On the potentials of multiple climate variables in assessing the spatio-temporal characteristics of hydrological droughts over the Volta Basin.

摘要: Multiple drought episodes over the Volta basin in recent reports may lead to food insecurity and loss of revenue. However, studies are rather generalised largely undocumented due sparse ground observations unsuitable framework determine their space-time occurrence. In this study, we examined utility standardised indicators (standardised precipitation index (SPI), runoff (SRI), soil moisture (SSI), multivariate (MSDI)) Gravity Recovery Climate Experiment (GRACE) derived terrestrial water storage assess hydrological characteristics basin. order patterns basin, Independent Component Analysis (ICA), a higher statistical technique was employed. The results show that SPI SRI exhibit inconsistent behaviour observed wet years presupposing non-linear relationship reflects slow response river discharge especially after previous extreme dry period. While SSI linear with correlation 0.63, between MSDIs from combining precipitation/river precipitation/soil indicates significant value 0.70 shows an improved skill monitoring during study ICA-derived spatio-temporal Burkina Faso Lake areas as predominantly zones. Further, statistically negative correlations pacific decadal oscillations (0.39 0.25) temporal evolutions Ghana suggest possible influence low frequency large scale regimes Finally, our approach assessment contributes broad for will complement existing methods while looking forward longer record GRACE observations.