Why do we droughts?
 

Why do we have droughts? Seriously and please be gentle with me.

Isn't the Earth mostly water? Don't we have the tech to make fresh out of the salty stuff? If "manufactured water" isn't fit for human consumption, can't there still be an available supply or source of it for doing laundry, etc?

Sure we have "tech". But at what price? It usualy requires expensive gear, high energy, high distribution costs. How much do you want to pay for water?

1. Atmospheric conditions (including climate change, ocean temperatures, changes in the jet stream, & some of these are cyclical (PDO, El Nino); others are progressive such as global warming)
2. yes
3. yes, but see above
4. yes, but you'd need to replumb your house and your city

Not sure of i can help -
I am sure we as humans have a very limited concept of what times is.
How do we know its a drought? serious?

Thought for sure you'd mention the Horse Latitudes. :cool:

[QUOTE=RWebb;7892826]...
2. yes

OK, I'm gonna give you a chance to reconsider your answer (to the question) before I post anything more :D

Desalinated water costs around $4 per thousand gallons, or an average of 40 cents per day per person.
That's pretty darned expensive compared to tap water. Too 'spensive to use for farming.



Plus you can't suck water out of the ocean to make fresh water without an intake pipe, and you can't have an intake pipe without the damned tree-huggers filing a lawsuit over some tiny fish or crab that might get sucked in.
In fact they convinced the brain-dead congress to make ocean intake pipes illegal cause they might kill plankton. :rolleyes: :rolleyes:
The law they passed that prevents desalination plants from taking sea water and making it into fresh clean water?
The clean water act. I sheet you not. :mad:

[QUOTE=KC911;7892851] Algore manbearpig says the center of the earth is millions of degrees F.
Missed it by that much .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................

The main reason for "droughts" is probably beacuse we prefer to live in areas that are basically dry. The Southern California area, for example, was not made for 20 million people living the modern life style.

That is why I'm moving to Las Vegas!!!!

Desalinization might supply drinking water for coastal areas but that is about it. I am old enough to remember the 7+ year drought in TX from 1950- 1957. The states economy was just recovering from the drought of the dust bowl years and depression when this drought started. It went on and on and nearly destroyed the states economy which was mostly agriculture based and started the mass shift from a mostly rural agricultural population to the cities.

The population of the state is now probably 10 times what it was in the 50's. Another drought like that would be an unmitigated disaster and not a damned thing anyone could do about it. No place to run or hide when it doesn't rain... and you can't drink oil.

you have failed to do a proper rain dance

Multi layered topic.

On one level, it is because our cities and agriculture use and waste water as if it were an abundant and cheap resource. That's why all the shower water, dishwater, sink water you use - 75% of your household water use - gets discarded to the ocean instead of reused for toilets, irrigation, industrial uses. That's why crops are grown in the Central Valley with spray irrigation and no evaporation barriers. That's why people living in deserts have bluegrass grass lawns. If the US used water at a gal/ household rate like most other countries, there would be no shortage of water in California, or Texas for that matter. Average Water Use Per Person Per Day

On another level, there would still be a drought, for the forests and mountains and rivers. That is partly cyclical and partly climate change-driven.

There is more water within the earth's mantle than on top of the crust.

Just sayin'.

I did an environmental due diligence for insurance on the De-Sal Plant in downtown Santa Barbara 20 years ago, it was pretty interesting. The City/County is now talking about reviving that plant. They ran an intake pipe inside an old sewage pipe that went a mile or two out into the ocean.

If you think about it, De-Sal plants make a lot of sense with nukes. They need cooling water, seawater turns to steam which is pure water vapor. Put in another seawater cooling loop and turn the steam into condensed fresh water.

They dismantled the plant and sold it to the middle east........

Actually I don't think so. I saw an article a few days ago in the LA Time where it is still there. They sold the filters to someone.

Here:

Restarting Desalination Plant Would Cost $20 Million | News - KEYT

Here's an interesting article.

Is the West's Dry Spell Really a Megadrought? | Climate Central

I wrote a sci fi thriller in the 4th grade about man trying to harness mother nature by manipulating the currents in the oceans to alleviate droughts and lessen the impact of poor weather.

In the story, if you were not in a fairly close proximity to either of the poles, it did not end well for you.

The teacher thought it was pretty gruesome and alarming but still gave me an A.

With all the CGI now it would play out as a pretty good movie scenario.

Don't mess with Mother Nature.

Someone shared this with me the other day and it certainly presents some concerns... We tend to look at climate very myopically. We look at it in relation to very recent past which does not present adequate data to tell us anything but micro-changes. Climate, geology, etc., require us to look well beyond the last 100 or 200 years. California may have been in an abnormally wet period when it was settled and farmed. When it becomes "normal" which is much drier if this and other sources are accurate, it will be quite a disaster for the cities and for agriculture.

angela

I've also pondered - how do we "waste" water? "Waste" seems to insinuate that the water is no longer water, but that's not really true. If you use water in your home, it is treated and returns to a creek, river, ocean, etc. Still water. If you wash your car or water your lawn, it evaporates as part of the Earth's natural cycle and eventually falls again as rain somewhere else. Still water. The only true "waste" that I could think of involves the use of water in production processes where it changes state, i.e. where it is an ingredient in a chemical reaction that produces a solid product.

In my mind we do a lot of things to move water, which can definitely be harmful on a local and regional scale. But it is still water. Am I wrong here?

From a practical perspective, I think there is a clear difference between seawater or contaminated water that is not usable for most human purposes, and clean freshwater that is usable. Converting the latter into the former without getting much value out of it is "waste" in a practical sense.

Analogy - if you blow $10K on nothing, the money hasn't changed state, but it has left your pocket and you probably call that "waste".

Using heat exchangers to boil sea water is one heck of a challenge. The salts tend to lay down and foul the exchangers in no time flat. That causes hot spots, corrosion, and loss of heat transfer.
The trick is to control the heat and pressure so the water flashes to steam at exactly the right moment and place so you can seperate the salts and dispose of them, but it's much harder than it sounds.

Standard rule of thumb is anything higher than a 250 F delta P requires purified water, 150 to 249 can use chemically treated treated (clean) water.

Some nuke plants use sea water as a coolant, but it's a three stage process from core to condensor.

The core heats pure water to turn it to steam.
That water flows through a heat exchanger where it transfers heat to purified water on the other side of the exchanger and turns it into steam but has no physical contact to prevent contamination.

That steam flows through the turbines where it gives up it's heat, and finally exits the low stage turbines into a condensor.
At that time it is technically still steam but it's around 140 degrees F because its under about 28 inches of mercury worth of vacuum created by the condensor.
Sea water flows through the other side of the condendor where it only has to reduce the temperature about 60 degrees and never goes through a phase change.
it still requires a great deal of backflusing, travelling screens, and other maintenance to keep that condensor relatively clean.

No, not exactly. The concept is called "return flows"

But we don't always use the appropriate level of purification or cleanliness for the task at hand.

Death Valley was a lake 10,000 years ago when it rained a lot more in the west. Geologically, that was yesterday.