Quantitative assessment of the proposed wave energy demonstration farm off the coast of Portland, Victoria

The attached report is another that I wrote as part of my studies and which I thought may be of interest.

It is an assessment of the viability of a wave energy farm off the coast of my home town Portland, Victoria, Australia.

The proposed wave energy farm is being developed using buoys which rise and fall with the passing waves. The heaving of the buoy, which consists of a stationary lower section under the water and an upper section moving up and down, in turn drives a mechanical generator.

One of the problems with the viability of wave energy technology is that the current devices tend to have optimum wave height and frequency ranges; the further away conditions are from ideal, the greater the drop in the efficiency of energy production. Ocean conditions are highly variable and difficult to predict.

Fortunately, immediately prior to researching the project Sustainability Victoria had just finished compiling 2 years worth of wave height and frequency data at a location not far from where the project is planned to be installed. The plethora of wave data in the area of the project allowed a reasonably detailed analysis of average wave height and frequency and standard deviations on either side of the average. January and June were selected as months providing an indication of wave conditions in summer and winter conditions and data from those months were analysed to get an idea of the range of conditions that the buoys would encounter.

My conclusion raised concerns about the particular buoys to be used combined with the variability of conditions being able to efficiently convert the energy stored in the passing waves into electrical energy.

Qualitative assessment of wave energy demonstration farm off Portland, Victoria

Sustainable Dairy Farming – Eutrophication and Greenhouse Gas Mitigation

This is my first foray into posting a paper that I originally produced for my studies, something I hinted at doing in a previous post.

This paper was written as part of a subject exploring the human effect on the natural environment.

I chose to explore the prospect of sustainable dairy farming; particularly, the obstacles top sustainability created by nutrient run-off from dairy farms into waterways (eutrophication) and greenhouse gas emissions.

Although focusing on dairy farming, parts of the paper are applicable to other farming activities.

Preconceived ideas as to who will have any interest in this work, I have none. Hopefully, someone will gain some ideas of the scale of these two problems and possible practical solutions, and be able to put the paper to use.

I would be glad to receive any comments.

Cheers.

Sustainable Dairy Farming – Eutrophication and Greenhouse Gas Mitigation

Lies, Damn Lies and Killing Sharks (Part 1)

On 15 January 2014 Greg Hunt, the Commonwealth Environment minister, approved a request by the Western Australian Government to be exempted from the Environment Protection and Biodiversity Act 1999 (Cth) so that it could proceed with plans to set up 72 baited drum lines in order to cull white sharks, tiger sharks and bull sharks greater than 3 metres long. The exemption is required due to the listing of those species being listed as threatened species.

The predominant reasons for granting the exemption were:

1. A statistically significant increase in shark attack strikes in Western Australia in the years 2010 to 2013 compared to population increase;

2. As a result of point 1, people are scared of entering the water and there is anecdotal evidence of tourist businesses suffering financially;

3. The proposed cull will reduce the incidence of shark attacks and will provide useful information to other states in dealing with the same problem;

4. The Western Australian government have implemented measures to reduce the risk of death to other sea life from the exercise; and

5. It is in the national interest (due to points 1 to 3 above) for the cull to be allowed, and therefore within the class of reasons the EPBC Act gives as being the basis for an exemption to be allowed.

1. Statistically significant rise in shark attacks

At the outset, I am not formally trained in statistics and have only learned small sections of statistical analysis in passing. I would be grateful for any comments from those with greater knowledge about my analysis and conclusions.

The assertion made is that, when adjusted for population increase over time, the number of shark attacks has risen by a statistically significant degree. The paper this is based on (here) doesn’t provide the population or shark attack numbers used. However, a comparison between graphs on pages 10 and 11 of that paper (showing frequency of attacks per year and frequency of attacks per year per 100,000 people respectively) don’t show any major distortion. On the basis of this lack of distortion, my analysis will use the non adjusted figure of shark attacks per year, which I have obtained from the Shark Attack File.

However, before doing so, one variable not taken taken into account for which it could be argued must be accounted for in order to properly analyse the data, is any increase in average time spent per person in the ocean. Such a variable could result in an increased number of attack incidents due to the same number of people entering the water, the same number of sharks in the water, but an increase in the chance the two will interact.

