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Browsing Theses and Dissertations by Author "Chikoore, H."
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Item Open Access Analysis of land use and land cover change and its impact on soil erosion in Nzhelele Valley, Limpopo Province, South Africa(2022-07-15) Mavhuru, Blessing; Nethengwe, N. S.; Odhiambo, B. D.O.; Chikoore, H.Globally, the rate of land use and land cover changes has affeceted the magnitude of soil eroion. Strategies to combat soil erosion can give assistance as solutions to provide food security in many agricultural areas. Although some changes are caused by natural factors, anthropogenic factors and an increase in population are major drivers of soil erosion. This study analyses land use and land cover change and its impact on soil erosion in Nzhelele Valley. To attain this goal, the objectives of this study are to classify land use and land cover change using GIS from 2005 to 2019 in Nzhelele Valley; assess the human influence of soil management strategies on soil erosion; determine the impact of soil fertility of different land use on soil erosion, and model soil erosion on different land-use areas of Nzhelele Valley. To select farmers, study used a stratified random sampling technique by dividing groups based on their villages. A systematic sampling technique was used to select 392 farmers. To collect 78 soil samples from Nzhelele Valley, the study used the Sampling Design Tool of ArcGIS 10.The study used supervised classification in Geographic Information System (GIS) to classify land use and land cover types. Semi-structured questionnaires were used to solicit data on human influence on soil management strategies on soil erosion. The study draws a systematic sample using Slovin’s formula to determine the size of the sample from the Nzhelele Valley, and with a target population size of 657 farmers from the village, 398 farmers were selected for the study. The study also measured soil organic matter, soil pH, phosphorus, and nitrogen from collected soil samples to determine the impact of soil fertility on soil erosion. To collect soil samples from Nzhelele Valley, the study used the Sampling Design Tool of ArcGIS 10. The tool assisted in selecting the soil sample points within the study area and a total of 78 soil samples were collected for the study. The Soil and Water Assessment Tool (ARCSWAT) with an interface of ArcView Geographic Information System software modelled soil erosion within Nzhelele Valley. In terms of LULCC, results show that from 2005 up to 2019, forest increased significantly by 5%, agricultural land cover significant decrease by 11% from 36% to 25% land use/cover, bare land built-up land increase by 3% from 14% to 17%, as well as grassland increase by 3% from 19% to 22%. The results also show a significant correlation (p < 0.05) between land use management strategies and economic support systems. The physical characteristics (slope and terrace) significantly correlate (p< 0.05) with soil management strategies that limit soil erosion. The results illustrate significant variation (p ≤ 0.0002) in nitrogen among different land-use classes. Significant variation was observed (p ≤ 0.0001) in soil pH, phosphorus, and organic matter among the different land-use areas. Changes in LULC are more likely to have an effect on soil erosion in the grassland and bare land/built-up areas where infiltration is very limited. The recorded decrease in agricultural land use and an increase in forest cover are likely to reduce the impact of soil erosion. Using SWAT to model soil erosion, 26-sub basin and 301 hydrological response units were delineated. The statistical elevation of the watershed obtained a minimum elevation of 384 m, maximum elevation of 1680 m with a minimum elevation of 808.81 m. Sub basins 13, 23, and 25 demonstrated high erosion-prone classes with average sediment yield of 15.3%, 11.26%, and 11.5% respectively. The lowest sediment yield (2.1 t/ha-1yr-1) in the study area was observed in sub-basin 3. Overall synthesis of the findings illustrates that research into land-use changes and type of land use activities factors were key aspects in addressing soil erosion challenges. These findings vibrate strongly on the need to develop a systematic land management system that can solve unplanned land cover and land-use change. Based on the results, fostering better management investments through collaborative land management in Nzhelele Valley might improve the dissemination of information. Farmer to farmer training can improve the skills of the individual, which might allow smooth dissemination of information vital for land management. The problem of soil nutrient deficiency can be a central issue put forward to the local government, which needs to be addressed with specific sectors of the government to create a better environment for agriculture and food security especially in the marginalized community of South Africa. Sediment output based on the land use classes is potentially influenced by cropland with the study. This allows for further solutions on the type of land use activities to be narrowed to understand the levels of soil erosion based on the activities. The study findings from this area can be used for comparison to other areas with the same characteristics to gain insight into possible solutions to the