Trend Analysis of Selected Hydro-Meterological Processes

Abstract

Identification of the precise nature and attributes of the time series of climatological data is very important and is usually the first step of water resources planning and management, The major objective of this study is to determine the presence or otherwise of trend over time for some selected Hydro-climatic components of Kaduna, Nigeria, and deduce (if trend is detected) it’s magnitude.To this end this study employed statistical approaches used to investigate the presence and extent of persistence, trend analysis in Hydro-climatic time series. The study investigated spatial distributional pattern (i.e. Trend) of the indicative Hydro-climatic variables based on Mann Kendall test, twenty six years of hydro-climatic data for Kaduna, Kaduna state were used. The non-parametric Man-Kendall test was used to detect monotonic trends, and the Mann-Kendall slope estimator was used to estimate the magnitude of trend on the variables. The study showed that there is an evidence of trend on all variables, The Temperature and Evaporation variables showed a positive and significant trend over time, while rainfall and stream flow have negative trend though not significant at the 95 or 99% level of confidence. Thus, it could be concluded that the trend of change in temperature around River Kaduna is on the increase, with no significant increase in change of rainfall.This is not favourable for stream-flow management and other related hydrological processes. Based on the results it is strongly recommended that proper water resource management strategy be put in place to avoid the water drying off; tests should be carried out on other hydro-climatic variables to ensure better management since there is no strong independence among hydro-climatic characteristics.

Keywords: Hydro-climatic, Man-Kendall, Rainfall, Stream-flow, Temperature, Trend