Accepted Papers
  • A Comparison of Small Area Estimation & Kriging in Estimating Rainfall in Sri Lanka
    Kalum Udagepola,Scientific Research Development Institute of Technology, Australia
    ABSTRACT

    Accurate prediction of rainfall is crucial for a country like Sri Lanka as its economy is mainly based on agriculture. Many statistical techniques have been used in the past to estimate rainfall. The main purpose of this study is to evaluate and compare accuracy of two techniques in estimating seasonal rainfall in Sri Lanka. The two techniques that were compared are namely; small Area Estimation and Kriging. The four rainfall seasons considered is first inter-monsoon, south west monsoon, second inter monsoon and Northeast monsoon. Monthly rainfall data collected at 75 rain gauges during the year 2011 were used in this study. Data were withheld from 14 stations were then used to compare the predictions of seasonal rainfall using both techniques. Root Mean squared error, Correlation coefficient and scatter plots of observed and fitted seasonal rainfall values were used to compare the two techniques. Comparison revealed that Kriging provided better predictions for rainfall in First Inter- monsoon and Southwest-monsoon. Predictions of both techniques were not much successful in estimating rainfall in Second Inter- monsoon. Small area estimation yielded more accurate predictions for rainfall in Northeast monsoon.