Megersa Olumana Dinka

University of Johannesburg | uj · Faculty of Engineering and the Built Environment

Rapid advances to industrialization and population increases have put aquatic ecosystems at high risk of pollution from various industrial and municipal effluents. The effluents consist of heavy metals (HM), micropollutants, nutrients, microorganisms, solids, particulates and dissolved matter. To this effect, pollutant remediation in such ecosystem...

Varied applications of nanomaterials have transformed various industries in the modern day. In recent years, magnetic nanoparticles (MNPs) have gained research interest from their applications in the environmental, agricultural, catalysis, medical and biosensing fields. This chapter explored the potential of MNPs in dye sensing and removal using pr...

Water pollution is a common problem for dams situated within an urban or agricultural catchment. This can negatively affect the hydro ecosystem, drinking, recreational and other uses of water. In this study, the drinking water quality class of the Roodeplaat Dam, South Africa which faces pollution problems was modeled using machine learning algoris...

The rapid spread of COVID-19 globally transformed the educational sector from the conventional face-to-face teaching to virtual learning to control the transmission of the virus. This study explored on the transition to online learning, the opportunities and challenges post-COVID-19 with specific focus on developing countries. It was found that vir...

Municipal waste management is growing to be the world’s greatest environmental issue. In this chapter, urban waste management was linked to sustainable development in the cities of Johannesburg and Nairobi. Using a comparative analysis of academic literature, the chapter explored the solid waste management practices and policies the cities have imp...

Kenya is one of the water-scarce nations in the sub-Saharan Africa region that is seeking for alternative water sources to meet the ever-rising demands of the resource for its growing population amidst climate variability. Desalination is one of the viable alternatives since it has no effect on the hydrological cycle. This research discussed the me...

In this chapter, recommendations to improve water management in sub-Saharan Africa towards universal access to the commodity were discussed. This was done with the precognition that the region is yet to make substantive progress in reference to sustainable development goal 6. Findings showed the need for the region to improve resilience to climate...

This chapter focused on the management measures that can be applied to reverse the water issues of sub-Saharan Africa (SSA) region. Findings showed that water challenges of the region emanate from institutional, policy and regulatory weaknesses in addition to physical and economic water scarcity. Therefore, measures geared to improved governance on...

Improved water access, supply and hygiene is one of the priorities defined in the sustainable development goals to be realized by 2030. However, sub-Saharan Africa (SSA) has had challenges making progress towards the realization. This chapter examined the impediments experienced by SSA countries towards universal water access. Findings showed that...

This chapter focused on assessing the progress towards realization of sustainable development goal (SDG) 6 on universal access to safe water in sub-Saharan Africa (SSA) region. Findings showed that progress had been made in providing access to safe drinking water and sanitation facilities in rural and urban areas though at a slow pace. Implementati...

This chapter explored the sources of water used by sub-Saharan Africa (SSA) for drinking and ways in which users access it. The total amount of renewable water in SSA was reported to be more than 8, 200 cubic kilometers annually (km3/year) mainly sourced from the western and central areas of the region near the Gulf of Guinea. Surface- and ground-w...

The focus of this chapter was to explore the challenges that prevent rural sub-Saharan Africa (SSA) from realizing universal water access. Findings showed that many waterpoints to acquire groundwater using handpumps had been installed in the region over the last two decades to provide access to improved water services. However, the waterpoints have...

Eutrophication is a common problem for the dams situated within an urban or agricultural catchment with a high source of untreated plant nutrients. This can negatively affect the hydro ecosystem, recreational and other uses of water. On the other hand, such eutrophic dams could also be a rich source of nutrients for agricultural use. Thinking irrig...

Rainfall forecast information is important for the planning and management of water resources and agricultural activities. Turksvygbult rainfall near the Magoebaskloof Dam (South Africa) has never been modelled and forecasted. Hence, the objective of this study was to forecast its monthly rainfall using the SARIMA model. GReTL and automatic XLSTAT...

The biological treatment process is responsible for removing organic and inorganic matter in wastewater. This process relies heavily on microorganisms to successfully remove organic and inorganic matter. The aim of the study was to model biomass growth in the biological treatment process. Multilayer perceptron (MLP) Artificial Neural Network (ANN)...

