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Saturday, February 28, 2009

Willows in braded streams

New Zealand's South Island has a rapidly rising range of mountains close to it's West Coast which is caused by the Australian plate in the West diving under the Pacific plate. In South Island, a great deal of material is shed from the mountains to be carried toward the east coast by streams and rivers. Wide plains have been formed by this material as braided rivers fill up, jump their banks, form new channels which in turn fill up and so on. The rivers work like a grouter spreading material back and forth across the land between the mountains and the sea.

All across the flood plains these braided rivers exist. They are seen most prominently as you land in Christchurch airport from the north. In many places, willows have been planted in the streams and they have spread upstream and down. There is considerable controversy with regard to the benefit or otherwise of the willows.

Some people feel that they cause flooding, that a flood can wash down trunks to pile up on the upper side of bridges and cause them to fail, that they take up water which could otherwise be used by farmers and that they are an eyesore. Some people seem unhappy that the streams aren't the way they were when they were children as if any change from the childhood situation is by definition bad.

There is a committee to try to enable various uses of the river, sometimes conflicting, without one interfering too badly with another. Some of these uses include:
a) people with farms along the stream who own the steam bed to the centre of the stream,
b) rabbit hunters,
c) gun sighters,
d) people collecting wood for their wood burners,
e) hikers,
f) 4 wheel drivers and
g)fossil hunters.

On a recent trip spread over two Saturdays from the mouth of the river to near the top an interesting fact came to light.

On the trip we had farmers adjacent to the stream talk to us as we reached their farms. Many of them remember fondly around the 50's when the Waipara was an open braided river. Many of them mentioned that they felt that the willows endangered the bridges since washed out trunks could collect against abutments and lead to their failure with the pressure of water. Almost all noted that back around the 50's we had some serious floods but since then there haven't been any bad floods. This was attributed to a lack of serious rainfall events since then. I wonder.

It would be most interesting to collect rainfall figures from local farmers and to collate them for the past century. Some farmers have records going back even more than a century. I have a strong suspicion that we would find rainfall events just as serious over the past 50 years when willows expanded their territory to fill the streams as over the previous 50 when there were few if any willows. If that turns out to be the case, the only obvious explanation is that the willows have reduced flooding. Quite a reasonable hypothesis when you think about it.

Willows roughen the stream in a macro sense. With willows there is more friction for the flowing water. The water has to burble and swirl past tree trunks and as it slows, it spreads out over its flood plain. All this slows the flow and lowers and lengthens the flood peak. Could this be the reason that flood peaks have been much less serious in the past 50 years than in the previous 50 rather than the lack of rain. Only collating rainfall events will clear up this point. While we are at it, lets look at some other likely effects of the willows.

Just like when there are beaver dams in a stream which slow down the flow of the water to the sea, with willows, the water will be held longer on the land. The Canterbury plains are one great large alluvial plane which is ideal for holding ground water. The slower a stream flows, the more time there is for the recharge of this ground water. Beavers do this in aces. It seems reasonable that if the willows are slowing the flow of the water to the sea and spreading it over a larger area that they will have the same effect of directing more water underground. Incidentally, if this is a significant factor it may in part help to explain lower flood peaks. More water is going underground. Underground water, of course is very much slowed in its flow downhill and is protected from evaporation. All good for people using well water.

In New Zealand we still have a nature that can supply those of us who are willing to make the effort with some of our daily bread. One can still get a rabbit for the pot with a modest effort or a deer or pig with a bit more effort. The willow streams provide fire wood. Here there is an interesting dichotomy. The same people who decry the willows seem to resent someone who chops some down for fire wood. Go figure. Envy?? I don't know. Everyone on the trip I mentioned above seemed to be uncertain of the legal situation. Most thought that anyone could cut down whatever they wanted. Others thought that it was only OK to take dead trunks. Whatever the case, it is a great resource for rural New Zealand and willows coppice and grow very fast so a reasonable amount of harvesting could be done with very little reduction in the standing crop. An ideal situation one would think. How about the use of water by the willows. Willows are very thirsty trees which may help to explain why they do so well in stream beds.

