Mines

Permanent URI for this collection

http://41.63.25.24:4000/handle/123456789/82

Browse

Now showing 1 - 20 of 129

A review of mine closure and rehabilitation plans during the operations of large-scale mines in Zambia: a case study of Nchanga open pit mine.
(The University of Zambia, 2022) Syafunko, Mutinta Esther
The world population continues to grow, with Africa projected to reach 2.4 billion people by the year 2050. This increase in population has resulted in a high demand for goods and services, which has subsequently triggered an increase in demand for mineral resources. Zambia, being a mineral rich country has seen an increase in exploration and exploitation of its mineral resources with some of the largest open pit mines in Africa being host to Zambia. Despite the positive economic impacts that come with mining, open pit mines have an adverse environmental impact, vis a viz, loss of biodiversity, land degradation, loss of ecosystems, etc. The country does not have any large-scale open pit mines that have closed which gives an opportunity for the mines to operate and close sustainably. The aim of this study was to review the incorporation of mine closure plans and progressive rehabilitation activities into the life cycle of large scale open pit mines in Zambia. This was done by an assessment of the current mine closure plans and a review of the benefits of incorporating these closure plans and progressive rehabilitation activities into the life cycle of large-scale open pit mines. The study focused on the Nchanga open pit mine, which is, a large-scale open pit mine in Zambia. The laws and regulations of Zambia were also examined in order to identify gaps and provide recommendations for improvement. The recommendations were drawn from an assessment of the current best practices and regulations and a review of international practices in Chile, South Africa and Western Australia. The methodology involved the use of survey questionnaires that were distributed to the local community, interviews that were conducted with key stakeholders, a site visit that was conducted at Nchanga Open Pit mine and the desktop review of the current laws and regulations on mine closure in Zambia. The results of the research revealed that the Environmental Protection Fund is the main framework used to deal with the issues of mine closure in the country. However, due to various factors including inability of local banks to provide bank bonds or guarantees to the mines and limited resources to carry out site inspections, the framework is not implemented effectively. There is therefore the need to review the effectiveness of this framework and revise it to be an effective tool for continuous rehabilitation and mine closure.
An assessment of the potential pollution risk of tailings dumps on the environment using multi criteria decision analysis (MCDA).
(The University of Zambia, 2022) Munanku, Teclah
The mining industry is one of the key economic drivers in Zambia and has tremendously grown since its genesis in the early 1900’s. Zambia is one of the largest copper producers in Africa and the world and this translates to thousands of tonnes of mining waste accumulated over the years. Mine tailings have a huge footprint over the environment and can have serious consequences that cannot be reversed during mining and long after mining has ceased. This has resulted into over 2000 dumps lying around the surface on the Copperbelt Province and other provinces. Despite several studies being done around tailing dumps, impact assessments of their risk have been a challenge. This challenge arises mainly from the lack of common criteria for risks to objects of environmental protection as well as the lack of time frames within which these criteria are evaluated and this has made it difficult to conduct impact assessment studies of the mine tailing dumps. This research assessed the potential pollution risk of tailings dumps using multi-criteria decision analysis, in this case, the analytical hierarchy process (AHP) method was applied to assess which dump has a higher potential pollution risk to the environment. AHP is a widely used assessment method and is based on the premise that decision-making related to complicated problems can be handled using a hierarchical structure that transforms complexity into a simple and comprehensible problem. Appropriate criteria went into the development of a framework for multicriteria decision support analysis and this enabled the determination of the potential pollution risk to the environment from the three tailings dumps selected. The tailings dumps were selected based on the criteria of age, working status of mine and more critically the availability of data needed to carry out the assessment on these dumps. The tailing dumps selected included one from a legacy mine (Kabwe Lead Mine, Kabwe) which is the oldest, one from a relatively older working mine (Mopani Copper Mine, Kitwe) and one from a relatively younger working mine (Lumwana Copper Mine, Mwinilunga). Criteria with five indicators was developed, the first being physical properties. This indicator considered three factors, size of the tailings dumps in hectares, particle size of dump material and consolidation status of dump. The second indicator was chemical properties that was computed as an index of contamination. The third indicator is properties of the environment around the dump, this considered four factors; the lithology underlying the dump area, the depth of the water table, the distance to the nearest surface water body, and the distance to the nearest anthropogenic facility. The fourth indicator was climatic factors around the dump area and focuses on the amount of rainfall received in the area. The fifth indicator was protective structures, this considered dust suppression at the site by means of tree cover. Results of the research revealed that Kabwe mine tailings dump had the highest pollution potential followed by the Lumwana mine tailings dump then Mopani mine tailings dump (TD15A) in Kitwe. The results of the assessment show a successful model for decision making. When compared against a severity of risk scale, the Mopani Mine tailings dump in Kitwe had a low risk while the Kabwe and Lumwana mine tailings had a medium risk. Although this study was conducted using three tailings dumps, the criteria developed can be used to guide assessments of potential pollution risk of any other tailings dump in Zambia. The developed pollution risk criteria were applied to Musina Copper Mine tailings in South Africa where an assessment was previously conducted using a different approach for comparison. The Musina tailings dump had a potential pollution risk score of 0.5 and thus of medium risk which was in agreement with previous studies hence validating the approach. The indicators used thus capture critical aspects related to physical and chemical properties of mine dumps in data scarce environmental settings. Using the developed tool in assessing the potential pollution risk before mining projects commence will consequently lead to the sustainable management of these dumps even before mining commences by taking deliberate steps to prevent pollution with the guidance of the criteria in the decision-making tool developed.
An integrated framework for hydrology-hydrodynamic modelling of the Barotse floodplains, upper Zambezi river basin.