Understanding the human-forest relationship is key to sustainable development and forest management. The increase of agricultural land expansion mainly focuses on satisfying the competing interest amongst stakeholders and rural households, which neglects the impact of forest losses. The study looked at rural households' farmland expansion dynamics...

The biological aeration unit consumes the highest energy (67.3%) in wastewater treatment compared with physical (18.8%) and chemical (13.9%) treatment processes. The high energy consumption is caused by the supply of oxygen using air pumps/blowers and temperature that controls microorganisms' growth. The purpose of this study was to model and optim...

The biological treatment process (BTP) is responsible for removing chemical oxygen demand (COD) and ammonia using microorganisms present in wastewater. The BTP consumes large quantities of energy due to the transfer of oxygen using air pumps/blowers. Energy consumption in the BTP is due to low solubility of oxygen, which results in low aeration eff...

The purpose of this study was to analyse the impact of temperature and airflow rate on the removal of COD and ammonia. This study showed for the first time that temperature has a significant impact on the removal of COD and ammonia compared with airflow rate. The impact of temperature and airflow rate on COD and ammonia removal was analysed using R...

The recognition of nature-based solutions (NbS) is on a growing trend worldwide in an era of climate change, and intensified demand for improved human health, better preparedness for disasters, food and water security. The solutions seek to restore, protect and sustainably manage natural and modified ecosystems to optimize biodiversity and human we...

The predominant scarcity of water globally has necessitated the invention of non-conventional resources to bridge the clean freshwater demand gap. Even in areas where there is access to water, inadequate quality and sanitation are pervasive problems, especially in developing countries. Resolving these intricate water-related problems, which emanate...

This study tried to assess the impact of climate change on water resources of the upper Awash River sub-basin (Ethiopia) using a statistical downscaling model (SDSM). The future climatic parameters (rainfall, maximum and minimum temperatures) were generated by downscaling outputs of HadCM3 (Hadley Centre Coupled Model, version 3) general circulatio...

The relevance of sustainability in contemporary society is on a growing trend owing to the predominance of economic development and environmental conservation plans amidst challenges of climate change. Eco-efficiency is a growing tool to qualify economic and environmental sustainability. In this chapter, the trends of eco-efficiency over the last t...

This study aimed at quantifying the heavy metal levels in soils and vegetables sampled from five suburban regions of Nairobi, Kenya. Using inductively coupled plasma-mass spectrometry (ICP-MS) the metals were quantified from the samples. The assayed heavy metals including Cd, Cr, Co. Cu, Fe, Hg, Mn, Ni, Pb, Zn and the metalloid arsenic were elevate...

Increased production of greywater prompted by the rise of urbanization and increased population in the industrial era is a growing environmental concern exacerbating the apparent water insecurity. Treatment and reuse of greywater is a promising solution to this problem since it will divert the use of limited freshwater resources to unavoidable cons...

This study reviewed the use of microorganisms for bioremediation of wastewater. The aim was to ensure enhanced transfer of findings on bioremediation experiments at laboratory level for field applications, which is currently limited. Using empirical studies and specified microbes, bioremediation was shown to clear or reduce concentrations of many p...

Textile industries produce large quantities of liquid and solid waste materials with toxic components that can pollute land and water resources. The treatment of liquid effluents is ongoing while management of solid wastes and sludge is neglected for their incineration and landfilling. The management approaches are not sustainable since they extend...

The production of plastic wastes is a growing environmental problem in the era of industrialization and economic growth due to the varied applications of polymeric materials. The wastes, which are mainly landfilled pollute land and waste resources due to the toxic and resistant to biodegradation nature of their components. Therefore, innovative app...

Landfill leachate is a noxious liquid with the potential to pollute groundwater resources following its horizontal and vertical mobilization from unsaturated to saturated zones. In this study, the characteristics of leachate from Roundhill landfill of South Africa were assayed using physicochemical analysis. Areal groundwater was sampled to assess...