challenges of soil erosion.Item Open Access Analysis of soil erodability and rainfall erosivity on the Soutpansberg Range, Limpopo Province, South Africa(2023-10-05) Kori, Edmore; Odhiambo, B. D. O.; Chikoore, H.; Van den Heever, S. C.Soil erosion is a global challenge that threatens ecological functionality. The need for better soil conservation practices keeps growing due to the twin challenges of climate change and population growth. However, effective soil erosion management solutions remain elusive to practitioners due to the complexity of the soil erosion process. This is especially true for mountainous tropical regions which experience rainfall as high intensity thunderstorms accompanied by gusts of wind. Therefore, the aim of this research was to analyse soil erodibility and rainfall erosivity on the Soutpansberg range to establish the characteristics of the factors that influence soil erosion. The specific objectives were to classify geomorphic features of the Soutpansberg range; to characterise the spatial-temporal aspects of potentially erosive rainfall; to assess the influence of topography on wind speed and rainfall erosivity; and to compare rainfall erosivity derived from the USLE and the SLEMSA incorporating WDR erosivity. The classification of geomorphic features needed soil, hydrology, slope, geology and land-use-land-cover data. Soil data were obtained from the Harmonised World Soil Database (HWSD v 1.21) layer downloaded from The International Institute for Applied Systems Analysis (IIASA) online database. Additional soil data were obtained from field samples and splash cups. Hydrological data were downloaded from Department of Water Affairs, Forestry and Fisheries (DWAFF) website. Slope data were derived from the 30m pixel size SRTM DEM obtained from National Geo- Spatial Information (NGI). Geological data were downloaded from South African Geosciences online database. Land-use-land-cover were extracted from the South African National Land Cover 2018 dataset accessed online on the Department of Forestry, Fisheries and Environment website. Rainfall and wind speed data for the spatial-temporal characterisation of rainfall from 2000 to 2019 were obtained from the South African Weather Services. The data analysis followed different tools. Erodibility was assessed using GIS tools to combine the five factors to create a final soil erodibility map. Potentially erosive rainfall spatial-temporal characterisation section was done using spatial GIS interpolation and spatial autocorrelation. Spatial interpolation was achieved through co-kriging. Spatial autocorrelation was determined by the fusion of the coefficient of variation and the Moran’s I. The influence of topography on wind speed and rainfall erosivity was analysed through a Likert scale, simple linear regression and MANOVA. Finally, simple regression analysis and simple comparison were employed to establish the influence of wind on rainfall erosivity. This was treated from the wind free rain (WFR) and wind driven rain (WDR) perspective. The analysis produced the following results. The geomorphic classification for erodibility was based on intrinsic erodibility, landform position, slope position, geological setting as well as rain exposure. The factors operate on fourteen soil types found on the Soutpansberg range that fall into five granulometric groups. The erodibility maps for both USLE and SLEMSA, a result of a weighted sum overlay of all the erodibility factors, show high to very high erodibility on the south facing slopes of the mountain range. A large part of the range Analysis of Soil Erodibility and Rainfall Erosivity on the Soutpansberg Range, Limpopo Province, South Africa on the western part of the mountain range is classified as of very low erodibility in the SLEMSA method. The spatial-temporal characterisation indicates that rainfall on the Soutpansberg Range is very highly variable. The potentially erosive rainfall distribution is spatially dependent on the mountain range and the spatial variation mostly simple. Most rainfall is concentrated in the central areas of the south facing slope. The epicentre is located at elevations above 1200 m.a.s.l. However, rain days are dominated by medium spatial variability. The spatio-temporal characterisation mapping indicates that flash flood hotspots are in low to very low rainfall regions. This implies that high erosion areas are not defined by total rainfall amounts only because the temporal distribution of the rainfall is also important. Furthermore, the simple linear regression analysis revealed that elevation influences erosivity. In addition, hypothesis tests showed that wind speed and topography increase rainfall erosivity. Empirical data confirm that WFR and WDR erosivity are different. Wind Driven Rain computations where wind is above 2 m/s1 produce results similar to samples collected from splash cups. The research concludes that a deep understanding of the factors controlling soil erodibility is the foundation of effective erosion control. The soils’ intrinsic characteristics and raindrop exposure (represented by land use and land cover) explains more of variation in soil loss on the Soutpansberg mountain range. Furthermore, the mountain setting causes rainfall to be concentrated on the central south facing slopes at elevations above 1000 m.a.s.l. sending the very low potentially