to adopt new financing methods in construction projects. Accordingly, Public-Private Partnership (PPP) projects are a popular choice mainly due to the reduction in transaction cost and innovation. PPP projects have spread from the typical use on infrastructure projects such as airports, roads, railways, ports, and water sanitation to the more recent use for projects in the higher education sector such as universities and colleges. Thus, adopting PPP for the higher education sector related construction projects in Sri Lanka is vital to consider. Accordingly, this research aims to observe the Critical Success Factors (CSF) for the successful delivery of PPP projects in the construction projects of the higher education sector in Sri Lanka. A comprehensive literature review was first conducted to identify the CSFs of PPP in higher education construction projects and 22 CSFs were identified. The survey method was used under quantitative phenomenon since this research required evaluating the identified CSFs. The identified factors were evaluated through a questionnaire survey, which was conducted among the 30 selected professionals who are aware on PPPs, such as Quantity Surveyors, Project Managers, Government Professionals, and Academic Professionals. As the key findings derived through analysis, “communication between parties”, “transparency in the procurement process”, financial capability and support”, “project technical feasibility” and “appropriate risk allocation and risk-sharing” were determined as the top five CSFs for PPP projects in the higher education sector related construction projects in Sri Lanka. Furthermore, strategies were also proposed to ensure the successful implementation of CSFs in the higher education sector in Sri Lanka.
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    PublicationOpen Access
    CIRCULAR ECONOMY (CE) BASED MATERIAL SELECTION: DEVELOPMENT OF A CE-BASED ‘10R’ EVALUATION FRAMEWORK FOR BUILDING CONSTRUCTION PROJECTS IN SRI LANKA
    (https://ciobwcs.com, 2022-06-24) Wanaguru, K; Mallawaarachchi, H; Vijerathne, D
    The building construction industry is globally identified as one of the major consumers of materials. Thus, the material wastage in building construction projects is very excessive. In the Sri Lankan construction industry, it was identified that the main reason for generating material wastage is the absence of proper material selection criteria. The concept of Circular Economy (CE) has been obtained the world attention in reducing material wastage in the construction industry as it targets zero waste and pollution throughout the lifecycle of materials. Applying CE principles in the material selection not only reduces the wastage of materials but also reduces the use of virgin materials. Hence, this research aimed for developing a CE-based 10R evaluation framework for materials selection in order to reduce the wastage of materials in building construction projects in Sri Lanka. A comprehensive literature review was first conducted to review the concept of CE, CE principles and its importance for reducing material wastage in the construction industry. Deductive approach was chosen as the suitable research approach in this study. Survey method was applied as the suitable research strategy under quantitative phenomenon. A questionnaire survey was conducted with a conveniently selected sample of 58 industry professionals to collect the data. The collected data were analysed by using Weighted Mean Average (WMA) technique. As key findings derived through analysis, the level of importance of each CE principle for selection of materials was determined. Accordingly, the CE-based 10R evaluation framework for material selection was developed as the main implication of this research. Various strategies, such as reusing demolition materials, adopting prefabricated building components, developing plans to on-site recycle and using alternative materials were also proposed to implement the all identified CE principles assuring a successful application of the developed framework.
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    PublicationOpen Access
    Statistical Evaluation and Trend Analysis of ANN Based Satellite Products (PERSIANN) for the Kelani River Basin, Sri Lanka
    (Hindawi, 2022-08-31) Perera, H; Gunathilake, M. B; Panditharathne, R; Al-mahbashi, N; Rathnayake, U
    Satellite-based precipitation products, (SbPPs) have piqued the interest of a number of researchers as a reliable replacement for observed rainfall data which often have limited time spans and missing days. The SbPPs possess certain uncertainties, thus, they cannot be directly used without comparing against observed rainfall data prior to use. The Kelani river basin is Sri Lanka’s fourth longest river and the main source of water for almost 5 million people. Therefore, this research study aims to identify the potential of using SbPPs as a different method to measure rain besides using a rain gauge. Furthermore, the aim of the work is to examine the trends in precipitation products in the Kelani river basin. Three SbPPs, precipitation estimation using remotely sensed information using artificial neural networks (PERSIANN), PERSIANN-cloud classification system (CCS), and PERSIANN-climate data record (CDR) and ground observed rain gauge daily rainfall data at nine locations were used for the analysis. Four continuous evaluation indices, namely, root mean square error (RMSE), (percent bias) PBias, correlation coefficient (CC), and Nash‒Sutcliffe efficiency (NSE) were used to determine the accuracy by comparing against observed rainfall data. Four categorical indices including probability of detection (POD), false alarm ratio (FAR), critical success index (CSI), and proportional constant (PC) were used to evaluate the rainfall detection capability of SbPPs. Mann‒Kendall test and Sen’s slope estimator were used to identifying whether a trend was present while the magnitudes of these were calculated by Sen’s slope. PERSIANN-CDR performed well by showing better performance in both POD and CSI. When compared to observed rainfall data, the PERSIANN product had the lowest RMSE value, while all products indicated underestimations. The CC and NSE of all three products with observed rainfall data were also low. Mixed results were obtained for the trend analysis as well. The overall results showed that all three products are not a better choice for the chosen study area.
