Study on probability distribution and trends of various climatic parameters in Bangladesh

Abstract

Probability Distribution and trend analysis are an important concern for a resource constraint country like Bangladesh. Reliable estimate of probability distribution and trend analysis with respect to various climatic parameters are a valuable guide for policy makers in determining return period and risk analysis of flood, drought, cyclones and other extreme climate events for the fixation of infrastructure required in future. Again, from trend analysis, gradual change of climatic phenomenon that is, global warming, global dimming, wetter summer, drier winter etc can be understood. Standard set of monthly, annual and seasonal data of different climatologic parameters of different meteorological stations in Bangladesh are analyzed in this study have been collected from BMD (Bangladesh Meteorological Department) and BARC (Bangladesh Agricultural Research Council). Different climatologic parameters are rainfall, temperature, evaporation, relative humidity, bright sunshine hours, wind speed & solar radiation. Trend analysis and probability distribution study has been carried out to analyze the data series. From trend analysis it can be understood that there is a gradual change of climatic phenomenon in Bangladesh over the last three decades. From the probability distribution study of different climatic parameters, it can be understood that, particular variable follows particular probability distribution. From the analysis of weighted average method, best fitted distribution has been fixed for a particular variable of a particular climatic parameter. From the analysis of different climatic parameters, it has been predicted that Bangladesh is in the risk of climate change i.e. global warming due to increase in overall temperature. Again, increasing tendency of relative humidity along with increasing rate of rainfall in summer predominating wetter summer and decreasing tendency of relative humidity along with decreasing rate of rainfall in winter indicates drier winter.