[01] Oluwaseyi Adeola Dasho, Department of Physical Sciences, Dominion University, Ibadan, Nigeria. [02] Ayomide Oluyemi Olabode, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria. [03] Emmanuel Abiodun Ariyibi, Department of Physics and Engineering Physics, Obafemi Awolowo University, Ile-Ife, Nigeria. [04] Francis Omowonuola Akinluyi, Department of Remote Sensing and GIS, Federal University of Technology, Akure, Nigeria. [05] Oluseye David Dare, Department of Physical Sciences, Dominion University, Ibadan, Nigeria.

Regional monitoring of available water resources across Nigeria for effective management is becoming very important with the encroaching desertification in the northern part of the country. Deploying a ground-based monitoring network across the country is not feasible due to the huge financial cost. GRACE satellite provides cost-effective means of regional-scale monitoring of water resources. This study analyzed the GRACE gravity data and observed the pattern of GRACE-derived Terrestrial Water Storage (TWS) and Ground Water Storage (GWS) anomalies across the five river basin divisions of Nigeria using data from 2006 to 2012. The data were interpolated using the moving average function to generate raster images of TWS for individual months. The plot of the seasonal TWS and GWS anomalies reveals seasonal variation patterns corresponding to the region’s rainfall pattern confirming the sensitivity of the satellite. The trend of the annual average TWS anomalies indicates that the TWS rose across the basins at rates between 0.19 cm/year and 1.28 cm/year. The trends of the annual average GWS plots reveal increasing GWS trends in three of the five basins. The study concludes that the increase in TWS, in most of the basins, is likely due to changes in groundwater recharge quantities and therefore suggests that increasing access to improved groundwater sources is likely to be highly successful in mitigating the adverse effect of climate change in Sub-Saharan Africa.

GRACE, Gravity, Ground Water Storage, Terrestrial Water Storage, Satellite, River Basin

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