STATISTICAL ANALYSIS AND TRENDS OF DRY DAYS IN SYLHET REGION OF BANGLADESH

Abstract

The rainfall distribution in Bangladesh is not uniform and reflecting topography. Hilly Sylhet region receives substantial rainfall every year compare to other regions of Bangladesh. Though Sylhet region is less vulnerable to drought but weather pattern is not constant and changing day by day. Hence as a part of drought analysis, behavior of dry days is important. This study focuses on dry days pattern and associated changes from daily records of last 54 years for Sylhet region. Monthly, yearly and seasonal variations of dry days were analyzed to check for major changes. In order to investigate extreme dry events, time history of monthly dry days data were transformed into frequency domain using the Fast Fourier Transform (FFT). Variability of dry days in time scale was also checked from filtered signals which is very useful for drought analysis, agricultural development and disaster management for the north-east region of Bangladesh.