Assessing the impact of access to climate services on smallholder farmers’ cropping decisions and household food security in Elundini Municipality, Eastern Cape province
- Authors: Yanga-Inkosi, Nocezo
- Date: 2023-11
- Subjects: Climatic changes , Food security -- Climatic factors , Crops and climate
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28222 , vital:73913
- Description: Climate variability has significant implications for crop production and overall food security. Climate services, which provide tailored and localised climate information, have the potential to enhance farmers' understanding of climate patterns and support informed decision-making. The purpose of the study was to assess the impact of climate services on smallholder farmers’ cropping decisions and household food security. The study adopted a cross-sectional household survey on 217 smallholder crop farming households from Elundini Municipality. Structured questionnaires and face-to-face interviews were used to collect the required data from the farmers. Descriptive analysis was used to identify the types of climate service accessed by smallholder crop farmers in the study area. The probit model was used to examine factors influencing smallholder crop farmers’ access to specific climate services. The household dietary diversity score was used to measure household food security among smallholder crop farmers. The propensity score matching model was used to assess the impact of accessing specific climate services on cropping decisions and household food security. The results indicated that most farmers 77 percent in the study area had access to climate services. The results further showed that many farmers had access to short-term weather forecast 79 percent with very few accessing seasonal forecast 22 percent. The results also revealed that access to both short-term weather and seasonal forecasts is positively influenced by ownership of mobile phones and access to extension services. Similarly, access to short-term weather forecasts is positively influenced by age, monthly income, ownership of radio, timely climate information, and perceiving that climate change has negative effects on crop production. Land size, knowledge of climate change, and climate services accuracy are positive and significant factors influencing access to seasonal forecasts. Most of the smallholder farming households in the study area had higher dietary diversity scores 66 percent. Moreover, access to short-term weather and seasonal forecasts has a positive and significant impact on cropping decisions and household dietary diversity scores. The study concludes that climate services improve cropping decisions and household food security among smallholder crop farmers in Elundini Municipality. The study recommends that there should be investments in awareness programmes that will educate farmers about the importance of climate services and how to acquire and interpret both weather and seasonal forecasts. Stakeholders interested in improving smallholder farmers’ access to climate services should consider whether farmers own smart phones and have access to extension services, arable land, knowledge of climate change, and if the climate services are accurate for smallholder farmers. In addition, to improve crop production and household food security in the face of climate change, access to climate services by smallholder farmers should be considered. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023-11
- Authors: Yanga-Inkosi, Nocezo
- Date: 2023-11
- Subjects: Climatic changes , Food security -- Climatic factors , Crops and climate
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/28222 , vital:73913
- Description: Climate variability has significant implications for crop production and overall food security. Climate services, which provide tailored and localised climate information, have the potential to enhance farmers' understanding of climate patterns and support informed decision-making. The purpose of the study was to assess the impact of climate services on smallholder farmers’ cropping decisions and household food security. The study adopted a cross-sectional household survey on 217 smallholder crop farming households from Elundini Municipality. Structured questionnaires and face-to-face interviews were used to collect the required data from the farmers. Descriptive analysis was used to identify the types of climate service accessed by smallholder crop farmers in the study area. The probit model was used to examine factors influencing smallholder crop farmers’ access to specific climate services. The household dietary diversity score was used to measure household food security among smallholder crop farmers. The propensity score matching model was used to assess the impact of accessing specific climate services on cropping decisions and household food security. The results indicated that most farmers 77 percent in the study area had access to climate services. The results further showed that many farmers had access to short-term weather forecast 79 percent with very few accessing seasonal forecast 22 percent. The results also revealed that access to both short-term weather and seasonal forecasts is positively influenced by ownership of mobile phones and access to extension services. Similarly, access to short-term weather forecasts is positively influenced by age, monthly income, ownership of radio, timely climate information, and perceiving that climate change has negative effects on crop production. Land size, knowledge of climate change, and climate services accuracy are positive and significant factors influencing access to seasonal forecasts. Most of the smallholder farming households in the study area had higher dietary diversity scores 66 percent. Moreover, access to short-term weather and seasonal forecasts has a positive and significant impact on cropping decisions and household dietary diversity scores. The study concludes that climate services improve cropping decisions and household food security among smallholder crop farmers in Elundini Municipality. The study recommends that there should be investments in awareness programmes that will educate farmers about the importance of climate services and how to acquire and interpret both weather and seasonal forecasts. Stakeholders interested in improving smallholder farmers’ access to climate services should consider whether farmers own smart phones and have access to extension services, arable land, knowledge of climate change, and if the climate services are accurate for smallholder farmers. In addition, to improve crop production and household food security in the face of climate change, access to climate services by smallholder farmers should be considered. , Thesis (MSc) -- Faculty of Science and Agriculture, 2023
- Full Text:
- Date Issued: 2023-11
Thermal physiology of juvenile red roman seabream, Chrysoblephus laticeps after long-term exposure to low pH conditions
- Authors: Allison, Caitlin
- Date: 2023-10-13
- Subjects: Climatic changes , Ocean acidification , Basal metabolism , Chrysoblephus laticeps , Thermal tolerance (Physiology) , Phenotypic plasticity , Fishes Climatic factors
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424323 , vital:72143