(The University of Zambia, 2023) Chomba, Innocent Chomba
In recent years the demand for improved assessments tools to help in understanding the wetland hydrological and hydrodynamic processes for the Barotse floodplains is ever increasing especially with the advent of climate change/variability. Despite several studies in the Upper Zambezi Basin, there was an absence of an integrated online (internal) framework for coupling hydrology and hydrodynamic model to be used to improve modelling of the Barotse floodplains. The objectives of this study were: (i) To investigate the mechanisms of groundwater-surface water interaction in the Barotse floodplains, (ii) To develop a rainfall runoff hydrologic model for Upper Zambezi River basin focusing on modelling Barotse floodplain, (iii) To develop an integrated hydrologic-hydrodynamic online (internal) coupling modelling framework for Barotse floodplains and (iv) To test and evaluate the performance of an online one-way Barotse Coupled Hydrological-Hydrodynamic Model developed based on the framework in objective iii. The study used field data sets, models, remote sensing data, and secondary data to address the objectives at hand. Based on the study objectives, the study has shown that the interaction between groundwater and surface water does occur in the Barotse Floodplain as evidenced by hydro-chemical and isotopic results. Such kind of groundwatersurface water interaction in floodplain, among other factors play a role in the hydrological and hydrodynamic modelling of the Barotse floodplains system. This postulation is partly supported by the results of simulated flows generated by wflow hydrological model, for the upstream gauge stations the results were closely matched the observed flow as indicated by the evaluation statistics; Chavuma, nse =0.738; kge = 0.738; pbias = 2.561 and rsr = 0.511; Watopa, nse=0.684; kge = 0.816; pbias = 10.577 and rsr = 0.557; Lukulu, nse=0.736; kge = 0.795; pbias = 10.437 and rse = 0.509. However, despite that wflow model was able to simulate the upstream hydrology very well, wflow model statistical objective function results of the downstream Barotse Floodplain gauge station (at Senanga) were not as good as the upstream results as indicated by evaluation statistics: nse = 0.132; kge = 0.509; pbias = 37.740 and rse = 0.923. The observed inaccuracy in goodness of fit between observed and simulated at Senanga Gauge Station maybe attributed to model forcing data as well as to the fact the representation of both floodplain channels hydrodynamics and hydrological processes are necessary to correctly capture floodplain dynamics for groundwater dependent systems. This aspect also suggested that standalone hydrological models are not very suitable in modelling the flows of the of groundwater-surface water dependant tropical floodplains. To this effect, one-way online (internal) hydrologic-hydrodynamic coupling framework for Barotse Floodplain has been developed in this study. The coupled model output relatively performed better than a standalone hydrological results. The significant improvements in coupled model results were observed at the downstream gauge station at Senanga with noticeable improvement in nse which improved from 0.132 to 0.535, kge improved from 0.509 to 0.699 and pbias from 37.724 to 21.495 indicating reduced model over estimation. The water levels results output from the online Barotse hydrologic-hydrodynamic model coupling also relatively matched the observed water levels as demonstrated by the statistical goodness of fit objective functions results: Mongu, kge 0.792, rse 0.762, nse 0.55; Senanga; kge 0.6707, rsr 0.827, nse 0.503 and Lukulu, kge 0.630, RSR 0.644, nse 0.301. In addition to water levels comparisons, the simulated results of coupled mode inundation area were compared with MODIS MOD09A1 imagery. The statistical objective functions were nse 0.637, kge 0.731, rsr 0.502 and pbias 25.234. In general terms, the statistical results of the simulated and observed data sets (flow, water level and inundated area) of the on-line hydrological-hydrodynamic coupled model falls within what is deemed to be a good performing model indicating that the integrated framework for online coupling of hydrology-hydrodynamic models for the Barotse floodplain was a successful in coupling the two models used in this study.
Analysis of electronic waste management practices in the mining industry of Zambia (case study of first quantum minerals limited and dangote cement Zambia limited).
(The University of Zambia, 2022) Kamutumwa, Namatama
The mining industry in Zambia is one of the sectors that contributes greatly to the country’s economy by contributing greatly to the Gross Domestic Product and according to the latest EITI report, the extractive sector accounts directly for 9.9% of GDP and 78.4% of exports in Zambia. With this at play, there has been a demand to high productivity and this has led to the use of electric equipment such as Computers, printers, electrical lightings and mostly Electronic, remote controlled and computerised heavy equipment machinery during production. Although the use of electronic appliances has great benefit to development of the economy, there has been a great impact on the amount of e-waste being generated as the components in e-waste are toxic and hazardous. This waste has been identified as a problem not just in Zambia but worldwide making the development of an e-waste management system cardinal in any industry. This study employed qualitative methods, purposive sampling techniques and two mining companies First Quantum Minerals Limited (FQML) Kansanshi site and Dangote Cement Zambia Limited (DCZL) were selected as case studies. A regulatory agency Zambia Environmental Management Agency (ZEMA) was also selected. The research methods were used to analyse the management practices of e-waste in the mining industry of Zambia and it was found that the two mining companies were struggling to manage the e-waste generated as there are no e-waste policies or legislation to give guidance on e-waste management practices and they relied on acts such as the Environmental Management Act of 2011 that address hazardous waste management. This study showed that the regulatory agency ZEMA had challenges in conducting sensitization and awareness campaigns and developing of e-waste technical guidelines due to lack of funding. The study concluded that the implementation of e-waste management practices can only be improved through the development of sustainable environmental strategies such as formulation, implementation and enforcement of e-waste management policies and development of e-waste technical guidelines that stress more on handling, storage, collection, sorting, dismantling, transportation in the country. Allocation of funds is needed to develop e-waste technical guidelines and support e-waste management programs such as sensitization and awareness, which have to be implemented, monitored and evaluated within an agreed time frame in these institutions in order to protect the environment from the pollution that comes with this type of waste. Therefore, the study recommended that ZEMA drives the development and implementation of e-waste management policies and legislation with policy makers and develop environmental strategies involving recycling of e-waste and for the mining companies, development of a comprehensive organizational e-waste inventory, development of a sustainable e-waste management system and introduction of EPR (Extended Producer Responsibility) and green procurement.
