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 was to determine the presence or otherwise of trend over time for some selected hydro-climatic components of Kaduna, Nigeria, and deduce the magnitude. Statistical approaches were used to investigate the presence and extent of persistence, trend analysis in hydro-climatic time series. Based on Mann Kendall test, twenty six years of hydro-climatic data 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. An evidence of trend was observed in all variables. Temperature and evaporation variables showed a positive and significant trend over time, while rainfall and stream flow had negative trend though not significant at the 95 % 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.