- Description: Climate change has caused a combination of effects on the physiology of fishes. Of particular concern are the effects of thermal variability and ocean acidification. Organismal energy budgets change throughout ontogeny and research into the metabolic scope during early life stages is particularly useful in identifying potential bottlenecks. The first part of this thesis aimed to assess the absolute aerobic scope (AAS, described as the difference between the maximum and standard metabolic rates) of individual juveniles from a protected population of the endemic, commercially important seabream, Chrysoblephus laticeps, across a range of ecologically relevant temperatures (T = 11, 14, 18, 22˚C) under present-day conditions (pH = 8.03, pCO2 ≈ 420 μatm) using intermittent flow respirometry. The second component sought to investigate how long-term exposure (from fertilisation to juvenile, ~100 days exposure) to high-pCO2/hypercapnic conditions (pH = 7.63, pCO2 ≈ 1400 μatm), would affect the AAS of juvenile C. laticeps over a range of temperatures. Lower pH conditions were predicted to cause a decrease in the AAS of treatment animals due to additional energetic costs of acid-base regulation. The findings of the first data chapter demonstrated that juvenile C. laticeps reared under current CO2 conditions are tolerant to a wide range of thermal conditions, and individuals with a broad aerobic scope will be the best suited to coping with enhanced thermal variability. In contrast to the expected outcomes of the second data chapter, juvenile C. laticeps reared under high pCO2 conditions displayed greater AAS at high and low temperatures when compared with specimens from high pH conditions. Whilst a high degree of individual phenotypic variation was observed in the metabolic response of both groups, this was reduced at the lower and upper extreme temperatures for high pH and low pH animals respectively. Notably, the variation in treatment animal’s SMR was significantly diminished across all temperatures tested, compared to only a localised reduction in the SMR of high pH animals at cold temperatures. This may be indicative of compensatory pathways affecting energy restructuring and thermally-governed physiological trade-offs under hypercapnia. Given these results, juvenile C. laticeps appear to be more resilient to ocean acidification than anticipated, potentially owing to intrapopulation metabolic phenotypic diversity. This is likely attributed to the parental lineage originating in the Tsitsikamma MPA, which is thought to boast greater phenotypic diversity as a consequence of the refuge that these conservation areas offer from exploitation. Owing to the restriction imposed by the availability of surviving, captive-reared juveniles, the sample size used in this study was relatively low. However, owing to the repeated-measures nature of this research the sample size was sufficient to offer suitable statistical power for the polynomial mixed model used in the analysis. Future research should incorporate both physiological and behavioural responses to multiple environmental stressors to better understand covariation between these two traits, and to detect any behavioural trade-offs that might arise through compensation. In addition, these trials should be repeated using offspring from outside of the MPA to compare whether the same level of resilience and metabolic phenotypic diversity would be present in an exploited population. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Allison, Caitlin
- Date: 2023-10-13
- Subjects: Climatic changes , Ocean acidification , Basal metabolism , Chrysoblephus laticeps , Thermal tolerance (Physiology) , Phenotypic plasticity , Fishes Climatic factors
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424323 , vital:72143
- Description: Climate change has caused a combination of effects on the physiology of fishes. Of particular concern are the effects of thermal variability and ocean acidification. Organismal energy budgets change throughout ontogeny and research into the metabolic scope during early life stages is particularly useful in identifying potential bottlenecks. The first part of this thesis aimed to assess the absolute aerobic scope (AAS, described as the difference between the maximum and standard metabolic rates) of individual juveniles from a protected population of the endemic, commercially important seabream, Chrysoblephus laticeps, across a range of ecologically relevant temperatures (T = 11, 14, 18, 22˚C) under present-day conditions (pH = 8.03, pCO2 ≈ 420 μatm) using intermittent flow respirometry. The second component sought to investigate how long-term exposure (from fertilisation to juvenile, ~100 days exposure) to high-pCO2/hypercapnic conditions (pH = 7.63, pCO2 ≈ 1400 μatm), would affect the AAS of juvenile C. laticeps over a range of temperatures. Lower pH conditions were predicted to cause a decrease in the AAS of treatment animals due to additional energetic costs of acid-base regulation. The findings of the first data chapter demonstrated that juvenile C. laticeps reared under current CO2 conditions are tolerant to a wide range of thermal conditions, and individuals with a broad aerobic scope will be the best suited to coping with enhanced thermal variability. In contrast to the expected outcomes of the second data chapter, juvenile C. laticeps reared under high pCO2 conditions displayed greater AAS at high and low temperatures when compared with specimens from high pH conditions. Whilst a high degree of individual phenotypic variation was observed in the metabolic response of both groups, this was reduced at the lower and upper extreme temperatures for high pH and low pH animals respectively. Notably, the variation in treatment animal’s SMR was significantly diminished across all temperatures tested, compared to only a localised reduction in the SMR of high pH animals at cold temperatures. This may be indicative of compensatory pathways affecting energy restructuring and thermally-governed physiological trade-offs under hypercapnia. Given these results, juvenile C. laticeps appear to be more resilient to ocean acidification than anticipated, potentially owing to intrapopulation metabolic phenotypic diversity. This is likely attributed to the parental lineage originating in the Tsitsikamma MPA, which is thought to boast greater phenotypic diversity as a consequence of the refuge that these conservation areas offer from exploitation. Owing to the restriction imposed by the availability of surviving, captive-reared juveniles, the sample size used in this study was relatively low. However, owing to the repeated-measures nature of this research the sample size was sufficient to offer suitable statistical power for the polynomial mixed model used in the analysis. Future research should incorporate both physiological and behavioural responses to multiple environmental stressors to better understand covariation between these two traits, and to detect any behavioural trade-offs that might arise through compensation. In addition, these trials should be repeated using offspring from outside of the MPA to compare whether the same level of resilience and metabolic phenotypic diversity would be present in an exploited population. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2023
- Full Text:
- Date Issued: 2023-10-13
Long-term trends in fish length-at-age, catch-at-length and condition of the Namibian and South African commercially exploited species
- Authors: Iyambo, Elago Martha
- Date: 2022-10-14
- Subjects: Fishery management South Africa , Fishery management Namibia , Fishes Growth , Fisheries Fishing effort , Climatic changes , Fishes Climatic factors
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362872 , vital:65370
- Description: Fish growth rate is a flexible trait that can evolve in response to fishing or environmental change. Therefore, knowledge of fish growth rate patterns, long-term and short-term responses to fishing effort and environmental change is important for fisheries management in the Benguela. Historical and current age length keys have been used as indicators of annual fish growth in the Benguela, the growth rate study on Merluccius paradoxus demonstrated long-term changes in growth over three decades as a response to fishing. However, the fish growth rate patterns, in relation to fishing effort and environmental change patterns are still not known for the many commercially important stocks in the Benguela. The specific objectives of the project were to determine the annual variability and long-term trends, in annual mean lengths-at-age, catch-at-length and fish condition of 17 commercially exploited resources, targeted and bycatch in Namibia and South Africa in relation to environmental changes (sea surface temperature). The results showed that there was a significant decrease in mean length at age 7 for Merluccius capensis (Namibian stock), a significant decrease in mean length at ages 3 to 7 for South African M. capensis and a significant increase in mean length at ages 2 to 6 for South African M. paradoxus Fishery-induced evolution may be the reason for the increase in mean length in the early stages of