Abstract:
With the advent of rapid developmental activities in the Eastern
province of Sri Lanka in the post-war scenario, the government’s mandates
focus on reviving plans for the agricultural sector to meet the growing
demands of the nation. Understanding the behavior of the climatic
parameters of a geographical area is a prerequisite for any effort towards
developing the agriculture sector. Climatic variability, especially the
unpredictability of rainfall regimes is a major constraint for agricultural
planners when it comes to deciding the time of planting in the Trincomalee
district. The aim of this paper is to explain and analyze the temporal
behavior of long-term monthly retrospective rainfall data of the district using
ARIMA technique. This paper focuses on a time-series modeling approach to
understand the behavior of rainfall patterns for the period from January 1952
to December 2009. The ARIMA model analysis proved to be a very valuable
technique in forecasting climatic trends for Agro-environmental planning
(Sabita Madhvi Singh, 2012). Rainfall time series data are analyzed using
ARIMA statistical techniques to study the annual and seasonal trend of
climates, fluctuation and variability. Various seasonal ARIMA models were
tried in this respect. Key findings indicate that the rainfall patterns in the
study area modeled as ARIMA(1,0,0)(1,1,1)12, as such the rainfall
predominantly depending on nonlinear trend and seasonal pattern of order
12 with the autoregressive of order one combined with lag12 process. This
indicates that comprehensive forecasting model for rainfall in Trincomalee
district is arrived. Further research is needed to focus on the influences of
non-endemic and regional-to-global climatic phenomena
