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9Lake Chad has recently been perceived to be completely desiccated and almost extinct due 10 to insufficient published ground observations. Given the high spatial variability of rainfall in 11 the region, and the fact that extreme climatic conditions (for example, droughts) could be 12 intensifying in the Lake Chad basin (LCB) due to human activities, a spatio-temporal ap-13 proach to drought analysis becomes essential. This study employed independent component 14 analysis (ICA), a fourth-order cumulant statistics, to decompose standardised precipitation 15 index (SPI), standardised soil moisture index (SSI), and terrestrial water storage (TWS) de-16 rived from Gravity Recovery and Climate Experiment (GRACE) into spatial and temporal 17 patterns over the LCB. In addition, this study uses satellite altimetry data to estimate vari-18 ations in the Lake Chad water levels, and further employs relevant climate teleconnection 19 indices (El-Niño Southern Oscillation-ENSO, Atlantic Multi-decadal Oscillation-AMO, and 20 Atlantic Meridional Mode-AMM) to examine their links to the observed drought temporal 21 patterns over the basin. From the spatio-temporal drought analysis, temporal evolutions of 22 SPI at 12 month aggregation show relatively wet conditions in the last two decades (although 23 with marked alterations) with the 2012 − 2014 period being the wettest. In addition to the 24 improved rainfall conditions during this period, there was a statistically significant increase of 25 0.04 m/yr in altimetry water levels observed over Lake Chad between 2008 and 2014, which 26 confirms a shift in the hydrological conditions of the basin. Observed trend in TWS changes 27 during the 2002 − 2014 period shows a statistically insignificant increase of 3.0 mm/yr at the 28 center of the basin, coinciding with soil moisture deficit indicated by the temporal evolutions 29 of SSI at all monthly accumulations during the 2002 − 2003 and 2009 − 2012 periods. Further, 30 SPI at 3 and 6 month scales indicated fluctuating drought conditions at the extreme south of 31 the basin, coinciding with a statistically insignificant decline in TWS of about 4.5 mm/yr at 32 the southern catchment of the basin. Finally, correlation analyses indicate that ENSO, AMO, 33 and AMM are associated with extreme rainfall conditions in the basin, with AMO showing 34 the strongest association (statistically significant correlation of 0.55) with SPI 12 month ag-35gregation. Therefore, this study provides a framework that will support drought monitoring 36 in the LCB. 37

PurposeThe purpose of this study is to analyse the risk factors associated with outsourcing of facilities management (FM) services.Design/methodology/approachThe study administered questionnaires on 146 registered members of International Facilities Management Association (IFMA), Nigeria chapter, who carry out their professional practice in Lagos, Nigeria. The survey, conducted in February, 2011 targeted facilities managers, property managers, maintenance officers and procurement officers cutting across the three levels of management. A total of 61 of them returned valid questionnaires, giving a response rate of 41.8 percent.FindingsFindings reveal that “poor quality of services” was rated the most critical risk factor associated with facilities management outsourcing, while “security” and “inexperience” closely followed in that order. Also, there was no significant difference in the rankings of the stakeholders on more than 75 percent of the factors.Research limitations/implicationsMost practitioners would have been left out of the survey due to non‐registration with IFMA due to the seeming novelty of facilities management practice in Nigeria.Originality/valueThis paper provides an unambiguous empirical‐based analysis of outsourcing risks from the perspective of facilities management practice in Nigeria.

The role of global sea surface temperature (SST) anomalies in modulating rainfall in the African region has been widely studied and is now less debated. However, their impacts and links to terrestrial water storage (TWS) in general, have not been studied. This study presents the pioneer results of canonical correlation analysis (CCA) of TWS derived from both global reanalysis data (1980−2015) and GRACE (Gravity Recovery and Climate Experiment) (2002 − 2014) with SST fields. The main issues discussed include, (i) oceanic hot spots that impact on TWS over tropical West Africa (TWA) based on CCA, (ii) long term changes in model and global reanalysis data (soil moisture, TWS, and groundwater) and the influence of climate variability on these hydrological indicators, and (iii) the hydrological characteristics of the Equatorial region of Africa (i.e., the Congo basin) based on GRACE-derived TWS, river discharge, and precipitation. Results of the CCA diagnostics show that El-Niño Southern Oscillation related equatorial Pacific SST fluctuations is a major index of climate variability identified in the main portion of the CCA procedure that indicates a significant association with long term TWS reanalysis data over TWA (r = 0.50, ρ < 0.05). Based on Man-Kendall's statistics, the study found fairly large long term declines (ρ < 0.05) in TWS and soil moisture (1982 − 2015), mostly over the Congo basin, which coincided with warming of the land surface and the surrounding oceans. Meanwhile, some parts of the Sahel show significant wetting (rainfall, soil moisture, groundwater, and TWS) trends during the same period (1982 − 2015) and aligns with the ongoing narratives of rainfall recovery in the region. Results of singular spectral analysis and regression confirm that multi-annual changes in the Congo river discharge explained a considerable proportion of variability in GRACEhydrological signal over the Congo basin (r = 0.86 and R 2 = 0.70, ρ < 0.05). Finally, leading orthogonal modes of MERRA and GRACE-TWS over TWA show significant association with global SST anomalies.

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