Anthropogenic activities associated with flood disaster: study based on Akurana area

Abstract

Every year in Sri Lanka, continuous monsoon rains are available from May to September in the South Westerly winds and from September to February due to Northeast monsoon winds. Sri Lanka receives an increased rainfall during the South West and North East monsoon seasons habitually. But today it is change due to climate change. This extraordinary trend is causing yearly flooding and increasing social and economic losses. Although the research area Akurana is situated in the Kandy- Matale A9 highway, which belongs to the Harispattuwa electorate in the kandy district of Central province, one of the Wet zone of Srilanka. It has been faced flood disasters for the past two decades. There is no forecast for today’s flash floods. Because of human activity rather than the influence of natural weather conditions such as Monsoon winds, Tropical cyclones and Hurricanes. The region received less than 60 MM of rainfall during the period 2006-2018. There is no change in the rainfall pattern here. If we look at the level of flooding that occurs every year, the human factors are influencing the flooding and the impacts. Pinga oya is the main river that causes floods. This oya is a tributary of the Mahaweli river which mainly runs through Akurana, Kudugala, Ampathenna and the finally reaches to the river Mahaweli at Katugastota. The urbanization of Akurana is increasing due to the population. Due to economic activity, the width of the river has shrunk due to the construction of various buildings, bridges, and walls to cover Pinga oya. The Kandy city boundary is rapidly expanding and is undergoing rapid urbanization moving to nearby Akurana. Here the city’s vertical construction, improper bridges development projects, dumping of river waste and lack of good drainage are the reasons for the flood. This can be determined by static factors such as the Pinga oya’s length, width, beneficial drainage of the pinga oya, its capacity, raw surface area storage, and the changing factors such as slope, flood control and the river’s normal functioning. Primary and Secondary data were used for this research. As primary data field observation, Questionnaire survey, discussion, interviews were used. As secondary data District Secretariat of Akurana, Climatic data, previous researches, Internet were used. And collected data were analyzed by GIS, SPSS, and MS. Excel software. And main objective in this research is identification of human causes of frequent flooding in Akurana, and Finding ways to prevent it. Finalized of this research is to prevent the flash floods caused by human activities to develop sustainable development with proper planning and to take action to mitigate the social and economic losses from such disasters in the future.