Papers by GLORIA C . OKAFOR
The economic implications of extreme climate changes are found to impact sub-Saharan Africa negat... more The economic implications of extreme climate changes are found to impact sub-Saharan Africa negatively. This study aimed to analyze projected changes in length of rainy season (LRS), and rainfall extreme indices at the Vea catchment, Ghana. The analysis was performed using high-resolution simulated rainfall data from Weather Research and Forecasting (WRF) model under moderate greenhouse gas emission scenario for the period 2020-2049 relative to 1981-2010 period. LRS was computed from the difference between rainfall onset and cessation dates, and its trends were assessed using Mann-Kendall test and Sen's slope estimator. Annual rainfall intensity and frequency indices were computed. Results showed an increase in mean LRS from 168 to 177 days, which was at a rate of 1 day/year in the future (2020-2049). The LRS increase would be more significant at northern and southwestern parts of the catchment. Rainfall intensity and frequency indices are projected to increase at spatial scale across the catchment. Projected changes in rainfall extremes could increase the frequency and intensity of drought and flood events. Thus, it is necessary to integrate suitable climate change adaptation measures such as rainwater harvesting, flood control measures, and development of early warning systems in the planning process by decision-makers at the catchment. Key words | length of rainy season, rainfall extreme indices, rainfall projections, regional climate model, Vea catchment HIGHLIGHTS • The spatio-temporal changes in length of rainy season and rainfall extreme indices were analyzed under moderate greenhouse gas emission scenario for the vea catchment. • High resolution regional climate model was employed in this study. • Rainfall intensity and frequency indices are projected to increase at the spatial scale across the catchment. • Mankendall-test, onset and cessation of rainfall were used for the data analsysis.
Modeling Earth Systems and Environment
Erosion hazard is a major environmental change in developing countries and therefore necessitates... more Erosion hazard is a major environmental change in developing countries and therefore necessitates investigations for effective erosion control measures. This study is hinged on the numerous advantages of a hybrid Multi-Criteria Decision Model (MCDM) to assess erosion vulnerability using remote-sensed data and the application of Geographical Information System (GIS). Nine risk factors of erosion were selected for this study and their thematic maps were utilized to produce a spatial distribution of erosion hazard in the state. An integrated IVFRN-DEMATEL-ANP model was used to investigate the interrelationships between the risk factors and also obtain their final weights. The assessment model identified Rainfall, Erosivity Index, Stream Power Index, Sediment Transport Index, Topographic Wetness Index, and Soil as the most influential factors of erosion in the study area. The weighted linear combination method was used to integrate the risk factors to produce the spatial distribution of erosion vulnerability model. The method was validated using Anambra State of Nigeria. The findings from the study revealed that Anambra State is vulnerable to erosion hazard with 45% of the state lying between Very High and Medium vulnerable zones. A good predictive model performance of 89.7% was obtained using the AUC-ROC method. The feasibility of integrating the IVFRN, DEMATEL, and ANP models as an assessment model for mapping erosion vulnerability has been determined in this study, and this is vital in managing the impact of erosion hazards globally. The model's identification of hydrological and topographical factors as major causes of erosion hazard emphasizes the importance of critical analysis of risk factors as done in this study for effective management of erosion. This study is a veritable tool for implementation of erosion mitigation measures.
Atmospheric and Climate Sciences, 2017
This study aimed to detect trends in the long-term hydro-climatic series using non-parametric met... more This study aimed to detect trends in the long-term hydro-climatic series using non-parametric methods. The annual and seasonal linear trends of rainfall, temperature, runoff, water level and evaporation were analysed for stations in downstream Kaduna River Basin during 1975-2014. The non-parametric Mann-Kendall and Sen's estimator of slope procedures were adopted to identify if there exists an increasing or decreasing trend with their statistical significance at 95% level of confidence. The datasets were checked to account for auto-correlation prior to determining trends using Mann-Kendall test. The existence of abrupt changes was detected by means of Cumulative Sum Charts and Bootstrapping analysis. The results of study indicated increasing trends for seasonal and annual temperature and runoff series. Water level and evaporation revealed statistically decreasing trends both on annual and seasonal periods. However, for the period 1975 to 2014 no significant distinctive trend was observed for rainfall at the investigated stations. Change-points in time series were identified in all the investigated hydro-climatic records for the sub-basin. Generally, the detection of the trend for hydro-climatic variables by Mann-Kendall test conforms to Sen's test results. It is concluded that the basin is sensitive to climate variability and water stress impacts which will affect food security. So, it would be necessary to make adjustments in the adaptive water-use strategies being adopted at present in the catchment.
