About
83
Publications
17,607
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,461
Citations
Introduction
Publications
Publications (83)
The calibration of hydrological models using multiobjective algorithms generates several competitive solutions, usually referred to as a Pareto-optimal set. Pareto-optimal solutions are nondominated (i.e., accurate in different ways) and give users several decision scenarios and alternative trade-offs between model evaluation objectives. For decisi...
Data assimilation (DA) has facilitated the design and application of
hydrological forecasting systems. DA methods such as the ensemble Kalman
filter (EnKF) and the particle filter (PF) remain popular in the
hydrological literature. But a comparative evaluation of these methods
to alternative techniques like the evolutionary based data assimilation...
Hydrological models are increasingly been calibrated using multi-objective genetic algorithms (GAs). Multi-objective GAs facilitate the evaluation of several model evaluation objectives and the examination of massive combinations of parameter sets. Usually, the outcome is a set of several equally-accurate parameter sets which make-up a trade-off su...
There is increasing trend in the use of multi-objective genetic algorithms (GAs) to estimate parameter sets in the calibration
of hydrological models. Multi-objective GAs facilitate the evaluation of several model evaluation objectives, and the examination
of massive combinations of parameter sets. Typically, the outcome is a set of several equally...
At the heart of this paper are concerns for food security and sustainability—two challenges of wide relevance for geographers. Our work focuses specifically on the Guinea northern savanna ecological zone of Ghana, where poverty is grim and livelihood opportunities are limited and the intersection of urban expansion and livelihood dynamics is not we...
Introduction;
Traffic-related air pollution (TRAP) is a serious public health risk in today's cities, causing premature death and a wide range of global diseases such as respiratory, cardiovascular, and neurological disorders. The study assessed the impacts of vehicle emissions exposure on the risk of health burden for residents near major urban in...
The study examines the association of bodily pain intensity and pain interference with sleep problems and investigates the mediating role of activity limitation and emotional distress in the pain-sleep problems link.
The study delves into how vehicle engine characteristics impact the release of air pollutants from various vehicle fleets in Lagos, Nigeria. It involved the direct measurement of emissions from the exhaust pipes of 88 vehicles using gas analyzers. The vehicle fleet encompassed motorcycles, tricycles, private cars, minibuses, large buses, and trucks...
The rise in automobiles within rapidly developing nations in Sub-Saharan Africa necessitates the exploration of sustainable transportation alternatives, especially in urban regions. Walking and cycling are essential active modes of transport that can improve city residents' well-being and economic vitality. However, their adoption as mobility choic...
Traffic-related air pollution (TRAP) is a serious public health risk in today's cities, causing premature death and a wide range of global diseases such as respiratory, cardiovascular, and neurological disorders. The study assessed the impacts of vehicle
emissions exposure on the risk of health burden for residents near major urban intersections in...
Road Surface Condition Survey of unpaved roads
Consideration of health equity is fundamental to enhancing the health of those who are economically/socially disadvantaged. A vital characteristic of health equity and therefore health disparity is the level of spatial access to health services and its distribution among populations. Adequate knowledge of health disparity is critical to enhancing t...
Identification and extraction of unpaved road surface parameters from images are emerging and essential to effective road surface condition survey. The vulnerability of unpaved roads—lacking protective surface, makes the situation more heighten. This paper seeks to illustrate an approach to identify and extract road surface condition parameters fro...
Emissions from vehicular traffic are one of the key drivers of urban environmental air pollution, degrading the ambient air quality in many African cities and across the globe. This study sought to assess the impact of traffic mobility measures on the emission levels of air pollutants from vehicle exhaust in Lagos, Nigeria. Traffic flow and vehicle...
The perception and behavior of the public is key in reducing Traffic-related air pollution health burdens which has become an increasingly alarming problem in many cities across the globe. The study assessed the perception of the public about vehicle traffic emissions and the health hazard associated with them in Lagos, Nigeria using structured que...
It is widely acknowledged that the tools for pedestrian navigation in indoor environments have been increasing while the internal spaces of buildings continue to grow in complexity. The majority of mobile applications for indoor navigation are mostly dependent on access to radio‐frequency identification (RFID) and WiFi, which are particularly limit...
In Sub-Saharan Africa, paratransit is the primary means of mobility where accessibility to its bus terminals offers access to diverse societal opportunities. This study accounts for the capacity of bus terminals, population demand, the geographic separations between demand and supply locations, and pedestrian response to congestion in the Greater K...
The study investigated the ambient air quality caused by vehicular emission and its implications on the public health around major roadways in Lagos metropolis Nigeria. Field data on vehicular volumes and mix were collected for three months in the morning, afternoon, and evening peak periods for the five (5) selected major routes. Concurrently, air...
It is widely acknowledged that geographic data in Ghana and most of Sub-Sahara Africa is patchy, and lack geographic coverage and detail. This has implications for mobility and access to socioeconomic, and cultural opportunities which require address and location data typically provided through geocoding. A critical component of geocoding is a refe...