An analysis of the performance of the manufacturing Industry in Zambia: The engineering manufacturing sub-sector
(2011-07-14) Munakaampe, M. Grain
The Zambian economy in 1964 was among the strongest in Sub-Saharan Africa. Through the years, however, it declined to among the weakest. The manufacturing sector's contribution to GDP declined from a peak of 30 per cent in 1992 to 24 per cent in 1996. The engineering manufacture sub-sector accounted for only 22 per cent of this contribution in 1971, peaking at 26 per cent (1975), but declining to 13 per cent (1996).This study analysed the performance of manufacturing particularly the engineering sub-sector in Zambia from 1964 to 1997. It identified the effects on performance of technology choices,product range, technical and management skills, and operating environment. It also examined the effects of government's economic policies on industry. Trends were compared at macro(sectoral) and micro (firm) levels by in-depth studies of some firms.Data collected was analysed using the Management Systems Analysis Model (MSAM), Statistical Methods (SM) and Total Factor Productivity Growth (TFPG) to determine sources of growth and/or decline in the performance of the manufacturing and engineering industries. Technologies employed by firms were analysed against the background of facility and job design, process variability, total quality management, level of labour skills, plant recapitalisation and modernisation, environmental and energy considerations. The manufacturing technologies in use were further compared with more advanced ones. It was found that TFPG contributed to the growth and decline of both manufacturing and engineering sectors. In both manufacturing sector and engineering sub-sector, there was rapid growth in output from 1964, but this growth declined after 1992 and 1982, respectively. Before 1991, government policies were commandist and did not encourage free enterprise and competition. Prior to 1991, it was also found that the energy crisis (1973), the Rhodesian border closure (1965), the freedom struggle in neighbouring countries and cost of spare parts affected the performance of the economy. However, after 1991, despite the liberalisation of the economy, there were no financial incentives for the struggling and emergent industries.Therefore, industry failed to re-invest in new and more efficient technologies, production methods and total quality management to meet the challenges of an open market economic policy in Zambia. Research and development were neglected both before and after 1991. From this study, it is recommended that both the government and industry need to play their respective parts, with government as a facilitator and formulator of policies conducive for growth of industry and industry itself taking initiatives that facilitate growth. Industrial initiatives must include research and development, investment into newer and more efficient technologies, improvement of existing facilities for better productivity and use of cheaper but sound raw materials. Organisational frameworks and information acquisition, generation, storage and dissemination must be improved. The report, further, concludes that unless this partnership between government and industry is recognised and exploited, all efforts by either the government or industry to resuscitate the economy will be futile.
Application of high precision mining as a way of optimizing loading and hauling operations at Kansanshi mining Plc, Zambia.
(The University of Zambia, 2021) Katongo, Kangwa
Mining at Kansanshi is currently conducted in two pits namely Main and North West pit. Mining at both pits is conducted by conventional open pit methods involving 18 hydraulic excavators and a mining fleet of haul 86 trucks.There has a been a general concern on the mined material tonnes (BCMs)/reconciliation and misplacements of material at Kansanshi Mining site which has led to increased mining costs as a result of: reduced truck deployment, increased truck and shovel waiting time, reduced production and reduced grade/quality of ore delivered to crushers.With the in-pit haulage distance increasing from 1335 RL to 1195 RL, there is need to address the issues causing the increase in mining cost which currently stands at US$12.4/BCMs as a matter of priority. The other problem has been on the inconsistencies of reporting fleet performances in terms of Availability and Utilisation. This has resulted into manipulation of figures by some operators. This study therefore seeks to monitor and compare the application of high precision mining through optimised loading and hauling operations. The study focuses on the optimization of haulage using High Precision Mining (HPM) through use of Wenco’s dispatching algorithm, which is designed to automatically assign trucks in order to achieve the best utilization of all mining equipment and maximize production. In order to accomplish the set objectives, the study involved establishing the precise bucket positioning, determining production rates and monitoring the material type and quality /grade of ore delivered to the crushers. With the tolerance of X=0.5m, Y=0.5m and Z=0.5m, it was noted that the events of a bucket mining out of the assigned polygon were reduced to a few cent meters in distance from 34% to 15% and from 10% to 8% in terms of mismatches and cannot reconcile bucket loads respectively. This entails a reduced mining dilution in the X and Y axis of about 85% based on the quality of ore delivered to the crushers. In terms of mining to correct elevations, a tolerance in the Z axis of ±0.3m was achieved based on the bucket size of the loading equipment. The X and Y axis tolerance was also reduced to ±0.3m for improved accuracy in between boundaries of various material types. The use of precision mining has therefore resulted in reduced mining cost of about US$10.3/BCM, improved fleet/production reporting, high grade of the material delivered to the crushers of about 75% from the previous 65%.
