COMPARATIVE ANALYSIS OF THE SPATIAL AND TEMPORAL VARIATIONS IN HYDROLOGICAL PARAMETERS AT KAINJI AND SHIRORO DAMS, NIGER STATE, NIGERIA

Abstract

ABSTRACT Climate variability has been one of the major issues of the 21st century. The idea is to understand the differences in the climatic conditions and long-term catchment regimes using mean monthly seasonality indices and to explore the differences in the hydrological parameters at the long-term event scale. This comparatively analyze of spatial temporal variations in hydrological parameters at Kainji and Shiroro Dams in Niger State towards achieving a better future plan in the area. Quantitative and qualitative research approach was used, geospatial techniques were used to analysis the landuse pattern of the dams areas. Landsat satellite imagery was also acquired for 1997 to 2017. The imagery was subjected to digital process and five landuse classes were generated. Mann-Kendall test and Sen’s slope test on the monthly coefficient of variation for rainfall, reservoir inflow, reservoir elevation. The results show rainfall deviations increased between 1998 and 1999. On decadal basis, the years 1998, 1999, 2004, and 2006 have positive rainfall deviations while the remaining years have negative and least rainfall deviations. It was also revealing that evaporation deviation was increased in the years 1995 but it reduced drastically between 1993 and 1994. The analyses revealed a negative trend, and a slight decrease in rainfall and it can be brought to conclusion that since evaporation and reservoir inflow has the greatest impact because increase evaporation will increase and there will be shortage of water in the dam. It recommended that operators optimize the release of water from Kainji dam and ensure continuous monitoring of changes in hydro metrological variables to provide early warning for effective performance of the dam and to protect the environment.