Drought Characterization Using Standardized Precipitation Index for Sustainable Crop Farming in Yola, North-East Nigeria

Abstract

In this paper, Standardized Precipitation Index (SPI) technique was employed to assess drought characteristics in Yola, Adamawa State. Monthly rainfall data for the period of fifty (50) years (1969-2018) was obtained from Upper Benue River Basin Development Authority, Yola. The data were analyzed to characterized drought using SPI method. The result shows that within the 50 years study period, Yola experienced 20 years (40 %) of drought events. The years 1973, 1987 and 2002 were classified as extremely dry and 1971, 1974 and 2006 as severely dry respectively. Analysis of drought duration in Yola shows that the area had few cases of sporadic events and more of one year with 4 incidences (50%) prolong back to back events of two years constitute 25 % of drought duration. Decade temporal analysis shows that the fourth decade 1999-2008 recorded the highest frequency with 7 incidences. Similarly, sever and extreme drought events were recorded in 3 years (6 %) each in the area. Generally, 1969-1978 and 1999-2008 decades were characterized as mildly drought events (SPI =-0.99 to 0). Out of the 40 % of drought events 18 % occurred with mildly drought, moderately drought (-1.0 to -1.49) constituted 10 % and 6 % were of the severely dry and extremely dry conditions (-1.5 to -3.0) respectively. Implications of findings were thoroughly discussed as it affects sustainable farming in the area. Due to seasonal drought episode identified in this study, farmers are therefore recommends to early maturing crop varieties and also adopt the use of soil water conservation techniques. Government should also provide drought resistant seedlings and the establishment of a drought monitoring and mitigation centre.