(Hat-tip Geoff)
"What we've found is that some of what we do to the land - we plough the fields and we add fertiliser - doesn't go through to the river for decades," said Dr Howden.
"There's a time delay. The water has to percolate through the soil, it's got to go through unsaturated rock, it's then got to go to the aquifer, and then it's got to be transported and discharged in the river."
":The realisation that the effects of land-use changes in the Thames catchment take more than 30 years to show themselves fully has profound implications for policies to monitor and manage the river's water quality.
It means, for example, the benefits from the 1990s' introduction of Nitrate Vulnerable Zones (NVZs), which put controls on the application of manures to the land, cannot properly be assessed for at least another 15 years.
It is clear also from an analysis of the various inputs and outputs over the period that a lot of nitrate accumulated in the catchment has yet to come out."
This British study of the Thames River and the effect incoming nitrates is having on it is a sobering read for anyone in Southland, looking at what's happening here with our rapid agricultural development.
It's well worth reading.
Tuesday, December 27, 2011
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4 comments:
Knowing a little about groundwater, I would expect that the recession curve would have a much longer tail than the rising curve, so it would take much monger for the effect to disappear than it takes to create them. I would also speculate that the soil chemistry could be irreversibly changed.
Where I'm trying to get to is that the timeframes to implement the solutions, which are complex and difficult to measure, are quite different to the timeframes for the bodies controlling the implementation of the solutions, i.e. it will take decades to address the problem, yet there are regional council elections every three years (except in Canterbury, when we can have an election as soon as National have finished stealing the water). All it takes is one bad council.
Have you a suggestion, culadvi, around the 'timeframes' issue?
I'm for bold action.
culadvi is me (the Armchair Critic), Robert, I must have typed in the anti-spam word twice. Can you correct it for me in the original comment?
I'll consider what can be done, at the moment I don't have a concise answer and even if I did, I doubt I could fit it into a single comment on a blog.
How Good is our Milk Now a days ? Yes back in the 1960s when I drank Milk in School @ Rangiora it was Clean & Green maybe a bit Smelly somedays. 50 years on I have a Huge Concern about Animal Cruelty in Gods Own. It's what is happening to most of NZs Dairy Cows Living on Large Farms. They are Feed on Grass Grown using UREA or Nitrogen this is Not Good for the Cows or us Humans or our Water or Soils. Just Look @ the Rear End of Most Dairy Cows on Large Farms ! Stand Well Back because it is Coming ? Runny SHIT, all the Time from the Grass they Eat which is Full of Water from the UREA . Look it up on the Net it's NOT GOOD for Any of Us !I don't know how we can Change this as Fonterra aren't that Keen on Organics & Working with Nature! Check out Link below to see how bad Nitrogen is in our Food http://www.hampdenparkcoop.com/node/251 Steamingmaddd
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