An analysis of flood activity over the past century based on the sedimentary deposits in the Mfolozi floodplain

Floods are natural phenomena that are of widespread interest to the scientific community, particularly in the context of understanding the impact of climate change as well as changing land use patterns and the security of infrastructure such as towns and roads. In northern KwaZulu-Natal, large flood events have been a reoccurring feature over the past century. The geographical position and extent of the region means that is affected by both inland and coastal weather phenomena, each with the potential to cause large flood events. While information pertaining to large floods in the region in the form of flow data is readily available, flow data is often incomplete and limited in terms of how far back in time the records extend. The Mfolozi River floodplain itself also houses a record of flood activity in the region in the form of sedimentary deposits, which have the potential to reveal flood activity over a much longer timescale, even when monitoring of flood activity in the region was not present. Establishing a link between the hydrological and sedimentary features of floods may be useful in establishing a record of flood activity extending beyond the limits of historical records. The aim of this project was to construct a record of major flood events on the Mfolozi River floodplain over the last century and determine their source. The first objective involved establishing the history of flood events in the Mfolozi River catchment utilising hydrological data recorded throughout the catchment. Thirty nine different large floods (defined as being over 800 m3.s-1) were recorded on the floodplain over the past century. The data also highlighted differences in the extent of known coastal and inland systems (tropical cyclones and cut-off lows respectively), allowing for inferences to be made about the area of the catchment most likely affected by each event; some flood events were identified as having mostly affected the upper reaches of the catchment, while others mostly affected the lower reaches, closer to the coast. The second objective was to identify the various physical, mineralogical and geochemical features of the sediment deposited on the Mfolozi floodplain. Multiple individual flood deposits were identified in the sedimentary record, with sediment tracing analysis providing insight into the source of the deposits within the catchment; no traces of igneous or metamorphic material could be found within the sediment. The source rocks were identified as mostly quartzite, with minor shale and sandstone deposits as well. This put the source of the sediment in the upper to middle reaches of the catchment. The sedimentary analysis was combined with the hydrological records to establish a chronology of flood events extending back to the 1960's. Unfortunately, this record could not be extended further due to the limited amount of sediment collected as well the limits of readily available analytical techniques; radionuclide dating methods were unsuccessful due to the low amounts of fallout radionuclides present in the sediment. The study has however successfully established a history of flood events in the region, as well as providing a link between the hydrological and sedimentary features of flood events that could potentially be useful for current and future research

Sustainability awareness and practices in the Zambian construction industry

The construction industry makes a significant contribution to the global green-house gas emission. It is, therefore, critical that construction industry professionals should be aware of and practise sustainable construction. However, there is a paucity of studies on the awareness of sustainability and their practices in developing countries, with some results seemingly contradicting. This article explored the awareness and practices of sustainability in the Zambian construction industry. Data was collected from construction industry professionals through a questionnaire survey and a total of 112 responses were received. The relative importance index (RII) and a series of linear regression analyses were used to analyse the data. The participants’ perception of sustainability was primarily enviro-centric as opposed to the economic or social context. However, social and economic sustainability practices ranked highest, while environmental sustainability practices ranked in the bottom five of the 16 practices. While the participants perceived the environmental context as more critical in their understanding of sustainability, their practice reflected a focus on the social and economic sustainability context. The findings imply that merely increasing the level of knowledge and awareness of environmental sustainability may not lead to gross improvements in environmental sustainability practices. Therefore, studies that recommended increasing knowledge and awareness, in order to increase the implementation of environmentally sustainable construction, may have neglected the effect of the other barriers to sustainable construction which may be more critical. Studies with multivariate analyses such as structural equation modelling are needed to establish the contributory effect of the various barriers to environmental sustainability practices and so establish the extent to which knowledge and awareness alone, and other factors, can improve environmental sustainability practices.&nbsp

Sustainability awareness and practices in the Zambian construction industry

The construction industry makes a significant contribution to the global green-house gas emission. It is, therefore, critical that construction industry professionals should be aware of and practise sustainable construction. However, there is a paucity of studies on the awareness of sustainability and their practices in developing countries, with some results seemingly contradicting. This article explored the awareness and practices of sustainability in the Zambian construction industry. Data was collected from construction industry professionals through a questionnaire survey and a total of 112 responses were received. The relative importance index (RII) and a series of linear regression analyses were used to analyse the data. The participants’ perception of sustainability was primarily enviro-centric as opposed to the economic or social context. However, social and economic sustainability practices ranked highest, while environmental sustainability practices ranked in the bottom five of the 16 practices. While the participants perceived the environmental context as more critical in their understanding of sustainability, their practice reflected a focus on the social and economic sustainability context. The findings imply that merely increasing the level of knowledge and awareness of environmental sustainability may not lead to gross improvements in environmental sustainability practices. Therefore, studies that recommended increasing knowledge and awareness, in order to increase the implementation of environmentally sustainable construction, may have neglected the effect of the other barriers to sustainable construction which may be more critical. Studies with multivariate analyses such as structural equation modelling are needed to establish the contributory effect of the various barriers to environmental sustainability practices and so establish the extent to which knowledge and awareness alone, and other factors, can improve environmental sustainability practices. &nbsp

A Long History of Low Productivity in Zambia: Is it Time to Do Away with Blanket Recommendations?