International Journal of Advanced Remote Sensing and GIS
Burkina Faso has long been experiencing intense land-use landcover changes (LULCC) which have res... more Burkina Faso has long been experiencing intense land-use landcover changes (LULCC) which have resulted in widespread land degradation. Hence, the need to obtain LULC information for improved land-use planning and sustainable management of land-resources cannot be overemphasized. This study examined the historical LULCC in the Dano catchment and projected the situation in 2050 for business-as-usual (BAU) and afforestation scenarios. Multitemporal Landsat images of 1990, 2000, 2010 and 2016 were classified with an overall accuracy of more than 90%. The Cellular-Automata Markov approach was used to project the future LULC pattern after identifying major driving forces of LULCC. The results revealed a substantial expansion in settlement and cropland area of about 62% and 6% respectively, which triggered a 15% decrease in forest cover, thus paving the way for severe soil degradation. The increase in cropland, settlement area, water bodies, and the decrease of forest were at an annual rate of 3.8%, 10.5%, 6.97% and 2.53% respectively within the past 26 years. The projected LULC under the BAU scenario revealed further forest loss from 46.72% in 2016 to 38.54%, owing to an extension in agriculture from 38.51% to 46.69%. The afforestation scenario projected a potential increase in forest by 2.13% and a decrease in cropland by 2.09% in the future relative to 2016. This study illustrates the accelerated land degradation and the challenges on ecosystem sustainability of the Dano landscape, hence, appropriate interventions like reforestation, protection measures and policy option in strategic land-use planning are needed to resolve the further loss of forest cover. https://doi.org/10.23953/cloud.ijarsg.445
Food and Bioproducts Processing
Abstract Increasing risk exposures emanating from slaughterhouses in developing countries calls f... more Abstract Increasing risk exposures emanating from slaughterhouses in developing countries calls for urgent attention, Risk Assessment (RA) was applied to five abattoirs using fuzzy logic system in Anambra State of Nigeria. Previous research works on abattoir operations asserted their risk assessment on subjective basis and descriptive statistics. The fuzzy based RA was therefore adopted because of its adeptness to incorporate operational, facility and locational risks. The risk evaluation criteria was developed by contributions from environmental experts in ministries, literatures and prepared by the authors. The evaluation criteria includes environmental risk with four sub-sections, personnel risk with two sub-sections and social risk with four sub-sections making it a total of 10 risks. Fuzzy Logic Toolbox in MATLAB software was used in the fuzzification and defuzzification process to obtain a 10 scale overall risk level ranging from 1 signifying ‘No Risk’ to 10 indicating “Very Strong/High risk”. The result of the study shows that the overall risk values of the abattoirs are 7.48, 5.05, 7.12, 6.83 and 7.48 for Ugwunabamkpa, Main Market, Marine, Ochanja and Bridge Head Abattoirs respectively. The overall fuzzy-based RA for the study location ranged from moderate to severe risk and is therefore proposed as appropriate tool for abattoir RA based on experts’ opinion and literatures from this study. It is therefore recommended that suitable equipment; personnel periodical training; improved meat plant sanitation; building adequate structures and good methods of abattoir effluent treatment with emphasis on biogas digestion should be employed as well as a thorough abattoir location analysis for risk reduction in the abattoirs.
Theoretical and Applied Climatology
Here, an evaluation of nine simulations of the regional climate models (RCM) performed within the... more Here, an evaluation of nine simulations of the regional climate models (RCM) performed within the frame of CORDEX-Africa Project to reproduce the Volta Basin climatology (1971–2005) is presented. Performance metrics of climatological means were computed from annual, seasonal, and monthly total values which detect differences in the spatial and temporal structures of the model outputs with observational datasets for precipitation and temperature evaluated over three sub-domains (the Guinea Coast, the Soudano-Sahel, and the Sahel) within the basin. The results reveal pronounced influence of the GCM-derived boundary conditions at homogeneous zones, for example, CNRM-induced model overestimations over the Sahel. A good replica of the spatial distribution of climatic parameters particularly for temperature with biases within 0.1 °C and obvious wet bias for precipitation up to 40% is detected predominantly over the Sahel with widespread differences in spatial extent and intensities. A better performance is obtained for summer and fall but worse in spring for precipitation. The analysis showed that the basic characteristics of the West African climate are reasonably reproduced by the models, including its variability in sign, amplitude, and spatial extent, but also, there are recognized deficiencies of the model simulations for some selected metrics, regions, and seasons. The study emphasizes on individual model skills than in ensemble performance, and CanESM2-RCA4 and NorESM1-RCA4 RCMs were realized to replicate best the observed dataset so these models are recommended for impact studies over the basin for most seasons. Results achieved will be valuable in the choice of GCMs/RCMs for impact study over the basin, and we conclude that this may also depend on the focus of interest, whether it is a study on variability and process representation or region of study or timescales.