The current policy and stakeholder debates suggest that climate change remains a risk factor for the rising urban floods situation in Ghana. However, there is a dearth of empirical works to explain the link between flood incidence and climatic-related factors. Using a long-term secondary climatic data, this paper analyses the extent to which climat...
Mobility and access to social, economic, and cultural opportunities are facilitated by the availability of practical location data. Practical location data are scarce in Ghana and most of Sub-Sahara Africa
where cities are typically characterized by informal settlements and a lack of standard address system. The problem is compounded by limited use...
Characterizing accessibility to healthcare is complex, requiring the consideration of geography, socioeconomic and cultural factors. The Three-Step Floating Catchment Area (3SFCA) was used to account for population demand, the capacity of health facilities, and the geographic separations between locations of demand and supply in the Greater Kumasi,...
It has been widely recognized that groundwater susceptibility to contamination is a function of a complex interplay of factors including land use dynamics, pollutant sources, hydrogeology, climate and biogeochemical reactions within the aquifer. Spatially targeting the risk levels and coverage of groundwater contamination is a challenging task, req...
Soil erosion is a global problem with severe consequences, which has become a widespread environmental challenge in the northern parts of Ghana in recent times. This research integrated RUSLE into GIS to estimate the annual soil erosion rates for the Northern, North-East, and Savannah Regions of Ghana. A soil erosion map was generated with an annua...
The frequency and severity of floods in Ghanaian cities have been increasing. Typically, increased floods have been attributed to climate change with limited evidence. Although this may be true in some cases, it minimizes the role of landscape change as a result of urban growth. Given the complexity of cities, this study characterizes urban morphol...
Address and location challenges are global, yet sub‐Saharan Africa (SSA) is the most poorly referenced geographically due to poor spatial referencing of mobility infrastructure and landmarks, poor road layout, and informal settlements. But there is a widespread use of informal geographic referencing especially for paratransit service, and landmarks...
Road networks are an integral part of any human settlement, facilitating the movement of people, goods, and information. The structural arrangement of a road network can have a profound impact on its performance, mobility and access to critical infrastructure. This study takes advantage of a computational network science approach to examine the str...
There has been tremendous adverse impact of fire outbreaks across the world over the last two decades. The human cost has been devastating and economic losses have exceeded an annual average of US$2500 million. Regardless of its importance in plant community regeneration, wildfires have been tremendously devastative to human societies and Earth's e...
Urban area expansion has often been cited as a flood inducing factor globally. However, there is a dearth of research on how the phenomenon influences the occurrence of floods in Ghana. This paper examines urban sprawl-induced green space depletion and its attendant implications for urban flood incidence in a developing world context. Focusing on K...
Road networks are by far the largest mobility infrastructure in Sub-Sahara Africa, and are key to providing access to economic and social opportunities. Yet the majority of road networks in Ghana and other countries in Sub-Sahara Africa are not geographically referenced, to facilitate their uses for road maintenance and management, transport planni...
Hydro-meteorological models form a cornerstone for critical societal decisions. The reliability of these models in terms of the trustworthiness of their outputs and the consistency of their performance across diverse hydro-meteorological conditions and time periods, has been widely recognized to be questionable. The major evaluation methods used to...
Major past floods that have resulted in huge losses to households along the Black and White Volta Basins have raised the question of whether they were consequences of climate change or direct anthropogenic activities. This paper therefore examines the physical and human contexts of fluvial floods in rural Central Gonja District of Ghana using mixed...
Soil erosion is a serious environmental problem that is associated with societal impacts including flooding, poor water quality, and loss of plant nutrient leading to low agricultural productivity. Soil erosion wears away the top soil and is controlled by the interaction between several factors including rainfall, steepness of slope, length of slop...
This study assesses social vulnerability to hazards by analyzing the nature of biophysical hazards, and the characteristics of exposures, susceptibilities and adaptive capacities in Kumasi. A mixed method approach was used to collect primary data from farms and nearby markets. Water, soil, and plant samples were collected and tested for total colif...
High-resolution X-ray tomography was used to observe a partially hydrated geosynthetic clay liner (GCL) specimen to gain a better understanding of the interaction of its compnents (i.e., geotextiles, fibres and bentonite) on partial hydration when deployed as part of a composite liner system. Detailed in-situ studies of hydration processes in GCLs...
Travel routing is vital for an efficient delivery of public and private services and the movement of people and goods. In Ghana, the major nature of travel routing is through the 'trotro' system. The trotro system uses an automobile to move people and goods along a prescribed travel route, with locally known stops where people get on and off the ve...
The sources of uncertainty in land surface models are numerous and varied, from inaccuracies in forcing data to uncertainties in model structure and parameterizations. Majority of these uncertainties are strongly tied to the overall makeup of the model, but the input forcing data set is independent with its accuracy usually defined by the monitorin...
The Soil Moisture and Ocean Salinity (SMOS) mission has the potential to improve the predictive skill of land surface models through the assimilation of its observations. Several alternate products can be distinguished: the observed brightness temperature (TB) data at coarse scale, indirect estimates of soil moisture (SM) through the inversion of t...
