ZIMP
Rainfall data
- Buy a rain gauge and
- Start recording the daily figures
- You can learn plenty from the exercise
- ..... and you will be contributing to the collective knowledge of the Zandvlei area.
If you measure rainfall data in the area, please let us have your records.
Contact Gavin Lawson for more info and questions you may have about setting up a rain gauge at home.
The annual total rainfall, averaged from the measured sites = 64.3 mm
General Notes.
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Rainfall data are measured daily using a standard funnel shaped rain gauge that can be purchased at any hardware store in Cape Town.
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The approximately 35cm long funnel is 12.8cm wide at the top and is graduated in 1mm units for the first 20mm, in units of 2mm up to 50mm and in units of 5mm thereafter to 100mm.
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The data may not indicate the current months rainfall, but will be updated regularly, and as close to the information being made available.
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Prof Timm Hoffman at the Spring Festival 2005, ZIMP - 5 year Reportback, highlighted that with the known rainfall data, a 50% accuracy figure can be calculated of the salinity levels in the Zandvlei estuary water body. This re-emphasises why it is so important to collect this data.
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As of Sept 2005 new graphs illustrating trends and emerging rainfall patterns will help to present clearer information we now have at our finger tips.
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Daily rainfall measurements are taken at 8 sites around the Zandvlei main water body at present.
1.
Mountain side (west)
of the main body of the vlei. From May 1999 to July 2002 this was at
Barbourne Rd,
Zandvlei and thereafter at Craig Road, Lakeside (a few hundred metres
north).
The data are collected by Timm Hoffman.
Jan Feb March April May June July Aug Sept Oct Nov Dec
2. Marina da Gama side (east) of the main body of the vlei. These data have been collected by
Peter Gray
at Park Island Way, Marina da Gama since April 1999 .
Jan Feb March April May June July Aug Sept Oct Nov Dec
Annual Rainfall for Park Island
3. Marina da
Gama side (north east) of the main body of the vlei. These data
have been collected by
Lucia Rodrigues, Texel Close, Marina da Gama since January 2006.
4. Marina da Gama side
(north east) of the main body of the vlei. These data have been
collected by
Gerrard Wigram, Michel Way, Marina da Gama since May 2003.
Jan Feb March April May June July Aug Sept Oct Nov Dec
5. Marina da Gama side
(south east) of the main body of the vlei. These data have been
collected by
Rob Hawke, The Row, Marina da Gama since June 1994.
Jan Feb March April May June July Aug Sept Oct Nov Dec
6. Marina da Gama side
(south east) of the main body of the vlei. These data have been
collected by
Bert Bron, Axminster Road, Marine Estate since June 2008.
Jan Feb March April May June July Aug Sept Oct Nov Dec
7. Mountain side (west) of the main body of the vlei. These data have been
collected by
John Fowkes, Spinnaker Road, Lakeside since January 2010.
Jan Feb March April May June July Aug Sept Oct Nov Dec
8. Marina da Gama side (south east) of the main body of the vlei. These data have been collected by
Tim Everett at
Battleridge
Road, Marina da Gama since November 2012.
End of April 2013 - This is the combined rainfall measured at the sites.
End of December 2012 - This is the
combined rainfall of all the measured sites,
with the annual
total rainfall, averaged from the
measured sites = 782 mm.
End of December 2012 - This is the combined rainfall measured at the sites.
End of December 2011 - This is the
combined rainfall of all the measured sites,
with the annual
total rainfall, averaged from the
measured sites = 575
mm.
End of December 2011 - This is the combined rainfall measured at the sites.
End of December 2010 - This is the
combined rainfall of all the measured sites,
with the annual
total rainfall, averaged from the
measured sites = 590.6
mm.
End of December 2010 - This is the combined rainfall measured at the sites.
End of December 2009 - This is the
combined rainfall of all the measured sites,
with the annual
total rainfall, averaged from the
measured sites = 538.4mm
End of December 2009 - This is the combined rainfall measured at the sites.
End of December 2008 - This is the
combined rainfall of all the measured sites, with the
monthly
average and the annual average.
End of December 2008 - This is the
combined rainfall of all the measured sites, with the
monthly
average and the annual average.
End of December 2007 - Annual accumulated total rainfall from the measured sites = 870.3mm.
End of December 2007 - This is the
combined rainfall of all the measured sites, with the
monthly
average and the annual average.
End of December 2006 - This is the
combined rainfall of all the measured sites, with the
monthly
average and the annual average.
End of December 2005 - This is the
combined rainfall of all the measured sites, with the
monthly
average and the annual average.
This graph illustrates the averaged west and east of the Zandvlei rainfall readings, established by Timm Hoffman and Peter Gray over this time scale.
This is one of the challenging pieces of information, from the "5 year report back" presentation by Timm Hoffman at the Zandvlei Trust - Spring Festival in Sept 2005.
Historical Rainfall Data
General rainfall measured from 1841 at
Observatory in Cape Town.
The red line through the graph is the
- 10 year running average.
This graph indicates recent droughts in
the 1990's and severe one in the 1930's during the Great Depression. The
graph is from SA Weather Service, and an article in the City of Cape Towns
Contact Newsletter - No 18 April 2005.