hake. A regime shift was detected in the mean length at age 1 for Etrumeus whiteheadi (South African stock) caused by changes in water temperatures. A decrease in mean length of the catch was observed for Namibian M. capensis and the reason for this could have been the stock being overexploited during the years of the observed trend (1968 to 1987). Historically both the Namibian Lophius vomerinus and Helicolenus dactylopterus were bycatch of the hake fishery, therefore, the decrease in their mean length of the catch may be due to increased bycatch mortalities due to increased hake catches. The improvement in the management measures of the Jasus lalandii fishery and possible favourable oxygen fluctuation might have caused the stock to increase in mean length of the catch between 1977 and 1982. Fish condition showed a significant difference in stocks between years. Fish condition of M. capensis, M. paradoxus and T. capensis were analysed. The rest of the commercial stocks were omitted because there was limited length-weight data. For Namibian M. capensis the spawning season may have caused fish to have the best condition in 1987 and while higher temperatures in 1983 may have led to the worst condition in 1983. Higher prey availability in 1979 for Namibian M. paradoxus could have been the reason for fish with best condition being found in 1979. T. capensis had the highest condition index in 1986 when cooler summer SST prevailed that may have been more favourable for T. capensis to live in. July, September and January SSTs were significantly negatively correlated with the mean length of M. capensis at age 3. This was perhaps due to upwelling intensity and plankton productivity which increases in winter and decreases in summer. A separate study of the impacts of fishery-induced changes and density-dependence on fish growth rate, as well as the effects of other environmental variables is recommended. Since data for some species was outdated, it is suggested to update biological variables and assessment for future work. This study can be used to understand the key life history characteristics of Namibian and South African exploited resources, targeted and bycatch. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Iyambo, Elago Martha
- Date: 2022-10-14
- Subjects: Fishery management South Africa , Fishery management Namibia , Fishes Growth , Fisheries Fishing effort , Climatic changes , Fishes Climatic factors
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362872 , vital:65370
- Description: Fish growth rate is a flexible trait that can evolve in response to fishing or environmental change. Therefore, knowledge of fish growth rate patterns, long-term and short-term responses to fishing effort and environmental change is important for fisheries management in the Benguela. Historical and current age length keys have been used as indicators of annual fish growth in the Benguela, the growth rate study on Merluccius paradoxus demonstrated long-term changes in growth over three decades as a response to fishing. However, the fish growth rate patterns, in relation to fishing effort and environmental change patterns are still not known for the many commercially important stocks in the Benguela. The specific objectives of the project were to determine the annual variability and long-term trends, in annual mean lengths-at-age, catch-at-length and fish condition of 17 commercially exploited resources, targeted and bycatch in Namibia and South Africa in relation to environmental changes (sea surface temperature). The results showed that there was a significant decrease in mean length at age 7 for Merluccius capensis (Namibian stock), a significant decrease in mean length at ages 3 to 7 for South African M. capensis and a significant increase in mean length at ages 2 to 6 for South African M. paradoxus Fishery-induced evolution may be the reason for the increase in mean length in the early stages of hake. A regime shift was detected in the mean length at age 1 for Etrumeus whiteheadi (South African stock) caused by changes in water temperatures. A decrease in mean length of the catch was observed for Namibian M. capensis and the reason for this could have been the stock being overexploited during the years of the observed trend (1968 to 1987). Historically both the Namibian Lophius vomerinus and Helicolenus dactylopterus were bycatch of the hake fishery, therefore, the decrease in their mean length of the catch may be due to increased bycatch mortalities due to increased hake catches. The improvement in the management measures of the Jasus lalandii fishery and possible favourable oxygen fluctuation might have caused the stock to increase in mean length of the catch between 1977 and 1982. Fish condition showed a significant difference in stocks between years. Fish condition of M. capensis, M. paradoxus and T. capensis were analysed. The rest of the commercial stocks were omitted because there was limited length-weight data. For Namibian M. capensis the spawning season may have caused fish to have the best condition in 1987 and while higher temperatures in 1983 may have led to the worst condition in 1983. Higher prey availability in 1979 for Namibian M. paradoxus could have been the reason for fish with best condition being found in 1979. T. capensis had the highest condition index in 1986 when cooler summer SST prevailed that may have been more favourable for T. capensis to live in. July, September and January SSTs were significantly negatively correlated with the mean length of M. capensis at age 3. This was perhaps due to upwelling intensity and plankton productivity which increases in winter and decreases in summer. A separate study of the impacts of fishery-induced changes and density-dependence on fish growth rate, as well as the effects of other environmental variables is recommended. Since data for some species was outdated, it is suggested to update biological variables and assessment for future work. This study can be used to understand the key life history characteristics of Namibian and South African exploited resources, targeted and bycatch. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Towards an improved understanding of episodic benthic turbidity events (Benthic Nepheloid Layer) on the Eastern Agulhas Bank, South Africa
- Authors: Johnstone, Brett Mordaunt
- Date: 2022-10-14
- Subjects: Nepheloid layer , Turbidity , Loligo reynaudii , Fisheries South Africa , Oceanography , Remote sensing , Altimetry , Climatic changes
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362883 , vital:65371
- Description: The harvest of Loligo reynaudii, or "chokka," represents a critical source of revenue and job creation in the historically impoverished Eastern Cape Province of South Africa. Due to the importance of visual stimuli in the reproductive processes, it has been hypothesized that a primary driver of successful reproduction is the clarity of the water column. The presence of increased particulate matter concentrations within the water column generates turbid conditions near the seafloor (visibility < 1m), that are proposed to restrict spawning activity. This benthic nepheloid layer (BNL) contains both organic and inorganic components, with the BNL intensity a function of bottom turbulence, substratum type, and detritus level. However, the spatial and temporal resolution of BNL intensity on the Eastern Agulhas Bank (EAB) and the environmental drivers thereof remain unknown. Here we show that benthic turbidity events are a common but highly variable occurrence on the EAB. Results from a 17-month time-series of in-situ and remote sensing data between 2002 – 2004 in Algoa Bay, supplemented by experiments in other bays important for spawning, show that turbid conditions existed for ∼ 30 % of the sample period. Exploration of environmental drivers, including the influence of wind, altimeter-derived significant wave height (Hs), sea surface temperature (SST), and chlorophyll-a (Chl-a) concentrations indicate that BNL intensity does not conform to a "one-size-fits-all" approach. Rather, complex local hydrological and physiochemical parameters control the BNL characteristics on the EAB. Global warming is likely to increase the frequency and intensity of extreme westerly-wind and storm events, promoting BNL events on the Eastern Agulhas Bank and possibly causing a shift in the reproductive strategy of chokka squid to the cooler mid shelf region. This is likely to have consequences for both the species in terms of reproductive success and the fishery, which is concentrated on inshore spawning aggregations. Future research needs to quantify and characterize the constituents, source particles and spatial-temporal variability of BNL events in order to build a predictive capacity. Through incorporating the qualitative analysis of the dynamics of nepheloid layers on the EAB into Regional Oceanographic Models (ROMS), General Linear Models (GLM) and particle distribution models such as DELFT-3D, it is possible to move toward predicting the timing and intensity of these events. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