Below is my tabling of shark attack data over the past 30 years extracted from the Shark Attack File. The data represents number of people injured per attack. Therefore, there may be incidents where one incident injures two people. Further, I’ve attempted to remove all reports listed as a hoax or reports where a shark has been caught in Australian waters with human parts found in their stomach contents (therefore not necessarily an incident which has occurred in Western Australia), but I cant guarantee that all instances of such data points have been completely removed.

One other point to note is the greater number of reports of minor incidents in the later years of the data. Data in the earlier years appears to be limited to incidents with either very serious or fatal outcomes, while there are greater reports of minor incidents or incidents where no injury is reported in the last decade or so. This may be a common finding in databases reliant on the reporting of events which are gaining increased importance or scrutiny for some particular reason. This skewing of the data can lead to false trends being extracted from it.

YEAR AUSTRALIA WESTERN AUSTRALIA
Incidents Fatalities Incidents Fatalities
2013 18 3 7 2
2012 22 3 7 2
2011 18 5 6 3
2010 16 2 5 2
2009 30 0 5 0
2008 18 2 3 1
2007 18 2 2 0
2006 12 1 2 0
2005 17 2 2 1
2004 16 4 6 1
2003 9 1 3 0
2002 12 3 1 0
2001 13 1 3 0
2000 18 5 2 1
1999 2 1 0 0
1998 4 2 0 0
1997 10 2 3 1
1996 15 1 2 0
1995 7 1 2 1
1994 3 1 1 0
1993 7 3 1 0
1992 6 1 0 0
1991 7 1 2 0
1990 8 1 0 0
1989 12 2 1 0
1988 7 3 1 0
1987 4 2 1 0
1986 5 0 2 0
1985 2 1 0 0
1984 3 1 1 0

Given the assertion about shark attacks being significant above the average in the years 2010 to 2013, I’ve decided to use the chi-squared test to assess the statistical significance of the number of attacks over those 4 years compared to the average of the proceeding 26 years (1.77 incidents per year):

Year Expected Average ( E ) Observed Number ( O ) O – E = D D²/E
2010 1.77 5 3.23 10.4329 5.8942937853
2011 1.77 6 4.23 17.8929 10.1089830508
2012 1.77 7 5.23 27.3529 15.4536158192
2013 1.77 7 5.23 27.3529 15.4536158192
           
      Sum D²/E   46.9105084746
      Degrees of freedom = 3    

A chi-squared value of 46.91 with three degrees of freedom gives an absurdly high, statistically significant p value of much less than 0.05, meaning that the likelihood of the increased number of shark incidents in those years could occur by chance alone is less than 5% (this is the level considered to give high enough confidence for the null hypothesis, such as “shark attack incidents per year remain static, to be rejected). This does not mean that shark incidents are definitely increasing, or that there is some underlying cause for an increase in shark incidents (such as a greater number of sharks in the ocean).

There may well be a better way of analysing this data than the chi-squared test given we are using a yearly data set and the chi-squared value I got being extremely high (and I’m open to suggestions in the comments).

There is a further assertion in the exemption statement that the increase in average attacks from 1995 on-wards is also made. Whether this is correct or not is not my main concern.

My concern with basing public policy on statistical analysis of this data is that the low number of attacks per year means any analysis will be of low statistical power. With such a low average number of attacks per year figure and a sampling of a small number of years to compare to the long term average, small deviations above or below the average can result in a statistically significant, but none-the-less erroneous, conclusion. Similar problems arise in medical trials when small sample sizes can lead to either significant improvements in effectiveness of, say, a specific treatment, not being found to be statistically significant, or, as in this case, statistical significance is found in a sample set which, after a few more years worth of data is collected, could yet be seen to be no more than a ‘blip’ in the data based on chance alone (see here, which I found to be useful in explaining the difficulties in making positive assertions about statistical significance test in large sample sizes and small sample sizes equally, and about drawing conclusions for analysis of single data sets by themselves).

