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为什么要用肥料给森林火灾灭火

Why Are We Dumping Fertilizer on Forest Fires?

Ever seen this before?
你见过这个东西吗?
It’s fertilizer.
这可是肥料
Judging by its color you probably guessed it wasn’t just water.
通过判断颜色 你可以猜到这不仅是水
It’s a long-term fire retardant
这是一种长效阻燃剂
that’s actually a combo of water, fertilizer,
实际上是一种结合 包括水 肥料
and small amounts of other stuff that color it and help it stick together as it falls.
及少量可上色 下落时可粘合起来的其他物质
And it’s not being dropped directly on the fire,
这种肥料不是直接洒在着火区
it’s being dropped just outside of it
而是洒在火区外围
Just one of a few tactics used to stop a destructive blaze.
这只是阻止一场毁灭性大火的少数策略之一
Wildfires are caused by your typical combustion reaction,
森林火灾是由典型的氧化反应引起的
which requires some kind of spark,
这需要一些火花
a fuel, and oxygen.
一种可燃物以及氧气
A spark can come from something in nature
火花可能源于一些自然事物
like a bolt of lighting, but more likely it’ll
比如一道闪电 但更可能是
come from…us.
由我们人类引发
Over the last couple decades,
在过去的几十年中
humans have been responsible for starting over 80 % of wildfires,
人为原因导致的森林火灾超过八成
with things like tossed cigarettes,
比如有人乱扔烟头
or some more bizarre things
或者更离奇的事
like the spark from a hammer hitting a metal stake to plug up a wasp nest.
像堵蜂窝时锤子打在金属桩上产生的火花
Even though fires are a natural part of our ecosystem,
尽管火是生态系统中的自然组成部分之一
when those fires happen on hot, windy days
但当火灾发生在炎热多风天时
they can pose a real threat to people and the environment.
它们会对人类和大自然造成很大威胁
A massive forest provides a whole lotta fuel,
广阔的森林能提供大量燃料
so unless we want our National Parks to become heaps of ash,
所以如果我们不想国家公园被烧成灰烬
there are some blazes that we need to shut down
有些火灾在一发生的时候
as quickly as they start.
我们就需要尽快扑灭
Dumping crazy amounts of water on a forest fire
往发生森林火灾的地方倾倒大量水
is one pretty effective approach.
就是一种十分有效的方法
Water does a couple big things.
水会帮很大的忙
First, water interferes with that combustion reaction
首先 水会干扰氧化反应
because as it vaporizes it creates a layer of water vapor
因为水蒸发时会产生一层水蒸气
that separates the fire’s fuel from the atmospheric oxygen that it needs to keep going.
能够把可燃物和大气中的氧气分离开来
Second,the water cools the fuel,
第二 水能给可燃物降温
which slows and ultimately extinguishes the reaction.
这减慢并最终会阻止氧化反应
During a forest fire,
在一场森林火灾中
firefighters work quickly to put out anything ablaze, including embers,
消防员会迅速扑灭任何着火物 包括余烬
which can fly around and spread the fire.
余烬四处飞扬会使火势蔓延开来
They spray water from the ground and sky,
消防员从地面和空中喷水
refilling tanks at nearby water sources
用附近的水源灌满水箱
like lakes, rivers, or even your family’s pool.
如从湖泊 河流 甚至是你家的泳池
At the same time crews are creating a fire break,
同时 消防员还会开辟一个防火带
which is exactly what it sounds like
就如听起来那样
— a break between the fire and its fuel.
它是在火和其燃料之间的一个隔离带
But dumping water and cutting down forest often isn’t enough.
但是倒水和砍伐森林往往是不够的
So, here’s where that bright red stuff comes in.
这时 这种鲜红色物质就派上用场了
It’s a long-term fire retardant,
它是一种长期阻燃剂
which means it can be sprayed on an area and,
这意味着被喷洒在一个区域时
unless it gets washed away by a rainstorm,
如果不被暴雨冲掉
it will stick around for months.
能保持几个月
It’s made of 85 % water, 10 % fertilizer,
它是由85%的水 10%的肥料
and 5 % other stuff like clay and gum thickeners that help keep it together
及5%其他有助于粘合的物质 如黏土和树胶增稠剂
so that it makes to the ground from the plane.
粘合物确保从飞机上洒的液体落地
And that bright red?
