I’m an Engineer, Geoinformatics and Environmental expert with 7 years’ experience in supporting Engineering, environmental, disaster risk, and occupational hazard management projects, programs and activities across various sectors including International Development, Academia and Oil
Extreme flood events are one of the most devastating global environmental disasters in recent tim... more Extreme flood events are one of the most devastating global environmental disasters in recent times, triggered by changing climatic conditions that alter weather patterns and resulting in more frequent and intense rainfall. In recent years, Nigeria particularly has experienced intense degrees of flooding instigated by excess water release from upstream dams due to extreme precipitation driven runoff, resulting in the damage of infrastructures, displacement of people, and loss of lives. Flood frequency information is required in planning for flood emergencies and designing structural measures to curtail flood impact. When hydrological gauge data is available, direct flood estimates are ascertained by fitting annual maximum flood time series to predefined probability distributions, else methods such as regional flood frequency analysis compensates for missing data deficiency by substituting time for space by collating data from various sites with similar hydrological characteristics, ...
ISPRS International Journal of Geo-Information, 2020
Consistent data are seldom available for whole-catchment flood modelling in many developing regio... more Consistent data are seldom available for whole-catchment flood modelling in many developing regions, hence this study aimed to explore an integrated approach for flood modelling and mapping by combining available segmented hydrographic, topographic, floodplain roughness, calibration, and validation datasets using a two-dimensional Caesar-Lisflood hydrodynamic model to quantify and recreate the extent and impact of the historic 2012 flood in Nigeria. Available segments of remotely-sensed and in situ datasets (including hydrological, altimetry, digital elevation model, bathymetry, aerial photo, optical imagery, and radar imagery data) available to different degrees in the Niger-South hydrological area were systematically integrated to draw maximum benefits from all available data. Retrospective modelling, calibration, and validation were undertaken for the whole Niger- South hydrological catchment area of Nigeria, and then these data were segmented into sub-domains for re-validation t...
In recent years, flooding has become a recurring problem in many regions including Nigeria, owing... more In recent years, flooding has become a recurring problem in many regions including Nigeria, owing to changing climatic conditions, as well as anthropogenic factors such as poor land use management and urbanization that aggravate flood impact. To effectively manage and mitigate flood impact, hydrological data is required, and in many developing regions gauging stations are established, and gauge readers recruited and trained to collect and transmit such data to designated hydrological or water resource management agencies. This study focuses on understanding the challenges associated with hydrological data collection in Nigeria, using the Ogun-Osun River as a typical case, while analytically assessing how these challenges result in uncertainties that propagate unto flood frequency estimates that are used to inform flood management decisions. The findings reveal that (i) capacity and institutional gaps; lack of maintenance of hydrological infrastructure and surrounding landscape; poor...
In developing regions missing data are prevalent in historical hydrological datasets, owing to fi... more In developing regions missing data are prevalent in historical hydrological datasets, owing to financial, institutional, operational and technical challenges. If not tackled, these data shortfalls result in uncertainty in flood frequency estimates and consequently flawed catchment management interventions that could exacerbate the impacts of floods. This study presents a comparative analysis of two approaches for infilling missing data in historical annual peak river discharge timeseries required for flood frequency estimation: (i) satellite radar altimetry (RA) and (ii) multiple imputation (MI). These techniques were applied at five gauging stations along the floodprone Niger and Benue rivers within the Niger River Basin. RA and MI enabled the infilling of missing data for conditions where altimetry virtual stations were available and unavailable, respectively. The impact of these approaches on derived flood estimates was assessed, and the return period of a previously unquantified...
Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling a... more Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling and inundation mapping, which require specific datasets that are often unavailable in developing regions due to financial, logistical, technical and organizational challenges. This review discusses fluvial (river) flood modelling and mapping processes and outlines the data requirements of these techniques. This paper explores how open-access remotely sensed and other geospatial datasets can supplement ground-based data and high-resolution commercial satellite imagery in data sparse regions of developing countries. The merits, demerits and uncertainties associated with the application of these datasets, including radar altimetry, digital elevation models, optical and radar images, are discussed. Nigeria, located within the Niger river basin of West Africa is a typical data-sparse country, and it is used as a case study in this review to evaluate the significance of open-access datasets for...