erosive rain zone to the western region of the mountain range. However, the highest peak of the mountain is in the western region. Erosion hazard potential is not confined to high rainfall zones only. Potentially erosive rainfall hotspots are located in low and very low rainfall zones. Furthermore, rainfall erosivity is not a function of rainfall amount only because topography increases both wind speed and rainfall erosivity. However, rainfall amount and wind speed are not correlated, and wind speed is not implied in rainfall amount. Nonetheless, wind speed is correlated with rainfall erosivity. Wind speed above 2m/s-1 increases rainfall erosivity. therefore, wind driven rain (WDR) erosivity is a better representation of rainfall energy than wind free rain (WFR). The research recommends soil erosion management approaches that also consider rainfall temporal distribution. In addition, further studies on rainfall spatial distribution need to be done using satellite-based rainfall data for more accuracy. Additional research on rainfall erosivity considering rainfall temporal distribution is necessary to identify erosion hazard zones. Intensive and extensive research on incorporating wind speed in the computation of rainfall erosivity can improve soil erosion estimation models. Analysis of Soil Erodibility and Rainfall Erosivity on the Soutpansberg Range, Limpopo Province, South AfricaItem Embargo Assessing climatic and non-climatic impacts on smallholder maize production in Tshimapha Irrigation Scheme, Limpopo Province.(2024-09-06) Mudzanani, Ntsemeni Rainah; Murungweni, F. M.; Chikoore, H.Globally, climatic extremes and non-climatic factors are a major concern due to their emerging and expected impacts on maize production. Climatic extremes come through drought and floods, whilst non-climatic factors include lack of education, poor management, and lack of support. The study evaluated the impacts of climatic extremes and non-climatic factors on the production of maize yield and further examined measures for sustainable production of maize yield in Tshimapha Irrigation Scheme, Limpopo Province of South Africa. The irrigation scheme was established in the 1960s, and today has 115 smallholder farmers, each having 1.5 hectares. Climate data was obtained from the Agricultural Research Council (ARC), South African Weather Services (SAWS) and from literature. Questionnaires were administered among the 115 smallholder farmers. The key informant interviews were conducted among the farmer’s leaders, community leaders and extension officers. The extension officer and smallholder farmers assisted with generating maize yield data. For the first objective, rainfall data was analysed using Mann- Kendall test analysis in R-Studio. Furthermore, Sen’s slope was also done to determine the magnitude of the trend of the rainfall, monthly, seasonal, and yearly and questionnaires were analysed using Microsoft Excel Version 2310. For the second objective, the Standardized Precipitation Index (SPI) was analysed using rainfall data in Microsoft Excel, and the last objectives were analysed using Statistical Package for the Social Sciences (SPSS) by looking at the percentage distribution. The findings of this study indicated an increase in the intensity and amount of rainfall received during flood years, with floods peaking in January and February. The SPI indicated that the area is not prone to severe drought as it is mountainous. The highest production of maize yield was 3.4 tons, with the least being 1 ton per year (based on the available data). Water and land for farming in the scheme were sufficient before the establishment of the Mutshedzi dam, which restricts access to dam water, and the land taken for some of the farmers during the establishment of the dam. This study is in response to national, regional, and global demand for knowledge on how smallholder farmers can adapt to erratic climates and in support of achieving the Sustainable Development Goal (SDG) Number 2. This study can be useful the in working towards alleviating challenges experienced by smallholder farmers in South Africa to ensure sustainability in smallholder production.Item Open Access Assessing the impacts of climate change and adaptation strategies on smallholder farming in the Vhembe District, South Africa(2020) Kom, Zongho; Nethengwe, N. S.; Mpandeli, N. S.; Chikoore, H.One of the major challenges facing all categories of farmers globally is climate change. African smallholder farmers are the most vulnerable to changes in climate. In most parts of South Africa, empirical evidence indicates the level to which climate change has impacted negatively on agricultural production. Rising temperatures, prolonged drought and decreasing rainfall have affected local farmers’ livelihood and crop production. In the Vhembe District of South Africa’s Limpopo Province, smallholder farming predominates and its vulnerability to climate change has increased for the past decades. This study, therefore, assesses the impact of climate change and adaptation strategies on smallholder farming systems in the Vhembe District To achieve this aim, qualitative and quantitative research methodologies were employed. A questionnaire was administered to a sample of 224 smallholder farmers to elicit data on perceptions; climate change impacts, adaptation and IKS based strategies to deal with