Recent Changes in Rainfall and Diurnal Temperatures in Selected Cities in Tropical Monsoon and Tropical Savanna Climatic Zones of Southern Nigeria (Published)
Statistical approach has been used to analyze trends of rainfall and diurnal temperatures in Southern Nigeria. Daily data from Nigerian Meteorological Agency from 2000 to 2019 in five stations are used for the analysis. XLSTAT software is employed in generating the Mann-Kendall (MK) trends for rainfall, DTR and, in plotting graphs. The results show that annual rainfall amount is on increasing trend in all the stations with the lowest increase of 1.2 mm/year in Owerri to 11.46 mm per year in Ibadan. The increasing annual trends, even though insignificant in all the stations except in Ikeja, is enough to cause negative impacts on the environment. Also, diurnal temperatures are in anti-correspondence with rainfall amount.
Keywords: Rainfall, Southern Nigeria, cities, diurnal temperatures, tropical monsoon, tropical savanna climatic zones
Climate Change and Perceived Climate Hazards: A Trend Analysis in Southeast Nigeria (Published)
Current global climatic trends show a deviation from historic trends and this has necessitated this study. The paper analysed climate change trend and the perceived climatic hazards in Southeast Nigeria. Proportionate sampling technique was used to select a sample of 260 food crop farmers for the study and 232 questionnaires were returned. Secondary time series data on mean annual climate variables for a period of thirty years (1984-2014) were collected from National Root Crop Research Institute Umudike and crop output data from National Bureau of statistics. Data were analysed using descriptive statistical tools like polygon/histograms and line graphs. Also, the extent of damage by climate hazards as perceived by respondents was obtained using likert scale. The rainfall volume variation showed a very unstable pattern with high volatility over years with slightly increasing trend in the study area. Result shows that temperature is significant at 1% level of significance while rainfall volume, rainfall days, relative humidity and sunshine duration were insignificant. Rain day was characterized by unsteady rise and fall trend pattern. The trend also indicated an unsteady change in the movements of the relative humidity and sunshine levels. The result for the occurrence of climate hazards as perceived by farmers show 86.2 %, 64.68%, 63.79%, 77.82% of the respondents perceived to a great extent the impact of flooding, sea level rise, longer period of dry spell and wind storm respectively. Based on the finding, it is concluded that the damaging and devastating effects of climate change is in the increase. It is recommended therefore that adequate adaptive measures and mitigations be put in place to cushion the effect of climate change.
Keywords: Climate Change, Climate Hazards, Rainfall, Relative Humidity, Sunshine Duration, Temperature