SciBlogs

Eco-friendly vs appropriate technology Daniel Collins Jul 14

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The BBC has a nice photo essay on the up-take of a low-tech irrigation device – a treadle pump. The BBC, perhaps echoing IDEI, is calling it “eco-friendly”. But it’s not. There’s nothing environmentally friendly about pumping out more water from an aquifer than is recharged. Even pumping less than the recharge rate can be problematic for groundwater-dependent ecosystems.

This treadle pump is better described as appropriate technology. Low-cost tech, that can be made or serviced locally.

Remember the declining aquifer levels in India? It’s because of insatiable pumping. And why so much pumping? For irrigation to feed the massive population. If higher pumping isn’t accompanied by lower birthrates, these pumps are just delaying the problem.

The case of the blue mozzarella Daniel Collins Jul 07

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Back in June, 70,000 balls of mozzarella were confiscated in Turin, Italy because they were blue. This was not an evolutionary step in cheese manufacturing – the offspring with an amorous roquefort – but a consequence of contaminated water.

Italians weren’t happy, with farmers demonstrating near the border with Austria, the blue cheese’s country of origin.

The cause of the blue hue was traced back to water apparently contaminated by
a natural, non-toxic bacteria called pseudomonas fluorescens
, known to occur is 14 European countries. The cheese maker, Milchwerk Jaeger, said it came from groundwater contaminated by a factory near its plant.

While pseudomonas fluorescens can be a health threat to elderly with respiratory ailments, in the countries where the bacterium is present, it appears that no-one has fallen ill from this this event. Blue mozzarella anyone? No takers? Not a surprise.

Texas GOP water platform Daniel Collins Jun 29

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The Texas Republican Party has renewed their election platform. In addition to opposing oral sex, a single world currency and membership in the UN, they have a few things to say about water:

“We believe that … groundwater is a vested ownership right;…”

That is to say, groundwater is a property right, and any groundwater that passes through your property is yours. This is in contrast, in the Texas context, with community-based management, where irrigation districts are able to set pumping limits as a means of sustainable management. Recall the 2009 Nobel Prize in Economics?

Which segues nicely into Texas GOP’s desire to…

“Create a free market for water to help meet future demand”… using “the relatively light-handed regulation of the oil and gas industry as a model for the state’s water market.”

That is to say, to let the efficiency of the market maintain sustainable water supplies. Perhaps like in Chile. After all, light-handed regulation of the oil industry hasn’t caused any problems, has it?

CSI-Silurian: The biological roots of landforms Daniel Collins May 24

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ResearchBlogging.orgImagine an episode of CSI-Silurian. The team of detective-scientists are investigating a case of wholescale graffiti in the middle Silurian, and they’re looking for fingerprints. Someone – or something – has taken a knife to the land and carved out a network of rivers and streams.

The usual suspect is quickly identified: the climate. In particular, climate’s main handy-man rainfall. But the detective-scientists suspect something more sinister, with the arrival of vascular plants on the scene. Could meagre plants have contributed to the large-scale river patterns?

This very question has been asked by geomorphologists for a while. Bill Dietrich and Taylor Perron put a spotlight on the question in a 2006 Nature review article. Asking if life leaves a tangible geomorphic signature, their main conclusion was that natural ecosystems probably don’t create any novel landforms – no hillvers or gullakes – just that they change the magnitude and frequency of those landforms that already can exists – hills, rivers, gullies and lakes.

But the question remained: How do the magitudes and frequencies change? And do these changes bear a uniquely biological signature?

In a recent paper of mine, Collins and Bras (2010), I argue that if you look at river systems from arid to humid climates you will see a uniquely biological signature. In particular, as arid climates give way to semi-arid, the number of rivers dissecting a landscape would decrease because the expanding vegetation offsets the erosion power of increasing rainfall. But as semi-arid climates give way to sub-humid and humid, rivers begin to dissect more of the landscape, because the heavier rainfall now overwhelms the resistive plants.

This geomoprhic pattern has been observed many times, but the biophysical chain of events had not been pinned down in as much detail. This detail was possible because of the use of a numerical biophysical model, albeit a simplified one. If there is one single culprit here, it is plant transpiration, which fundamentally alters the landscape’s water balance and thus its erosivity,

Despite their comparatively small stature and life expectancy, then, the evolution of vascular plants in the middle Silurian probably started to alter the trajectory of landform evolution, and fundamentally so. While I did not focus on this point in my paper, it is an easy inference to make.