This minireview characterizes waste materials and their composition in African cities using existent literature , highlights methods that can be used to convert waste materials to energy and examines the progress and prospects of use of wastes to enhance energy security in the regions. It was found that African cities produce about 125 million tons...

In river basins such as the Olifants, the evapotranspiration has been documented as the biggest water user and therefore one of the most important hydrological processes in the basin. Thus, using the Soil and Water Assessment Tool (SWAT) model, this study attempted to assess the hydrological responses of evapotranspiration (ET) to climate change in...

Water contamination by microbes is a growing environmental challenge that has exacerbated the apparent scarcity of safe drinking water. To alleviate this challenge, it is important to screen water for pathogens to reduce the risk of contracting waterborne diseases among consumers. The use of the quantitative microbial risk assessment (QMRA) tool to...

Background: Land use/land cover (LULC), change is one of the major contributors to global environmental and climate variations. The ability to predict future LULC is crucial for environmental engineers, civil engineers, urban designers, and natural resource managers for planning activities. Methods: TerrSet Geospatial Monitoring and Modelling Syste...

This study presents the novelty artificial intelligence in geospatial analysis for flood vulnerability assessment in Dire Dawa, Ethiopia. Flood-causing factors such as rainfall, slope, LULC, elevation NDVI, TWI, SAVI, K-factor, R-factor, river distance, geomorphology, road distance, SPI, and population density were used to train the ANN model. The...

Increased consumption and demand for freshwater has resulted to massive production of wastewater, which has toxins and is harmful to the environment if not treated. The use of permeable reactive barriers using activated carbon has proven to be a low cost and environmental friendlier solution to the problem compared to conventional methods. This min...

The aim of the paper was to analyze factors affecting domestic water consumption in Thohoyandou, Limpopo province, South Africa. A structured questionnaire was used to collect qualitative and quantitative data in the study area. A total sample of 100 households participated in answering the questionnaire. The results of the analysis found that aver...

Background: Land cover/land cover (LULC) change is one of the major contributors to global environmental and climate variations. The ability to predict future LULC is crucial for environmental engineers, civil engineers, urban designers, and natural resources managers for planning activities. Methods: TerrSet Geospatial Monitoring and Modelling Sys...

Study region Lower Baro River, Ethiopia. Study focus This paper presents the novelty of ANN and HEC-RAS model for flood inundation mapping in lower Baro Akobo Basin River, Ethiopia. ANN and HEC-RAS model is applied and successfully improves the accuracy of prediction and flood inundation in the region. This study uses 14 meteorological stations on...

As a result of poor MSW management in South Africa, leachate generation has been reported in lined and unlined landfills, which calls for measures to quantify and safely return it to the environment without causing adverse effects on the facilities' vicinity. This paper presents a review of studies on leachate assessment and quantification in South...

Integration of advanced irrigation systems and technology is essential to improve crop water productivity and yields, especially in developing countries. This study aims at investigating the effects of adopting a drip irrigation system combined with hand-dug wells on crop water productivity and yields of household farmers and their perception on th...

Assessing available water resources and their potential for irrigation water use is vital for sustainable agricultural development and planning. This is particularly of interest in developing countries like Ethiopia, where a small portion of largely accessible land for surface irrigation applications has been utilized, despite the majority of the p...

Evaluating climate change impacts and the suitability of potential land resources is crucial for sustainable irrigated agricultural systems. This study applied a multi-criteria analysis supported by the Geographic Information System (GIS) application to produce irrigation suitability maps for the Anger River basin's (Ethiopia) irrigation command ar...

Study Region Lake Basaka is a volcanically dammed closed basin-type lake located within Matahara plain area, northern part of the Main Ethiopian Rift Valley (MERV) region. The MERV is situated within the Great East African Rift Valley (GEARV) region, which is hydrgeologically unstable and complex. Study Focus In the current study, a conceptual lak...

sssBacteria in biological wastewater treatment process play an important role in the removal of substrate concentration. When bacteria removes the substrate, they continuously growth until such time when the substrate concentration is depleted. This paper aims to review the performance of kinetic growth rate models that describe specific bacteria g...