Application of remote sensing using a GIS based soil water assessment tool(SWAT)to estimate river discharge in the Kabompo river basin-Zambia
(2012-01-18) Mwiza, Muzumara
The Kabompo river basin with an area of 72,000 km2, in North-Western Zambia is one of the major tributaries of the upper Zambezi River. Key water resources management problems in the Kabompo include water allocation to agriculture and ecosystems, effects of land-cover change on the flow regime and potential impacts from mine tailing dams. The objectives for the study were to apply Remote Sensing and a GIS based Soil Water Assessment Tool (SWAT) to estimate river discharge for the basin in order to address the water resource management challenges. Because of paucity of observed data in the Kabompo basin, the model primarily depended on remote sensing datasets for calibration and validation. The Kabompo basin was discretized into 177 sub-basins with a total of 1004 hydrological response units. Methodology included the use of a semi-distributed; ArcGIS based Soil Water Assessment Tool (SWAT) software for hydrological modeling. Remote sensing data sets that included weather data, drainage network and slopes, landuse/ land cover and soils were used to create a database for the sub-basins using ArcGIS. The simulated flow from the SWAT model was calibrated with ESA ERS-2 and ENVISAT radar altimetry river stage values converted to discharge. Observed river flow data for six stations over different time periods between 1990 and 2007 were used in validation and uncertainty analysis of the radar altimetry flow data and remotely sensed weather data, respectively. The model’s results showed good correlation with observed data giving a Nash Sutcliffe coefficient of 0.87 and an R² value of 0.93, after calibration. The simulation results obtained from the model can be used in a number of water resources management activities like water rights, water allocation, and flood warning. The model is able to generate estimated river flow and stage values even for un-gauged streams. It’s also able to simulate long-term data of a wider area including inaccessible locations than conventional hydrological techniques. It is concluded that remote sensing is a useful tool for estimation of hydrological data where it is lacking or in unguaged and in accessible areas. Its wide use in a country like Zambia should greatly improve water resources management in a number of areas.
An application of the mass balance technique to study the impacts of the mining operations on the hydrogeochemistry of the Kafue River as it crosses the Copperbelt of Zambia
(2012-08-15) Nkandu, Christopher
A mass balance technique was used to investigate the hydrogeochemistry of the Kafixe river as it crosses the Copperbelt mining area between Raglans farm and Machiya feiTy. Tlie study is done by examining the mass flow-rates often chemical parameters, namely: total dissolved solids, total suspended soUds, elemental cadmium, cobalt, copper, hon, manganese, lead, barium and sulphur. In this study, the aqueous concentrations in the rivers where obtained from samples collected at four sampling stations along the Kafiie river and one station on the Mwambashi river. The volume discharge rates were obtained from the Department of Water aflfaks. Further data was obtained from Zambia ConsoHdated Copper Mines Limited.The mass flows for the parameters are computed on a monthly basis as the average of the product of the concentrations of the parameters and discharge rates for the particular month.Results obtained indicate that the mass flows of these chemical constituents increase after the river enters the mining areas and decrease after exiting the areas. W\IQ relative impact of the mining operations on the river basin varies fiom place to place and chemical to chemical. In the Mwambashi river on one hand, practically all the total dissolved sohds flowing in the river during the dry season seem to emanate from mining operations. On the other hand, dissolved uon flow rates at certain times of the year actually drop as the river enters the area of the mining operations.Redox conditions also seem to have an effect on the speciation of metals hke iron, lead and manganese. Photosynthesis by aquatic plants has been found to determine the level of dissolved oxygen and the redox potential level.Copper flow^s from Fishers farm to Machiya appear to be affected by iron speciation as a result of the ability of iron oxyhydroxides in adsorbing various heavy metals. Hie same seems to apply to lead. For cadmium, mining activities may not be major factor m the mobihsation of the metal since the biggest input of the metal appears to come between Fishers farm and Machiya ferry samphng point. Most of the mining activities discharge their effluent into the Kafiie at points upstream of Fishers farm. This study has thrown some hght on the hydrogeochemical processes taking place in the Kafiie river. It has shown how mine effluent is effecting the water quality in the Kafue river and how the river itself effects the effluent.
Assessing agricultural expansion in upper Lunsemfwa river catchment: a case study of the upper Lunsemfwa river catchment, central province, Zambia.
(The University of Zambia, 2025) Zulu, Natasha
Understanding dynamics occurring in land utilization and land cover is essential for analysing and assessing long-term transformations. These transformations in land cover primarily result from deforestation, which involves the conversion of forests into other land cover types such as agricultural land and human settlements or infrastructure development for economic growth. The problem highlighted in this study is the increasing dominance of agricultural activities in the Upper Lunsemfwa River Catchment (ULRC) and their potential impact on land cover. It also emphasizes the threats posed to land and water resources by agricultural expansion and the loss of natural resources due to economic development. To help with understanding and assessing the magnitude of change and possible future changes in the study area land use and land cover classification was done using remote sensing and GIS. This was done using remotely accessed imagery for the years 1990, 2005 and 2020 from climate engine (Landsat 5 and 8). The images where processed and analysed using QGIS and IDRISI. The main objective of this study was to evaluate the extent agricultural expansion within the Upper Lunsemfwa River Catchment, focusing specifically on the evaluation of various land uses. With specific objectives to evaluate Land Use and Land Cover change trends in the Upper Lunsemfwa River Catchment and Simulate future scenarios of land cover and agricultural expansion of the study area. The findings showed that from 1990 to 2020 observations indicate a -10.3% decrease in forest cover and a 25.90% increase in agriculture land cover, accompanied by minimal changes of -0.4% in water bodies, and stable decrease in built-up areas from 3.20% to 1.9% and 68% to 54.01% in grasslands. The results also showed a dominance in agriculture and a decline in non-agricultural land. Agricultural land increased from 13.60 % to 39.52 % between 1990 and 2020 respectively. On the other hand, there was a reduction in non agricultural land from 86.38 % to 60.48% in 2020. From the predicted 2050 land cover map, the observations suggest a positive trend of 16.24% towards increased forest coverage, a reduction of -20.66% in crop land, stabile reduction of -0.16% in water bodies. Built-up areas showed an expansion of 2.98%, and an increase of 1.69% in grassland. This shows a clear trend of agricultural expansion and a corresponding reduction in non-agricultural land over the decades. Thus, the importance of monitoring and managing these changes sustainably to ensure the well-being of both humans and the environment.
