Farmers in Bangladesh Pump So Much Water It May Help Reduce Floods (newscientist.com) 25
Millions of smallholder farmers in Bangladesh pump huge amounts of groundwater for irrigation, helping to triple the country's rice production and possibly mitigate floods during monsoon season. From a report: Intensive irrigation and other agricultural improvements since the 1980s have enabled Bangladesh to produce enough food each year to be nearly self-sufficient. "In Bangladesh we rely heavily on groundwater for irrigation," says Kazi Matin Ahmed at the University of Dhaka in Bangladesh. He says Bangladesh has a lot of groundwater but there are concerns it could be depleted. Using millions of groundwater measurements from 465 sites across Bangladesh, Ahmed and his colleagues estimated how much groundwater was pumped by more than 16 million farmers between 1988 and 2018.
Together, the farmers operate more than 1 million diesel and electric pumps to flood rice paddies during the dry season, which has enabled more food to be produced on more land. Thanks to irrigation and other agricultural improvements, rice production in the 2018-2019 season was more than triple what it was in the early 1970s. At roughly 25 per cent of the sites, the records showed depleting groundwater levels. At around 40 per cent levels during the dry season and monsoon remained steady. In the remaining 35 per cent, levels declined during the dry season due to irrigation but aquifers were completely refilled during the monsoon.
Together, the farmers operate more than 1 million diesel and electric pumps to flood rice paddies during the dry season, which has enabled more food to be produced on more land. Thanks to irrigation and other agricultural improvements, rice production in the 2018-2019 season was more than triple what it was in the early 1970s. At roughly 25 per cent of the sites, the records showed depleting groundwater levels. At around 40 per cent levels during the dry season and monsoon remained steady. In the remaining 35 per cent, levels declined during the dry season due to irrigation but aquifers were completely refilled during the monsoon.
Reduce floods? (Score:1)
Pump up too much groundwater and the very ground itself starts to sink. That doesn't spell reducing floods.
All those diesel pumps means their production is dependent on fossil fuels, though perhaps one relatively easily changed to solar panels. I sincerely hope they get with reducing that dependency before the diesel becomes so expensive that it starts to drive up consumer food prices.
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That is true only in specific geologies.
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Two obvious lies in your challenge: "expansion was claimed" and "water used for irrigation is removed from the ground permanently, rather than simply cycled back through the top soil".
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Sadly, I don't think the world cares enough to help Bangladesh build a rigorous system. The rising sea may turn it into some kind of ghost nation on the fringes of a bay t
Re:Reduce floods? (Score:5, Interesting)
The entire country is essentially a river delta draining the Himalayas. This silt doesn't sink like Florida, California, etc.
The ADB and World Bank are financing solar pv pumps to benefit farmers and also reduce the load on the national grid.
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Pump up too much groundwater and the very ground itself starts to sink...
Could be, I'm not a geologist so I can't say.
What I was wondering is where that water goes. I don't think the plants will soak it all up. Some will evaporate, some will soak in, some will flow into drainage ditches. I wouldn't bet my paycheck that pumping water from underground to a surface drain system is a win as far as floods are concerned.
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South-East Asia features riverine systems with exceptionally fertile land. That's one of the original cradles of modern humanity, places where high density population could develop because land was fertile enough to provide surplus that could sustain cities.
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Someone else mentioned they also doubled their population over the same period. Seems like they're on the right track, and almost there.
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This is your brain on Green ideology, where people are a net negative.
When in real world, the more people you have, the more specialization you can have, and the more productive each individual person becomes due to a network effect. It's why the place where things like electricity were invented, that Green ideologues use to tell the world how little they understand about it come from cities.
Which are food insecure by definition. Fed by surplus generated elsewhere. Since the invention of farming.
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Usually, the people increasing the efficiency aren't the ones increasing the need. Unless you're talking at a national level - in which case Americans especially are in no position to bad mouth anyone else, we're the more vastly wasteful culture on the planet by a huge margin.
Re:Population (Score:4, Interesting)
Actually, agrisolar is an increasingly popular system, and works great. It can even increase yields in some cases.
The thing is, most plants can't actually use anywhere near all the sunlight that reaches them over the course of the day - I seem to remember something like 40% being a typical number. Their metabolisms just can't process more energy than that per day, so the amount of sunlight isn't the limiting factor to their growth.
So, you mount solar panels up high enough for farm equipment to pass underneath unobstructed, in a sparse pattern that still lets ~50% of the sunlight through, and you can generate huge amounts of electricity without sacrificing crop growth rates. In fact, in hotter and drier climates the intermittent shade throughout the day also reduces evaporation losses, and thus the amount of irrigation needed, as well as reducing thermal stress on the crops, increasing yields.
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>So, good job burning all those fossil fuels, to produce food on land not suitable for producing food.
You could say basically the same thing about the entire US Midwest - aka the breadbasket of the world.
Good rich land, but the water is all underground. You can either pump, or leave the land to native deep-root vegetation that's no use to people.
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so in this case, the fossil fuel and the associated burning thereof were exempt from whatever vague point you were making?
Full of arsenic (Score:2)
It shouldn't really be used for food production.