climatic shocks. Focus group discussions (FGDs), semi-structured interviews with the extension officers elicited thematic data that complemented the interview survey. Climate data were obtained from the South Africa Weather Service (SAWS) for the period 1980 to 2015. Smallholder farmers’ perceptions about climate change were validated by an analysis of climatic trends from 1980-2015. A thematic analysis of qualitative data and the Multi Nominal Logit (MNL) regression model was used based on socio-economic and biophysical attributes such as access to climate knowledge, gender, farm size, education level, and farmers’ experience, decreasing rainfall and increasing temperature as farmers’ determinants of their adaptation options to climate change. Furthermore, farmers’ perceptions tallied well with climatic trends that showed flood and drought cycles. Most of the smallholder farmers were aware of climate change and its impacts over the past decades. The study further indicated that, due to the marked climate change over this period, farmers have adopted different coping strategies at on-farm and off-farm levels. In terms of adaptation, the major adaptive strategies used by smallholder farmers included the use of drought-tolerant seeds; planting of short-seasoned crops; crop diversification; changing planting dates; irrigation and migrating to urban areas. The study recommends a framework that would include water conservation (rainfall harvesting); investment in irrigation schemes and other smart technologies that integrate indigenous knowledge systems and modern scientific knowledge to enhance crop production.Item Open Access An assessment of community flood vulnerability and adaptation: A case study of Greater Tzaneen Local Municipality, South Africa(2017-09-18) Munyai, Rendani Bigboy; Musyoki, A.; Chikoore, H.The Limpopo lowveld is at risk of floods from tropical storms from the South West Indian Ocean. The flood risk is particularly high in low altitude areas with poor infrastructure and limited resources. This study assessed flood vulnerability and adaptation at Lenyenye, Ga-Kgapane Masakaneng and Nkowankowa Section B and C within the Mopani District in the Limpopo Province of South Africa. The research objectives were to establish the determinants of flood vulnerability, assess the levels of flood vulnerability and the community‟s coping strategies. A quantitative survey approach was employed using questionnaires which were administered to affected households to identify determinants of flood vulnerability, indicators and coping strategies by communities. A qualitative survey was also undertaken to supplement the information obtained from the quantitative survey. Key informant interviews were conducted with disaster management authorities in the study area to provide information on indicators, flood experience, adaptation and mitigation measures. Field observations were undertaken to observe the physical landscape and flood impacts. Secondary data were acquired through records, maps, Census 2011 and from the South African Weather Service. Collected data were imputed into the flood vulnerability index to measure the level of flood vulnerability. The results of this study will contribute to flood disaster risk reduction in the lowveld. The results indicate that flood vulnerability in the study areas is determined by dwelling quality, poor or lack of drainage, education levels, employment status, rainfall amount and topography. The calculated flood vulnerability levels in the three case study villages indicate that Ga-Kgapane Masakaneng, Lenyenye and Nkowankowa Section B and C have a „vulnerability to floods‟ level. However, the FVI also showed that the economic aspect scored a high vulnerability to floods in Ga-Kgapane. In Nkowankowa Section B and C; physical component obtained a „high vulnerability to floods.‟ Major coping strategies in the three case villages were: making „Le-guba‟ around houses; sand-bags; making a furrow and channel around houses and on roads; temporary relocation and lastly relocating to a safer area. Key recommendations are public awareness; integrating modern mitigations with local knowledge; development of programs to ensure resilience through incorporation of (Integrated Development Planning) IDP and flood management and flood early warning system.Item Open Access Characteristics of deep moist convection and rainfall in cut-off lows over South Africa(2019-09-20) Muofhe, Tshimbiluni Percy; Chikoore, H.; Bopape, M. M.; Nethengwe, N. S.Out of all rain-producing weather systems, cut-off lows (COLs) are linked with the occurrence of high impact rainfall and in some cases short-lived floods which can last for 24 hours over South Africa. This study examined the characteristics associated with the present occurrence of the severe COL systems over South Africa from 2011 to 2017. The accuracy of the 4.4 km Unified Model (UM) which is currently in use for simulating areas of deep moist convection in South Africa was evaluated. The UM simulated geopotential height at 500 hPa as well as the associated 24 hours precipitation which were compared against the daily fields of geopotential height and 6-hourly precipitation from the European Centre for Medium-Range Weather Forecasts (ECMWF). COL events were categorized and analyzed according to the associated surface circulation patterns at 850 hPa. The