Assessing the impact of policy changes on small-scale mining in Tanzania
(2011-07-14) Ngowi, A. Oforo
The Small-Scale Mining (SSM) sub-sector makes a significant contribution to the economy of Tanzania. Major benefits include foreign exchange earnings, generation of income for rural population where alternative means of income are limited and also employs over 500,000 people. Minerals being mined are gold, gemstones, diamonds, construction materials and other minerals. SSM has also played a major role in the discovery of mineral deposits.Because of the above positive factors, the Government of Tanzania has realizedthe importance of this sub-sector and hence instituted measures to develop it.These measure include:The National Investment Policy (1997),Tanzania Investment Act (1997),The Financial Laws (Miscellaneous Amendments) Act (1997),The Mineral Policy of Tanzania (1997), The Mining Act (1998) and The Environmental, Health and Safety Mining Regulations (1999) However, since the inception of these measures, no thorough investigations have been done to assess the impact of the measures. The main objectives of this study, therefore, are to analyse these measures and assess their impact on the SSM subsector.The major constraints hindering the development the sub-sector and the strategies for overcoming them are also analysed.As part of the study, a field survey was carried out in major SSM centres in Dares-Salaam, Arusha and Songea. The survey was carried out by use of questionnaires and direct interviews with eighty-five people in the categories of small-scale miners (50), mineral traders (20) and Government officials (15). Results from the study indicate that while some of the measures being persued by the Government are adequate and well understood by all the stakeholders in the mining sector, some are not. Some of the areas which need improvements were identified as human resource management, infrastructure, training and legal framework. In the final analysis it was concluded that the measures have produced more positive impacts than negative ones. Recommendations/suggestions to reduce or eliminate the negative impacts are also presented.
Assessing the use of exfiltration pervious pavements as a best management practice for storm water management for Lusaka urban
(The University of Zambia, 2020) Banda, Naphtallie
Stormwater management is being justified as a fundamental line of consideration in achieving sustainable urban development. Lusaka urban experiences impacts ensuing from developments in form of urban floods. This study was undertaken in Lusaka urban to assess the use of a full exfiltration pervious pavement system as a best management practice for stormwater management. Based on the ICPI guidelines, the study involved a feasibility assessment to select areas supporting full exfiltration pervious pavements, construction of pervious pavements (PICP) in 3 sites, conducting infiltration tests on the constructed pavement systems and monitoring of water infiltrating below the pavement systems succeeding storm events for the study period. A t-test was used to compare significant differences and regression analysis was used for determining relationships. Key observations are that the central eastern part of the study area has soil physical characteristics supporting full exfiltration pavement systems under which the sites were selected. Infiltration rates on the installed pavement systems with 5mm spacers ranged from 774cm/hr. to 823cm/hr. The average depth of water estimated to have been contributed to the immediate unsaturated zone below the pavement systems through infiltration during each observed rainfall events ranged from 140mm to 211.4mm in 1100mm depth of soil. The study concluded that full exfiltration pervious pavement systems as a best management practice can be integrated with drainage networks for Lusaka urban to reduce floods ensuing from developments. The system will mimic natural environments which allow infiltration of stormwater to potentially contribute to groundwater. Key words: Stormwater, Best management practices, Pervious pavement, Exfiltration
Assessing the use of exfiltration pervious pavements as a best management practice for storm water management for Lusaka urban
(The University of Zambia, 2020) Banda, Naphtallie
Stormwater management is being justified as a fundamental line of consideration in achieving sustainable urban development. Lusaka urban experiences impacts ensuing from developments in form of urban floods. This study was undertaken in Lusaka urban to assess the use of a full exfiltration pervious pavement system as a best management practice for stormwater management. Based on the ICPI guidelines, the study involved a feasibility assessment to select areas supporting full exfiltration pervious pavements, construction of pervious pavements (PICP) in 3 sites, conducting infiltration tests on the constructed pavement systems and monitoring of water infiltrating below the pavement systems succeeding storm events for the study period. A t-test was used to compare significant differences and regression analysis was used for determining relationships. Key observations are that the central eastern part of the study area has soil physical characteristics supporting full exfiltration pavement systems under which the sites were selected. Infiltration rates on the installed pavement systems with 5mm spacers ranged from 774cm/hr. to 823cm/hr. The average depth of water estimated to have been contributed to the immediate unsaturated zone below the pavement systems through infiltration during each observed rainfall events ranged from 140mm to 211.4mm in 1100mm depth of soil. The study concluded that full exfiltration pervious pavement systems as a best management practice can be integrated with drainage networks for Lusaka urban to reduce floods ensuing from developments. The system will mimic natural environments which allow infiltration of stormwater to potentially contribute to groundwater. Key words: Stormwater, Best management practices, Pervious pavement, Exfiltration
Assessment of geotechnical considerations for ground control and stability at Nkana Synclinorium copper mine Mopani Plc, Zambia.