Soil moisture retrievals, delivered as a CATDS (Centre Aval de Traitement des Données SMOS) Level-3 product of the Soil Moisture and Ocean Salinity (SMOS) mission, form an important information source, particularly for updating land surface models. However, the coarse resolution of the SMOS product requires additional treatment if it is to be used...
The Soil Moisture Ocean Salinity (SMOS) satellite mission routinely provides global multiangular observations of brightness temperature TB at both horizontal and vertical polarization with a 3-day repeat period. The assimilation of such data into a land surface model (LSM) may improve the skill of operational flood forecasts through an improved est...
Numerous land surface models exist for predicting water and energy fluxes in the terrestrial environment. These land surface models have different conceptualizations (i.e., process or physics based), together with structural differences in representing spatial variability, alternate empirical methods, mathematical formulations and computational app...
Land surface model validation at distributed scales is important for model improvements. Recent advances in satellite technology provide an opportunity for distributed calibration and validation of land surface models. In the past years, a number of active and passive microwave soil moisture products have become available. While passive microwave s...
Soil moisture information is critically important for water management operations including flood forecasting, drought monitoring, and groundwater recharge estimation. While an accurate and continuous record of soil moisture is required for these applications, the available soil moisture data, in practice, is typically fraught with missing values....
Data assimilation (DA) has been widely used in hydrological models to improve model state and subsequent streamflow estimates. However, for poor or non-existent state observations, the state estimation in hydrological DA can be problematic, leading to inaccurate streamflow updates. This study evaluates the soil moisture and flow variations and fore...
Radiometric observations from the Soil Moisture and Ocean Salinity (SMOS) mission are processed to Level 1 brightness temperature (Tb) with ~ 42-km spatial resolution and reported on a 15-km hexagonal Discrete Global Grid (DGG). While these data should be used at the 42-km resolution which the oversampled DGG represents, this paper poses the questi...
Data assimilation has allowed hydrologists to account for imperfections in observations and uncertainties in model estimates. Typically, updated members are determined as a compromised merger between observations and model predictions. The merging procedure is conducted in decision space before model parameters are updated to reflect the assimilati...
Data assimilation (DA) methods are commonly used for finding a compromise between imperfect observations and uncertain model predictions. The estimation of model states and parameters has been widely recognized, but the convergence of estimated parameters has not been thoroughly investigated. The distribution of model state and parameter values is...
Land surface model validation at distributed scales is important for model improvements. Recent advances in satellite technology provide an opportunity for distributed calibration and validation of land surface models. In the past years, a number of active and passive microwave soil moisture products have become available. While passive microwave s...
Data assimilation (DA) methods continue to evolve in the design of streamflow forecasting procedures. Critical components for efficient DA include accurate description of states, improved model parameterizations, and estimation of the measurement error. Information about these components are usually assumed or rarely incorporated into streamflow fo...
Data assimilation (DA) has emerged as a valuable tool for the design and application of streamflow forecasting systems. But DA applications for streamflow simulations in ungauged basins are still very limited primarily because most updated ensemble members are not usually associated with converged state and model parameterizations. Other limitation...
Multi-objective evolutionary algorithms (MOEAs) have gained popularity for their capability to handle complex and nonlinear problems. MOEAs are population-based search tools which employ the concept of biological evolution and natural selection. While MOEAs have been applied in numerous hydrological studies for parameter estimation, their formulati...
Soil moisture information is of critical importance to real-world applications such as agriculture, water resource management, flood, fire and landslide prediction, mobility, etc. Many of these applications require soil moisture information at high resolution. While this may be estimated from land surface models, the predictions are often poor due...
Multi-objective genetic algorithms are increasingly being applied to calibrate hydrological models by generating several competitive solutions usually referred to as a Pareto-optimal set. The Pareto-optimal set comprises non-dominated solutions at the calibration phase but it is usually unknown whether all or only a subset of non-dominated solution...
This study has applied the Nondominated Sorting Genetic Algorithm II (NSGA-II) in a two-step assimilation procedure to jointly assimilate brightness temperature into a radiative transfer model and soil moisture into a land surface model. The first assimilation procedure generates a time series of soil moisture by assimilating brightness temperature...
Continuous time series of soil moisture data are important for water resource applications including streamflow predictions and weather forecasting. In practice, most soil moisture data have missing values which require infilling to generate complete datasets. This study investigates six methods for infilling missing values for high resolution soil...
There is an increasing trend in the use of multi-objective optimization methods for estimating parameter sets in the calibration of hydrological models. Typically, the outcome is a set of several parameter sets usually referred to as Pareto set (or Pareto frontier) which forms a trade-off between the objective functions. The Pareto set is a set of...
Lithologies for water wells in Canada constitute a major data source for describing the subsurface geology. Generally the
datasets contain inconsistent descriptions and consequently have limited utility for deriving relevant geological information.
The Geological Survey of Canada (GSC) has developed a standardization scheme to address the problem b...
Census data has been widely used for community evaluation based on demographic and socioeconomic variables. However, the analysis is typically associated with specific areal units and the results often change when the size of the census configuration changes leading to scale distortions. Various approaches such as optimal zoning systems and multiva...