Climate change impact on rainfall and temperature extreme indices in the Vea catchment was analyz... more Climate change impact on rainfall and temperature extreme indices in the Vea catchment was analyzed using observation and an ensemble mean of bias-corrected regional climate models datasets for Representative Concentration Pathway (RCP 4.5) scenario. Rainfall extreme indices such as annual total wet-day precipitation (PRCPTOT), extremely wet days (R99P), consecutive wet days (CWD), consecutive dry days (CDD), and temperature indices such as warmest day (TXx) and warmest night (TNx) from the Expert Team on Climate Change Detection Monitoring Indices (ETCCDMI) were computed for both the historical (1986–2016) and future (2020–2049) period using the RClimdex. The parametric ordinary least square (OLS) regression approach was used to detect trends in the time series of climate change and extreme indices. The results show an increase in mean annual temperature at the rate of 0.02 °C/year and a variability in rainfall at the catchment, under RCP 4.5 scenario. The warmest day and warmest n...
Elsevier Journal of Food and Bio-products Processing , 2020
Increasing risk exposures emanating from slaughterhouses in developing countries calls for urgent... more Increasing risk exposures emanating from slaughterhouses in developing countries calls for urgent attention, Risk Assessment (RA) was applied to five abattoirs using fuzzy logic system in Anambra State of Nigeria. Previous research works on abattoir operations asserted their risk assessment on subjective basis and descriptive statistics. The fuzzy based RA was therefore adopted because of its adeptness to incorporate operational, facility and locational risks. The risk evaluation criteria was developed by contributions from environmental experts in ministries, literatures and prepared by the authors. The evaluation criteria includes environmental risk with four subsections , personnel risk with two subsections and social risk with four subsections making it a total of 10 risks. Fuzzy Logic Toolbox in MATLAB software was used in the fuzzification and defuzzification process to obtain a 10 scale overall risk level ranging from 1 signifying 'No Risk' to 10 indicating "Very Strong/High risk". The result of the study shows that the overall risk values of the abattoirs are 7.48, 5.05, 7.12, 6.83 and 7.48 for Ugwunabamkpa, Main Market, Marine, Ochanja and Bridge Head Abattoirs respectively. The overall fuzzy-based RA for the study location ranged from moderate to severe risk and is therefore proposed as appropriate tool for abattoir RA based on experts' opinion and literatures from this study. It is therefore recommended that suitable equipment; personnel periodical training; improved meat plant sanitation; building adequate structures and good methods of abattoir effluent treatment with emphasis on biogas digestion should be employed as well as a thorough abattoir location analysis for risk reduction in the abattoirs.
Journal of Water and Climate Change
The economic implications of extreme climate changes are found to impact sub-Saharan Africa negat... more The economic implications of extreme climate changes are found to impact sub-Saharan Africa negatively. This study aimed to analyze projected changes in length of rainy season (LRS), and rainfall extreme indices at the Vea catchment, Ghana. The analysis was performed using high-resolution simulated rainfall data from the Weather Research and Forecasting (WRF) model under moderate greenhouse gas emission scenario for the period 2020–2049 relative to the 1981–2010 period. LRS was computed from the difference between rainfall onset and cessation dates, and its trends were assessed using Mann–Kendall test and Sen's slope estimator. Annual rainfall intensity and frequency indices were computed. Results showed an increase in mean LRS from 168 to 177 days, which was at a rate of 1 day/year in the future (2020–2049). The LRS increase would be more significant at northern and south-western parts of the catchment. Rainfall intensity and frequency indices are projected to increase at spati...