(The University of Zambia, 2024) Mpaka, Barnabas
Nkana Synclinorium Mine is in the Southern part of the Nkana mining license area in Kitwe. The mine has been an underground operation since 1930 when the first shaft was sunk at Central Shaft. Vertical Crater Retreat (CVR) and Sub-Level Curving (SLC) are the main copper ore mining methods used at the mine. Due to increase in mine depth by 137m, from 3510ft to 3960ft (1.070 to 1.207km), mining operations have been encountering geotechnical challenges related to ground control and ground stability. This study applied Empirical methods (Barton’s Q system, 1974, Bieniawski (1973) classification and Hoek, 1994) for rock mass classification. Scanline mapping of geological structures was done to identify joints, bedding planes, schistosity and folds. The mapping was carried out along the crosscuts or tunnel walls at a 1.50m grade line elevation with geological features being picked along a stretched 100m tape. Borehole cores were examined for geological formations, grain size, colour, joints, and RQD. The assessment of rock reinforcement and surface support elements like cable bolts and shotcreting were done by using pull tests and uniaxial compressive strength (UCS) tests. Pull Testing was done in selected mine excavations to provide a quantitative measure of the relative performance of different anchor systems and compressive strength tests on concrete cubes were used to assess the quality and strength of the material used in shotcreting underground. Collection of survey data for over-break and under-break in tunnels mined underground was done by the author with the assistance of mine surveyors. The Theodolite was the major instrument used. Numerical modelling using MAP3D and Finite Element Analysis (FEA) softwares was used to assess ground stability around underground excavations. Evaluation of design systems for ground support and pillars was carried out with the reviewing of current design flow charts in comparison with design charts from literature for other mines around the world. Results of study indicate that the rock mass ratings (RMRs) for the samples of Basal Quartzite (BQ), Foot Wall Conglomerate (FCON), South Orebody Shale (SOBS) and Hanging Wall Argillite (HWA) rock formations compared well with Barton’s Q system RMR ranges except for Foot Wall Sandstone (FSAN) which was out of range. All pull tests conducted at 3 sites had an average failure rate of 22.3% while compressive tests gave a high failure rate of 83.3%. Numerical analysis using Finite Element Analysis (FEA) software indicate more stresses and displacement around the excavation before rock bolt support, and less stresses and displacement after rock bolts are installed around the same excavation. Over-break and under-break data did not show any correlation with mined linear meters of the tunnels. Geological factors like jointing, weathering and shearing as well as drill-and-blast challenges were attributed to over-break and under-break. In conclusion, folds and joints are major factors affecting ground and stability at Synclinorium mine, and the geotechnical database has insufficient data. The confidence of the current geotechnical database at Synclinorium mine needs to be improved through more data collection. Design excavation and ground support designs need to be improved and matched with the real situation underground. The key issues affecting drill-and-blast like varying powder factors in the shots, lack of pragmatic consideration of geological and geotechnical information in the design, and diligent adherence to the blast designs need to be addressed.
Assessment of river-groundwater interactions in the Barotse floodplain, Western Zambia.
(The University of Zambia, 2022) Mataa, Mulema
Floodplains are among the most dynamic, productive, diverse, and threatened ecosystems in the world. Their interactions between ground and surface water is a key element in understanding the resilience of floodplains to hydrological changes, especially with the advent of climate change and variability that has affected many aquatic ecosystems. Conjunctive evaluation of ground and surface water in floodplains is critical for integrated water resources management. The main objective of this study was to evaluate groundwater-surface water interactions in the Barotse Floodplain. To achieve this objective, remote sensing was employed to identify perennial green vegetated areas with a shallow depth to groundwater table in the floodplain. Normalised Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) using Sentinel-2 imagery from 2015 to 2020 using a cloud computing approach in Google Earth Engine (GEE), were used to identify riverine perrennially green vegetation. Digital filtering using “EcoHydRology Library” in R statistical package was used to determine the Base Flow Index (BFI) from the hydrograph discharge data collected from the three main gauging stations (Lukulu, Matongo and Senanga) along the Zambezi River. Hydrochemistry was employed to determine the composition of the different water sources and identify the genetic link between the local and regional flow of ground water and interactions with the Zambezi River. In addition, water samples collected from various water sources were analysed for stable isotope [deuterium (2H) and oxygen (18O)] to determine the origin and identify the relationships between ground and surface water. Statistical analysis was applied to determine the significance of the correlation between remote sensed data and ground based measurements including, pH, electrical conductivity (EC) and dissolved oxygen (DO).The results of the NDVI map shows a high occurrence of groundwater dependent vegetation downstream of the floodplain. These locations have a shallow depth to groundwater table and other locations had occurances of springs. The average baseflow index (BFI) in five hydrological years from October 2004 to September 2009 shows an average of 46.5 percent baseflow to the river flow across the wet and dry season. Furthermore, baseflow averages up to 90 percent of the flow during the dry season between August to October when the flood water has receeded. The hydrochemistry shows a high concentration in calcium and the bicarbonate ion in both river and groundwater. The water was concluded to be that of a CaHCO3 type. From the stable isotopes the results show recharge from precipitation as values plotted on the meteoric line. Both river and groundwater stable isotopes (δ18O: -57.4 ‰ to 1.4 ‰ and δ2H :-7.5 ‰ to 3.3 ‰ ) had a similar signature indicating that groundwater was discharging into the river channel. Results of statistics between base flow as an index and ground based measurements show a strong correlation between baseflow index (BFI) and dissolved oxygen (DO) indicating that an increase in baseflow increases the dissolved oxygen concentration in the river system. Overall, results show that the lower reach of the Zambezi River channel was a ‘gaining stream’ as groundwater is discharging into the river, whereas the upper reach was a ‘losing stream’ as the river channel tends to discharge into the groundwater. This study demonstrates that the Barotse Floodplain is a proportionally groundwater dependant ecosystem as its functionality in provision of ecosystem products and services requires groundwater. Conservation of this wetland requires prudent protection of groundwater aquifer systems.
Assessment of river-groundwater interactions in the Barotse floodplain, Western Zambia.
