Pattern Recognition of Rainfall Using Wavelet Transform in Bangladesh

Abstract

The aim of the study is to explore the regional variation of changing patterns of rainfall in Bangladesh using wavelet transform. The study is completed using rainfall variation of the five regions of Bangladesh as Dhaka, Cox's Bazar, Rajshahi, Bogra and Sylhet. The duration of the study period was 69 years for Dhaka, 64 years for Cox's Bazar, 40 years for Rajshahi, 54 years for Bogra and 55 years for Sylhet. The results of the wavelet analysis reveals that, in Rajshahi the amount of rainfall are decreasing in a significant rate among the other study regions. It also explores the annual periodicity of rainfall for all the study regions along with a special 6-month periodicity in the Cox's Bazar. In addition, this analysis also explores a dominating 3 -4 year cycle of rainfall in all the study regions. Besides the climate change in Cox's Bazar and Sylhet are pretty much alarming.

Study on Long-Term Variation in Hydrometeorology Data and Correlation and Causality of Grobal-Scale Phenomena in the Bengal Region

“…For example, Lairenjam et al 39) analyzed the long-term trends of precipitation, average temperature, and number of rainy days at 30 meteorological stations in northeastern India for 30 years and observed significant changes. In Bangladesh, Rahman et al 40) analyzed the pattern change in precipitation for up to 69 years using Wavelet analysis. In addition, Nury and Hasan 41) analyzed the correlation between the change tendency of the Standardized Precipitation Index (SPI) and SOI for 30 years.…”

Power Spectrum Inception of F2 Layer at Solar-Terrestrial Region of Pakistan

“…This bestows the accurate power scale of the ionospheric observations and consequently, the GWS is a simple and powerful approach to illustrate the dynamics of ionosphere and accommodating to defined spatial and temporal anomaly in the pattern of the F 2 region and compared with bordering regions. The GWS structure is initially prescribed using distribution of different levels (Rahman et al 2018). The Fig.…”

Power Spectrum Inception of F2 Layer at Solar Terrestrial Region of Pakistan

“…This bestows the accurate power scale of the ionospheric observations and consequently, the GWS is a simple and powerful approach to illustrate the dynamics of ionosphere and accommodating to defined spatial and temporal anomaly in the pattern of the F2 region and compared with bordering regions. The GWS structure is initially prescribed using distribution of different levels (Rahman et al 2018).…”

“…Moreover, the smooth deviation in the continuous type wavelet is used for smoothly nature function, for example a Morlet wavelet (Jan et al 2019). This concept utilized to highlight the hidden points of the signal in uninterrupted wavelet and gives more localization in time and frequency that are explained by the Fourier transform (Rahman et al 2018). On the other hand, this study focus on the amplitude and time that is a convolution functions of the Morlet wavelet that can be selected to justify the cyclic character of the observations (Adewale et al 2017).…”