An Estimation of Rainfall Anomaly Index and Its Impact on Crop Production in Yola and Environs

Abstract:

Rainfall anomalies of a given geographical area over a long period is considered as the major hydro-meteorological variable that caused climatic change and also a dominant factor affecting crop production which requires ardent attention of research. The paper aimed to estimate rainfall anomaly index and its impacts on crop production in Yola and environs. The climatic raw data for the periods of forty (40) years were computed and estimated using rainfall anomaly index (RAI10) techniques developed by van Rooy. The findings revealed that the study area falls under wetness conditions for the period of 19 years, normal wetness occurred in 6 years and dry conditions were estimated in 15 years which mostly occurred in the recent decades (2002, 2003, 2004, 2005, 2006, 2007, 2008, 2011 and 2013) which signifies apparent climatic change of rainfall deficit and consequently affects crop growth respectively. However, 2016 and 2012 were estimated as extremely and very wet conditions that led to exacerbated flooding in the area which damaged hundred hectares of farmlands. Farmers in the area are therefore recommends to use an improved seeds variety with low water use efficiency and drought resistant crop varieties with the aim of coping with dryness conditions. Similarly, farming on flood prone areas should be avoided and preventing measures on sediment deposition should also be considered recommendable.