(The University of Zambia, 2022) Mataa, Mulema
Floodplains are among the most dynamic, productive, diverse, and threatened ecosystems in the world. Their interactions between ground and surface water is a key element in understanding the resilience of floodplains to hydrological changes, especially with the advent of climate change and variability that has affected many aquatic ecosystems. Conjunctive evaluation of ground and surface water in floodplains is critical for integrated water resources management. The main objective of this study was to evaluate groundwater-surface water interactions in the Barotse Floodplain. To achieve this objective, remote sensing was employed to identify perennial green vegetated areas with a shallow depth to groundwater table in the floodplain. Normalised Difference Vegetation Index (NDVI) and Soil Adjusted Vegetation Index (SAVI) using Sentinel-2 imagery from 2015 to 2020 using a cloud computing approach in Google Earth Engine (GEE), were used to identify riverine perrennially green vegetation. Digital filtering using “EcoHydRology Library” in R statistical package was used to determine the Base Flow Index (BFI) from the hydrograph discharge data collected from the three main gauging stations (Lukulu, Matongo and Senanga) along the Zambezi River. Hydrochemistry was employed to determine the composition of the different water sources and identify the genetic link between the local and regional flow of ground water and interactions with the Zambezi River. In addition, water samples collected from various water sources were analysed for stable isotope [deuterium (2H) and oxygen (18O)] to determine the origin and identify the relationships between ground and surface water. Statistical analysis was applied to determine the significance of the correlation between remote sensed data and ground based measurements including, pH, electrical conductivity (EC) and dissolved oxygen (DO).The results of the NDVI map shows a high occurrence of groundwater dependent vegetation downstream of the floodplain. These locations have a shallow depth to groundwater table and other locations had occurances of springs. The average baseflow index (BFI) in five hydrological years from October 2004 to September 2009 shows an average of 46.5 percent baseflow to the river flow across the wet and dry season. Furthermore, baseflow averages up to 90 percent of the flow during the dry season between August to October when the flood water has receeded. The hydrochemistry shows a high concentration in calcium and the bicarbonate ion in both river and groundwater. The water was concluded to be that of a CaHCO3 type. From the stable isotopes the results show recharge from precipitation as values plotted on the meteoric line. Both river and groundwater stable isotopes (δ18O: -57.4 ‰ to 1.4 ‰ and δ2H :-7.5 ‰ to 3.3 ‰ ) had a similar signature indicating that groundwater was discharging into the river channel. Results of statistics between base flow as an index and ground based measurements show a strong correlation between baseflow index (BFI) and dissolved oxygen (DO) indicating that an increase in baseflow increases the dissolved oxygen concentration in the river system. Overall, results show that the lower reach of the Zambezi River channel was a ‘gaining stream’ as groundwater is discharging into the river, whereas the upper reach was a ‘losing stream’ as the river channel tends to discharge into the groundwater. This study demonstrates that the Barotse Floodplain is a proportionally groundwater dependant ecosystem as its functionality in provision of ecosystem products and services requires groundwater. Conservation of this wetland requires prudent protection of groundwater aquifer systems.
Assessment of sunflower (helianthus annuus l) for phytoremediation of heavy metal polluted mine tailings: a case study of Nampundwe mines tailings dam.
(The University of Zambia, 2023) Chileshe, Kaela Beverly
Mining is the main source of export income and contributes significantly to the Zambian gross domestic product. Besides its contributions to exports, the mining industry plays a pivot role in the economic and socio-political development of Zambia. It also provides essential mineral based raw materials to the local industry. However, mining activities have led to a generation of heavy metals laden wastes which are released into the environment in an unsustainable way causing the contamination of the ecosystems and posing a risk to human health. Most mining companies have not employed any rehabilitation or remediation program for the heavy metal laden wastes. For this purpose, this study was conducted to assess the potential of sunflower for phytoremediation of heavy metal polluted Pyritic mine tailings. Phytoremediation is an emerging technology in the remediation of mine tailings that uses tolerant plants species to clean up contaminated sites. It uses plants with high biomass and sunflower has been identified as such. These plants can extract, transfer, sequester and stabilize a variety of metals through mechanisms such as phytoextraction, phytostabilization, phytoaccumulation and phytovolatilization. In this study, pot experiment was conducted by growing sunflower (Helianthus annuus L) in pyrite mine tailings and in agricultural soil as a control. The study showed that the concentration of Cu reduced from 40.76mg/kg to 36.59mg/kg, Zn reduced from 3.58mg/kg to 3.49mg/kg andFe reduced 23.70mg/kg to 10mg/kg respectively in the mine tailings after six (6) weeks. Analysis of harvested sunflower (roots, stems, leaves) showed that sunflower could remove heavy metals from the tailings and the highest removal efficiency was 56.16% and the highest translocation factor was 0.25. Based on the results obtained it can be concluded that sunflowers have the potential to remediate contaminated pyritic mine tailings and phytoremediation is a viable and efficient technology to treat soils contaminated with heavy metals.
Assessment of surface water availability in Solwezi River Basin, NothWestern Province, Zambia
(University of Zambia, 2016) Fulayi, Mirriam
This study assessed surface water availability in Solwezi River basin in Northwestern Province of Zambia. The main objective was to quantify various components of the water balance to ascertain surface water availability in Solwezi River Basin in view of the increasing water demand. Climate data collected comprising rainfall, temperature and water abstraction were analyzed using Runoff coefficient approach, Thornthwaite and Water Balance methods to determine inflows and outflows in the catchment. The water balance model developed revealed that the total inflows of the surface runoff generated in the catchment was 985,841m3/day while the outflows amounted to 1,078,209.8 m3/day. The outflows were comprised of 885,938m3/day of water lost via evapotranspiration, 42,678.9 m3/day water abstracted for anthropogenic activities, 13,599.36m3/day environmental flow and 135, 993.6m3/day water leaving the catchment as stream flow. The inflows were exceeded by the outflows such that the water balance results indicated a negative value of -92,368.86m3/day of the surface water available in the catchment. Consequently, there was a surface water deficit indicating that there is no surplus water in the catchment to meet the current water demand. However, the river was still flowing because of the groundwater recharge which was not accounted for as the study only focused on the surface water runoff generated from rainfall received in the catchment. Overall, it is concluded that there is inadequate water in Solwezi River Basin to meet the current water demand. The local water utility company is encouraged to find additional water sources to meet the apparent current surface water deficit in Solwezi River basin.
