Full Text Available
Note: Clicking the button above will open the full text document at the original institutional repository in a new window.
Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008
Dissertation (MSc)--University of Pretoria, 2016.
Saved in:
| Other Authors: | |
|---|---|
| Format: | Thesis |
| Language: | English |
| Published: |
University of Pretoria
2016
|
| Subjects: | |
| Tags: |
No Tags, Be the first to tag this record!
|
| _version_ | 1867613498973880320 |
|---|---|
| access_status_str | Open Access |
| author2 | Sumner, P.D. (Paul) |
| author_browse | Sumner, P.D. (Paul) |
| author_facet | Sumner, P.D. (Paul) |
| collection | Thesis |
| dc_rights_str_mv | © 2016 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MSc)--University of Pretoria, 2016. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/57245 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:37:06.816Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/57245 Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 Sumner, P.D. (Paul) alexiahaupt@hotmail.com Nel, Werner Hauptfleisch, Alexia UCTD Dissertation (MSc)--University of Pretoria, 2016. Topographic complexity and island-scale weather systems on Mauritius result in highly variable spatial and temporal rainfall distribution. This, in combination with the intense agricultural activity, predisposes the island to a high risk of rainfall induced soil erosion. Thus it is important to investigate intra-storm attributes of erosive events, as these events are most likely to cause significant degradation and reduced productivity of the soils on the island. Intra-storm analysis allows for the identification of critical intensity peaks in rainfall events that potentially impact the severity of erosion. Six Mauritius Meteorological Services automated weather stations (measuring rainfall at 6 minute intervals) located on the west coast and in the interior providing rainfall data over a 5 year period (2004 to 2008), enabled the first detailed intra-storm analysis on the island to occur. For the purpose of this study, erosive events were defined as a total rainfall exceeding 12.5 mm and a maximum 6-minute intensity exceeding 30 mm/h. The analysis found that there were 444 erosive events during the study period which are responsible for generating the bulk of the rainfall erosivity. A total of 120 erosive events (the top twenty erosive events for each weather station with the highest total kinetic energy generated ) were analysed to investigate the intra-storm distribution of rainfall depth, extreme rainfall intensity and cumulative kinetic energy. General climatological characteristics and weather circulation patterns were also determined. Erosive events were found to vary both in rainfall depth and duration, but all the stations indicate a clear exponential distribution of cumulative kinetic energy generated over the duration of the rainfall events. Extreme rainfall intensities display noticeable temporal differences between the stations in different climatic regions on the island. All the stations received more than 80% of the potential kinetic energy content generated by the storms within the first 2500 minutes of the storm, as well as 80% of the cumulative rainfall available. Investigating the distribution of the extreme rainfall intensity (above 30 mm/h) as a function of storm duration, reveals that 57% of the erosive events generate peak intensities within the first half of the storm duration. Erosive events were not restricted to tropical cyclones, but include other weather systems such as cold fronts. The elevated centre of Mauritius, which is responsible for a high rainfall gradient across the island, influenced the spatial and temporal variability in erosive events. Results indicate that the intra-storm attributes of rainfall events are strongly dependent on the geographic features within the immediate surroundings of the weather stations, and distance between weather stations did not always lead to predictable differences in intra-storm attributes. Although the erosive events on Mauritius share common characteristics, the within-storm distribution shows that no two events are similar and no two stations show comparable event pattern distributions. However, the intra-storm analysis of the erosive events suggests that, despite the spatial differentiation in the structure and nature of the erosive rainfall generalisations can be made regarding the erosion experienced in the coastal and interior regions of the island. The inclusion of more automated weather stations is warranted as this will provide a better representation of rainfall characteristics across the remaining regions of the island. Further research is necessary to determine the relationship between event structure and synoptic conditions experienced on the island. tm2016 Geography, Geoinformatics and Meteorology MSc Unrestricted 2016-10-14T07:32:51Z 2016-10-14T07:32:51Z 2016-09-01 2016 Dissertation Hauptfleisch, A 2016, Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008, MSc Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/57245> S2016 http://hdl.handle.net/2263/57245 en © 2016 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title | Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title_full | Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title_fullStr | Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title_full_unstemmed | Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title_short | Intra-storm attributes and climatology of extreme erosive events on Mauritius 2004 - 2008 |
| title_sort | intra storm attributes and climatology of extreme erosive events on mauritius 2004 2008 |
| topic | UCTD |
| url | http://hdl.handle.net/2263/57245 |