In a Nor Wester, water which transpired from willows on the Eastern plain will most likely be swept out to sea and lost to New Zealand and in this situation, willows could use up some water that would otherwise be available for use. Perhaps balancing this is if the Nor western is humidified by the trees, there may be less evaporation from cultivated fields. However, I think we are clutching at straws with this line of argument.

When the wind is blowing from the East, by contrast, rising up over the alps and releasing its water, the situation is different. In this case all the additional water transpired into the westward moving air should be precipitated out to flow down the stream again. It would be interesting to quantify these effects to see if they are significant. How about the effect on fish.

Trout have been introduced to many of our streams and are found in pools all along the streams. Trout go into riffles but tend to live in pools. Anyone who has walked a stream with and without willows will know where the pools are. Clumps of willows hold the gravel together, the current washes around the roots and hollows out pools. A willow filled stream is a series of pools connected by riffles. A stream lacking willows in our area is virtually all riffle. The only place you find pools in a stream without willows is in the higher reaches in the foot hills where the river has hollowed out pools in the rock. On the out wash plain, there is virtually no deep slow flowing water until you get almost down to the tidal zone. A paralell situation exists in streams on both the east and west coasts of North America. Here it is the presence of large logs in the streams which has a similar effect of slowing the water and causing pools to form. It has been observed that streams with "big wood" in the water are far better for both spawning and rearing of salmon.

Willows have another interesting effect. Willow leaves have little red bumps on them. These are willow grubs. Fishermen know to tie lures which mimic these in the willow grub season. It is any ones guess how much food the willow grubs contribute to the trout in the stream. Another interesting subject for research and quantification.

As humans we have a tendency to notice the bad things that happen. We will note when a storm damages our property. We don't take any special note when no damage occurs along with a rainfall event. We notice when a stream floods and takes out a bridge. We don't really notice when there are no floods and the bridge sits there perfectly happily and does what bridges are supposed to do. We almost need a disaster to emphasize what is real. If, for instance, someone could wave a magic wand and eliminate all the willows from one of our river systems, we would then see what the results are. If we had severe flooding and damage to property, we might then appreciate the role of the willows. Baring such a magic wand, the only course we have is to use records of rainfall and flood peaks where they exist and to try to deduct the effect of the willows. This is much less sharp and clear and is always open to interpretation but it is what Humans do well if allowed to. Before we condemn willows, we should embark on a few studies to try to quantify what their role actually is.

Thursday, February 19, 2009

Malthus, pyramid schemes, starvation and birth control

Malthus, the much maligned, stated that populations increases exponentially; ie 1,2,4,8,16 ......, while food production increases arithmetically; ie 1,2,3,4,5 ...... In reality, populations such as humans which lack predators are limited by starvation. A possibly more useful way of stating the principle, with apologies to Parkinson is that Population expands to use up any advance in food production*.

Richard Dawkins on P391 of his excellent book The Greatest Show on Earth stated it succinctly and I quote.  "If there is ever a time of plenty, this very fact will automatically lead to an increase in population until the natural state of starvation and misery is restored."  One would hope that humans who, at least individually, show a modicum of foresight might learn to show collective foresight.

Malthus didn't count on various technical advances we would make in food production ever since we left the hunter gatherer life style but was completely correct. Each increase in food production has been used up by population increase. The recent, much vaunted green revolution which started around the 1960's was the latest of such jumps in food production and gave India and some other countries, a few decades without starvation. A recent estimate is that there are now 700m more people on earth due to this latest green revolution.Link
So with a few delays, Malthus has proven to be completely correct.

Note (Sept 2019)  In his excellent recent set of programs, David Attenborough states, as the film shows the earth rising over the horizon of the moon, that since we landed on the moon 50 years ago, the world population has more than doubled.  

What he didn't know is how our knowledge of contraception would advance. It has often been observed that when populations reach a fairly high level of economic well being, birth rate falls. Everyone is mystified by this and explains that women are delaying having babies as they pursue a career; people are not having any children so that they can enjoy the fruits of their labor and so forth. 

No argument there but how do you think they are avoiding having children. Abstinence??? I don't think so!! Abstinence went out of fashion more than half a century ago. One of the reasons for not having children (not often stated) is so you can enjoy non-abstinence uninterrupted. The simple fact of the matter is that with a certain level of economic development, contraception becomes affordable. 