Soil is a vital media in transmitting contaminants in the environment. Contamination of soils by trace metals has received much attention due to their associated toxicity, persistence, bioaccumulation and non-biodegradability that is harmful to the ecology. This study assayed the concentrations of trace metals in topsoils of the vicinity of Roundhi...

Soil is a vital media in transmitting contaminants in the environment. Contamination of soils by trace metals has received much attention due to their associated toxicity, persistence, bioaccumulation and non-biodegradability that is harmful to the ecology. This study assayed the concentrations of trace metals in topsoils of the vicinity of Roundhi...

Within the context of catchment hydrology, using the Soil and Water Assessment Tool (SWAT) model, this paper attempts to assess the past and present spatial precipitation variability in the upper middle catchment (UMC) of the Olifants River basin. The study shows a strong decreasing trend of east-to-west direction of spatial precipitation with most...

Soil erosion is a monumental land degradation problem in many parts of the world, threatening the well‐being of humans and ecosystems. The Lake Basaka catchment is heavily affected by serious land degradation problems related to land use–land cover changes (LULC), population dynamics and settlement, introduction of large‐scale irrigation schemes, e...

The efficiency of an irrigation system greatly depend on the quality of water it is using. The suspended solids (amount and nature) found in irrigation water has a significant effect on irrigation water supply, especially on sprinkler and drip irrigation systems. In such irrigation systems, sediment in canal structures has both technical and econom...

The Lake Basaka catchment (Ethiopia) has undergone a significant land use–land cover (LULC) change and lake level rise over the past five decades. Significant quantities of water and sediment flow annually into the lake through erosion processes. An appropriate method of estimating the surface run‐off from such ungauged and dynamic catchment is ext...

Contamination of soils by trace elements is a worldwide concern and has negative effects on environmental sustainability. Geochemical assessment of soils using appropriate indicators and pollution indices has received much attention in recent years in efforts to rehabilitate this resource. This study quantified pollution of soils by trace elements...

This study used the Soil and Water Assessment Tool (SWAT) model together with regional climate downscaled (RCD) data from the CORDEX (Africa project), to assess the local seasonal precipitation variability in the upper middle catchment (UMC) of the Olifants River basin. The study results, based on two scenarios (RCP4.5 and RCP8.5), showed a wider m...

This study evaluated the possibility of conjunctive use (CU) of shallow groundwater (SGW) and surface water for irrigation at the Wonji Shoa Sugar Estate (WSSE) (Ethiopia). Irrigation suitability was investigated by taking 46 SGW samples from piezometers and hand‐dug wells. Many physicochemical parameters (Mg ²⁺ , Na ⁺ , Ca ²⁺ , K ⁺ , CO 3 ⁻ , SO4...

Solid waste management (SWM) is a challenge in developing countries such as the Republic of South Africa (RSA). This book chapter highlights the drivers and state of SWM in RSA and suggests alternatives to make solid waste a resource. The SWM strategy of the country has a role in pushing waste up its hierarchy towards minimal generation, reuse, and...

The effect of the pipe material plays a preeminent role in the overall water leakage behaviour of cracks, and specifically of longitudinal cracks for pipes composing Water Distribution Systems. Due to pipe material properties, a longitudinal crack on a pipe exhibits expansion behaviour under internal pressure increases, taken up by hoop stresses, w...

This study presents the spatial variability and dynamics of soil organic carbon ( SOC ), soil organic matter ( SOM ) and soil pH contents at the Wonji Shoa Sugar Estate (WSSE), Ethiopia. Soil samples were collected immediately after the sugarcane was harvested and then analysed for SOC , SOM and pH content using standard procedures. The analysis re...

Heavy metal contamination and toxicity in soils results from anthropogenic and lithologic factors and is a potential hazard to land and water resources. Sources of such pollution include landfills, domestic sewage, agricultural fertilisers and industries. In this work, soils from Roundhill landfill vicinity in South Africa were sampled and analyzed...

Precise estimation of metals in samples remains a challenge as a result of analytical biases and errors, which occur at sample collection, preparation, and measurement stages. A poor understanding of the nature and occurrence of these errors further aggravates this challenge. This study aimed at comparing the effectiveness of inductively coupled pl...