seasonal distribution and duration of the systems over northern (10°E-33°E //22°-32°S) and southern (10°E-33°E //32°-35°S) regions of the study area were also analyzed. Results show COL systems shifting with season towards the north eastern parts of the country, with an increased number of events during the austral winter season during the study period. Systems which lasted for long time were observed during the austral winter and spring seasons. The UM tends to simulate areas of heavy precipitation accurately with poor simulation during the initial stages of the systems. The UM provided a more realistic-looking closed geopotential height and rainfall fields for systems which are coupled with a cold front at the surface. Application of the knowledge about the evolution in the characteristics of COL events from this study can improve the operational forecasting of these weather systems over the country.Item Open Access Effects of climate variability on citrus production and rural livelihoods in Mopani District Municipality, South Africa(2022-07-15) Tshitavhe, Tanganedzani; Chikoore, H.; Kori, E.Climate variability has always had an impact on citrus production in South Africa. Climate models have projected increases in temperature and changes in rainfall patterns. These changes are likely to present a risk to farmers and rural individuals who depend on citrus production for their livelihoods at district level. Rural livelihoods are subjected to multiple climatic shocks and stresses that can increase household vulnerability. It is important to assess and understand the negative impacts of climate variability on citrus production and rural livelihoods to provide the best adaptive measures and strategies. This study, therefore, analyses the influence of climate variability on citrus production and rural livelihoods in Mopani District Municipality. To achieve this aim, quantitative and qualitative research methodologies were employed. Climate data from 1987 to 2017 was obtained from the South African Weather Service. Citrus production data, citrus farm net revenue, and citrus market chain statistics for the study period were obtained from citrus farms and government records such as the Department of Agriculture and Rural Development. Mann-Kendall trend analysis was applied to analyse temperature, rainfall, and citrus production trends. Standardized Precipitation Index (SPI) was applied to analyse precipitation anomalies in the study area. Multiple linear regression analysis was utilised to establish the relationship between climate variability and citrus production. Whilst simple linear regression was used to determine the influence of citrus production on farmers’ income and rural livelihood by establishing the relationship between citrus production and farm net revenue. The relationships were consistent at a 95% confidence level showing a ±5% margin of error (confidence interval). Semi-structured questionnaires were administered to citrus farmers, citrus workers, and citrus vendors to elicit data on climate variability impacts, perceptions, and adaptation strategies to deal with climatic shocks and stresses. Statistical Package for Social Science (SPSS version 22) was used for its bivariate and univariate analysis capabilities. The findings show a variable significant relationship between climate variability and citrus production. Results indicated a very strong positive significant relationship between citrus production and farm net revenue. The study shows a significant relationship between livelihood variables and climate variability variables. Furthermore, the perceptions of citrus farmers, citrus workers, and citrus vendors correspond well with climatic trends that indicated flood and drought cycles. Due to the considerable climate variability over the study period, citrus farmers, citrus workers, and citrus vendors have adopted various coping strategies at on-farm and off-farm levels. The study concludes that climate variability and citrus production influence farmers' income and rural livelihoods. The study recommends a framework that includes water conservation, investment in irrigation systems, and other climate-smart agricultural technologies that would merge modern scientific knowledge and indigenous knowledge systems to maximise citrus productivity and improve rural livelihoods.Item Open Access Integrating indigenous and scientific knowledge in community-based early warning system development for climate-related malaria risk reduction in Mopani District of South Africa(2020) Ramutsa, Brenda Nyeverwai; Nethengwe, N. S.; Chikoore, H.Malaria is a climate-change concatenated biological hazard that may, like any other natural hazard, can lead to a disaster if there is a failure in handling emergencies or risks. A holistic solution for malaria mitigation can be provided when indigenous knowledge is complemented with scientific knowledge. Malaria remains a challenge in South Africa and Limpopo province is the highest burdened malaria-endemic region. Specifically, Vhembe District is the highest burdened followed by Mopani District (Raman et al., 2016). This research sought to mitigate malaria transmissions in Mopani District through the integration of indigenous and scientific knowledge. The study was carried out in Mopani District of South Africa and 4 municipalities were involved. These are Ba-Phalaborwa, Greater