References

Dietrich WE, & Perron JT (2006). The search for a topographic signature of life. Nature, 439 (7075), 411-8 PMID: 16437104

Collins, D., & Bras, R. (2010). Climatic and ecological controls of equilibrium drainage density, relief, and channel concavity in dry lands Water Resources Research, 46 (4) DOI: 10.1029/2009WR008615

Cloud seeding you can bank on Daniel Collins May 21

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Estimated price of a cloud seeding experiment in the Southern Alps: $300,000
Estimated price of annual cloud seeding operations: $1,000,000
Balancing water supply and demand: priceless

Canadian house swallowed by sarlacc Daniel Collins May 12

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Okay, so the house wasn’t swallowed by a sarlacc. But nor was it swallowed by a sinkhole, as the Associated Press is telling us.

You may have seen the news: “Family killed as home swallowed up by giant sinkhole in Quebec”, or variations upon a theme. If you look at the aerial photos, you’ll see scars of slumped land on one side, severing the road, cutting across the fields in an arc. But this slumped earth was not swallowed by a sinkhole, to disappear under ground, but simply moved sideways towards the river. The river channel is now buried, as is the land beside the river.

This is a landslide not a sinkhole.

Sinkholes truly are holes in which the land surface disappears into cavities below ground, or when these cavities collapse causing a depression. Landslides are lateral displacements of earth that occur when there isn’t enough friction between the layers of soil to keep the ground in one place. The ground surface slides down this low-friction surface, carrying and shunting dirt and houses down with it.

Drought, kiwi and ecological dominoes Daniel Collins Apr 27

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Two weeks ago news hit the TV of the impact the Northland drought is having on kiwi. It had already been picked up far and wide back in February, but as the drought continues, so does the story. The story is this: drought has caused nocturnal kiwi to forage for food during the day.

These normally nocturnal birds forage for insects in the leaf litter on a forest floor. Normally. But the onset of one of the most severe droughts on record has set off the collapse of a line of ecological dominoes. Low rain begets low soil moisture, which begets lower plant growth and harder soils, which beget less food for insects and more inaccessible insects, which means less food for kiwi, which means more excursions by kiwi into the unsafe light of day and potentially higher mortality.

This game of ecological dominoes, triggered by water shortfalls, is seen the world over.

The seasonal swing to dry conditions in the Florida Everglades concentrates fish and other aquatic critters into ever smaller pools of water. These pools become the fast food joints of the bird world, and of bird watchers. The same applies to watering holes from Africa to Australia.

But while this seasonal swing is par for the course in Florida, a sustained climatic shift in the US Southwest that started in the 1970s caused several common animal species to go locally extinct, and some rare species to increase. The middle man in this case was the expansion of shrubs that fared better in the wetter winters. Shrubs have deeper roots than herbaceous plants, giving them a competitive advantage when more water infiltrates deeper into the soil, as would occur during wetter winters.

Back to kiwi, drought is not the number one threat – that dishonour goes to introduced mammals. But I imagine that the threats posed by drought would be substantially alleviated in predator-proof sanctuaries, where daylight foraging is less risky.

Discontent bubbling to the surface in Canterbury Daniel Collins Apr 16

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When it comes to Canterbury water governance, the balance of satisfaction has shifted dramatically over the last few weeks. Some are happier now that government-appointed commissioners will replace elected councilors at ECan. Some are not. And those who are not are increasingly making themselves heard.

At two meetings recently the malcontents voiced their feelings, from calm criticism to vociferous outrage. Running through both events were the feelings of eroded trust, lost democracy and endangered water. There is no way I can relay every nugget of observation, partly because I wasn’t omnipresent. But in the interests of shedding some light on the cogs between water and society, here are a few.

First, from Wednesday night:

• Yani Johanson, Christchurch City Councilor, reiterated the remark that Christchurch City Mayor, Bob Parker, did not consult with the city council on ECan’s performance. Indeed, there appeared to be substantial tension between Mayor and Council.

• David Sutherland, ECan Councilor, said: “No use crying over spilled milk.” People have to find positive things to do, like getting a new mayor. This view seemed to be shared by most people present. Two outgoing ECan councilors are possible candidates.

• Lianne Dalziel, Labour MP, saw the Creech Report as the start of a nation-wide effort to undermine conservation orders.

• Russell Norman reiterated his belief that the debate over water is a debate about who we are as a nation. He also noted Bill English’s recent statements at a Deloitte business function, that the ECan Bill was passed in the interests of fostering irrigation.

• Eugenie Sage, ECan councilor, remarked that there has been tension between ECan and the territorial authorities because of ECan’s demands regarding storm water and sewage operations.

• The lone Mayor to join the panel, Garry Jackson of Hurunui District, received a lot of harsh questioning but also a lot of applause for having the guts to show up.

• And on a social analysis of the attendees, the dominant hair colour was silver, and many heard about the event from a Green Party email. It was a Green Party event after all. A couple hundred were in attendance, inside out out, with a passers-by stopping to listen.

