Dynamics of Hydrological Growing Season at Kano as Evidence of Climate Change
Asian Journal of Agricultural Sciences
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
... 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.