Floods are one of the most devastating disasters known to man, caused by both natural and anthrop... more Floods are one of the most devastating disasters known to man, caused by both natural and anthropogenic factors. The trend of flood events is continuously rising, increasing the exposure of the vulnerable populace in both developed and especially developing regions. Floods occur unexpectedly in some circumstances with little or no warning, and in other cases, aggravate rapidly, thereby leaving little time to plan, respond and recover. As such, hydrological data is needed before, during and after the flooding to ensure effective and integrated flood management. Though hydrological data collection in developed countries has been somewhat well established over long periods, the situation is different in the developing world. Developing regions are plagued with challenges that include inadequate ground monitoring networks attributed to deteriorating infrastructure, organizational deficiencies, lack of technical capacity, location inaccessibility and the huge financial implication of dat...
This study presents a remote sensing approach of using freely available Landsat8satelliteIndicato... more This study presents a remote sensing approach of using freely available Landsat8satelliteIndicators(LandSurfaceTemperature(LST), Soil AdjustedVegetationIndex(SAVI)) and Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) geospatial data to assess the impact of dump sites on the environment in Benin City, Nigeria. The finding reveals that the average derived LST at the dumpsites were higher than the immediate surrounding, and the average SAVI values were lower than the immediate surrounding. The high values of LST at the dumpsites depict the effect of gases released because of decomposition activities, while low values of SAVI indicate vegetation response to soil and groundwater contamination due to leachate infiltration. The average elevation within the dumpsite area derived from SRTM DEM was also applied as a proxy to estimate disposed waste quantity, and related closely with LST that depict biodegradation activities. The result presented here shows that bacterial and fungal counts correlate strongly with the LST and SAVI values at each of the dumpsites R2: LST vs Bacteria Count = 0.982, LST vs Fungi Count = 0.951; SAVI vs Bacteria Count = 0.745, SAVI vs Fungi Count = 0.664, thereby suggesting remote sensing can be applied to aid longterm dumpsite monitoring and management.
In developing regions missing data are prevalent in historical hydrological datasets, owing to fi... more In developing regions missing data are prevalent in historical hydrological datasets, owing to financial, institutional, operational and technical challenges. If not tackled, these data shortfalls result in uncertainty in flood frequency estimates and consequently flawed catchment management interventions that could exacerbate the impacts of floods. This study presents a comparative analysis of two approaches for infilling missing data in historical annual peak river discharge timeseries required for flood frequency estimation: (i) satellite radar altimetry (RA) and (ii) multiple imputation (MI). These techniques were applied at five gauging stations along the floodprone Niger and Benue rivers within the Niger River Basin. RA and MI enabled the infilling of missing data for conditions where altimetry virtual stations were available and unavailable, respectively. The impact of these approaches on derived flood estimates was assessed, and the return period of a previously unquantified devastating flood event in Nigeria in 2012 was ascertained. This study revealed that the use of RA resulted in reduced uncertainty when compared to MI for data infilling, especially for widely gapped timeseries (>3 years). The two techniques did not differ significantly for data sets with gaps of 1–3 years, hence, both RA and MI can be used interchangeably in such situations. The use of the original in situ data with gaps resulted in higher flood estimates when compared to datasets infilled using RA and MI, and this can be attributed to extrapolation uncertainty. The 2012 flood in Nigeria was quantified as a 1-in-100-year event at the Umaisha gauging station on the Benue River and a 1-in-50-year event at Baro on the Niger River. This suggests that the higher levels of flooding likely emanated from the Kiri and Lagdo dams in Nigeria and Cameroon, respectively, as previously speculated by the media and recent studies. This study demonstrates the potential of RA and MI for providing information to support flood management in developing regions where in situ data is sparse.
Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling a... more Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling and inundation mapping, which require specific datasets that are often unavailable in developing regions due to financial, logistical, technical and organizational challenges. This review discusses fluvial (river) flood modelling and mapping processes and outlines the data requirements of these techniques. This paper explores how open-access remotely sensed and other geospatial datasets can supplement ground-based data and high-resolution commercial satellite imagery in data sparse regions of developing countries. The merits, demerits and uncertainties associated with the application of these datasets, including radar altimetry, digital elevation models, optical and radar images, are discussed. Nigeria, located within the Niger river basin of West Africa is a typical data-sparse country, and it is used as a case study in this review to evaluate the significance of open-access datasets for local and transboundary flood analysis. Hence, this review highlights the vital contribution that open access remotely sensed data can make to flood modelling and mapping and to support flood management strategies in developing regions.