The proof of this is a number of countries which have made contraception affordable before they achieved a western level of development. They did it by subsidizing contraception and lo and behold their birth rate fell. Of course, with birth rate under control, economic development is much more likely. There are less mouths to eat up  advances in productivity.

While we are at it, lets look at the most recent  green revolutions that began in the 60's. The Yield of a number of grain crops was greatly increased. Some say tripled. This production was achieved by careful selective breeding but the new varieties only fulfilled their potential with irrigation, fertilizer, herbicides and  insecticides. Despite being free of starvation for a number of decades. the change was not an unmitigated success. Part of the dark side has been:

   a) mining of the water table to provide water for the new, highly productive varieties, lowering it disastrously, notably in China and India,
   b) accessing deeper layers of water which are contaminated with arsenic, notably in Bangladesh and parts of India,
   c) Pesticide pollution of aquifers, which along with arsenic contamination has led to a greatly increased incidence of cancer, especially in Bangladesh and parts of India
   d) salination of soils, rendering them unfit for agriculture.
   e) more land in production pushing nature and her free provision of food, fuel, fibre medicine waste disposal and clean water further into a corner*.

*(you would have thought that land would have been taken out of production due to higher yields.- go figure)

   f) production of greatly increased grain yield but with less vitamins and minerals per kg of grain than in traditional varieties resulting in nutrient malnutrition,
   g) huge loss of a genetic diversity as locals switched to the new varieties, abandoning their traditional varieties.
   h) the loss of small farms to large land owners as the peasants borrowed to buy fertilizer, got into debt and defaulted on their loans.
   i) an increase in population of about 700,000,000 mouths that are only with us because of this most recent green revolution.

We really have got to the point of diminishing returns. Every advance in agriculture production makes us poorer and poorer. It makes us poorer by:

*decreasing the availability of food, fuel, fibre, clean water and clean air that we obtain gratis from nature as more land is put into agriculture for profit.
*decreasing the ability of nature to process our wastes safely
*decreasing the variety of foods available to us as areas which once grew fruit and vegetables are given over to the more profitable growing of grain crops for cash.
*reducing the space we have to live in as we are crowded by more and more people.
* facilitating diseases of crowding that we would otherwise not have had and increasing the possibility that a pandemic will be much more severe.
* pushing us closer to a disastrous collapse in our Gia support system as we test the theory of sudden climate change with gay abandon.

There is talk now of the need for a second (actually more like the 100th) green revolution, this one based on splicing new genes into varieties of grain. This will probably work and will further increase production. As has happened since agriculture began, population will increase until the new advances in production are used up. In the mean time all those extra people will further degrade the natural environment that we depend on for our existence.

If you want to see the other likely consequenses, go back and read what resulted from the 60's green revolution.

Note: It has been reported that a number of genetically changed plants caused organ failure when fed to rats.

Extra agricultural production only pushes us closer to the brink. The last thing you want when you are standing at the edge of a cliff is a great leap forward.

As was mentioned above, since the 60's it has been noted that when a country achieves a certain level of prosperity, birth rate falls. This is a modern phenomenon. It didn't happen anywhere in Europe before the last century. Britain's birth rate remained high all through the industrial revolution with well off Brits having as many children as their poorer cousins. Think back to your grandfather and great grandfather's family. How many children did each of your ancestors have as far back as you can trace. The difference, as previously mentioned,  in the 'modern era' is contraception.

Contraception has been available at least from Roman times, but it only became truly effective when it was modernized and put into the hands of women. Both the pill and the effective IUD (as opposed to previous less than adequate models) only became practical from about 1960 onward and they have had a huge effect in countries where they are affordable either because the economic level of the population makes them so or because the government has subsidized them.  In both cases, birth rate has fallen precipitously. Ignoring immigration, which is another story, most European countries have decreasing populations. What a success - and they are fighting against it tooth and nail. That is also another story.

I lived in South Africa for 15 years, much of the time in the homeland of Gazankulu.  Despite an educational level of around grade 2 amongst many of the women, they would come into the clinic for their 3month jab to keep them from getting pregnant.  There is a vast difference between not having a formal education and being stupid.  These women were clever and fully realized the advantages of having less children.  Their men were not so smart.  They would have beaten the women if they knew what was happening.