Journal of Water and Land Development, Sep 1, 2018
A-study design B-data collection C-statistical analysis D-data interpretation E-manuscript prepar... more A-study design B-data collection C-statistical analysis D-data interpretation E-manuscript preparation F-literature search
Burkina Faso has long been experiencing intense land-use landcover changes (LULCC) which have res... more Burkina Faso has long been experiencing intense land-use landcover changes (LULCC) which have resulted in widespread land degradation. Hence, the need to obtain LULC information for improved land-use planning and sustainable management of land-resources cannot be overemphasized. This study examined the historical LULCC in the Dano catchment and projected the situation in 2050 for business-as-usual (BAU) and afforestation scenarios. Multitemporal Landsat images of 1990, 2000, 2010 and 2016 were classified with an overall accuracy of more than 90%. The Cellular-Automata Markov approach was used to project the future LULC pattern after identifying major driving forces of LULCC. The results revealed a substantial expansion in settlement and cropland area of about 62% and 6% respectively, which triggered a 15% decrease in forest cover, thus paving the way for severe soil degradation. The increase in cropland, settlement area, water bodies, and the decrease of forest were at an annual rate of 3.8%, 10.5%, 6.97% and 2.53% respectively within the past 26 years. The projected LULC under the BAU scenario revealed further forest loss from 46.72% in 2016 to 38.54%, owing to an extension in agriculture from 38.51% to 46.69%. The afforestation scenario projected a potential increase in forest by 2.13% and a decrease in cropland by 2.09% in the future relative to 2016. This study illustrates the accelerated land degradation and the challenges on ecosystem sustainability of the Dano landscape, hence, appropriate interventions like reforestation, protection measures and policy option in strategic land-use planning are needed to resolve the further loss of forest cover.
JOURNAL OF WATER AND LAND DEVELOPMENT, 2018
Changes in runoff trends have caused severe water shortages and ecological problems in agricultur... more Changes in runoff trends have caused severe water shortages and ecological problems in agriculture and
human well-being in Nigeria. Understanding the long-term (inter-annual to decadal) variations of water availability in river basins is paramount for water resources management and climate change adaptation. Climate
change in Northern Nigeria could lead to change of the hydrological cycle and water availability. Moreover, the
linkage between climatic changes and streamflow fluctuations is poorly documented in this area. Therefore, this
study examined temporal trends in rainfall, temperature and runoff records of Kaduna River basin. Using appropriate statistical tools and participatory survey, trends in streamflow and their linkages with the climate indices
were explored to determine their amplifying impacts on water availability and impacts on livelihoods downstream the basin. Analysis indicate variable rainfall trend with significant wet and dry periods. Unlike rainfall,
temperature showed annual and seasonal scale statistically increasing trend. Runoff exhibit increasing tendency
but only statistically significant on annual scale as investigated with Mann–Kendall trend test. Sen’s estimator
values stood in agreement with Mann–Kendall test for all variables. Kendall tau and partial correlation results
revealed the influence of climatic variables on runoff. Based on the survey, some of the hydrological implications and current water stress conditions of these fluctuations for the downstream inhabitants were itemized.
With increasing risk of climate change and demand for water, we therefore recommend developing adaptive
measures in seasonal regime of water availability and future work on modelling of the diverse hydrological characteristics of the entire basin.
Theoretical and Applied Climatology, 2019
Here, an evaluation of nine simulations of the regional climate models (RCM) performed within the... more Here, an evaluation of nine simulations of the regional climate models (RCM) performed within the frame of CORDEX-Africa
Project to reproduce the Volta Basin climatology (1971–2005) is presented. Performance metrics of climatological means were
computed from annual, seasonal, and monthly total values which detect differences in the spatial and temporal structures of the
model outputs with observational datasets for precipitation and temperature evaluated over three sub-domains (the Guinea Coast,
the Soudano-Sahel, and the Sahel) within the basin. The results reveal pronounced influence of the GCM-derived boundary
conditions at homogeneous zones, for example, CNRM-induced model overestimations over the Sahel. A good replica of the
spatial distribution of climatic parameters particularly for temperature with biases within 0.1 °C and obvious wet bias for
precipitation up to 40% is detected predominantly over the Sahel with widespread differences in spatial extent and intensities.