With the Increasing developmental trend in Malaysia, vehicular and other sources of pollution has... more With the Increasing developmental trend in Malaysia, vehicular and other sources of pollution has been increasing correspondingly. The study assessed the levels of Nitrogen dioxide at the indoor (booth) and outdoor environment in relation to traffic count and meteorological factors (Wind intensity, Rainfall, Temperature and Humidity), using passive sampling technique (1month duration-weekly intervals), in a bid to approximate the Nitrogen dioxide (NO2) exposure levels of Tool Booth Operators. NO2 levels measured varied from (0.045-0.102ppm) for indoors and (0.047-0.102ppm) for outdoors. The study concluded the difference in Nitrogen dioxide concentrations between indoor and outdoor of tool booths were insignificant, and outdoor NO2 concentration was mostly influenced by traffic density and rainfall.
Municipal Solid waste management has in recent times been regarded as one of the most challengin... more Municipal Solid waste management has in recent times been regarded as one of the most challenging environmental issue facing developing countries. The traditional waste management techniques employed is mostly transferring waste to open dumpsites and poorly managed landfills. Considering the detrimental consequence of leachate on ground water, air pollution, visual nuisance and foul smell that emanates from these landfills calls for an alternative waste management technique. Composting provides us a means of managing municipal organic waste through the activities of various living organisms. This study is aimed at exploring the composting potential of Benin City waste under diverse physical control environments. Twenty five physio-chemical properties were analysed in a bid to ascertain the influence of aerobe, anaerobe and aerobe with Musca domestica maggot enhancements on organic waste for a period of four months. The study revealed that Benin City municipal waste is compostable and Musca domestica maggot inducement leads to improved compost which contains a higher nutrient quality especially in the production of nitrates, phosphates and potassium that are instrumental to plant growth. Composting provides an appropriate alternative approach for sustainable waste management and if employed on a large scale can reduce all the negative impacts of poor waste management.
Extreme flood events are one of the most devastating global environmental disasters in recent tim... more Extreme flood events are one of the most devastating global environmental disasters in recent times, triggered by changing climatic conditions that alter weather patterns and resulting in more frequent and intense rainfall. In recent years, Nigeria particularly has experienced intense degrees of flooding instigated by excess water release from upstream dams due to extreme precipitation driven runoff, resulting in the damage of infrastructures, displacement of people, and loss of lives. Flood frequency information is required in planning for flood emergencies and designing structural measures to curtail flood impact. When hydrological gauge data is available, direct flood estimates are ascertained by fitting annual maximum flood time series to predefined probability distributions, else methods such as regional flood frequency analysis compensates for missing data deficiency by substituting time for space by collating data from various sites with similar hydrological characteristics, ...
ISPRS International Journal of Geo-Information, 2020
Consistent data are seldom available for whole-catchment flood modelling in many developing regio... more Consistent data are seldom available for whole-catchment flood modelling in many developing regions, hence this study aimed to explore an integrated approach for flood modelling and mapping by combining available segmented hydrographic, topographic, floodplain roughness, calibration, and validation datasets using a two-dimensional Caesar-Lisflood hydrodynamic model to quantify and recreate the extent and impact of the historic 2012 flood in Nigeria. Available segments of remotely-sensed and in situ datasets (including hydrological, altimetry, digital elevation model, bathymetry, aerial photo, optical imagery, and radar imagery data) available to different degrees in the Niger-South hydrological area were systematically integrated to draw maximum benefits from all available data. Retrospective modelling, calibration, and validation were undertaken for the whole Niger- South hydrological catchment area of Nigeria, and then these data were segmented into sub-domains for re-validation t...
