Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Why are Pakistan’s floods so extreme this year?

nature.com

Post reply on HN
Print view View original

71–80 of 187 posts

Re: Why are Pakistan’s floods so extreme this year?

#71

Post by pengaru »

handoflixue wrote: post #68
aeternum wrote: post #65

Earlier quoted context omitted.

Except it has happened about every 12 years throughout history The ancients even created a name for it: La Nina.

Huh, I didn't believe you at first but apparently there was indeed very severe flooding in 2010, and again in 1992. That said, back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before

> back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before

Or the distribution of people living in the flood plane drastically changed in that period. See my other comment @ https://news.ycombinator.com/item?id=32653203

Re: Why are Pakistan’s floods so extreme this year?

#72

Post by hahaitsfunny »

handoflixue wrote: post #68
aeternum wrote: post #65

Earlier quoted context omitted.

Except it has happened about every 12 years throughout history The ancients even created a name for it: La Nina.

Huh, I didn't believe you at first but apparently there was indeed very severe flooding in 2010, and again in 1992. That said, back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before

No post body was provided.

Re: Why are Pakistan’s floods so extreme this year?

#73

Post by joshuajill »

Panino wrote: post #36
peteradio wrote: post #15

Earlier quoted context omitted.

Sounds ridiculous on its face, and that is as a practitioner of permaculture. I couldn't really get my head around how it could possibly make even a slight dent against the massive flooding witnessed here.

When Gabe Brown switched from conventional agriculture to regenerative agriculture, he increased water infiltration in his soil from 0.5 inches (1.25cm) per hour to 30 inches (75cm) per hour. So imagine if he and all his neighbors had the same beautiful soil -- flooding just couldn't happen. I haven't seen a list of such measurements from permaculture, but I know it can be used to regreen deserts (as shown in Jordan,…

Maybe even relatively simple but massive reforestation efforts could help mitigate climate change effects in the long run.

Re: Why are Pakistan’s floods so extreme this year?

#74

Post by sremani »

nerdponx wrote: post #60
mring33621 wrote: post #50

Climate change is real and has changed the temporal distribution of rainfall, often increasing the interval between rainfalls, while also increasing the amount that falls, during rainy periods. Longer durations of 'no rain' cause the ground harden to a much less porous, concrete-like surface that cannot absorb the rain, when it does come, fast enough. So the water pools and flows, causing flood conditions.

The article also blames high amounts of glacial melt (to the point of bursting through glacial dams) sending a lot of extra water through waterways in a short amount of time.

With all due respect why are Glaciers melting in August.. or July or June. April and May are hot as hell in Indian Subcontinent.

edit: glaciers melt in summer, I am surprised why they are melting in rainy season. No matter how you vote, just explain why this odd behavior.

Re: Why are Pakistan’s floods so extreme this year?

#75

Post by IX-103 »

alar44 wrote: post #53
Panino wrote: post #36

Earlier quoted context omitted.

When Gabe Brown switched from conventional agriculture to regenerative agriculture, he increased water infiltration in his soil from 0.5 inches (1.25cm) per hour to 30 inches (75cm) per hour. So imagine if he and all his neighbors had the same beautiful soil -- flooding just couldn't happen. I haven't seen a list of such measurements from permaculture, but I know it can be used to regreen deserts (as shown in Jordan,…

Yeah just imagine if a billion people completely changed their way of life.

I'm not sure if you're being sarcastic or not. Climate change is going to require changes of at least that scale, whether we reduce emissions or not.

Re: Why are Pakistan’s floods so extreme this year?

#76

Post by Melatonic »

_eht wrote: post #19
jmyeet wrote: post #9

While it's absolutely true there is a confluence of factors here (eg glacial melt, heat wave and a depression) and that these events are more likely with global warming, I'm disappointed this article didn't cover another important factor: dams. Flooding used to be a much bigger problem in the Western United States and it was solved with dams. Yes, there is thd risk of dam failure but we're weighing up the real and pr…

We need to airdrop more beavers, clearly.

This might actually not be a bad idea. That being said I think a lot of the environments would be too dry for beavers and not contain enough trees. Or conversely be too alpine.

So basically we need genetically engineered super beavers that are adapted for high altitude mountaineering.

On another note I find it hilarious and also cruel that beavers are apparently absolutely obsessed with stopping the sound of any running water. To the point that if one wanders near your home and can regularly hear water running inside of pipes it drives them crazy.

Re: Why are Pakistan’s floods so extreme this year?

#77

Post by piceas »

handoflixue wrote: post #68
aeternum wrote: post #65

Earlier quoted context omitted.

Except it has happened about every 12 years throughout history The ancients even created a name for it: La Nina.

Huh, I didn't believe you at first but apparently there was indeed very severe flooding in 2010, and again in 1992. That said, back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before

Land-use matters. I don't have a good link but there has been reporting on the topic.

e.g. https://www.reuters.com/article/us-pakistan-environment-fore...

Re: Why are Pakistan’s floods so extreme this year?

#78

Post by fiftyfifty »

aeternum wrote: post #65
mring33621 wrote: post #50

Climate change is real and has changed the temporal distribution of rainfall, often increasing the interval between rainfalls, while also increasing the amount that falls, during rainy periods. Longer durations of 'no rain' cause the ground harden to a much less porous, concrete-like surface that cannot absorb the rain, when it does come, fast enough. So the water pools and flows, causing flood conditions.

Except it has happened about every 12 years throughout history The ancients even created a name for it: La Nina.

Except this is our third La Nina year in a row, the first time that's ever happened:

https://www.reuters.com/business/environment/wmo-forecasts-f...

Re: Why are Pakistan’s floods so extreme this year?

#79

Post by bombcar »

nerdponx wrote: post #63
asah wrote: post #59

Earlier quoted context omitted.

naive q: does that still help if the aquifer gets saturated?

Is an aquifer ever likely to get saturated? I have no expertise in this area, but in the US at least the concern is always over aquifers being depleted , not so fully saturated that they can't absorb more water. My understanding was that it takes very long time for water to actually get from ground level down into an aquifer.

At some point the ground cannot accept anymore water, no matter what.

Proof: oceans exist.

The key to the whole thing is if you can slow it down enough so that a sudden deluge over a day/week/month has time to slowly drain out.

Getting water into an aquifer takes time depending on how the soil is, but eventually the aquifer would rise to the surface and you'd have a marsh. Or it would rise higher and you'd have a lake.

Re: Why are Pakistan’s floods so extreme this year?

#80

Post by bmismyname »

Higher temperatures mean more moisture in the atmosphere and aridification at the same time. That's why there can be drought plus record breaking rainfall at the same time.

Plus, when you have drought, it damages the soil and plant life which would normally aid in capturing and retaining the rainfall. And when the rain does fall, instead of being absorbed into the soil it just creates erosion instead as the top layer dies.

People think about soil as just dirt, which it is not. Soil is effectively a living organism (or ecosystem of organisms).

Post reply on HN