Further, debate continues about the ability reliably draw conclusions based on a statistically significant finding from a single or small number of experiments or trials – how reproducible the result is is a greater determinant of whether the statistics are describing an event or occurrence that is really occurring, as does the debate about whether some tests are actually useful in drawing meaningful conclusions from otherwise good data. See here, here, here for example.

Statistical analysis is an extremely useful tool to study a given hypothesis and be able to draw conclusions as to the probably that an effect shown in the data gathered is due due to chance alone. But these tools are subject to limitations. The presentation of statements about statistical significance give undue legitimacy to policy decisions where the limitations to the analysis are not provided or explained.

2. Effect on people entering the water and on tourism businesses

Statistics are given of the number of holiday makers to Western Australia, how many intend to enter the water and what percentage of the State’s economy comes from tourism. A further generalised assertion that “There is substantial public concern about the safety of water based activities in Western Australia, and anecdotal evidence that the frequency of shark strikes is impacting on businesses in Western Australia”, and this is followed by a report of report of dive business saying that it had had a 90% drop in people wanting to learn to dive.

If the improper use of data and statistics is the failing in attempting to give legitimacy to the assertion that there is problem with shark attack frequency, then the lack of legitimate, grounded, provable evidence of these asserted problems is the failing with this trumping up of the effects of the ‘problem’.

One would be excused for thinking that the application for exemption has been put forward by people have done no more than read the newspapers and searched holiday stats from their own tourism department website to create a narrative it could use to promote the plan.

The real difficulty with realistic concern about increasing shark safety is the ‘zero infinity problem‘ – the chance of it happening to any particular person is so low that it barely warrants concern, but the effect on the victim if it does occur are infinite (in a non-mathematical sense of that term). To, at least in part, base policy decisions with likely deleterious effects on a population of any living thing by playing on heightened concern of something so unlikely to happen, and then in turn superimpose that on financial reasons, must be considered poor leadership.

Conclusion

Reliance on these two factors to support such a move as actively killing threatened species is significantly flawed. Statements about the statistical significance of a problem on minimal data points, followed by generalised statements of the effect of the problem with no proper basis in evidence, cannot pass as being reasonable premises to infer that action must be taken, let alone the mode of action to be taken.

Future Food – A Short story

One website I regularly enjoy reading is Big Think, a site with commentary covering numerous categories of progressive throught, such as in science, politics, ethics and philosophy.

Some time ago, the site held a short story competition, with contestants given a weekend to write a science fiction tale around the subject of ‘future food’. I couldn’t help but give it a go, and here is the final product.

It didn’t win any prizes, but I enjoyed telling the story. I hope you enjoy.

“What does it taste like?”

I cant remember the taste of a real apple. Or a strawberry.

Now that I think about it, there are lots of foods that I cant remember eating. You know, the real ones. The ones grown in the dirt or picked from really big trees.

Mum says that I did get to eat some when I was much smaller. I ask her how old I was when I ate them. She always replies “when you were about 2 or 3 buddy”. I’m 11 and half now.

Whenever I ask Mum about what the real ones taste like and why cant we have them now, she seems a bit sad, gives a little sigh and explains to me that they don’t grow very well now, its too hot for them, and that only people with a lot of money can afford the ones that are left.

I dont really understand what Mum means. The other day at school I secretly used my Google Goggles to see if I could find a better explanation on the internet, but I still dont understand it really. It says something about a tipping point when suddenly the temperature all around us jumped up really quickly. Snow melted in places it hadn’t for millions of years. Lots of animals went extinct. The internet says it happened in 2052. Lots of people, old people like my Nan, died when it happened.

I don’t remember Nan, but Mum says she would be fond of me and all the questions I ask.

The little black machine makes a funny noise when Mum uses it. Woooshhhzappppp! Woooshhhzapppp!

The kitchen benches are too high for me to see what happens when Mum points the machine at the tub and pulls the trigger. I grab the box that it came in down from next to where Mum is getting dinner ready. Food Matter Materialisation Device says the box. “With improved nano-wave particle identification technology – better tasting food for you and your family at every meal”.

Mum grabs another tub of pure matter particles from the cupboard, points the gun-like machine at it and starts pulling the trigger again.

Woooshhhzapppp! Woooshhhzappp!