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    PublicationOpen Access
    Spatio-Temporal Rainfall Variability and Concentration over Sri Lanka
    (Hindawi, 2022-09-28) Pawar, U; Karunathilaka, P; Rathnayake, U
    Changes in precipitation patterns significantly affect flood and drought hazard management and water resources at local to regional scales. Therefore, the main motivation behind this paper is to examine the spatial and temporal rainfall variability over Sri Lanka by Standardized Rainfall Anomaly Index (SRAI) and Precipitation Concentration Index (PCI) from 1990 to 2019. The Mann–Kendall (MK) trend test and Sen’s slope (SS) were utilized to assess the trend in the precipitation concentration based on PCI. The Inverse Distance Weighting (IDW) interpolation method was incorporated to measure spatial distribution. Precipitation variability analysis showed that seasonal variations are more than those of annual variations. In addition, wet, normal, and dry years were identified over Sri Lanka using SRAI. The maximum SRAI (2.27) was observed for the year 2014 for the last 30 years (1990–2019), which shows the extremely wet year of Sri Lanka. The annual and seasonal PCI analysis showed moderate to irregular rainfall distribution except for the Jaffna and Ratnapura areas (annual scale-positive changes in Katugastota for 21.39% and Wellawaya for 17.6%; seasonal scale-Vavuniya for 33.64%, Trincomalee for 31.26%, and Batticaloa for 18.79% in SWMS). The MK test, SS-test, and percent change analyses reveal that rainfall distribution and concentration change do not show a significant positive or negative change in rainfall pattern in Sri Lanka, despite a few areas which experienced significant positive changes. Therefore, this study suggests that the rainfall in Sri Lanka follows the normal trend of precipitation with variations observed both annually and seasonally.
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    PublicationEmbargo
    Variation of Leaf Area Index (LAI) under Changing Climate: Kadolkele Mangrove Forest, Sri Lanka
    (Hindawi, 2022-10-10) Makumbura, R.K; Rathnayake, U
    Mangroves are an essential plant community in coastal ecosystems. While the importance of mangrove ecosystems is well acknowledged, climate change is expected to have a considerable negative impact on them, especially in terms of temperature, precipitation, sea level rise (SLR), ocean currents, and increasing storminess. Sri Lanka ranks near the bottom of the list of countries researching this problem, even though the scientific community's interest in examining the variation in mangrove health in response to climate change has gained significant attention. Consequently, this study illustrates how the leaf area index, a measure of mangrove health, fluctuates in response to varying precipitation, particularly during droughts in Sri Lanka's Kadolkele mangrove forest. The measurements of the normalized difference vegetation index (NDVI) were used to produce the leaf area index (LAI), which was then combined with the standard precipitation index (SPI) to estimate the health of the mangroves. The climate scenario, RCP8.5, was used to forecast future SPI (2021–2100), and LAI was modeled under the observed (1991–2019) and expected (2021–2100) drought events. The study reveals that the forecasted drought intensities modeled using the RCP8.5 scenario have no significant variations on LAI, even though some severe and extreme drought conditions exist. Nevertheless, the health of the mangrove ecosystem is predicted to deteriorate under drought conditions and rebound when drought intensity decreases. The extreme drought state (-2.05) was identified in 2064; therefore, LAI has showcased its lowest (0.04). LAI and SPI are projected to gradually increase from 2064 to 2100, while high fluctuations are observed from 2021 to 2064. Limited availability of LAI values with required details (measured date, time, and sample locations) and cloud-free Landsat images have affected the study results. This research presents a comprehensive understanding of Kadolkele mangrove forest under future droughts; thus, alarming relevant authorities to develop management plans to safeguard these critical ecosystems.