Although there have been calls to ramp up efforts to design and implement a fertiliser programme that recognises the spatial variability of soil fertility and climatic conditions in the country, Zambia like most countries in Africa, continues to rely heavily on outdated general fertiliser recommendations, which are uniform across geographic locations and crops. This could be one of the main reasons why Zambia continues to record low crop productivity despite government fertilizer subsidy programmes. Using soil analysis and household data collected in rural Zambia, this study presents a comparative analysis of location-specific fertilizer application versus blanket recommendation to demonstrate why it is important for the Zambian government to invest in area-specific fertiliser recommendations in order to raise crop productivity. As expected, the results show that soil fertility varies across the country. This was observed in all the mapped soil properties with ranges of 2.7 to 7.8 for soil pH, 0.08% to 10.1% for soil organic carbon and 1.0 ppm to 333.6ppm for soil Phosphorus. These values belong to different classes in terms of acidities and levels of adequacy and deficiency. These results indicate that blanket fertiliser recommendations, or even liming, may not be well suited across the entire country. Instead, they support the need for Zambia to promote area-specific fertiliser recommendations. It is recommended that soil testing be promoted as part of extension messages, and that the government’s Farmer Input Support Programme (FISP) should consider including soil testing as a requirement for the subsidy

An analysis of flood activity over the past century based on the sedimentary deposits in the Mfolozi floodplain

Floods are natural phenomena that are of widespread interest to the scientific community, particularly in the context of understanding the impact of climate change as well as changing land use patterns and the security of infrastructure such as towns and roads. In northern KwaZulu-Natal, large flood events have been a reoccurring feature over the past century. The geographical position and extent of the region means that is affected by both inland and coastal weather phenomena, each with the potential to cause large flood events. While information pertaining to large floods in the region in the form of flow data is readily available, flow data is often incomplete and limited in terms of how far back in time the records extend. The Mfolozi River floodplain itself also houses a record of flood activity in the region in the form of sedimentary deposits, which have the potential to reveal flood activity over a much longer timescale, even when monitoring of flood activity in the region was not present. Establishing a link between the hydrological and sedimentary features of floods may be useful in establishing a record of flood activity extending beyond the limits of historical records. The aim of this project was to construct a record of major flood events on the Mfolozi River floodplain over the last century and determine their source. The first objective involved establishing the history of flood events in the Mfolozi River catchment utilising hydrological data recorded throughout the catchment. Thirty nine different large floods (defined as being over 800 m3.s-1) were recorded on the floodplain over the past century. The data also highlighted differences in the extent of known coastal and inland systems (tropical cyclones and cut-off lows respectively), allowing for inferences to be made about the area of the catchment most likely affected by each event; some flood events were identified as having mostly affected the upper reaches of the catchment, while others mostly affected the lower reaches, closer to the coast. The second objective was to identify the various physical, mineralogical and geochemical features of the sediment deposited on the Mfolozi floodplain. Multiple individual flood deposits were identified in the sedimentary record, with sediment tracing analysis providing insight into the source of the deposits within the catchment; no traces of igneous or metamorphic material could be found within the sediment. The source rocks were identified as mostly quartzite, with minor shale and sandstone deposits as well. This put the source of the sediment in the upper to middle reaches of the catchment. The sedimentary analysis was combined with the hydrological records to establish a chronology of flood events extending back to the 1960's. Unfortunately, this record could not be extended further due to the limited amount of sediment collected as well the limits of readily available analytical techniques; radionuclide dating methods were unsuccessful due to the low amounts of fallout radionuclides present in the sediment. The study has however successfully established a history of flood events in the region, as well as providing a link between the hydrological and sedimentary features of flood events that could potentially be useful for current and future research

Management of Spent and Disused Radiation Sources - The Zambian Experience

Zambia like all other countries in the world is faced with environmental problems brought about by a variety of human activities. In Zambia the major environmental issues as identified by Nation Environmental Action Plan (NEAP) of 1994 are water pollution, poor sanitation, land degradation, air pollution, poor waste management, misuse of chemicals, wildlife depletion and deforestation. Zambian has been using a lot of radioactive materials in its various industries. The country has taken several projects with help of external partners. These partners however left these projects in the hands of the Zambians without developing their capacities to manage these radioactive sources. The Government recognized the need to manage these sources and passed legislation governing the management of radioactive materials. The first act of Parliament on Radiation Protection work was passed in 1975 to legislate the use of ionizing radiation. However, because of financial constraints the Country is facing, these regulations have remained unimplemented. Fortunately the international Community has been working in partnership with the Zambian Government in the Management of Radioactive Material. Therefore this paper will present the following aspects of radioactive waste management in Zambia: review Existing Legislation in Zambia regarding management of spent/radioactive sources; capacity building in the field of management of radioactive waste; management of spent and disused radiation sources; existing disposal systems in Zambia regarding spent/orphaned sources; existing stocks of radioactive sources in the Zambian industries