We must learn to live in our respective countries with a stable and then a reducing population. This , of course will result in a population in which the age distribution curve is heavily skewed toward older people. We have to work out ways to live and live well in such a society. For far too long we have been living in a pyramid scheme in which each generation had to be larger than the previous one. 

This was necessary so that there were enough young people to fill the more menial jobs before they rose up to higher levels.  It was also necessary in order to have enough working people to provide the pensions of the retired. This, quite frankly, is a stupid system.  The pension contributions of the working public should go into buying up the means of production.  Pensions are then paid  from the dividends from these companies and even from selling the shares to presently working people.  The elderly become a boon rather than a drain on the economy as they spend their pensions.  

Our system can't go on.  We must stop importing so-called cheap labor to fill the positions of the children we are not having. In the long term, cheap labor is very expensive.

Note that people are now worried about robots taking over our jobs.  Surly these two phenomenon fit together beautifully.  We have less jobs available and less young people to fill the positions.  The critical factor is taxing  the companies who are producing their goods by automation instead of by people.  Too many large corporations now get away with paying little if any tax.  If collected this tax money then should go to the unemployed, whether young or pensioners.  The companies should also face up to reality.  If people have no money they can't buy the goods they produce by automation.  It is in the interest of the companies to have money in the pockets of the people.

Pyramid schemes collapse and the mini collapse we are going through at present (2008ff) is nothing compared to what is to come if we keep increasing agricultural production rather than concentrating on reducing population. If we continue this way, we will soon have an answer to the question of who is correct regarding sudden climate change. If the climate change sceptics are wrong, we may very soon achieve the lovelock number.

Note (2017) Get the book by David R Montgomery, Growing a revolution

* Starvation killed an estimated 50m Chinese over the 19th century, 20m Indians in the latter half, 1m Irish between 1845 and 1852, 1/3 of the population of Ethiopia from 1888 and 1892 and 3m in Bengal in 1943. Imagine the effect of the failure of the wheat and rice crop for just one year due to sudden climate change or even from a mega volcano one spring. (link)

** If you double your population or your GDP, you pretty well double your use of water, wood and minerals, double your production of pollution and garbage and double the area of land you cover in buildings.  You continue to eat into unoccupied land, you eliminate all the benefits unoccupied land brings to the human population for free. Below is a table of how long it takes to double all of the above as a function of yearly GDP growth rate. You can calculate it for yourself with a high-school calculator if you put in (for 3% growth rate, for instance) log 2/log1.03.  The '2' is a doubling time, 1.03 is the interest (growth rate).

Annual growth and number of year to double the economy

70 years

2% 35 years
3% 23 years
4% 18 years
5% 14 years

How many countries in the world do you know that can find twice the water, wood, minerals and produce twice the pollution and garbage and still have any quality of life.  The only two I  can think of off hand are Canada and New Zealand.  We don't want to live like this.

Monday, February 2, 2009

Lets get our economy growing again

I strongly suspect that President Obama will succeed brilliantly in getting the world economy back on track. Surprisingly, I think some of the small things he does such as his anti-sleaze proclamation for congress and his shutting down the Guantanamo's around the world will be his most effective measures. It won't hurt also if he succeeds in pushing through his health reform, a project that has stymied president after president. These measures will give the world confidence that a strong, moral, sensible person is at the helm. We all know how important confidence is for world markets. And it scares the socks off me.

The economies of the world have elements of a pyramid (Ponzie)* scheme. They always need to be growing to prosper. We talk sustainability but no one has a clue how to structure an economy which is sustainable (read not growing) while still keeping everyone reasonably well off. Recently the only way we could keep the economy growing was to give ridiculously easy credit by, for instance, no deposit housing loans and pushing credit cards on people with higher and higher spending limits. This allowed people to buy more and more 'stuff' much of which they didn't need and perhaps, if you looked deep down, didn't even want. Pyramid schemes always collapse and this one did as expected.