Turning to the Thursday night meeting, this one was about what people can do from here. Held in the Arts Centre’s Great Hall, the meeting was an ideas fest. Direct action was a common theme. Here are some of the ideas put forward:

• David Moorhouse, Christchurch Green Party, advocated a “rates resistance” or rates revolt. The rationale being “no taxation without representation.”

• The Melvin Hills Protection Society suggests a hikoi, starting at rivers on either end of Canterbury to converge on Christchurch’s main square.

• Brendan Burns, Labour MP, presented a petition to the House of Representatives.

• Polly Miller, President of Whitewater NZ, offered to give the in-coming commissioners a whitewater tour of the Hurunui River. This was perhaps the suggestion with the most potential for influence water governance before the next elections.

• Cantabrian artist Sam Mahon suggested both a black-clad candle-light vigil in the square, and monkey-wrenching of possible dams.

• And on the audience, it seemed a bit more youthful than the previous night – mostly middle-aged this time – but there was also a significant 20-something turnout. Probably about 200 came.

Introducing a new series: Horton’s Index Daniel Collins Apr 14

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After much mulling, distilling and filtering, Crikey Creek is introducing another new series: Horton’s Index.

Many readers will know the name Horton. Not the one who heard a who, but Robert E. Horton – hydrologist extraordinaire. Horton was instrumental in the 20th century quantitative revolution in hydrology. He even got his name attached to one of the water cycle’s cogs – Hortonian overland flow.

Many readers, I’d like to think, also know of a certain Index – Harper’s Index. This index is a monthly index of ironic and often-pointedly political factoids, with numbers as the punch-lines. They can be funny, surprising and blunt. Numbers are good that way. No doubt that’s why Peter Gleick, water resources expert at the Pacific Institute, chose as a theme to his blog “Water by Numbers”.

With the above in mind, the all-new Horton’s Index will present water-related factoids, touching on the science and the society.

Percentage of the Earth’s surface area covered by water: 71

Total mass in metric tons of the Earth’s hydrosphere: 1,400,000,000,000,000,000

Mass in metric tons of the Earth: 5,980,000,000,000,000,000,000,000

Ratio of Earth’s mass to its hydrosphere: 4,300,000

Nominal upper range for the mass in metric tons of one gulp of a blue whale: 70

Equivalent number of regular Big Gulp drinks from 7-Eleven: 70,000

Number of votes tallied in an online Greenpeace poll during 2007 to name a humpback whale in the South Pacific: 152,000

Percentage that favoured the name “Mr. Splashy Pants”: 79

Land use hydrology paradox in Central Texas Daniel Collins Apr 13

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ResearchBlogging.orgWhen it comes to conversion of grassland to shrubs or trees, the typical story goes like this. More rainfall is caught be the foliage and evaporated straight back into the air. Higher rates of transpiration deplete soil moisture faster, and deeper roots inhibit drainage of water from soil to aquifer. This story is typical because it is observed time and time again [1], but it is not the whole story. Nor is it always true.

A recent paper in Geophysical Research Letters, by Bradford Wilcox and Yun Huang, tells a different story [2]. They document annual streamflow for several rivers in the Edwards Plateau, central Texas. While the region has experienced an expansion of shrubs and trees – AKA, “woody encroachment” – spring-fed river flow has paradoxically increased.

The reason, they propose, is that while woody plants have expanded, grazing has reduced. Livestock trample and compact the soil, and eat the herbaceous plants, both of which reduce infiltration of water into the soil, and ultimately reducing recharge of the aquifers that feed the springs. But as grazing declined, spring-flow seems to have increased. It thus seems that grazing in the Edwards Plateay has a greater impact of river flow than woody encroachment.

While Wilcox and Huang have started to tell a different story, the story is far from over. They have eliminated historical rainfall as the source of the change, but they have not eliminated historical evaporative demand. And while spring-fed river flow has increased, it seems that flow from other sources has also paradoxically increased. If spring-flow increased due to herbaceous plants favouring infiltration, you’d think surface runoff would drop accordingly, but apparently not.

Whatever the answer, the researchers are on the case, and it is fair to say that another exception to the rule of land use hydrology will be found.

[1] Farley, K., Jobbagy, E., & Jackson, R. (2005). Effects of afforestation on water yield: a global synthesis with implications for policy Global Change Biology, 11 (10), 1565-1576 DOI: 10.1111/j.1365-2486.2005.01011.x

[2] Wilcox, B., & Huang, Y. (2010). Woody plant encroachment paradox: Rivers rebound as degraded grasslands convert to woodlands Geophysical Research Letters, 37 (7) DOI: 10.1029/2009GL041929

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