Assessment of the dynamics of surface hydrology and water quality of the Barotse floodplains, western Zambia.
(The University of Zambia, 2022) Chabala, Anthony
The seasonal interactions among rivers, floodplains, vegetation and anthropogenic activities result in highly dynamic systems, which tend to exhibit distinctly different biogeochemical patterns throughout the wet and dry seasons. An assessment and characterization of the spatial-temporal variability of water quality of the Barotse Floodplain, Western Zambia was based on three major components: biological, physical and chemical properties. Samples were collected and analysed for two successive years for both wet and dry seasons. Further, a hydrological model was developed using the Soil and Water Assessment Tool (SWAT) for predicting sediment yields into the floodplain. This was done to investigate for any heavy metal presence in water and sediments due to upstream mining activities, and nutrient transport mechanisms for the separate seasons. Results from bacteriological tests indicated that coliforms were highest on the Mongu-Senanga Transect (85.7%), which had Too-Numerous-To-Count (TNTC> 200 coliforms) readings on several points due to a number of human induced activities. Physio-chemical characteristics generally showed a low pH (6.5-6.9) for the dry season as compared to the pH (6.9-7.5) for the wet season. The Luanginga River, at the confluence of the Zambezi River, had the highest turbidity (87.9 NTU), electrical conductivity (EC) and total dissolved solids (TDS). Results from the hydrological model gave sediment distribution in the floodplain with 0.609 tons/year/subbasin as the highest yield of sediments in the floodplain from the Luanginga River. The model calibrated and validated with its performance monitored by the P and R-factor. The parameters read of: P-factor 0.5 to 0.75; and R-factor 0.56 to 1.36 respectively. In conclusion, this study shows that the Barotse Floodplain is still in a pristine state and therefore results from this research may be used as baseline information for future work. Due to the upstream large scale copper mining and increased anthropogenic activities via the Luanginga River leading to high turbidly, a proxy to the high sedimentation observed, continuous monitoring is encouraged
Assessment of the Impact of Climate Change on Water Resources in the Lwitikila River, Mpika District
(2012-01-19) Mphande, Goodfellow
This study assesses the impact of Climate Change on water resources in the Lwitikila River located in Mpika District of Northern Zambia. In the past few years, downstream water users have had conflicts over the use of limited water resources in Lwitikila River. There are reports that the old furrows taking water from the river have dried up. The local people have also indicated that the quantity of the water in the river has reduced greatly such that they have been forced to construct new furrows that take water to their gardens. Therefore, the main aim of this study is to find out the impact of climate change on water resources in the Lwitikila River. The study analyses the effects that temperature, sunshine hours and rainfall variations have on discharge and water level measurements. Furthermore, the study assesses the local people’s response and adaptability strategies to the effects of climate change. In order to effectively conduct this study, hydrological and meteorological data ranging from 1969 to 2008 has been used and was obtained from the Departments of Water Affairs and Meteorology respectively. The data which originally consisted of daily readings was computed using Excel into monthly and annual averages and thereafter analysed using graphical correlation method. An interview guide was used to obtain qualitative data from the locals and other professionals with knowledge and experience of climate change and its adaptability strategies. Results obtained from the study indicate that mean temperatures and maximum October temperatures have increased in the last ten years in the range of about 0.15⁰C to 0.20⁰C and have probably led to increased annual rainfall ranging between 30mm and 40mm which has in turn contributed to high water levels and flows thereby causing flooding in some low lying areas of Mpika District. The study has shown that apart from variations in temperature, sunshine hours and rainfall, there are many other factors that affect water level and discharge in Lwitikila River. Among the prominent factors observed to be affecting water level and stream flow are unlawful diversions of water through construction of furrows upstream, cutting down of trees along the river course and poor methods of cultivation. The results obtained from this study will be useful in the formulation of better adaptation strategies that will lessen the impact of climate change on water resources in Lwitikila River.
An assessment of the lapidary industry in Zambia
(2012-10-08) Simwanza, Zion Ephraim
Zambia is one of the major gemstone producers of the world. The global value of rough Emerald production is estimated at US$1 billion a year. Available data indicate that Zambia accounts for about 20% of this value. Apart from emeralds, there are also several other important gemstones produced in Zambia. These include beryl, aquamarine, tourmaline, garnets, amethyst, citrine and rock crystal. Although the country is endowed with an abundance of these precious stones backed by a long history of gemstone mining, there has been no corresponding growth in downstream processing i.e. the lapidary industry. Zambia exports almost all of its gemstones as rough material. This obviously costs the country value-added earnings. The importing countries cut and polish gemstones and sometimes set them in jewellery, which they later re-export to major markets of the world under their respective national identities at a far higher value. Despite the national mining policy stressing downstream processing before export of any mineral commodity with penalties imposed for flouting, there has been laxity in its application to gemstones. Paradoxically, rough gemstones have even been granted a Non-Traditional export Status although they do not enjoy the 15% income tax, which the members of this category normally pay.Given the significant economic potential of setting up a lapidary industry, this study provides a major attempt at investigating problems (constraints) that have adversely affected the development of the sector. Included in the study are issues, affecting production (i.e. supply) as well as marketing constraints. Finally based on the findings of the study, recommendations are proposed.