Global Journal of Science Frontier Research, H: Environment & Earth Science, Volume 21 Issue 6

value of r 2 (0.47) indicates a 47% variability in the mean minimum temperature in the study area. This results conform with the findings of Okoroha, (2018). Source: Author’s computation, 2021. All the annual temperature was reading high with just little variations from 2003.-2018 respectively (Fig. 1). This probably could be because of the fact that, it’s a natural phenomenon with natural occurrences (Ayoade, 2004). And the increased temperature could further be traced to agricultural practices as well which resulted to the upsurge of temperature this in the area. i.e logging down of trees, setting of bushes on fire in search for games could be probably be a cause or factors to this high range of temperature witnessed within this period in the study area (Ayoade, 2004). iii. Rainfall The trend of rainfall was also taken into consideration in assessing the variability trend of climatic variables in the study area. The trend chart depicted in Figure 4.3 shows the nature of the trend of mean rainfall in the study area between 2003 and 2018. From the trend chart, it can be observed that the trend line is upward in nature, signifying an increasing trend in the average (mean) rate of rainfall in the study area. Although some years like 2006, 2009, 2011, 2015, and 2017 recorded slight decline in rainfall, this decline was not significant to warrant step fall in the trend plot. During these periods mean rainfall data recorded were 27.4mm, 36.5mm, 30.8mm, 87.1mm, and 74.5mm respectively. More so, the significant increase in rainfall (average) in the study area was experienced in the year 2014. During this period, the mean rainfall recorded was 102.1mm. The highest mean rainfall recorded in the study area was in the year 2016. Mean rainfall during this period was recorded at 107.1mm, while the lowest rainfall experienced, and was in the year 2006, which was recorded at 27.4mm. The trend equation suggests a goodness of fit of the trend plot, while the value of r 2 (0.629) indicates a 63% variation in the mean rainfall recorded in the study area between 2003 and 2018. This result conforms with the studies of Bulus (2018). y = -0.104x + 231.7 R² = 0.47 19.5 20 20.5 21 21.5 22 22.5 23 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 Mean Minimum Temperature (oC) Year(s) Mean Minimun Temperature Linear (Mean Minimun Temperature) Relationship between Climatic Variables and Incidence of Malaria and Asthma in Keffi Local Government Area of Nasarawa State, Nigeria 1 Global Journal of Science Frontier Research Volume XXI Issue VI Year 2021 57 ( H ) © 2021 Global Journals Version I Fig. 2: Trend chart mean minimum temperature ( o C) in the study area