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An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season
Includes bibliographical references (leaves 113-124).
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| Other Authors: | |
| Format: | Thesis |
| Language: | English |
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Department of Environmental and Geographical Science
2014
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| _version_ | 1867613305728663553 |
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| access_status_str | Open Access |
| author | Hachigonta, Sepo Promise |
| author2 | Reason, Chris |
| author_browse | Hachigonta, Sepo Promise Reason, Chris |
| author_facet | Reason, Chris Hachigonta, Sepo Promise |
| author_sort | Hachigonta, Sepo Promise |
| collection | Thesis |
| description | Includes bibliographical references (leaves 113-124). |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/4857 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:34:00.978Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2014 |
| publishDateRange | 2014 |
| publishDateSort | 2014 |
| publisher | Department of Environmental and Geographical Science |
| publisherStr | Department of Environmental and Geographical Science |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/4857 An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season Hachigonta, Sepo Promise Reason, Chris Environmental and Geographical Science Includes bibliographical references (leaves 113-124). Recurring dry/wet spells and decreased agricultural productivity during the last decade in the southern and northern parts of Zambia point to the need for a clearer understanding of these events, their frequencies and their possible connection to large-scale climate modes. Apart from having a high number of dry spells during the December-February (DJF) core rainy season, the southern part of Zambia is frequently subjected to late onset dates and short durations of the rainy season whereas the northern and northwestern region frequently have high numbers of wet spells which in most cases lead to flooding. Using CMAP and station data, rainfall variability in terms of dry spells, wet spells, onset and cessation dates of the Zambian rainy season and the associated circulation anomalies are investigated. The study also looks at relationship between these extreme events with Nin03.4 SST anomalies. Low level easterly anomalies over Zambia are enhanced during seasons with high dry spells. As a result, there is reduced moisture penetration into Zambia from the Angola low and reduced low level moisture convergence over the country and hence increased dry spells. During the seasons with high numbers of wet spells, there are low level westerly anomalies over southern Angola and western Zambia implying a strong moisture influx from the tropical South East Atlantic and increased convergence over Zambia. It was shown that El Nino (La Nina) events typically result in above (below) average DJF dry spell frequency in Zambia. Early onset dates over the northern parts of Zambia were observed to occur during strong El Nino seasons and the strength of the observed relationship with Nin03.4 SSTs seems to be stronger for years during the 1980s than those during the 1990s. Early onset dates tend to occur for years with higher than average dry spell frequency in the following DJF season. This suggests that early onset may be a disadvantage in that it often leads to more dry spells during the subsequent peak growing period of the season. 2014-07-31T08:04:49Z 2014-07-31T08:04:49Z 2005 Master Thesis Masters MSc http://hdl.handle.net/11427/4857 eng application/pdf Department of Environmental and Geographical Science Faculty of Science University of Cape Town |
| spellingShingle | Environmental and Geographical Science Hachigonta, Sepo Promise An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| thesis_degree_str | Master's |
| title | An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| title_full | An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| title_fullStr | An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| title_full_unstemmed | An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| title_short | An investigation into dry and wet spell characteristics over Zambia and into the onset of the rainy season |
| title_sort | investigation into dry and wet spell characteristics over zambia and into the onset of the rainy season |
| topic | Environmental and Geographical Science |
| url | http://hdl.handle.net/11427/4857 |
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