Open AccessCharacterization of Monsoonal Rainfall in the Sudano-Sahelian Zone of Northwestern Nigeria
Author(s) -
Abdullahi Umar,
Saadu Umar Wali,
Ibrahim Mustapha Dankani
Publication year - 2021
Publication title -
indonesian journal of earth sciences/indonesian journal of earth sciences
Language(s) - English
Resource type - Journals
eISSN - 2798-1134
pISSN - 2797-3549
DOI - 10.52562/injoes.v1i2.261
Subject(s) - monsoon , morlet wavelet , environmental science , wavelet transform , climatology , precipitation , geography , spearman's rank correlation coefficient , physical geography , geology , wavelet , meteorology , discrete wavelet transform , mathematics , statistics , artificial intelligence , computer science
Wavelet transform has been underutilized in characterization of rainfall (Real Onset Dates and Real Cessation Dates) in the study area. This study aims at the characterization of monsoonal rainfall. Daily rainfall data of four stations for the period 1981-2018 were collected from Nigerian Meteorological Agency. The Intra-seasonal Rainfall Monitoring Index (IRMI) was generated and used in determining the RODs and RCDs. The Mann–Kendall test was used to detect trends of the rainfall characteristics. Wavelet transform was used in modelling RODs and RCDs. Findings revealed that RODs vary between stations. There is low (0.3 Spearman’s Rank r) correlation between latitudes and Early Cessations (ECs) of rains. The Morlet wavelet analysis revealed that from 1999 to 2018, there were more of EOs and NOs especially in Kano station. We conclude that from 1981 to 2018 there has been a minimal increase in the retreat dates of rainfall in the study area.