Wonji Shoa Sugar Estate (WSSE), located in the flood plain of the Awash River (Ethiopia), has been under long-term (>60 years) irrigation, industrial activities and agro-chemical usage. In this study, the hydrochemical properties of groundwater bodies available at WSSE have been characterized for quality compositions. Water samples were collected f...

Land use/land cover changes (LULCC) at Adei watershed (Ethiopia) over a period of 23 years (1986–2009) has been analysed from LANDSAT imagery and ancillary data. The patterns (magnitude and direction) of LULCC were quantified and the final land use/land cover maps were produced after a supervised classification with appropriate post-processing. Ima...

The main task in treating the wastewater in South Africa is to reduce the pollutants (solids, organic matter, nutrients, and micro-organisms) to meet the standard requirements from Department of Water and Sanitation (DWS). That means the discharged effluent should be without polluting the environment and posing safety risks. The objective of this s...

In this study, the effect of land use–land cover change (LULCC) on surface (direct) runoff was estimated for Lake Basaka catchment using the soil conservation services—curve number model in the geospatial information system (ArcInfo), assisted by remote sensing. The result indicated that Lake Basaka catchment experienced a significant LULCC. About...

Owing to an increasing demand for irrigation water associated with the massive expansion of irrigated sugarcane farms in Ethiopia, there is a need to use the available water efficiently and effectively. Accordingly, a study was conducted to evaluate the effect of operating pressure and nozzle size on the field performance of dragline sprinkler syst...

Knowledge of future river flow information is fundamental for development and management of a river system. In this study, Waterval River flow was forecasted by SARIMA model using GRETL statistical software. Mean monthly flows from 1960 to 2016 were used for modelling and forecasting. Different unit root and Mann–Kendall trend analysis proved the s...

As opposed to most of the other closed basin type rift valley lakes in Ethiopia, Lake Basaka is found to be expanding at an alarming rate. Different studies indicated that the expansion of the lake is challenging the socio-economics and environment of the region significantly. This study result and previous reports indicated that the lake's expansi...

This paper considers the extent and usefulness of reviewing existing literature on the significance of direct and indirect impacts of climate change on groundwater resources with emphasis on examples from the Olifants River basin. Here, the existing literature were extensively reviewed, with discussions centred mainly on the impacts of climate chan...

The composition of different surface water and groundwater constituents of the Matahara region (Ethiopia) were studied to understand their hydrochemical sources. Potential hydrochemical origins of different water sources were identified based on ionic indices and standard Piper plots. The findings indicate that pH, electrical conductivity, and conc...

Reservoir operation policies cannot be functional in instant decision making without forecasting the future reservoir inflows. For forecasting inflows into reservoirs with only hydrological data is available like Koga irrigation dam, multivariate forecasting models cannot be used to generate accurate river flow information. As a result, an evaluati...

The Matahara Sugar Estate (MSE), after nearly 60 years of irrigation, is experiencing the effects of waterlogging and salinization in some fields. The problem is believed to be the result of the expansion of (saline and alkaline) Lake Basaka towards the plantation fields. The objective of this study was to determine the geometry of the lake (area a...

This study presents the general water quality status and temporal quality dynamics of Lake Basaka water in the past about 5 decades. Water samples were collected and analysed for important physico-chemical quality parameters following standard procedures. The result showed that Lake Basaka water is highly saline and alkaline and experiencing a gene...

Lake Basaka is expanding at a significant rate. Before the establishment of Matahara Sugar Plantation, the lake was like a small surface pond created during rainy season and used as grazing area. The lake expansion has certain negative consequences to the region. Thus, appropriate method of quantification of the Lake expansion is extremely importan...

The success of a sprinkler irrigation system largely depends on its actual performance in field conditions. Although the uniformity of water application is the most important aspect of the sprinkler system's performance, adequacy better explains the performance of the system. In this study, the adequacy of irrigation performance was measured in fie...

This study highlights the physicochemical compositions of different water sources available at Matahara Plain and evaluates their suitability for irrigation purpose. Various surfaceand ground-water samples were collected and then analysed for important major physicochemical quality parameters (pH, EC, cations and anions) following standard procedur...