Our new food gun isn’t as great as Sam’s one. Sam’s my best friend at school. His family live in a big house in Werribee, an inner suburb of Melbourne. Their house is much bigger than ours. I think Sam’s family is rich. Their food gun does everything really quickly, even cooking the food perfectly when it forms.

Dad had to buy a new one the other week because I had broken the last one. Before Mum had finished cleaning up after dinner I grabbed it ran to my room, pretending to shoot things. I accidently pulled the trigger and a piece of my desk started to melt and turn into a zucchini. Mum had just made some zucchinis for dinner and had forgotten to turn it off. The gun didn’t work quite as well after that.

I ask Mum how the gun works. She says she’s not really sure, some very smart scientists built it. She says that all she knows is that the processor shoots energy waves of different lengths into the particles and, depending on what food you ask the processor to make, it pulls out the particles it needs to make that food.

“Why can’t I see the waves Mum? I can see waves at the beach!” Mum explains that the waves are tiny and made of light, and we can’t see them without special goggles.

“And then” says Mum, “the processor assembles all the little bits of matter into the right order so that it makes something that looks like, feels like and tastes like the real thing”.

I hear the front door close and then something heavy falling to the ground. It was Dad.

“Please turn your skateboard off and put it away when you’re finished playing with it!’ He cries out. Whoops! I must have left it hovering next my shoes when I came in.

Rosie, the automatic vaccum cleaner, weaves it’s way around my legs. It’s name isnt’ really Rosie. I named it that after the cleaner robot on The Jetsons. Nan first showed me The Jetsons which she said was from her childhood.

Woooshhhzapppp! Woooshhhzappp!

Mum puts the last bits of the freshly made vegetables in the oven.

“Do they taste as good as the real thing Mum?” I ask.

“Sorry?” Mum asks. The beep of the super-conductor oven setting itself must have drowned out my question.

“The apples. The ones from the tree. Do they taste different to the ones we have now?” I repeated.

Mum kneeled down to me.

“Well buddy, sometimes the real ones looked a bit funny, or had some marks on their skin. Not like the ones we have now. But, when the juice from a real apple runs onto your tongue, it was delicious.”

“Mum!” I begged.

“Yes”.

“You didn’t answer my question! Do the ones we eat taste as good as the real ones?” I asked impatiently.

Mum glanced away, and then turned back to me with a kind of pitied look. The kind of look she gives me when we lose footy by a few points on the weekend but tells me we played really well.

She turned away slowly again.

Her shoulders lowered a bit and her back hunched forward a little. She stared out the window.

I was starting to get impatient with the pause.

“Close enough Buddy. Close enough”.

When it rains, is stores!

As with most of my projects, the search for the right materials without resorting to a visit to the local hardware store results in some time passing before I have everything I need to finish a job.

Recently I was fortunate enough to get together the final bits and pieces (and a helping hand from my sister’s boyfriend) I needed to build a stand for my water tank and connect it to my shed.

I already had the tank and had given it a good rinse, bought second hand from a local. I’d been given a heavy duty plastic pallet which could handle the weight of a full tank of water. And recently I sourced some sleepers from the in-laws property, and some plumbing supplies from the local tip shop.

And alas, the tank is now set up and, after some decent rain, is full and being put to good use.

Image

The tank is set up from the ground so that my watering can can fit under the tap, and to also use gravity to force the water out at a reasonable rate without using a pump. The faucet has a hose connector attached to it to make for easy watering.

The bottom level of the stand is made up with the three sleepers making up the border, with sleepers screwed in inside the box to support the plastic pallet and the tank. The pallet is sitting on top of the enclosed bottom level sleepers, with another three sleepers screwed together to make a border around the pallet to keep it in place.

The resulting stand, I think, looks pretty good and a does a great job!

Plumbing the tank wasn’t as difficult as I thought it might. I pulled the down pipe which connects the gutters to the drain out and using some existing pipe elbows and some found at the tip shop, re-routed the rainwater out from behind the shed, along the side of the shed and into the inlet hole.

All it takes is some good measurements, and the simple understanding that water can’t run up – you can see from the pipe attached along the side of the shed that it is on a slight angle down to ensure that the water runs properly down into the tank.