In recent years, flooding has become a recurring problem in many regions including Nigeria, owing... more In recent years, flooding has become a recurring problem in many regions including Nigeria, owing to changing climatic conditions, as well as anthropogenic factors such as poor land use management and urbanization that aggravate flood impact. To effectively manage and mitigate flood impact, hydrological data is required, and in many developing regions gauging stations are established, and gauge readers recruited and trained to collect and transmit such data to designated hydrological or water resource management agencies. This study focuses on understanding the challenges associated with hydrological data collection in Nigeria, using the Ogun-Osun River as a typical case, while analytically assessing how these challenges result in uncertainties that propagate unto flood frequency estimates that are used to inform flood management decisions. The findings reveal that (i) capacity and institutional gaps; lack of maintenance of hydrological infrastructure and surrounding landscape; poor...
In developing regions missing data are prevalent in historical hydrological datasets, owing to fi... more In developing regions missing data are prevalent in historical hydrological datasets, owing to financial, institutional, operational and technical challenges. If not tackled, these data shortfalls result in uncertainty in flood frequency estimates and consequently flawed catchment management interventions that could exacerbate the impacts of floods. This study presents a comparative analysis of two approaches for infilling missing data in historical annual peak river discharge timeseries required for flood frequency estimation: (i) satellite radar altimetry (RA) and (ii) multiple imputation (MI). These techniques were applied at five gauging stations along the floodprone Niger and Benue rivers within the Niger River Basin. RA and MI enabled the infilling of missing data for conditions where altimetry virtual stations were available and unavailable, respectively. The impact of these approaches on derived flood estimates was assessed, and the return period of a previously unquantified...
Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling a... more Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling and inundation mapping, which require specific datasets that are often unavailable in developing regions due to financial, logistical, technical and organizational challenges. This review discusses fluvial (river) flood modelling and mapping processes and outlines the data requirements of these techniques. This paper explores how open-access remotely sensed and other geospatial datasets can supplement ground-based data and high-resolution commercial satellite imagery in data sparse regions of developing countries. The merits, demerits and uncertainties associated with the application of these datasets, including radar altimetry, digital elevation models, optical and radar images, are discussed. Nigeria, located within the Niger river basin of West Africa is a typical data-sparse country, and it is used as a case study in this review to evaluate the significance of open-access datasets for...
Floods are one of the most devastating disasters known to man, caused by both natural and anthrop... more Floods are one of the most devastating disasters known to man, caused by both natural and anthropogenic factors. The trend of flood events is continuously rising, increasing the exposure of the vulnerable populace in both developed and especially developing regions. Floods occur unexpectedly in some circumstances with little or no warning, and in other cases, aggravate rapidly, thereby leaving little time to plan, respond and recover. As such, hydrological data is needed before, during and after the flooding to ensure effective and integrated flood management. Though hydrological data collection in developed countries has been somewhat well established over long periods, the situation is different in the developing world. Developing regions are plagued with challenges that include inadequate ground monitoring networks attributed to deteriorating infrastructure, organizational deficiencies, lack of technical capacity, location inaccessibility and the huge financial implication of dat...
This study presents a remote sensing approach of using freely available Landsat8satelliteIndicato... more This study presents a remote sensing approach of using freely available Landsat8satelliteIndicators(LandSurfaceTemperature(LST), Soil AdjustedVegetationIndex(SAVI)) and Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) geospatial data to assess the impact of dump sites on the environment in Benin City, Nigeria. The finding reveals that the average derived LST at the dumpsites were higher than the immediate surrounding, and the average SAVI values were lower than the immediate surrounding. The high values of LST at the dumpsites depict the effect of gases released because of decomposition activities, while low values of SAVI indicate vegetation response to soil and groundwater contamination due to leachate infiltration. The average elevation within the dumpsite area derived from SRTM DEM was also applied as a proxy to estimate disposed waste quantity, and related closely with LST that depict biodegradation activities. The result presented here shows that bacterial and fungal counts correlate strongly with the LST and SAVI values at each of the dumpsites R2: LST vs Bacteria Count = 0.982, LST vs Fungi Count = 0.951; SAVI vs Bacteria Count = 0.745, SAVI vs Fungi Count = 0.664, thereby suggesting remote sensing can be applied to aid longterm dumpsite monitoring and management.