Tzaneen, Greater Letaba, and Maruleng. A pragmatism philosophy was adopted hence the study took a mixed approach (sequential multiphase design). Data was collected from 381 selected participants through in-depth interviews, a survey and a focus group discussion. Participants for the in-depth interviews were obtained through snowballing and selected randomly for the survey, while for the focus group discussion purposive sampling was used. The study applied constructivist grounded theory to analyze qualitative data and to generate theory. Statistical Package for Social Sciences version 23.0 was used for quantitative data. Based on empirical findings, it was concluded that temperature and rainfall among other various factors exacerbate malaria transmission in the study area. Results of the study also show that people in Mopani District predict the malaria season onset by forecasting rainfall using various indigenous knowledge based indicators. The rainfall indicators mentioned by participants in the study were used in the developed early warning system. An Early warning system is an essential tool that builds the capacities of communities so that they can reduce their vulnerability to hazards or disasters. In the design of the system, Apache Cordova, JDK 1.8, Node JS, and XAMPP software were used. The study recommends malaria management and control key stakeholders to adopt the developed early warning system as a further mitigation strategy to the problem of malaria transmission in Mopani District.Item Open Access Meteorological influences on malaria transmission in Limpopo Province, South Africa(2019-09-20) Ngwenya, Sandile Blessing; Nethengwe, N. S.; Chikoore, H.; Bopape, M. M.Semi-arid regions of Africa are prone to epidemics of malaria. Epidemic malaria occurs along the geographical margins of endemic regions, when the equilibrium between the human, parasite and mosquito vector populations are occasionally disturbed by changes in one or more meteorological factors and a sharp but temporary increase in disease incidence results. Monthly rainfall and temperature data from the South African Weather Service and malaria incidence data from Department of Health were used to determine the influence of meteorological variables on malaria transmission in Limpopo from 1998-2014. Meteorological influences on malaria transmission were analyzed using time series analysis techniques. Climate suitability for malaria transmission was determined using MARA distribution model. There are three distinct modes of rainfall variability over Limpopo which can be associated with land falling tropical cyclones, cloud bands and intensity of the Botswana upper high. ENSO and ENSO-Modoki explains about 58% of this variability. Malaria epidemics were identified using a standardized index, where cases greater than two standard deviations from the mean are identified as epidemics. Significant positive correlations between meteorological variables and monthly malaria incidence is observed at least one month lag time, except for rainfall which shows positive correlation at three months lag time. Malaria transmission appears to be strongly influenced by minimum temperature and relative humidity (R = 0.52, p<0.001). A SARIMA (2, 1, 2) (1, 0, 0)12 model fitted with only malaria cases has prediction performance of about 53%. Warm SSTs of the SWIO and Benguela Niño region west of Angola are the dominant predictors of malaria epidemics in Limpopo in the absence of La Niña. Warm SSTs over the equatorial Atlantic and Benguela Niño region results in the relaxation of the St. Helena high thus shifting the rainy weather to south-east Africa. La Niña have been linked with increased malaria cases in south-east Africa. During El Niño when rain bearing systems have migrated east of Madagascar ridging of the St. Helena high may produce conducive conditions for malaria transmission. Anomalously warmer and moist winters preceding the malaria transmission season are likely to allow for high mosquito survival and the availability of the breeding sites thus high population in the beginning of the transmission season hence resulting in increased epidemics.Item Open Access Simulating South African Climate with a Super parameterized Community Atmosphere Model (SP-CAM)(2019) Dlamini, Nohlahla; ; Chikoore, H.; Bopape, M. M.; Nethengwe, N. S.The process of cloud formation and distribution in the atmospheric circulation system is very important yet not easy to comprehend and forecast. Clouds affect the climate system by controlling the amount of solar radiation, precipitation and other climatic variables. Parameterised induced General Circulation Model (GCMs) are unable to represent clouds and aerosol particles explicitly and their influence on the climate and are thought to be responsible for most of the uncertainty in climate predictions. Therefore, the aim of the study is to investigate the climate of South Africa as simulated by Super Parameterised Community Atmosphere Model (SPCAM) for the period of 1987-2016. Community Atmosphere Model (CAM) and SPCAM datasets used in the study were obtained from Colorado State University (CSU), whilst dynamic and thermodynamic fields were obtained from the NCEP reanalysis ll. The simulations were compared against rainfall and temperature observations obtained from the South African Weather Service (SAWS) database. The