A better performance is obtained for summer and fall but worse in spring for precipitation. The analysis showed that the basic
characteristics of the West African climate are reasonably reproduced by the models, including its variability in sign, amplitude,
and spatial extent, but also, there are recognized deficiencies of the model simulations for some selected metrics, regions, and
seasons. The study emphasizes on individual model skills than in ensemble performance, and CanESM2-RCA4 and NorESM1-
RCA4 RCMs were realized to replicate best the observed dataset so these models are recommended for impact studies over the
basin for most seasons. Results achieved will be valuable in the choice of GCMs/RCMs for impact study over the basin, and we
conclude that this may also depend on the focus of interest, whether it is a study on variability and process representation or
region of study or timescales.
Water stress is one of the risks emanating from worsening climatic variations. It poses serious t... more Water stress is one of the risks emanating from worsening climatic variations. It poses serious threats on vulnerable continents, people and livelihoods globally. However, little information is available on how the specific climate threat is impacting people's livelihoods and water resources on different temporal and spatial scales in Nigeria basins. This study aimed at investigating household vulnerability and adaptation to water stress induced by climate variability on a downstream Kaduna River basin with the goal of support-ing/facilitating climate change adaptation. The research analyzed hy-dro-climatic data and employed vulnerability-based framework consistent with stakeholders' participatory approach, within the context of current climate conditions experienced, and/or water stress conditions already affecting household livelihoods in six communities at three study sites; Shiroro, Gbako and Lavun, and adaptive strategies engaged to deal with water stress. Findings revealed that households have been exposed and experienced changes in water availability through variations in rainfall, temperature and runoff. Consequently , these changes have impacted on food production and livelihoods. Households have individually and collectively employed adaptation techniques which are reactive, short-term indigenous coping strategies usually adopted during periods of stress to minimize water-related vulnerabilities. The study demonstrated how an understanding of the local household vulne-rabilities will enable the recognition of early indicators of water stress in addition to the occurrence of extreme events. Overall, households' vulnerability decreased from one village to another due to differences in sensitivity to stress, access to resources and local institutional capacity. Resilience of households can be increased through early warning system during flood 248 events, providing access to water from rainwater harvesting techniques, and integration of climate change adaptation into policies regarding development initiatives especially in the area of agriculture.
This study aimed to detect trends in the long-term hydro-climatic series using non-parametric met... more This study aimed to detect trends in the long-term hydro-climatic series using non-parametric methods. The annual and seasonal linear trends of rainfall, temperature, runoff, water level and evaporation were analysed for stations in downstream Kaduna River Basin during 1975-2014. The non-parametric Mann-Kendall and Sen's estimator of slope procedures were adopted to identify if there exists an increasing or decreasing trend with their statistical significance at 95% level of confidence. The datasets were checked to account for auto-correlation prior to determining trends using Mann-Kendall test. The existence of abrupt changes was detected by means of Cumulative Sum Charts and Bootstrapping analysis. The results of study indicated increasing trends for seasonal and annual temperature and runoff series. Water level and evaporation revealed statistically decreasing trends both on annual and seasonal periods. However, for the period 1975 to 2014 no significant distinctive trend was observed for rainfall at the investigated stations. Change-points in time series were identified in all the investigated hydro-climatic records for the sub-basin. Generally, the detection of the trend for hydro-climatic variables by Mann-Kendall test conforms to Sen's test results. It is concluded that the basin is sensitive to climate variability and water stress impacts which will affect food security. So, it would be necessary to make adjustments in the adaptive water-use strategies being adopted at present in the catchment.
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Papers by GLORIA C . OKAFOR
human well-being in Nigeria. Understanding the long-term (inter-annual to decadal) variations of water availability in river basins is paramount for water resources management and climate change adaptation. Climate
change in Northern Nigeria could lead to change of the hydrological cycle and water availability. Moreover, the
linkage between climatic changes and streamflow fluctuations is poorly documented in this area. Therefore, this
study examined temporal trends in rainfall, temperature and runoff records of Kaduna River basin. Using appropriate statistical tools and participatory survey, trends in streamflow and their linkages with the climate indices
were explored to determine their amplifying impacts on water availability and impacts on livelihoods downstream the basin. Analysis indicate variable rainfall trend with significant wet and dry periods. Unlike rainfall,
temperature showed annual and seasonal scale statistically increasing trend. Runoff exhibit increasing tendency
but only statistically significant on annual scale as investigated with Mann–Kendall trend test. Sen’s estimator
values stood in agreement with Mann–Kendall test for all variables. Kendall tau and partial correlation results
revealed the influence of climatic variables on runoff. Based on the survey, some of the hydrological implications and current water stress conditions of these fluctuations for the downstream inhabitants were itemized.