In developing regions missing data are prevalent in historical hydrological datasets, owing to fi... more In developing regions missing data are prevalent in historical hydrological datasets, owing to financial, institutional, operational and technical challenges. If not tackled, these data shortfalls result in uncertainty in flood frequency estimates and consequently flawed catchment management interventions that could exacerbate the impacts of floods. This study presents a comparative analysis of two approaches for infilling missing data in historical annual peak river discharge timeseries required for flood frequency estimation: (i) satellite radar altimetry (RA) and (ii) multiple imputation (MI). These techniques were applied at five gauging stations along the floodprone Niger and Benue rivers within the Niger River Basin. RA and MI enabled the infilling of missing data for conditions where altimetry virtual stations were available and unavailable, respectively. The impact of these approaches on derived flood estimates was assessed, and the return period of a previously unquantified devastating flood event in Nigeria in 2012 was ascertained. This study revealed that the use of RA resulted in reduced uncertainty when compared to MI for data infilling, especially for widely gapped timeseries (>3 years). The two techniques did not differ significantly for data sets with gaps of 1–3 years, hence, both RA and MI can be used interchangeably in such situations. The use of the original in situ data with gaps resulted in higher flood estimates when compared to datasets infilled using RA and MI, and this can be attributed to extrapolation uncertainty. The 2012 flood in Nigeria was quantified as a 1-in-100-year event at the Umaisha gauging station on the Benue River and a 1-in-50-year event at Baro on the Niger River. This suggests that the higher levels of flooding likely emanated from the Kiri and Lagdo dams in Nigeria and Cameroon, respectively, as previously speculated by the media and recent studies. This study demonstrates the potential of RA and MI for providing information to support flood management in developing regions where in situ data is sparse.
Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling a... more Flood modelling and mapping typically entail flood frequency estimation, hydrodynamic modelling and inundation mapping, which require specific datasets that are often unavailable in developing regions due to financial, logistical, technical and organizational challenges. This review discusses fluvial (river) flood modelling and mapping processes and outlines the data requirements of these techniques. This paper explores how open-access remotely sensed and other geospatial datasets can supplement ground-based data and high-resolution commercial satellite imagery in data sparse regions of developing countries. The merits, demerits and uncertainties associated with the application of these datasets, including radar altimetry, digital elevation models, optical and radar images, are discussed. Nigeria, located within the Niger river basin of West Africa is a typical data-sparse country, and it is used as a case study in this review to evaluate the significance of open-access datasets for local and transboundary flood analysis. Hence, this review highlights the vital contribution that open access remotely sensed data can make to flood modelling and mapping and to support flood management strategies in developing regions.
With the Increasing developmental trend in Malaysia, vehicular and other sources of pollution has... more With the Increasing developmental trend in Malaysia, vehicular and other sources of pollution has been increasing correspondingly. The study assessed the levels of Nitrogen dioxide at the indoor (booth) and outdoor environment in relation to traffic count and meteorological factors (Wind intensity, Rainfall, Temperature and Humidity), using passive sampling technique (1month duration-weekly intervals), in a bid to approximate the Nitrogen dioxide (NO2) exposure levels of Tool Booth Operators. NO2 levels measured varied from (0.045-0.102ppm) for indoors and (0.047-0.102ppm) for outdoors. The study concluded the difference in Nitrogen dioxide concentrations between indoor and outdoor of tool booths were insignificant, and outdoor NO2 concentration was mostly influenced by traffic density and rainfall.
Municipal Solid waste management has in recent times been regarded as one of the most challengin... more Municipal Solid waste management has in recent times been regarded as one of the most challenging environmental issue facing developing countries. The traditional waste management techniques employed is mostly transferring waste to open dumpsites and poorly managed landfills. Considering the detrimental consequence of leachate on ground water, air pollution, visual nuisance and foul smell that emanates from these landfills calls for an alternative waste management technique. Composting provides us a means of managing municipal organic waste through the activities of various living organisms. This study is aimed at exploring the composting potential of Benin City waste under diverse physical control environments. Twenty five physio-chemical properties were analysed in a bid to ascertain the influence of aerobe, anaerobe and aerobe with Musca domestica maggot enhancements on organic waste for a period of four months. The study revealed that Benin City municipal waste is compostable and Musca domestica maggot inducement leads to improved compost which contains a higher nutrient quality especially in the production of nitrates, phosphates and potassium that are instrumental to plant growth. Composting provides an appropriate alternative approach for sustainable waste management and if employed on a large scale can reduce all the negative impacts of poor waste management.
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