accuracy of the model output from CAM and SPCAM was tested in simulating rainfall and temperature at seasonal timescales using the Root Mean Square Error (RMSE). It was found that CAM overestimates rainfall over the interior of the subcontinent during December - February (DJF) season whilst SPCAM showed a high performance in depicting summer rainfall particularly in the central and eastern parts of South Africa. During June – August (JJA), both configurations (CAM and SPCAM) had a dry bias with simulating winter rainfall over the south Western Cape region in cases of little rainfall in the observations. CAM was also found to underestimate temperatures during DJF with SPCAM results closer to the reanalysis. The study further analyzed inter-annual variability of rainfall and temperature for different homogenous regions across the whole of South Africa using both configurations. It was found that SPCAM had a higher skill than CAM in simulating inter-annual variability of rainfall and temperature over the summer rainfall regions of South Africa for the period of 1987 to 2016. SPCAM also showed reasonable skill simulating (mean sea level pressure, geopotential height, omega etc) in contrast to the standard CAM for all seasons at the low and middle levels (850 hPa and 500 hPa). The study also focused on major El Niño Southern Oscillation (ENSO) events and found that SPCAM tended to compare better in general with the observations. Although both versions of the model still feature substantial biases in simulating South African climate variables (rainfall, temperature, etc), the magnitude of the biases are generally smaller in the super parameterized CAM than the default CAM, suggesting that the implementation of the super parameterization in CAM improves the model performance and therefore seasonal climate prediction.Item Open Access Vegetation change in response to climate extremes in Limpopo Province, South Africa(2020) Thavhanyedza, Humbulani; Nethengwe, N. S.; Chikoore, H.An increase in the level of greenhouse gases (GHGs) in the atmosphere, combined with climatic variability, is likely to bring about extreme climate events, such as tropical storms, heat waves, floods, and droughts. In addition, a small change in the variance and mean of climate parameters might result in a strong shift in the intensity and frequency of extreme climatic events. The climatic conditions over southern Africa are highly variable and, and as such, southern Africa region becomes highly vulnerable to changes in extreme climatic conditions. Changes in climate extremes exert much pressure on the vegetation cover, thereby threatening the ecological stability of an area. This study analysed changes in vegetation cover and responses to extreme climate and weather events in the Limpopo Province, South Africa. The specific objectives of the study are to determine the nature of climate extremes from 2000 to 2017; to examine vegetation change in the study area, and analyse vegetation responses and sensitivity to climate extremes. In order to achieve these objectives, various quantitative techniques were employed. Extreme climate characterisation was done using GPCP precipitation, maximum temperature, and standardized precipitation evapotranspiration index (SPEI), whilst MODIS satellite was used for land use/ land cover change and vegetation response. To analyse vegetation response to extreme weather events, MODIS vegetation indices i.e. NDVI, EVI, and LSWI were used to analyse vegetation conditions and sensitivity in relation to extreme climatic events. Using the interannual rainfall variability and anomalies, seasons with abnormal rainfall patterns were chosen and analysed. Season with anomalous heavy rainfall occurred in 1999/00 and 2005/06 over Limpopo Province, whilst the anomalous low rainfall occurred during the summer season (DJF) in 2002/03 and 2015/16. Over the region, heavy rainfall was observed to be negatively associated with maximum temperatures (r = -0.66). Severely dry or drought conditions were associated with very poor vegetation conditions due to excessive temperatures and increased evaporation rate resulting in land surface water loss (LSWI < 0) and vegetation stress, meanwhile, heavy rainfall had a strong association with good vegetation conditions. However, vegetation tends to lag by one month from heavy rainfall. Using the Pearson moment correlation coefficient, the vegetation conditions (NDVI and EVI) were correlated with Land Surface Water Index (LSWI) and climate variables i.e. GPCP precipitation and maximum temperatures, with correlation coefficient of LSWI against GPCP, Tmax, NDVI, and EVI (r = 0.83, r = -0.78, r = 0.73, r = 0.87 respectively), NDVI and EVI against GPCP precipitation and Tmax (r = 0.31, r = -0.70, r = 0.53, and r = -0.73 respectively). The study shows a link between extreme weather events i.e. drought/ floods conditions and vegetation conditions. The findings of the study could serve as a scientific baseline data for better understanding the effects of drought and floods in relation to vegetation for sustainable management of the ecosystems. With enough details or information about the vegetation, it can be possible to generate policies and launch programs to save ecosystems and the environment. Foresters, biodiversity officers, and policymakers could also find the information important in the formulation