It is time to stop quivering in our boots in pointless fear of the future and just roll up our sleeves and build it.
- Ray Pierrehumbert

Sunday, August 15, 2010

A fifth of Pakistan?

A fifth of Pakistan is NOT under water. It's intense and horrible, but it has not actually reached a condition that is physically impossible.

Update: Via CNN,

Pakistani Prime Minister Yousaf Raza Gilani said Saturday that as many as 20 million of his countrymen have been affected by the flooding. The Pakistan Humanitarian Forum put the number at 14 million on Monday.

The death toll from the flooding that's raged more than a fortnight is up to 1,463, and more than 2,000 people have been injured, the National Disaster Management Authority said Sunday.

With about one-fifth of the country underwater, almost 900,000 homes had been damaged, the agency said.

United Nations Secretary-General Ban Ki-moon said Sunday that while he has visited sites of natural disasters around the world, he has never seen anything like the devastation created by flooding in Pakistan. He said the disaster is worse than the 2004 Indian Ocean tsunami and the 2005 Pakistani earthquake combined.

So, a "fifth underwater" is an official Pakistan statement! But NASA says different. However, contrary to my expectation, it turns out much of Pakistan is flat terrain. So maybe it depends how you count. Maybe the satellite doesn't see puddles, which nevertheless may be enough to damage crops.

(via Wikipedia)

It's hard for me to reconcile 900,000 homes damaged in a country of 120,000,000 with 20% by area "under water". If the homes were evenly distributed that would be 25 people per home; if the homes were preferentially in the flooded area that would be more. Normally if you had a building "under water" you'd expect some damage.

I still doubt it. If we had a better press they would be showing us pictures of typical conditions in low lying areas, as well as worst conditions.


Jay Alt said...

UN press releases said 20% of Pakistan was affected by flooding. I interpret that as 20% of Pakistan is (or was) underwater. The distinction irrelevant to the residents.

"Floods as bad as 1947 partition, says PM:
anger grows among 20 million people left homeless"

Alexander Ac said...

Anybody noticed Niger

"Niger is now facing the worst hunger crisis in its history, the UN's World Food Programme says, with almost half the population - or 7.3 million people - in desperate need of food."

Michael Tobis said...

20 % of the population is affected. This may be the worst flooding disaster on record. I don't mean to demean it.

But 20% of the surface area is not under water, and I don't think it helps anyone to propagate confusion about geophysics.

John Mashey said...

Of course not, sloppy meme propagation. However, knowing that a lot of Pakistan is arid, with low population density one can put together:
Pakistan flood hazard map, and popluation map, unsurprisingly, a large fraction of people live in flood zones. Without checking, one cannot tell, but it is quite possible that this was sloppy wording for "land where 20% of the population lives" is flooded.

DavidP said...

Strange that MT quotes "20% of the population is affected" while the NYT article says "About 14 million people have been affected" out of a population of 177 million (CIA factbook)

Meaningful statistics are hard to come by.

Michael Tobis said...

The fraction quoted has been increasing day by day. I don't vouch for it; I just say it's a lot more plausible than the way it's being stated as 20% flooded.

On the other hand, as I understand it the crest hasn't hit the major city of Hyderabad yet.

Ban-Ki Moon who has seen a lot of stuff like this (including the Haiti earthquake) says it is the worst disaster he has seen.

Aaron said...

I took the statement to mean, 20% of Pakistan's “crop land”. That would include the rice and wheat fields in the bottom of the valleys, but not the goat pasture on the steep hill sides.

The floods will be a blow to Pakistan’s agricultural production.

Serinde said...

Perhaps this might help visually?

Michael Tobis said...

Serinde, check the first link in the article!

Hank Roberts said...

"The United Nations warns that unless farmers in hard-hit Punjab and Sindh provinces manage to plant their winter crop of wheat in mid-September as normal, there might be food shortages in the region and the nation as a whole."

The fields don't need to be "under water" -- deep mud is enough to prevent timely planting. And Russia, on the other end of the weather system, won't be exporting wheat for a while.

John Mashey said...

This is akin to the early reports about the BP oil problem..'
It's like death toll of 1,463...

Like MT, I doubt that 20% of the total land is/has/been flooded. On the other hand, it is useful to see Population density map. By eyeball, I'd guess that hardly anyone lives in ~30% of the land.
A lot of them live among all the rivers. It may well be that 20% of the area in which there is any noticeable population has been flooded. That doesn't mean 20% of the population, since population is dense in big cities. it might mean there are a lot of flooded villages and small towns in farming areas.

Anyway, the main message is: don't get too crazy about numbers that must have big error bars, produced by people in middle of huge disaster. Such numbers are rarely right.

Alastair said...

How about this news report?
but it may only be available to people in the UK.


Michael Tobis said...

Notice how the camera angle is always downward on these shots? All I am asking is to see the horizon.