Abstract
The semi arid region of Nigeria is experiencing the impact of climate change. Daily rainfall records from 1976-2011 were used to examine the impact of climate change on the hydrological growing season at Kano. The onset, cessation and length of rainy season at Kano were determined. The estimated parameters were subjected to time series analysis. Trend lines and fitted linear trend line equations for each of the parameters were produced. The Mann-kendall tau (τ) statistic was used to investigate the significance of these trends. The results show that the rainy season has progressively been starting late as signified by the positive trend line equation of y = 0.183x+41054. Trend analysis showed that the rains ceases earlier in recent decades. This is corroborated by the negative linear trend line equation (y = -0.438x+41184). The results also indicated that the hydrological growing season is progressively shortening. The implication of late onset and early cessation is the decreasing length of the hydrological growing season as indicated by a negative linear trend line equation (y = -0.395x+1289). The length of the hydrological growing season has decreased from an average of about 140±5 days to about 120 ±5 in the state. The Mann-kendall tau (τ) statistic showed significant trends for all the parameters at 0.05 level. The results of this study have great implications for both surface and underground water resource management, agriculture and sustainable food security not only for the Kano region but Nigeria at large. Increased irrigation agriculture is eminent in this environment.
Highlights
Climate, rainfall is a limiting factor in agricultural production in the arid region of the tropics, northern Nigeria inclusive
The onset and cessation dates, on which the length of Hydrological Growing Season (HGS) depends, were first determined before the HGS was calculated for the study area
This research has brought to the fore that the rainy season has of recent been starting late but ending earlier, progressively shortening the duration of the hydrological growing season at Kano
Summary
Rainfall is a limiting factor in agricultural production in the arid region of the tropics, northern Nigeria inclusive. A shift in the average climatic conditions of an area would, lead to a shift in the pattern of agricultural activities in the area. Global warming has and is still altering the global rainfall regime. Extremes of this climatic parameter are on the increase in some areas while its average is on the decrease at some. The area suitable for agriculture, the length of the growing season and yield potential, along the margins of the arid and semi arid areas of Africa are expected to decrease. In some countries in Africa, yields from rain-fed agriculture could be reduced by up to 50%. Rainfall is the most critical factor in the estimation of the Hydrological Growing Seasons (HGS) in the tropics
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