With increasing risk of climate change and demand for water, we therefore recommend developing adaptive
measures in seasonal regime of water availability and future work on modelling of the diverse hydrological characteristics of the entire basin.
Project to reproduce the Volta Basin climatology (1971–2005) is presented. Performance metrics of climatological means were
computed from annual, seasonal, and monthly total values which detect differences in the spatial and temporal structures of the
model outputs with observational datasets for precipitation and temperature evaluated over three sub-domains (the Guinea Coast,
the Soudano-Sahel, and the Sahel) within the basin. The results reveal pronounced influence of the GCM-derived boundary
conditions at homogeneous zones, for example, CNRM-induced model overestimations over the Sahel. A good replica of the
spatial distribution of climatic parameters particularly for temperature with biases within 0.1 °C and obvious wet bias for
precipitation up to 40% is detected predominantly over the Sahel with widespread differences in spatial extent and intensities.
A better performance is obtained for summer and fall but worse in spring for precipitation. The analysis showed that the basic
characteristics of the West African climate are reasonably reproduced by the models, including its variability in sign, amplitude,
and spatial extent, but also, there are recognized deficiencies of the model simulations for some selected metrics, regions, and
seasons. The study emphasizes on individual model skills than in ensemble performance, and CanESM2-RCA4 and NorESM1-
RCA4 RCMs were realized to replicate best the observed dataset so these models are recommended for impact studies over the
basin for most seasons. Results achieved will be valuable in the choice of GCMs/RCMs for impact study over the basin, and we
conclude that this may also depend on the focus of interest, whether it is a study on variability and process representation or
region of study or timescales.
human well-being in Nigeria. Understanding the long-term (inter-annual to decadal) variations of water availability in river basins is paramount for water resources management and climate change adaptation. Climate
change in Northern Nigeria could lead to change of the hydrological cycle and water availability. Moreover, the
linkage between climatic changes and streamflow fluctuations is poorly documented in this area. Therefore, this
study examined temporal trends in rainfall, temperature and runoff records of Kaduna River basin. Using appropriate statistical tools and participatory survey, trends in streamflow and their linkages with the climate indices
were explored to determine their amplifying impacts on water availability and impacts on livelihoods downstream the basin. Analysis indicate variable rainfall trend with significant wet and dry periods. Unlike rainfall,
temperature showed annual and seasonal scale statistically increasing trend. Runoff exhibit increasing tendency
but only statistically significant on annual scale as investigated with Mann–Kendall trend test. Sen’s estimator
values stood in agreement with Mann–Kendall test for all variables. Kendall tau and partial correlation results
revealed the influence of climatic variables on runoff. Based on the survey, some of the hydrological implications and current water stress conditions of these fluctuations for the downstream inhabitants were itemized.
With increasing risk of climate change and demand for water, we therefore recommend developing adaptive
measures in seasonal regime of water availability and future work on modelling of the diverse hydrological characteristics of the entire basin.
Project to reproduce the Volta Basin climatology (1971–2005) is presented. Performance metrics of climatological means were
computed from annual, seasonal, and monthly total values which detect differences in the spatial and temporal structures of the
model outputs with observational datasets for precipitation and temperature evaluated over three sub-domains (the Guinea Coast,
the Soudano-Sahel, and the Sahel) within the basin. The results reveal pronounced influence of the GCM-derived boundary
conditions at homogeneous zones, for example, CNRM-induced model overestimations over the Sahel. A good replica of the
spatial distribution of climatic parameters particularly for temperature with biases within 0.1 °C and obvious wet bias for
precipitation up to 40% is detected predominantly over the Sahel with widespread differences in spatial extent and intensities.
A better performance is obtained for summer and fall but worse in spring for precipitation. The analysis showed that the basic
characteristics of the West African climate are reasonably reproduced by the models, including its variability in sign, amplitude,
and spatial extent, but also, there are recognized deficiencies of the model simulations for some selected metrics, regions, and
seasons. The study emphasizes on individual model skills than in ensemble performance, and CanESM2-RCA4 and NorESM1-
RCA4 RCMs were realized to replicate best the observed dataset so these models are recommended for impact studies over the
basin for most seasons. Results achieved will be valuable in the choice of GCMs/RCMs for impact study over the basin, and we
conclude that this may also depend on the focus of interest, whether it is a study on variability and process representation or
region of study or timescales.