Finally, I’ve added another pipe to the overflow outlet, which currently runs into a big old pot. The idea will be to find another container for this overflow to run into, possibly an old wheelie bin which can then be adapted with a tap to allow this to be used as a portable water source.

The project wasn’t as daunting as I thought it might be, and would encourage anyone to have a go at it. Even if it isn’t with recycled materials, hardware stores carry equipment to divert rainwater from downpipes so that it can stored and used when needed. And of course it adds a further degree of sustainability to your garden and, in my case, to my growing veggies. Even a small roof area can collect a usable amount of water.

I am blessed by the fact that the gutters installed on the shed roof are constructed in a way to stop leaves and other objects from flowing down into the downpipes. For a normal gutter, it would be best to put some shade cloth or other gauze like material to trap leaves and dirt from running into the tank.

Although I haven’t done it yet, I’m planning on adding something to the pipes to catch smaller object from falling into the tank, with the idea of being able to use the tank water (after testing it properly of course) as drinking water.

I’d love to hear any stories or suggestions from people who have done the same thing, or are planning on doing so.

The tragedy proprietary rights impose on the commons

A recent focus of Australia’s attention was on the actions of three protestors who boarded a Japanese whaling ship to remonstrate with the crew members catching whales in and around designated Australian sanctuaries.

The three activists were then detained on board, requiring intervention by the Australian Government to have them released.

Viewpoints on this issue varied significantly within Australia, even though it can be said with confidence that most people disagree with Japanese whaling in all forms and in all areas.

Conservative chants about the sanctity of the protection of property by law were widespread. The act of trespassing by these three men on the Japanese ship was abhorred as illegal, immoral and detracting, if not completely destroying, the noble intent of their actions.

Greenpeace recently reported an incident with similar connotations, where a Court in Denmark was asked to punish an activist for trespassing on boats found to be illegally fishing in an area barred from such activity to save an endangered endemic species of Cod.

Whilst I am relying solely on the Greenpeace report as to the conduct of the court proceedings, and making an assumption that the law of trespass on private property by persons not acting with a greater authority than an ordinary person, there could be no doubt that the protection of property would see the activist convicted, despite the cause and the positive impact the actions had in enforcing the fishing ban. As far as I am aware, there exists no ‘noble cause’ exception to either the criminal or civil trespass laws.

However, the Danish Court, quite surprisingly and despite a plea of guilty to the charge, acquitted the activist and Greenpeace Nordic on the basis that the trespass was justified.

From a purely legal perspective, this finding is absurd, but a debate about how a court could find the two not guilty without a legal basis, and given the plea of guilty, is not the intent of this article.

The immutability of legal protections granted by law in all its forms, even where the protections are contra to ideas of morality, justice or equality (which you may read as equality between all life or equality between humans) is the current concern, as is mantle on which such rules are placed.

The most extreme extrapolation of this concern, where pronounced laws are all-powerful and must be obeyed despite their effect, can be seen in the Nuremberg trials of Nazi criminals. The regular defence raised in these trials was that despite the allegations that their acts were ‘crimes against humanity’ and international law, they were acts in accordance with the laws of Germany. Therefore, they argued, they could not be prosecuted, given that the laws were assented to by a sovereign government.

Modern day examples that might be used are the forced evictions of people from public areas which featured prominently in the Arab Spring uprisings and Occupy movements. Whether you agree with these movements or not, the actions of such protestors of voicing their concerns and seeking change, in their view, for the betterment of society, were met with the enforcement of proprietary laws over the land on which they stood to voice these concerns, even where these actions in themselves did not cause damage.

A more regular example is the removal of protestors from otherwise public lands where logging licences have been granted to a private company. The removal, and the following charges laid, are based on a legal protection to the licensee over the land from adverse actions of people who, other than their intent to protest, would be allowed on the land.

The imbalance seems most striking where law securing property rights is utilised to protect the furtherance of activities that in themselves may be illegal, immoral (whether that morality be derived from religion, ethics or otherwise) or against the will of some part of society, whether it is a majority or minority will. Further, where the damage caused by such protected activities is not caused to a person or to an object over which another person has proprietary rights that can be enforced, the law, particularly criminal law, struggles to appreciate the validity of those ‘criminal’ actions such as trespass taken to halt the destructive, but protected, activities.

