Standardized Precipitation Index Valuation of Climate Change in Bamenda

Rainfall events across the earth’s surface, for varied reasons, are unevenly distributed. Such variation is reflective of the availability of water for human use and the cycles of activities like agriculture [1]. In this era of global environmental changes, a sound knowledge of the climate of human-populated territories is indispensable, considering the current phenomenon of climate change [2]. Rainfall variability, which refers to changes in the amount of rain received in a specified geographic space within a defined period, can be daily, monthly, seasonal or annual. Precipitation change averaged over global land areas is low before 1951 and medium afterwards because of insufficient data, particularly in the earlier periods of the records [3]. The long-term mean rainfall for a month, season or year does not often indicate the regularity with which given amounts of rainfall can be expected, especially in the low latitudes where rainfall is known to be highly variable in its incidence from one year to another [1]. In the tropics, rainfall tends to be more variable seasonally than annually. Rainfall variability is a measure of the degree of likelihood that the mean amount of rainfall may be repeated each year, season or month depending on the period under consideration [4-6]. The paper bridges some methodological gaps in previous studies on climate variability in Cameroon. Ngakfumbe [7] analysed rainfall probability and reliability over Cameroon, using Standard Deviation (SD) and Coefficient of Variation (CV), with no other climatic index. Molua and Lambi [8] made a descriptive analysis of rainfall variability and its impact on water resources over Cameroon, to note that mean annual rainfall decreases inversely to latitude, without specifying the indices that show regional variations. Tume [9-11] assessed the susceptibility of water resources to climate variability on the Bui Plateau, using the Rainfall Seasonality Research Article