-----In 2004 we bought a falling-down house and 30 acres. This blog documents our progress-----

Sunday, January 28, 2007

Cottage verandah quote

We're picking up again on plans for the old house, aka the 'cottage'.

To help give us more clarity in the decision over what type of verandah, and how big, to install Dad roughed out a quote for doing a 3m area which I then put into a spreadsheet.

Basically, for the 3m area it comes out to near enough to $1800 if you include all the fittings like fancy fretwork and railing; or $1100 without.

Now we have a proper understanding of the materials cost, we've decided to make a little cutback on the verandah area. Now, except for a landing type area near the backdoor and laundry, we're not going to put verandah on the back side of the
house. Instead it will be L shaped, running along the side facing the dam, and partially across the front.
old house revised verandah

By our calculations, using the scale on the plans, this smaller area is 17 square metres. So, as a rough estimate, the cost would be (17 divided by 3 =) 5.67 times the cost of the 3m section. So, materials cost around $11000 in total, but dropping to around $7000 if we delayed on investing in frieze, fancy balustrade, etc.

This is still a sizeable chunk, but it'll be a worthwhile I think. I don't think we can reasonably cut out any more verandah area without it looking stupid or feeling cramped. I imagine we'll live on that verandah a lot of the time. :-)

Sunday, January 21, 2007

Understanding impact of El Nino

It's often mentioned that 'El Nino' is what causes droughts in Australia and that it's because we're in an El Nino year that it's been so dry. So I thought I'd find out a bit more about El Nino and see if I could find a connection between El Nino and the Maryborough historical rainfall.

Here's what I learned (I wish I'd paid more attention in school now!)

For Australia, the key El Nino metric is the SOI = Southern Oscillation Index. As the bureau of meteorology says:

"The SOI is calculated using the pressure difference between
Tahiti and Darwin. The SOI gives an indication of the stage of
El Niño or La Niña events in the Pacific Ocean. The accuracy of
the SOI in determining the three-month outlook for rain around
Australia is highest between midwinter and midsummer in eastern
Australia. A strongly negative SOI (below -10) is characteristic
of El Niño, which is often associated with below average rainfall
over eastern Australia... A strongly positive SOI (above +10) is
characteristic of La Niña, which is often associated with above
average rainfall over parts of eastern Australia..."

Weatherzone's site expands on this a little:

"A strongly and consistently positive SOI pattern (e.g.
consistently above about +6 over a two month period) is
related to a high probability of above the long-term average
(median) rainfall for many areas of Australia, especially
areas of eastern Australia... Conversely, a 'deep' and
consistently negative SOI pattern (less than about minus 6
over a two month period, with little change over that period)
is related to a high probability of below median rainfall ...
However, it is important to remember that the pattern of
relationship between SOI and rainfall can vary depending on
the particular season and region. Additionally, the change
in SOI over a specified period can be as important in
understanding relationships between SOI and rainfall as is
the absolute value in SOI".

Finally, some more from the bureau of meteorology:

"El Nino events occur about every four to seven years
and typically last for around 12 to 18 months... Each
El Niño event is unique in terms in terms of its strength
(as measured by numbers such as the Southern Oscillation
Index or changes in ocean temperature), as well as its
impact in terms of altered rainfall patterns... For example,
the 1982/83 and 1997/98 events were both very strong as
measured by changes in the Pacific, yet their impacts in
Australia were completely different. Eastern and southern
Australia was gripped by severe drought in 1982/83, but
in 1997 average to above average falls were common in May,
and a dry spell over winter was broken by widespread and
heavy rains in September. Severe drought can sometimes
result from a relatively weak event, as occurred in 2002/03.
Furthermore, changes in the Indian Ocean can enhance the
general tendency for reduced rainfall in eastern Australia,
or mask it by contributing to timely falls".

OK. What I take from this is that the SOI is only one factor to consider so not a fully reliable indicator... but useful to some extent given we're in Eastern Australia.

So I decided to try and see if I could spot any correlation between monthly rainfall and monthly SOI for Maryborough.