It cannot however be said that pedestal of proprietary rights over land has remained at its lofty heights throughout time. Much like free market capitalism, exceptions to the general rule have been introduced so that the tragedy of the commons does not forever plague us.

For instance, laws regulating pollutants contaminating and emanating from private land is regulated through Environmental Protection laws, as they do for proposed constructions on private land which may affect protected public land, such as in the Environmental Protection and Biodiversity Conservation Act 1999 (Cth).

A more regularly used piece of regulation which acts to restrict the use of private land is found in local planning regulations, which of late have been updated to involve considerations of climate change and rising sea level when local Councils are considering a building or planning permit.

The questions for the future must be: Can (or will) government imposed regulation adapt to the evolving environmental conscience in a timely manner? Further, equitable outcomes achieved through regulation, at least historically, require complex legislation. Just look at the taxation laws in most developed countries which have this aim.Therefore, will environmental prosperity through equitable regulation be so complex as to end up being unworkable?

Finally, will the idea of private property forever restrict appropriate environmental action which alters the allowed use of land where competing economic interests are effected?

Although small-scale or singular domestic housing application have been rejected outright under current regulations (see reports of the recent Narrawong Planning Control Decision for example), large-scale, environmentally destructive but economically advantageous (depending on who you are) developments continue to get approval. Looking outside Australia, the Tar Sands Pipeline between Canada and the USA is another example of environmental issues being in conflict private proprietary rights to the use of land and natural resources.

Could the idea of property, an idea that was once exclusively linked with power, and which wields lesser but still formidable power now, be the problem itself? Could the abolition of private property be the means of overcoming the accumulation of private wealth with legal protection to the detriment of adjacent land, rivers, oceans and atmosphere?

Were use of property influenced not by private interests in an economically driven society but by a truly communal, active, local community, the considerations of local environmental features effected by any action taken on that community’s land would receive paramount recognition and protection, and not a disconnected, procedural, uninterested view that such consideration generally receive now.

Such a change would need to be preceded by changes both in societal organisation and in psyche. The time for economic rationalisation of all actions and the strive for global economic growth would need to be replaced with concern for local issues and communal provision of the necessities for life such as shelter, food, water and clothing. Personal growth and satisfaction would need to flow away from consumptive self-gratification and into self-awareness, awareness of other people and awareness of other living things. Rights dependent on legal proclamation need to be replaced by universal rights of all beings, whether human, faunal, floral or natural.

The future of protecting environmental qualities requires more than just further incremental encroachments on historical ideals of rights to property and profit, attempting to leave the remainder of the economic system intact. It requires a relinquishing of these ideas, replaced with small-scale, communal, self-sufficient, conscious and conscientious existence.

Dig it up! The veggie patch bears more fruit

I was watering the veggie patch the other night, when I spotted the tops of a number of carrots in the line of seeds I had planted and which had been growing the quickest.

Eager as I have been lately to taste more of what I had grown after recently picking the peas I had grown, I started to pull up the carrots that were just showing their tops out of the soil.

One by one, the thick orange roots that supported the green foliage I had been feverishly watering for the last number of weeks came out of the ground. It is amazing that these had started from some of the tiniest seeds that I had grown.

There are still more carrots waiting to be pulled up which need some more time to grow.

Given that the shrubs that had grown from the potatoes that I had planted had mostly died off, bar one which continued to grow, I decided that it was time to see if the potatoes had flourished to the same extent that the carrots had. Unfortunately, only the potatoes growing as tubers to the longest lasting plant had grown to a decent size.

Although a little disappointing, trial and error is part of the fun. Next time, I’ll try planting the potatoes in a sunnier part of the patch to see if that will promote better growth.

Apart from the remaining carrots, only the brussels sprouts are left, and they need some tending to eradicate their growing attraction to some moths – but that will be part of another article looking at organic ways to deter pests.

If any gardeners out there have any suggestions or questions I’d be happy to hear from you!