of policies, and programs that require development planning.Item Open Access Vulnerability and Adaptation to Drought Hazards in Mopani District Municipality, South Africa: Towards Disaster Risk Reduction(2019-09-20) Nembilwi, Ndamulelo; Chikoore, H.; Korl, E.South Africa was badly affected by the recent 2015/16 severe drought. Water levels in dams declined drastically resulting in decimation of livestock herds and widespread crop failure. Mopani District Municipality is comprised of many agricultural activities that contribute to the economy and social development of the country. The study evaluated the nature of the drought hazard - its impacts, vulnerability and adaptation strategies employed by rural communities of Mopani District. The study used a mixed method approach with both quantitative and qualitative datasets. The district was divided into two distinct climatic areas, the eastern lowveld which includes the Greater-Giyani, Ba-Phalaborwa and Maruleng Local Municipalities and the western highveld which includes Greater- Tzaneen and Greater- Letaba Local Municipalities. Questionnaires were administered among community members whilst key informant interviews were conducted among relevant government and municipal officials. Anomalies in long term climate data were analysed to determine the frequency and intensity of drought in the district. Drought characterisation was done using a Standardised Precipitation and Evapotranspiration Index whilst vegetation anomaly maps, maize yields and dam level data were used to analyse the impacts of drought across the district. Levels of vulnerability to drought were determined using the Household Vulnerability Index. Spatially distinct patterns of drought conditions across the district were remarkable with wet conditions on the western highveld along the escarpment and harsh dry conditions towards the eastern lowveld. It was found that nearly half the time there is some form of drought or another in the district which may be linked to the remote El Nino phenomenon. Community vulnerabilities have a direct impact on human welfare and different strategies are employed to adapt to drought hazards both at community and district levels. The study showed a link between drought hazard extent and vulnerability. Community members are adapting using conservation agriculture, selling fire-wood, accessing boreholes and rearing chickens, amongst other means to survive in these harsh climatic conditions. Local government intervention strategies include supply of seeds and fertilisers, selling fodder at a cheaper price and supplying water using trucks. The findings of this study contribute to disaster risk reduction efforts in Mopani District MunicipalityItem Open Access Water security in rural Limpopo in a changing climate: A study of the Greater-Giyani Local Municipality, South Africa(2019) Mmbadi, Elelwani; Chikoore, H.; Okaka, F.; Netshisaulu, K. H.Many rural communities of South Africa are living without adequate water supplies mainly due to historical lack of infrastructure and effective water reticulation systems. Day to day challenges of accessing water from distant boreholes and rivers are a reality particularly for women and children in rural Limpopo. This study investigates the nature and extent of water supply problems and how communities are living without adequate water in three rural communities of Greater-Giyani Local Municipality in South Africa. The study area lies in a semi-arid region which regularly experiences climate extremes such as droughts and floods which can reduce the ability of the municipality to supply water. Primary data was collected through questionnaires, key informant interviews and field observations while population, climate and hydrological data are also analyzed. A mixed methods research design was employed using qualitative methods such as content analysis whilst quantitative methods were dominated by time series analysis techniques and online interactive climate platforms such as the Climate Engine. It was found that households, schools and clinics in the study area rely mainly on boreholes for water supply but sometimes rivers supply those living nearby. An incomplete and poor water reticulation system coupled with erratic and shortening summer rainfall seasons are some of the major causes of water shortages in the study area. In order to cope with inadequate water, community members and public institutions in the study area have drilled boreholes and the sustainability of groundwater in the area is not well established. During summer, most households and institutions practise rainwater harvesting while a few resort to purchasing water from vendors. Despite these challenges which are not well documented, it was concluded that most of the rural poor households and institutions in the study area are well adapted to cope with water scarcity in the short term, while being vulnerable in the long term due to population growth and climate change. The study recommends the need for government and municipalities to invest in water reticulation systems in the long term whilst providing water to affected rural communities through water tankers, drilling more boreholes and maintenance of existing ones. Lessons learnt from this study may be useful to other municipalities across South Africa that are grappling with challenges of water access and supply.