Time Series Analyses of Total Monthly Precipitation and Mean Monthly Temperature for Sustainable Drought Management in Mannar, Sri Lanka

Article type: Research Article

Authors: Ranasinghe, Gayani^a | Piyadasa, Ranjana U.K.^{b; *}

Affiliations: [a] Department of Town and Country Planning, University of Moratuwa, Sri Lanka | [b] Department of Geography, University of Colombo, Sri Lanka

Correspondence: [*] Corresponding Author. [email protected]

Abstract: Sri Lanka is a rapidly urbanizing country with 70% of its urban population and 80% of national economic infrastructure concentrated along the coastal cities of the country which are more susceptible for climate change impact and disaster risks. Drought is one of the worst natural disasters that affect Sri Lanka and create numerous problems by making adverse impacts to the economy of the country. Forecasting the drought period before the occurrence and implementation of appropriate drought management strategies may help to reduce the disaster risk and its related impacts mainly in coastal cities of Sri Lanka. Meteorological droughts eventually trigger other forms of droughts in Sri Lanka and it leads to water scarcity due to insufficient precipitation and high evaporation or combination of both. This study analyses the time series characteristics of total monthly precipitation and mean monthly temperature from year 1950 to 2013 for Mannar urban development area located in coastal zone of Sri Lanka to identify specific drought period in Mannar urban development area since it has been changing due to different climate change scenarios. Brainstorming approach was applied to identify sustainable drought management strategies and to validate the above identified drought period as an outcome of time series analyses and location specific information on drought in ground situation by consulting community and other prospective stakeholders in the area. Weather data was analyzed applying decomposition method of time series analyses which include trend, cycle, seasonal and irregular components. Considering results of time series analyses, high temperature and severe drought situation can be identified in Mannar urban development area from March to September while observing highest rainfall during October to December every year. The total monthly precipitation in Mannar has been increasing by 0.0194 mm while mean monthly temperature is increasing by 0.0004°C. As drought management strategies, the excess water of three months rainy season could be better utilized by developing new irrigation tanks and existing abundant tanks in many parts of the Mannar urban development area. Rain water harvesting and introducing new crops suitable for changing climatic conditions will be encouraged for sustainable dry farming activities in Mannar urban development area. Vertical greenery on walls, greenery on roof tops and green paving are being planned and building design strategies that can be promoted to reduce the heat environment of Mannar urban development area in sustainable Mannar.

Keywords: Drought, Forecasting, Reducing the risk

DOI: 10.3233/JCC-160014

Journal: Journal of Climate Change, vol. 2, no. 2, pp. 15-23, 2016