没有淡水存款重新水循环吗?- 江南体育网页版- - - - -地球科学堆江南电子竞技平台栈交换 最近30从www.hoelymoley.com 2023 - 07 - 07 - t01:39:51z //www.hoelymoley.com/feeds/question/15754 https://creativecommons.org/licenses/by-sa/4.0/rdf //www.hoelymoley.com/q/15754 8 没有淡水存款重新水循环吗? user14513 //www.hoelymoley.com/users/0 2018 - 12 - 11 - t17:22:54z 2020 - 11 - 21 - t00:11:15z

I have recently watched the documentary "How Many People Can Live on Planet Earth?" with David Attenborough. In it, the main factors that will limit total human population Earth can support are named. One of these was the limited amount of fresh water. There also was a part where it described how fresh water is distilled from astronaut urine on the International Space Station .

My current understanding is that all the water (fresh or not) in nature (i.e. on planet Earth) is infinitely going through a water cycle, and thus non-fresh water is sort of distilled into fresh by this natural process.

My questions are:

  1. Where am I wrong in my assumption about natural water distillation (i.e. is rain water not as clean as it should be in theory)?
  2. Why don't we collect rain water (at least for plant watering, if it is not suitable for drinking)?
  3. Theoretically, after an animal has consumed some amount of water, say a glass, how long will it take, after that animal urinates on the ground, for that water to go through the water cycle and become ready for drinking again?
//www.hoelymoley.com/questions/15754/-/15755 # 15755 2 弗雷德回答的不是淡水存款重新水循环吗? 弗雷德 //www.hoelymoley.com/users/2470 2018 - 12 - 11 - t19:37:19z 2018 - 12 - 11 - t19:37:19z < p >雨水仍然是最干净的水源之一。这其中可能有某些像是古代的地下蓄水层清洁未被污染的水。< / p > < p >雨水的一个问题是大气水分-水循环的一部分需要凝结气溶胶在大气中才能发展成雨。的污染人类倾倒到大气中一些能够形成气溶胶,最终发展成雨使雨水脏比以前,如< a href = " http://paos.colorado.edu/ ~ fasullo / 1060 /气溶胶/ aeroimp.html”rel = " nofollow noreferrer " > < / >形成酸雨当硫时倾倒到大气中二氧化碳高硫煤燃烧电站。其他气溶胶包括< a href = " http://www.homepages.ed.ac.uk/shs/Climatechange/Data%20sources/Jensen%20marine%20cloud%20aerosol.pdf " rel = " nofollow noreferrer " >盐从海洋中< / >。< / p > < p >雨水的另一个问题是在集水区土壤受到污染。雨落在集雨能吸收一些污染物从而使合成的雨水集水脏,它可能已经过去。< / p > < p >关于动物的尿液生产速度,这取决于类型的动物。鼠标将处理水以不同的速度一头大象或国内股票。它也通过为每个类型的动物昼夜节律的影响。< / p > //www.hoelymoley.com/questions/15754/-/15759 # 15759 1 答案由埃里克不是淡水存款重新水循环吗? 埃里克 //www.hoelymoley.com/users/14194 2018 - 12 - 12 - t07:38:25z 2018 - 12 - 12 - t07:38:25z < p >雨水排水问题是,它阻碍了地下水的形成,因此消耗这些资源,使其不可用期间干旱。另外,地下水往往比雨水清洁据我所知,没有提供水力压裂或地下核废物存储。< / p > //www.hoelymoley.com/questions/15754/-/20358 # 20358 1 LazyReader回答的不是淡水存款重新水循环吗? LazyReader //www.hoelymoley.com/users/21028 2020 - 10 - 19 - t23:44:01z 2020 - 11 - 06 - t03:38:56z < p >农业用水主要是< a href = " https://en.wikipedia.org/wiki/Fossil_water " rel = " nofollow noreferrer " > < / >化石水,花了成千上万年的积累和工业活动使用了一个世纪。沙特阿拉伯< br / >是< a href = " https://www.world-grain.com/articles/6275-saudi-arabia-ends-domestic-wheat-production-program " rel = " nofollow noreferrer " >放弃计划种植小麦< / >实现自给自足,但耗尽沙漠王国的稀缺的水资源供应。从< a href = " https://en.wikipedia.org/wiki/Agriculture_in_Saudi_Arabia " rel = " nofollow noreferrer " > 6日最大出口国< / >。人类水源来自山区径流、地下水或河流/湖泊池塘.........它必须来自源更快速雨再生是有用的。水渗透到地下。这需要几个月或几年........和蓄水层问题他们已经有10000年的积累。人工降雨再生,水可以在暴风雨后转移部分过滤,允许流量通过排水沟、涵洞、壕沟等流入保留盆地,它会渗透到挖井。威尼斯人使用这种技术作为城市威尼斯没有可靠的水位。水会通过致密层的沙子和通过一个水箱。这是几千年的水排水技术的顶峰。江南登录网址app下载 enter image description here Another is the recharge pit used to regenerate abandoned wells that have been drained by prolonged use. The well's main pipe is dug 10 feet down and several feet out, then the bottom foot of the pipe is drilled to permit water to flow into it. Wrapped in a mesh/protective layer so water can flow but debris and particles cannot. Then the first 3 feet are lined with large rocks/boulders then the next 3 feet lined with smaller rocks and cobble. This is to press against the pit to keep it's inner wall from collapsing in on itself. often the next layer is a permeable filter fabric filled with activated charcoal then lined with course sand and regular fine compacted sand. Redirected rainwater entering the pit will slowly filter into the layers then fill the well. This discharge allows water wells long abandoned to be refilled using the rainy monsoon seasons water to sustain agricultural activity in the hotter dry season. enter image description here