- Authors: Johnstone, Brett Mordaunt
- Date: 2022-10-14
- Subjects: Nepheloid layer , Turbidity , Loligo reynaudii , Fisheries South Africa , Oceanography , Remote sensing , Altimetry , Climatic changes
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/362883 , vital:65371
- Description: The harvest of Loligo reynaudii, or "chokka," represents a critical source of revenue and job creation in the historically impoverished Eastern Cape Province of South Africa. Due to the importance of visual stimuli in the reproductive processes, it has been hypothesized that a primary driver of successful reproduction is the clarity of the water column. The presence of increased particulate matter concentrations within the water column generates turbid conditions near the seafloor (visibility < 1m), that are proposed to restrict spawning activity. This benthic nepheloid layer (BNL) contains both organic and inorganic components, with the BNL intensity a function of bottom turbulence, substratum type, and detritus level. However, the spatial and temporal resolution of BNL intensity on the Eastern Agulhas Bank (EAB) and the environmental drivers thereof remain unknown. Here we show that benthic turbidity events are a common but highly variable occurrence on the EAB. Results from a 17-month time-series of in-situ and remote sensing data between 2002 – 2004 in Algoa Bay, supplemented by experiments in other bays important for spawning, show that turbid conditions existed for ∼ 30 % of the sample period. Exploration of environmental drivers, including the influence of wind, altimeter-derived significant wave height (Hs), sea surface temperature (SST), and chlorophyll-a (Chl-a) concentrations indicate that BNL intensity does not conform to a "one-size-fits-all" approach. Rather, complex local hydrological and physiochemical parameters control the BNL characteristics on the EAB. Global warming is likely to increase the frequency and intensity of extreme westerly-wind and storm events, promoting BNL events on the Eastern Agulhas Bank and possibly causing a shift in the reproductive strategy of chokka squid to the cooler mid shelf region. This is likely to have consequences for both the species in terms of reproductive success and the fishery, which is concentrated on inshore spawning aggregations. Future research needs to quantify and characterize the constituents, source particles and spatial-temporal variability of BNL events in order to build a predictive capacity. Through incorporating the qualitative analysis of the dynamics of nepheloid layers on the EAB into Regional Oceanographic Models (ROMS), General Linear Models (GLM) and particle distribution models such as DELFT-3D, it is possible to move toward predicting the timing and intensity of these events. , Thesis (MSc) -- Faculty of Science, Ichthyology and Fisheries Science, 2022
- Full Text:
- Date Issued: 2022-10-14
Acceleration of Climate Change and the Impact on the Built Environment
- Authors: Van Rooyen, Mauritz Kenneth
- Date: 2022-04
- Subjects: Climatic changes , Natural disasters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58532 , vital:59751
- Description: Climate change is widely acknowledged as one of humanity's most pressing problems in the twenty-first century. The emission of greenhouse gases (GHGs) has changed the earth's normal climate cycle by raising the earth's surface temperature. The severity and frequency of various natural catastrophes, such as storms, floods, heat waves, and droughts, have increased as the earth's surface temperature has risen. These events have a devastating effect on populated areas; contaminating clean drinking water, leading to uncontrollable wildfires, damaging properties and infrastructure, environmental pollution, and loss of life. The increase in GHG emissions is largely contributed to by the built environment and the human activities within these areas. This research aimed to investigate the current state of climate change and the impact on the built environment. Furthermore, a quantitative approach was taken with regards to the research and a descriptive survey was conducted among professionals that work within the built environment, namely architects, project managers, construction managers, and electrical and mechanical engineers. The salient findings are: very few participants actively participate in activities to enhance their knowledge of climate change; most participants have a good understanding of what climate change is, although they make no extra effort to implement mitigating strategies on their projects other than what is required by the local council; most participants are unsure with respect to the impact that climate change has on the built environment, and most participants are unaware of global initiatives that South Africa has contributed to, to reduce GHG emissions. Governments and organisations around the world have implemented rules and regulations to regulate and decrease GHGs in the atmosphere, but it is still increasing at an accelerated rate. The increase of GHG emissions is devastating on all sectors of the built environment and will only intensify over time. As advancements are made to reduce GHG emissions progress has also been made to adapt to an ever-changing climate, specifically in the construction industry. Architecture and building processes have evolved to not only reduce the harmful effects on the environment but also to be more efficient and sustainable. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Van Rooyen, Mauritz Kenneth
- Date: 2022-04
- Subjects: Climatic changes , Natural disasters
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58532 , vital:59751
- Description: Climate change is widely acknowledged as one of humanity's most pressing problems in the twenty-first century. The emission of greenhouse gases (GHGs) has changed the earth's normal climate cycle by raising the earth's surface temperature. The severity and frequency of various natural catastrophes, such as storms, floods, heat waves, and droughts, have increased as the earth's surface temperature has risen. These events have a devastating effect on populated areas; contaminating clean drinking water, leading to uncontrollable wildfires, damaging properties and infrastructure, environmental pollution, and loss of life. The increase in GHG emissions is largely contributed to by the built environment and the human activities within these areas. This research aimed to investigate the current state of climate change and the impact on the built environment. Furthermore, a quantitative approach was taken with regards to the research and a descriptive survey was conducted among professionals that work within the built environment, namely architects, project managers, construction managers, and electrical and mechanical engineers. The salient findings are: very few participants actively participate in activities to enhance their knowledge of climate change; most participants have a good understanding of what climate change is, although they make no extra effort to implement mitigating strategies on their projects other than what is required by the local council; most participants are unsure with respect to the impact that climate change has on the built environment, and most participants are unaware of global initiatives that South Africa has contributed to, to reduce GHG emissions. Governments and organisations around the world have implemented rules and regulations to regulate and decrease GHGs in the atmosphere, but it is still increasing at an accelerated rate. The increase of GHG emissions is devastating on all sectors of the built environment and will only intensify over time. As advancements are made to reduce GHG emissions progress has also been made to adapt to an ever-changing climate, specifically in the construction industry. Architecture and building processes have evolved to not only reduce the harmful effects on the environment but also to be more efficient and sustainable. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