Here's a graph showing the monthly SOI's. (Click on it if you want to enlarge). The data came from here.

el nino monthly SOI

A rough scan of this suggests that the most pronounced periods of El Nino and La Nina were as follows. The years in bold are those where the effect was possibly particularly strong, because there was such a prolonged and high spiked period:

El Nino (relating to dryer times):

  • 1878
  • 1881-1882
  • 1885
  • 1888
  • 1896-1897
  • 1905
  • 1911-1912
  • 1914-1915
  • 1919
  • 1923
  • 1925-1926
  • 1934
  • 1940-1941
  • 1953
  • 1957-1958
  • 1961
  • 1965-1966
  • 1969
  • 1972
  • 1977
  • 1982
  • 1987
  • 1991-1994
  • 1997
  • 2002
  • 2005

La Nina (relating to wetter times):

  • 1879-1880
  • 1886
  • 1889-1890
  • 1892-1893
  • 1898
  • 1903-1904
  • 1906
  • 1908
  • 1910
  • 1916-1917
  • 1921
  • 1924
  • 1928
  • 1931
  • 1938-1939
  • 1942-1943
  • 1945
  • 1950
  • 1954-1956
  • 1960
  • 1962
  • 1964
  • 1968
  • 1971
  • 1973-1975
  • 1981
  • 1988-89
  • 1996
  • 1999-2000

Here's what it looks like plotting each of those years against the historical Maryborough rainfall.

El Nino:
rainfall and elnino

La Nina:
rainfall and la nina

Overall, there's some correlation but it's not perfect. There are a few extreme anomalies that I don't understand, but maybe it's to do with the timing of the high SOI's (it's more pronounced in some seasons). Maybe for another iteration I can look at the seasonal factors in more detail, but I'm a bit el-nino'ed out for the moment! It's curious though.

historical monthly rainfall for Maryborough

The kind people at the bureau of meteorology in Australia have sent me even more historical data about Maryborough's weather... thank you thank you thank you. :-)

The most important variable for me is the rainfall. Here's a chart showing the rainfall for each year that they've kept records. Every bar represents a year, and is made up of the rainfall by month, in order from January at the bottom to Dec at the top. The shading represents the season: red = summer, orange = autumn, blue = winter, green = spring.

historical maryborough rainfall

I'm still surprised about the amount of rainfall that falls in summer.

Overall, to be safe it seems we should count on getting around 400mm per year, which will be the case for 70-80% of years. Other years we'll get more which will offset against years where we get less. Even in the worst years, there's still some rainfall, around 250-300mm, and last year counted as one of them. (Ignore the year 1899, it wasn't really that low, but the data is missing for 6 months).

Wednesday, January 17, 2007

Talbot is booming, according to Weekly Times

Today my Mum emailed me an article which appeared in The Weekly Times (a big country newspaper in Australia) on January 3rd 2007.

It seems Dave and I aren't alone in stumbling upon Talbot and its environs as a place to migrate to when we make our downshifting escape. Which is brilliant news, as it means we won't be the odd ones out for having lived overseas. :-)

As the article says... "What is it about this little town, perched on the edge of hard, old gold country that pulls savvy business types and human curios from cities?"

Speaking still as a part-outsider I reckon it's a combination of things... it's close enough to Melbourne you can get there if you need. It's got lovely old buildings, walking down the main street on our first visit it felt like it had just been put gently to sleep 100 years ago and was just waiting to be brought back to life. And there's an underlying buzz and friendliness to the place that gets more every time I visit.

The article says that a vintage clothing shop has opened there now, and there's plans for an art gallery as well as a permanent museum dedicated to the history of communications - from aboriginal days right through to mobile phones. (how ironic considering what I do). Maybe I can get involved, donate some time to helping them with their 'what's coming in the future' exhibit if they have one. It would be nice to be able to start contributing something to the town. Hmmm.

Click on the pictures to read.

article about Talbot PART 1

article about Talbot PART 2

article about Talbot PART 3

Friday, January 12, 2007

Historical Maryborough weather

After I did the 2006 weather post, I contacted the local bureau of meteorology to see if they had any historical information. A few days later I got a friendly email from Tim Forster, their Victorian information officer, who sent me some summary sheets with information about averages and weather extremes for Maryborough.

Here and here are the files he sent me, and below are some summary charts I put together using the information (although there's a lot more in the files than what I used). Thanks so much Tim. :-)

This first chart shows the average monthly rainfall per month for Maryborough. The lighter green bars are the average based on the 100+ years they've kept records for. The darker green bars are what happened in 2006. It vividly shows why there's a drought. Even though some months, like July, there was tons of rain, about a third more than the average, in every other month it was less. And for many months less than half the average. Wow. Depressing.

maryborough rainfall

This second chart shows the temperature range. Average max/min temperatures per month, plus the extremes of each. Click to view the chart in detail and see the legend.

maryborough temperatures