//www.hoelymoley.com/questions/15754/-/20429 # 20429 2 Bruzote回答的不是淡水存款重新水循环吗? Bruzote //www.hoelymoley.com/users/7800 2020 - 11 - 03 - t05:15:46z 2020 - 11 - 20 - t22:03:32z 李< blockquote > < ol > < >我错在我假设自然水蒸馏(即是雨水不像它应该清洁理论上)?< /李> < / ol > < /引用> < p >一般来说,雨水很干净。这不是一个问题。另外,我们对待地下水和水库河/湖/水,所以我们很容易把雨水。你真的不能错过的是地下水和水库河/湖/只是雨水。水从雨水很多。用水时,人类正在水更快的地面比地面可以收集它。现在,如果地面不能收集水足够快,和地面覆盖了几乎所有的土地(建筑物、水体的除外),那么我们人类不能几乎收集了比地面雨水。So, as long we use up more ground water than the ground can "collect" due to rain fall, we're going to run out of water. Now, there are some technical ways we could collect water better than the ground (e.g., don't let it evaporate, don't let it runoff into unused rivers). However, there is no way we could get as much water as all the land on Earth collects!

  1. Why don't we collect rain water (at least for plant watering, if it is not suitable for drinking)?

We do collect rainwater. We normally collect rainwater when it is easier to collect it locally than to get it from where it naturally flows to. If you count dams, we hold back water and collect water that way so it doesn't flow too quickly to the ocean, where it becomes too salty to drink or use for irrigation. Some people also collect rainwater from their roof, while others just leave out an open barrel (that's not much of surface area for collecting rain).

  1. Theoretically: after an animal consumed some amount of water, say a glass, how long will it take, given that animal just urinated on the ground, for that water to go through water cycle and become ready for drinking again?

That depends on if the urine is going eventually into a river, shallow groundwater only 50 feet (or less), or a subterranean aquifer a few thousand feet down. It can evaporate immediately from the ground or flow into a river and evaporate the same day. On the other hand, some groundwater percolates far down into the Earth into "aquifers". We remove water from those using wells, and we say those aquifers "recharge" when more water moves into them.

The famous Oglalla aquifer recharges at a rate of about 0.85 inches per year. That is, if we draw it down an inch in a year, it won't even fill up to where it was in the next year. How long it takes water to get to a specific level from the surface is affected by porosity and the amount of water already in the rock. Water can't flow when it is blocked by water, right? Also, much water also moves horizontally as well as vertically. So, asking how long it takes for water to go from X to Y directly below it would assume that water even follows that path. It might be that Y only gets water from a far-away location Z. So, I will pass on the "how long" part of the question. I will add, though, that some groundwater is tens of thousands of years old. There are 12,000 inches per thousand feet. If an aquifer is 3,000 feet below the surface, it is 36,000 inches down. If the aquifer recharges at 1 in/yr, then dividing the distance (36,000) by the speed (the average flow of 1 in/yr) give you the time of travel -> 36,000 years. Again, that is an idealized vertical drainage with no feedback mechanisms and constant flow rate. The situation is more complex than that, but that's how you can think about it. :-)

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