Feminization of agriculture, livelihoods and climate change in Chivi district, Zimbabwe
- Authors: Muzapi, Admire
- Date: 2022-04
- Subjects: Climatic changes , Women in agriculture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58002 , vital:58489
- Description: Given the historically disadvantaged position of women and their heavy reliance on climate-sensitive activities in many societies, the vagaries of the climate threaten the agrarian livelihoods of women in Chivi district. This study focuses on the impacts of climate change on women working in agriculture in one ward of Chivi district and on the feminization of agriculture during the period from 2000 to 2019. It explores how the roles of women have changed in agricultural production and in relation to household food security. It assesses women’s involvement in decision-making in agriculture as well as in household food security, and analyses the socio-economic impacts of climate change on women subsistence farmers, exploring the adaptation strategies that rural women working in agriculture implement in response to climate-risk events and threats. The study was influenced by ecofeminist theories and the Sustainable Livelihood Framework. Comparative analysis of household types was done after data gathering using participatory rural appraisal tools with women from three villages. Interviews were conducted with key informants from government departments and development institutions. The results show that climate-risk events and threats have resulted in feminization of agricultural labour as men branch out into wage labour, but that changing power relations in the form of decision-making in agriculture and issues related to household food security vary with the type of the household. Worsening climatic conditions have made it difficult for women to ensure household food security and to generate income through agrarian livelihoods. However, women have implemented adaptation strategies including conservation agriculture to mitigate crop failure, and to improve agricultural output and household daily consumption, and thus survive peak hunger periods. The study contributes to our understanding of the resilience of women in the Global South to climate-risk events and threats and contributes to our understanding of participatory rural appraisal tools in addition to conventional data collection tools. The study recommends that development institutions promote gender equality and that development institutions construct dams, rehabilitate collapsed irrigation schemes and accelerate the implementation of novel climate smart technologies in arid regions. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Muzapi, Admire
- Date: 2022-04
- Subjects: Climatic changes , Women in agriculture
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58002 , vital:58489
- Description: Given the historically disadvantaged position of women and their heavy reliance on climate-sensitive activities in many societies, the vagaries of the climate threaten the agrarian livelihoods of women in Chivi district. This study focuses on the impacts of climate change on women working in agriculture in one ward of Chivi district and on the feminization of agriculture during the period from 2000 to 2019. It explores how the roles of women have changed in agricultural production and in relation to household food security. It assesses women’s involvement in decision-making in agriculture as well as in household food security, and analyses the socio-economic impacts of climate change on women subsistence farmers, exploring the adaptation strategies that rural women working in agriculture implement in response to climate-risk events and threats. The study was influenced by ecofeminist theories and the Sustainable Livelihood Framework. Comparative analysis of household types was done after data gathering using participatory rural appraisal tools with women from three villages. Interviews were conducted with key informants from government departments and development institutions. The results show that climate-risk events and threats have resulted in feminization of agricultural labour as men branch out into wage labour, but that changing power relations in the form of decision-making in agriculture and issues related to household food security vary with the type of the household. Worsening climatic conditions have made it difficult for women to ensure household food security and to generate income through agrarian livelihoods. However, women have implemented adaptation strategies including conservation agriculture to mitigate crop failure, and to improve agricultural output and household daily consumption, and thus survive peak hunger periods. The study contributes to our understanding of the resilience of women in the Global South to climate-risk events and threats and contributes to our understanding of participatory rural appraisal tools in addition to conventional data collection tools. The study recommends that development institutions promote gender equality and that development institutions construct dams, rehabilitate collapsed irrigation schemes and accelerate the implementation of novel climate smart technologies in arid regions. , Thesis (PhD) -- Faculty of Business and Economic science, 2022
- Full Text:
- Date Issued: 2022-04
Greening Ndlambe Village
- Authors: Vithi-Masiza, Noluthando
- Date: 2022-04
- Subjects: Climatic changes , Sustainable development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58396 , vital:59082
- Description: In 1994 the new democratic government of South Africa introduced the Reconstruction and Development Programme (RDP) which was aimed at massive infrastructure expansion. Tackling the housing crisis has been encountered by growing demands for low carbon footprint, reduced use of non-renewable resources and as part of the green agenda. In line with the Sustainable Development Goals (SDGs), the South African government set a variety of objectives aimed at achieving an environmentally sustainable future for all. While South Africa has embraced green economy principles, tested integrated approaches are still to be seen in housing construction. This study sought to explore the greening of Ndlambe green village in the Port Alfred area in the Eastern Cape Province of South Africa. To achieve the study objectives, a qualitative research approach was used, employing the case study research strategy and primary data was collected by means of focus groups. Community members, engineers, environmentalists and town planners constituted the study sample. Secondary data sources were also used in this study, along with field observation. The collected data was analysed using the thematic analysis technique. Findings from the study revealed that community members perceived Green village initiative as important and is required in South Africa given the challenges that are experienced such as energy consumption load shedding, water shortages. The economic value proposition of green building is measured through two different lenses, namely economic profit and social profit. The municipalities must take a leading role in by forming policies supporting environmentally friendly activities, with building being one crucial area. Recommendations from the study proposed that partnerships involving communities, private companies, the government and other various interest groups are imperative in order to accelerating the green building agenda. The government must be challenges to develop sustainable funding solutions for a green economy. Lastly, increased awareness about green building among the society may also drive better acceptability and ultimately, a strong social reputation. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Vithi-Masiza, Noluthando
