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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

An Impact Assessment of Agro-Ecology on Climate Change Mitigation and Economic Sustainabilty: A Case of Mopani District

Manyanya, Tshilidzi Cloudia 05 1900 (has links)
MENVSC / Department of Geography and Geo-Information Science / See the atttached abstract below
22

Influence of climate change on flood and drought cycles and implications on rainy season characteristics in Luvuvhu River Catchment

Dagada, K. 18 September 2017 (has links)
MESHWR / Department of Hydrology and Water Resources / This study dealt with the influence of climate variability on flood and drought cycles and implications on rainy season characteristics in Luvuvhu River Catchment (LRC) in Limpopo of South Africa. Extreme weather events resulting in hazards such as floods and droughts are becoming more frequent due to climate change. Extreme events affect rainy season characteristics and hence have an influence on water availability and agricultural production. Annual temperature was obtained from Water Research Commission for stations 0723485W, 0766628W and 0766898W from 1950-2013 were used to show/or confirm if there is climate variability in LRC. Daily rainfall data was obtained from SAWS for stations 0766596 9, 0766563 1, 0723485 6 and 0766715 5 were used to detect climate variability and determine the onset, duration and cessation of the rainy season. Streamflow data obtained from the Department of Water and Sanitation for stations A9H004, A9H012, and A9H001 for at least a period of 30 years for each station were used for climate variability detection and determination of flood and drought cycles. Influence of climate variability on floods and droughts and rainy season characteristic were determined in the area of study. Trends were evaluated for temperature, rainfall and streamflow data in the area of study using Mann Kendall (MK) and linear regression (LR) methods. MK and LR detected positive trends for temperature (maximum and minimum) and streamflow stations. MK and LR results of rainfall stations showed increasing trends for stations 0766596 9, and 0766563 1 whereas stations 0723485 6 and 0766715 5 showed decreasing trends. Standardized precipitation index (SPI) was used to determine floods and droughts cycles. SPI results have been classified either as moderately, severely and extremely dry or, moderately, very and extremely wet. This SPI analysis provides more details of dominance of distinctive dry or wet conditions for a rainy season at a particular station. Mean onset of rainfall varied from day 255 to 297, with 0766715 5 showing the earliest onset compared to the rest of the stations. Cessation of rainfall for most of the hydrological years was higher than the mean days of 88, 83 and 86 days in 0766596 9, 0766563 1 and 0723485 6 stations. Mean duration of rainfall varied from 102 to 128, with station 0766715 5 showing shortest duration of rainfall. The results of the study showed that the mean onset, duration and cessation were comparable for all stations except 0766715 5 which had lower values. The study also found that climate variability greatly affects onset, duration and cessation of rainfall during dry years. This led to late onset, early cessation and relatively short duration of the rainfall season. Communities within the catchment must be educated to practice activities such as conservation of indigenous plants, reduce carbon dioxide emissions.
23

Assessing the impacts of climate change and adaptation strategies on smallholder farming in the Vhembe District, South Africa

Kom, Zongho January 2020 (has links)
PhD (Geography) / Department of Geography and Geo- Information Sciences / 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. / NRF

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