Browsing by Author "Wimalaratne, P."

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Debris Run-Out Modeling Without Site-Specific Data
(International Journal of Advanced Computer Science and Applications, 2020) De Silva, N.M.T.; Wimalaratne, P.
Recent population growth and actions near hilly areas increase the vulnerability of occurring landslides. The effects of climate change further increase the likelihood of landslide danger. Therefore, accurate analysis of unstable slope behavior is crucial to prevent loss of life and destruction to property. Predicting landslide flow path is essential in identifying the route of debris, and it is essential necessary component in hazard mapping. Horvever, current methodologies of determining the flow direction of landslides require costly sitespecific data such as surface soil type, categories of underground soil layers, and other related field characteristics. This paper demonstrates an approach to predict the flow direction without site-specific data, taking a large landslide incident in Sri Lanka at Araranyaka region in the district of Kegalle as a case study. Spreading area assessment was based on deterministic eight-node (D8) and Multiple Direction Flow (MDF) flow directional .algorithms. Results acquired by the model were compared with the real Aranayaka landslide data set and the landslide hazard map of the area. Debris paths generated from the proof of concept software tool using the D8 algorithm showed greater than 760/o agreement, and MDF showed greater than 87oh agreement with the actual flow paths and other related statistics such as maximum width of the slide, run-out distance, and slip surface area.
A Randomized Controlled Trial of a brief Intervention for delayed psychological effects in snakebite victims
(Public Library of Science, 2015) Wijesinghe, C.A.; Williams, S.S.; Kasturiratne, A.; Dolawaththa, N.; Wimalaratne, P.; Wijewickrema, B.; Jayamanne, S.F.; Isbister, G.K.; Dawson, A.H.; Lalloo, D.G.; de Silva, H.J.
BACKGROUND: Snakebite results in delayed psychological morbidity and negative psycho-social impact. However, psychological support is rarely provided to victims. AIM: To assess the effectiveness of a brief intervention which can be provided by non-specialist doctors aimed at reducing psychological morbidity following snakebite envenoming. METHOD: In a single blind, randomized controlled trial, snakebite victims with systemic envenoming [n = 225, 168 males, mean age 42.1 (SD 12.4) years] were randomized into three arms. One arm received no intervention (n = 68, Group A), the second received psychological first aid and psychoeducation (dispelling prevalent cultural beliefs related to snakebite which promote development of a sick role) at discharge from hospital (n = 65, Group B), while the third received psychological first aid and psychoeducation at discharge and a second intervention one month later based on cognitive behavioural principles (n = 69, Group C). All patients were assessed six months after hospital discharge for the presence of psychological symptoms and level of functioning using standardized tools. RESULTS: At six months, there was a decreasing trend in the proportion of patients who were positive for psychiatric symptoms of depression and anxiety from Group A through Group B to Group C (Chi square test for trend = 7.901, p = 0.005). This was mainly due to a decreasing trend for symptoms of anxiety (chi-square for trend = 11.256, p = 0.001). There was also decreasing trend in the overall prevalence of disability from Group A through Group B to Group C (chi square for trend = 7.551, p = 0.006), predominantly in relation to disability in family life (p = 0.006) and social life (p = 0.005). However, there was no difference in the proportion of patients diagnosed with depression between the three groups (chi square for trend = 0.391, p = 0.532), and the intervention also had no effect on post-traumatic stress disorder. CONCLUSIONS: A brief psychological intervention, which included psychological first aid and psychoeducation plus cognitive behavioural therapy that can be provided by non-specialist doctors appeared to reduce psychiatric symptoms and disability after snakebite envenoming, but not depression or post-traumatic stress disorder. TRIAL REGISTRATION: Sri Lanka Clinical Trials Registry: SLCTR/2011/003.