- Date: 2022-04
- Subjects: Climatic changes , Sustainable development
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/58396 , vital:59082
- Description: In 1994 the new democratic government of South Africa introduced the Reconstruction and Development Programme (RDP) which was aimed at massive infrastructure expansion. Tackling the housing crisis has been encountered by growing demands for low carbon footprint, reduced use of non-renewable resources and as part of the green agenda. In line with the Sustainable Development Goals (SDGs), the South African government set a variety of objectives aimed at achieving an environmentally sustainable future for all. While South Africa has embraced green economy principles, tested integrated approaches are still to be seen in housing construction. This study sought to explore the greening of Ndlambe green village in the Port Alfred area in the Eastern Cape Province of South Africa. To achieve the study objectives, a qualitative research approach was used, employing the case study research strategy and primary data was collected by means of focus groups. Community members, engineers, environmentalists and town planners constituted the study sample. Secondary data sources were also used in this study, along with field observation. The collected data was analysed using the thematic analysis technique. Findings from the study revealed that community members perceived Green village initiative as important and is required in South Africa given the challenges that are experienced such as energy consumption load shedding, water shortages. The economic value proposition of green building is measured through two different lenses, namely economic profit and social profit. The municipalities must take a leading role in by forming policies supporting environmentally friendly activities, with building being one crucial area. Recommendations from the study proposed that partnerships involving communities, private companies, the government and other various interest groups are imperative in order to accelerating the green building agenda. The government must be challenges to develop sustainable funding solutions for a green economy. Lastly, increased awareness about green building among the society may also drive better acceptability and ultimately, a strong social reputation. , Thesis (PhD) -- Faculty of Engineering, the Built Environment, and Technology, 2022
- Full Text:
- Date Issued: 2022-04
The role of climate change on food security in Northern Uganda a case study of Lira district
- Authors: Aciro, Prudence Estel
- Date: 2022-04
- Subjects: Food security -- Uganda , Food security -- Climatic factors , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57513 , vital:58054
- Description: The study examines the effects of climate change in Northern Uganda to create food security solutions through the improvement of local resilience mechanisms and adaptation devices. The study adopted the interpretive paradigm within the qualitative research methodology as it investigated the subjective opinions of the respondents about the role of climate change on food security in the Lira district. The researcher used non-probability purposive sampling to identify nine officials that possessed knowledge on resilience mechanisms and also interacted directly with individual farmers. The researcher used semi-structured interviews as a tool to collect data and thematic analysis to make conclusions on findings based on the emerging themes. The findings from the study revealed that the four determinants of food security are greatly affected by climate events and these are: food utilisation, food production, food availability and access to food as well as the stability of food supply. Food storage is a problem facing the community of Lira due to extreme climate events. Climate change was found to affect food prices in such a way that when agricultural inputs are bought expensively, it leads the cost of producing crops to increase, which in turn makes food more expensive at the market. The findings also displayed that Lira’s local communities are trying to apply adaptive farming practices to ensure there is an adequate food supply, such as planting a local variety of seeds that withstand the effect of climate change, such as sorghum millet and cassava. Based on the findings, valuable recommendations are offered. These include the government rolling out a national irrigation scheme to ease the use of the drip irrigation mechanism. Also, there is a need for more interventions that support local resilience mechanisms such as the use of agricultural inputs, as these require subsidisation. It emerged from the findings of this study that there is a need for better interventions to deal with flooding. For future researchers, it was found that there is a need to explore the best post-harvest handling methods as well as food storage. , Thesis (MA) -- Faculty of Business and Economic Sciences, 2022
- Full Text:
- Date Issued: 2022-04
- Authors: Aciro, Prudence Estel
- Date: 2022-04
- Subjects: Food security -- Uganda , Food security -- Climatic factors , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/57513 , vital:58054
- Description: The study examines the effects of climate change in Northern Uganda to create food security solutions through the improvement of local resilience mechanisms and adaptation devices. The study adopted the interpretive paradigm within the qualitative research methodology as it investigated the subjective opinions of the respondents about the role of climate change on food security in the Lira district. The researcher used non-probability purposive sampling to identify nine officials that possessed knowledge on resilience mechanisms and also interacted directly with individual farmers. The researcher used semi-structured interviews as a tool to collect data and thematic analysis to make conclusions on findings based on the emerging themes. The findings from the study revealed that the four determinants of food security are greatly affected by climate events and these are: food utilisation, food production, food availability and access to food as well as the stability of food supply. Food storage is a problem facing the community of Lira due to extreme climate events. Climate change was found to affect food prices in such a way that when agricultural inputs are bought expensively, it leads the cost of producing crops to increase, which in turn makes food more expensive at the market. The findings also displayed that Lira’s local communities are trying to apply adaptive farming practices to ensure there is an adequate food supply, such as planting a local variety of seeds that withstand the effect of climate change, such as sorghum millet and cassava. Based on the findings, valuable recommendations are offered. These include the government rolling out a national irrigation scheme to ease the use of the drip irrigation mechanism. Also, there is a need for more interventions that support local resilience mechanisms such as the use of agricultural inputs, as these require subsidisation. It emerged from the findings of this study that there is a need for better interventions to deal with flooding. For future researchers, it was found that there is a need to explore the best post-harvest handling methods as well as food storage. , Thesis (MA) -- Faculty of Business and Economic Sciences, 2022
- Full Text:
- Date Issued: 2022-04
Effects of climatic variability on maize productivity in South Africa from 1937-2018
- Awum Awum, Rudin https://orcid.org/ 0000-0002-8740-6163
- Authors: Awum Awum, Rudin https://orcid.org/ 0000-0002-8740-6163
- Date: 2022-03
- Subjects: Crops and climate , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21410 , vital:48576