We are now in the situation of the bacteria who (yes! who) was put in a test tube full of food. It doubles every minute and in one hour will have used up all the food. At the end of the hour the tube is full of bacteria and no food is left. (with apologies to Dr. David Suzuki). Dr Suzuki then poses the question "when will the test tube be half filled with bacteria". The answer, of course, is not at 30 minutes as many people answer but at 59 minutes**. The run of the mill, fairly intelligent bacteria would look around at 59 minutes and ask "Why are the doom-sayers panicking. The test tube is still half empty". Well we are in the 59th minute in more and more parts of the world with respect to more and more of our resources.

Civilizations have collapsed again and again over history. In fact, it seems to be the eventual fate of all civilizations.*** However, the collapse of a civilization in South America (Aztecs), for instance, had no effect on a civilization in Europe. One didn't even know the other existed. This is the first time that we have had a global, highly linked world civilization (multinational globalization) and this mini economic crisis of 08-09 has shown us how closely we are linked. The closer and tighter the links, the faster an economic-quake in one part is transmitted to every other part. If the ecoquake occurs in the largest economy of the world, the intensity of the quake is huge.

Add to that the very good chance (Jim Hansen of Goddard Space Inst.) that we will soon reach a tipping point that will shift our climate into a different stable state resulting in a shift of growing zones for wheat, rice and so forth. We once had a year's supply of food for the world stored up in our warehouses. They don't exist any more. The burgeoning economies of the East have bought them up. Some estimates suggest our food reserves are a little under 2 months at present. Even if it only takes a couple of years to learn how to handle agriculture in the new climate regime, we will have starvation that will make the historic Asian famines pale in comparison; that is if we can adjust at all. More worrying is paleantological data that suggests that when the climate changes suddenly there is a period in which it flick flacks back and forth between the two phases. Such instability would be even more devastating than a sudden change to a new stable climate regime.

The present economic down turn may be our savior. It is shutting down our economies to an extent, reducing our mining of minerals, use of fossil fuels, excess consumption and our production of garbage and Carbon dioxide. It just may give us the necessary breathing space to get our act together and stop our precipitous slide toward the destruction of our ecosystems which give us so much of our wealth for free (pure water from an uncontaminated catchment, for instance). Here Obama may be our salvation. One, amongst many of his aims is to have America produce all her energy within the borders of America and much of that energy from renewables. His other policies are equally essential, looking far beyond his 8 years in the White House. That is if he can overcome the opposition of the Republicans and even many Democrats with huge vested interests (shares in oil companies for instance) in the status quo.

However, if he does get world economies back to a modest 2% growth rate, that will result in a doubling of our economies every 35 years (log2/log1.02). How many economies do you know that could find twice as much water, twice the amount of minerals and wood, produce twice as much garbage and pollution and still have any quality of life left. Not many. Certainly not America's.

ps. The IMF, just the other day, announced that they expect the world's economy to be back to 3% annual growth rate by 2010. Doubling time 23 years (log2/log1.03). I hope they are wrong. We have seen our future and it won the Academy award for best picture this year. (who wants to be a milonair!!!!)

We are standing at the edge of a precipice. The last thing we need is a great leap forward.

*In a pure Ponzie scheme the operator takes money from investors, saying he is going to invest it in something and he guarantees great returns. He invests in nothing. He then uses the money from later investors to pay off the first investors including the interest he has promised. The investors who have got this windfall tell their friends who, seeing a chance of getting something for nothing, invest their money. At some point along the pyramid, when the operator feels that he has the maximum amount of money possible, he scampers. Unfortunately, many legitimate investment companies also have elements of a Ponzie scheme and even some banks have adopted some policies that edge on Ponzie schemes. Many have recently collapsed.

**if you double the number of bacteria each minute going forward in time, you half the number each minute going backwards in time. Full at 60 minutes, half full at 59 minutes, quarter full at 58 minutes etc.

***Huricane Katrina that hit New Orleans gave an indication of how fragile the largest economy of the world is and how over extended. No one before this disaster would have predicted how ineffective America's response would have been to a crisis of this magnitude on her own soil. Katrina was tiny compared to the economic effect that climate change along with a fairly rapid rise in sea level would cause. (New York Subways flooded with sea water, for instance) Note that continental ice sheets are not melted much by the huge amounts of polar radiation that fall on them in the winter. They are melted by Foen winds. By what we might expect with a new climate regime.