- Description: Climate is an important factor in agricultural production. The world is facing climate change and variability, which result in high temperatures, low rainfall patterns, shortage of water and persistent droughts. Climate change poses a significant threat to South Africa’s water resources, food security, health, infrastructure, ecosystem services and biodiversity. Negative impacts of climate variability on agriculture, especially on maize the staple crop, will worsen the food security status of the nation as most of South Africa’s maize crop is produced in summer and highly depends on rainfall. This study attempted to assess the impact of climate on maize production in South Africa using secondary time series data for the period 1937 to 2018. Rainfall and temperature were used as proxies for climate variability. The Granger Causality Model was used to examine the causal linkages between climatic variables (temperature or rainfall) and maize output in South Africa for the study period. The major outcome of the analysis was that there is a two-way causal relationship between maize production and temperature. The results also indicated that there is uni-directional causality between maize yield and rainfall. Furthermore, the Variance Decomposition Model was used to forecast the relationship between climatic elements and maize production in South Africa. The result showed that all variables have an effect on maize yield, with temperature having the least effect. The last objective of the study was to profile the maize output trend for the period from 1937 to 2018. The main findings from the analysis indicate that maize production in South Africa has a general upward slope. The study recommends that the government should intensify the provision of irrigation systems for the farmers in the most vulnerable areas to mitigate the climate change. Government should also embark on massive campaigns using a variety of media to create the needed public awareness on climate change and its impact on food security. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-03
- Authors: Awum Awum, Rudin https://orcid.org/ 0000-0002-8740-6163
- Date: 2022-03
- Subjects: Crops and climate , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/21410 , vital:48576
- Description: Climate is an important factor in agricultural production. The world is facing climate change and variability, which result in high temperatures, low rainfall patterns, shortage of water and persistent droughts. Climate change poses a significant threat to South Africa’s water resources, food security, health, infrastructure, ecosystem services and biodiversity. Negative impacts of climate variability on agriculture, especially on maize the staple crop, will worsen the food security status of the nation as most of South Africa’s maize crop is produced in summer and highly depends on rainfall. This study attempted to assess the impact of climate on maize production in South Africa using secondary time series data for the period 1937 to 2018. Rainfall and temperature were used as proxies for climate variability. The Granger Causality Model was used to examine the causal linkages between climatic variables (temperature or rainfall) and maize output in South Africa for the study period. The major outcome of the analysis was that there is a two-way causal relationship between maize production and temperature. The results also indicated that there is uni-directional causality between maize yield and rainfall. Furthermore, the Variance Decomposition Model was used to forecast the relationship between climatic elements and maize production in South Africa. The result showed that all variables have an effect on maize yield, with temperature having the least effect. The last objective of the study was to profile the maize output trend for the period from 1937 to 2018. The main findings from the analysis indicate that maize production in South Africa has a general upward slope. The study recommends that the government should intensify the provision of irrigation systems for the farmers in the most vulnerable areas to mitigate the climate change. Government should also embark on massive campaigns using a variety of media to create the needed public awareness on climate change and its impact on food security. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-03
The use of earth observation multi-sensor systems to monitor and model Pastures: a case of Savannah Grasslands in Hluvukani Village, Bushbuckridge Local Municipality, Mpumalanga Province, South Africa
- Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
- Authors: Nduku, Lwandile https://orcid.org/0000-0001-9168-4548
- Date: 2022-01
- Subjects: Climatic changes , Grassland conservation
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/22578 , vital:52470
- Description: Grassland degradation associated with climate change and inappropriate grassland management has been characterized as a global environmental concern driving decreased grassland ecosystem's ecological functioning. More than 60% of South African grassland is degraded or permanently transformed to other land uses and nearly 2% properly conserved. Yet, grasslands are a major source of food for livestock grazing and provide material and non-material benefits to many livelihoods. Therefore, grassland above-ground biomass (AGB) estimation is crucial in planning and managing pastoral agriculture and the benefits derived from it. However, current grassland monitoring techniques used in rural smallholder livestock farms rely on conventional methods, which are destructive, labour-intensive, costly, and restricted to small areas. This study investigated the monitoring and modelling of protected grasslands biomass using current Earth observation systems (EOS), an approach, which is non-destructive, cost-effective, cover larger areas and is a time-saving alternative to conventional methods. Hence, the research objectives were: (i) to map the trends and advances in data and models used in the monitoring of grassland (pastures) with Earth observation systems, and (ii) to assess above-ground biomass estimation in semi-arid savannah grassland integrating Sentinel-1 and Sentinel-2 data with Machine-Learning. This goal was to assess if this approach could provide the requisite information, which could contribute to the long-term goal of developing a semi-automated system for data processing, and mapping grassland biomass to benefit local communities. For this investigation, it was crucial to understanding what research had achieved so far in this area of pasture management. An assessment of the Scopus database showed the recent developments in European Union (EU) programs and Sentinel missions, including statistical models and machine learning for monitoring grassland changes at multiple scales. However, Sentinel-1 and Sentinel-2 data, machine learning models, and variable importance techniques were applied for grassland AGB estimation. These techniques have been used in similar studies to determine optimum machine learning models, influential variables, and the capability of integrated Sentinel datasets for mapping grassland AGB, spatial distribution, and abundance. Results showed improved performance with the Random forest regression (RFR) model (R² of 34.7%, RMSE of 9.47 Mg and MAE of 7.68 Mg ). The study also observed optimum sensitivity of Difference Vegetation Index (DVI) and Enhanced Vegetation Index (EVI) in all three machine learning models for modelling grassland AGB estimation in the study area. A further, statistical comparison of all three machine learning models showed an insignificant difference in the predictive capacity for AGB in the study area with Gradient Boosting regression (GBR) model (R² of 27.7, RMSE of 9.97 Mg and MAE of 8.03 Mg ) and Extreme Gradient Boost Regression (XGBR) model (R² of 17.3%, RMSE of 10.66 Mg and MAE of 8.83 Mg ). The study revealed that an integration of Sentinel-1 and Sentinel-2 has improved capabilities for monitoring grassland AGB estimation. This research sheds light on the timely and cost-effective techniques for grassland management strategies to enhance or restore the ecological functioning of grassland ecosystems and promote community sustainability. , Thesis (MSc) -- Faculty of Science and Agriculture, 2022
- Full Text:
- Date Issued: 2022-01
Monitoring the impact of deforestation on an aquatic ecosystem using remote sensing: a case study of the Mngazana mangrove forest in the eastern cape province.
- Authors: Madasa, Akhona
- Date: 2020-12
- Subjects: Remote sensing , Mangrove forests , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20815 , vital:46598
- Description: Coastal mangrove vegetation at Mngazana continues to be threatened and reduced periodically due to unmonitored harvesting. Covering an area of 148ha, the Mngazana mangrove forest remains unreserved, thus, research on the Mngazana mangroves is essential in order to monitor their state and sustainable management. Since in-situ monitoring of mangrove areas is both challenging and time-consuming, remote sensing technologies have been used to monitor these ecosystems. This study was carried out to monitor the impact of deforestation using ASTER satellite images over ten years: from 2008 - 2018. Validation was carried out by comparing classification results with the ground-referenced data, which yielded satisfactory agreement, with an overall accuracy of 94.64 percent and Kappa coefficient of 0.93 for 2008; and in 2009, the overall accuracy was 88.62 percent and a Kappa coefficient of 0.85. While the overall accuracy of 95.08 percent and a Kappa coefficient of 0.92 for 2016 and 2018 were observed, the overall accuracy of 93.58 percent and a Kappa coefficient of 0.91 was yielded. NDVI and SAVI indices were used as monitoring indicators. The results obtained in the study indicated that the canopy density of the mangrove forest remained unchanged in the years under investigation. However, insignificant changes in canopy density were identified between 2009 and 2016. , Thesis (MSc) (Applied Remote Sensing & GIS) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
- Authors: Madasa, Akhona
- Date: 2020-12
- Subjects: Remote sensing , Mangrove forests , Climatic changes
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20815 , vital:46598
- Description: Coastal mangrove vegetation at Mngazana continues to be threatened and reduced periodically due to unmonitored harvesting. Covering an area of 148ha, the Mngazana mangrove forest remains unreserved, thus, research on the Mngazana mangroves is essential in order to monitor their state and sustainable management. Since in-situ monitoring of mangrove areas is both challenging and time-consuming, remote sensing technologies have been used to monitor these ecosystems. This study was carried out to monitor the impact of deforestation using ASTER satellite images over ten years: from 2008 - 2018. Validation was carried out by comparing classification results with the ground-referenced data, which yielded satisfactory agreement, with an overall accuracy of 94.64 percent and Kappa coefficient of 0.93 for 2008; and in 2009, the overall accuracy was 88.62 percent and a Kappa coefficient of 0.85. While the overall accuracy of 95.08 percent and a Kappa coefficient of 0.92 for 2016 and 2018 were observed, the overall accuracy of 93.58 percent and a Kappa coefficient of 0.91 was yielded. NDVI and SAVI indices were used as monitoring indicators. The results obtained in the study indicated that the canopy density of the mangrove forest remained unchanged in the years under investigation. However, insignificant changes in canopy density were identified between 2009 and 2016. , Thesis (MSc) (Applied Remote Sensing & GIS) -- University of Fort Hare, 2021
- Full Text:
- Date Issued: 2020-12
An exploratory study of the impacts of climate variability on food production availability and access in Chivi district 6, Zimbabwe
- Authors: Gwindi, Raphael
- Date: 2013
- Subjects: Climatic changes , Food security , Agricultural development projects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26696 , vital:65852
- Description: The impacts of climate variability have been of global concern for many years. These impacts are affecting economic, social, cultural, agricultural, health and political structures in different countries. Although the impacts of climate variability on agricultural production are being experienced globally, it is generally accepted that developing countries are the worst affected due to a variety of reasons. Given the high susceptibility of developing countries to climate variability, this study maps and analyses the impacts of climate variability on agricultural production, food production, availability and access in Chivi District, Zimbabwe. The study aimed at finding out experiences, so it used a qualitative approach. The study uses in-depth and focus group discussions to collect data. Chivi district is experiencing erratic weather patterns which are impacting agricultural production in general and food production in particular. Consequently, food availability and access is on the decline in the district. Even though smallholder farmers have devised coping and adaptation strategies, this is not sufficient to help them fully deal with the impacts of climate variability. This is due to their limited assets, inadequate technology and climate information among other things. In an attempt to assist these smallholder farmers cope and adapt to the impacts of climate variability, NGOs and Government Departments have instituted a number of community interventions. This assistance includes agricultural extension services, farming input support and provision of climate change information and a lot of other things. In view of these findings, the study recommends the universal adoption and growing of small grain drought resistant crops in climate variability affected Chivi. It further recommends that farmers adopt conservation agriculture, get into partnerships and co-operatives to practice irrigation gardening where those without water sources provide equipment, labour and knowledge. The study also recommends that more climate science research be conducted in Zimbabwe by both NGOs and Government Departments. Furthermore, government and NGOs should provide more support for farmers in the form of climate change related training, knowledge and technology transfer among other things. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2013
- Full Text:
- Date Issued: 2013
- Authors: Gwindi, Raphael
- Date: 2013
- Subjects: Climatic changes , Food security , Agricultural development projects
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/26696 , vital:65852
- Description: The impacts of climate variability have been of global concern for many years. These impacts are affecting economic, social, cultural, agricultural, health and political structures in different countries. Although the impacts of climate variability on agricultural production are being experienced globally, it is generally accepted that developing countries are the worst affected due to a variety of reasons. Given the high susceptibility of developing countries to climate variability, this study maps and analyses the impacts of climate variability on agricultural production, food production, availability and access in Chivi District, Zimbabwe. The study aimed at finding out experiences, so it used a qualitative approach. The study uses in-depth and focus group discussions to collect data. Chivi district is experiencing erratic weather patterns which are impacting agricultural production in general and food production in particular. Consequently, food availability and access is on the decline in the district. Even though smallholder farmers have devised coping and adaptation strategies, this is not sufficient to help them fully deal with the impacts of climate variability. This is due to their limited assets, inadequate technology and climate information among other things. In an attempt to assist these smallholder farmers cope and adapt to the impacts of climate variability, NGOs and Government Departments have instituted a number of community interventions. This assistance includes agricultural extension services, farming input support and provision of climate change information and a lot of other things. In view of these findings, the study recommends the universal adoption and growing of small grain drought resistant crops in climate variability affected Chivi. It further recommends that farmers adopt conservation agriculture, get into partnerships and co-operatives to practice irrigation gardening where those without water sources provide equipment, labour and knowledge. The study also recommends that more climate science research be conducted in Zimbabwe by both NGOs and Government Departments. Furthermore, government and NGOs should provide more support for farmers in the form of climate change related training, knowledge and technology transfer among other things. , Thesis (MSoc) -- Faculty of Social Sciences and Humanities, 2013
- Full Text:
- Date Issued: 2013
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