那怎么会有鲜红色
That’s from iron oxide, which gives things a red tint,
鲜红色来自氧化铁 它使物品显红色
or from the dyes like you’d find in food.
也可能是食物中的染料
The color usually fades quickly
鲜红色通常会很快褪去
and is only there to help firefighters see
仅是为了帮助消防员了解
where the long-term retardant has been dropped and
阻燃剂已经被倾倒在哪些地方
what areas still need to be covered.
还有哪些区域需要覆盖
The key is the fertilizer,
阻燃剂关键在于肥料
which is made of di- and mono- ammonium phosphate.
肥料由磷酸二铵和磷酸铵组成
Unlike water it doesn’t extinguish a fire —
不像水那样 肥料不能灭火
it keeps it from ever starting.
但它能阻止火的发生
It reacts with the cellulose in trees and other plant-based fuels
当附近的火焰使空气变热时
when nearby flames cause the air to really heat up.
它会和树中的纤维素及植物燃料反应
This reaction produces carbon, in the form of ash, and water vapor.
这个反应产生以灰烬形式存在的碳以及水蒸气
That vapor then helps cool the fuel around it
水蒸气能帮助冷却周围的燃料
so that it’s less likely to catch fire,
减小着火的可能性
slowing the spread of the fire until it burns out.
同时减缓火势的蔓延直至熄灭
So, we wanted to see it with our own eyes.
我们很想亲眼见识一下
We went to the Department of Fire Protection Engineering at the University of Maryland
我们前往了马里兰州大学的消防工程系
to see this long-term fire retardant in action.
去了解长期阻燃剂的效果
And it worked really well!
它真的非常有效
You can see here that our retardant-soaked
你能看到屏幕左边的
pine needles to the left of the screen never caught fire.
浸有阻燃剂的松针一直未着火
But the untreated ones were burnt to a crisp.
但是未经处理的松针已经烧焦了
So this retardant helps keep fire from spreading,
虽然这种阻燃剂有助于阻止火势蔓延
but how about shutting down a raging fire?
但是如何扑灭一场熊熊大火呢?
That’s where, in addition to water,
灭火时 除了水
foams and gels are so useful.
泡沫和凝胶也非常有用
Foams are surfactants —
泡沫是表面活性剂
they lower the surface tension of water
它们能降低水的表面张力
so that it can penetrate, say, a burning piece of wood.
从而使水易渗入 比如 一块燃木
If you’re interested in learning more about surfactants,
如果你想更加了解表面活性剂
check out our video on shaving cream.
观看我们关于剃须泡沫的视频
But back to wildfires.
回归正题
Foams are dropped out of planes onto a blaze,
泡沫会从飞机倾倒到火焰上
or sprayed from the ground.
或由消防员在地面上喷洒
Although they only stick around for about 30 minutes,
尽管它们只能停留大约30分钟
they keep water from evaporating as quickly as it normally would in such a hot environment.
在这炎热环境中它们仍能快速防止水蒸发 跟平时一样
Keeping water around longer increases the likelihood of a fire going out.
把水留住能增加灭火的可能性
Gels are made up of super absorbent polymers,
凝胶是由高吸水性聚合物组成的
like those you’d find in a baby’s diaper.
你在婴儿尿不湿上也能发现它们
They aren’t used all that often
它们的使用不是很普遍
because they can be kind of a pain to store and separate
因为如果温度不合适
if they aren’t at the right temperature.
它们很难被存储和分离
Their big selling point is that
凝胶最大的卖点在于
they can go on a vertical surface,
它们能保持在垂直表面上
like the wood roof of a home, and stick to it,
如家里的木屋顶
unlike foams or water which drip off.
不像泡沫或水会滴落
The polymers in the gel can soak up a ton of water,
凝胶中的聚合物可以吸收大量的水
keeping whatever it’s stuck to well hydrated.
保持粘住的表面湿润
In a hot environment, like is the case for wildfires,
在炎热的环境中 例如森林火灾
the gel will really only stick around for a couple hours.
凝胶实际只能停留大约几个小时
And because they don’t last all that long,
因为不能持续很久
water, foams and gels should mostly be used to put out a fire,
所以水 泡沫和凝胶应该主要用于灭火
not to prevent it.
而不是防火
This means that, if you’re trying to protect your home from flames,
这意味着如果你不想你的房子着火
your best bet is to clear any flammable materials around it,
最好是清理掉房子周围的任何可燃物
so that the area is less likely to ignite,
以减小这片区域起火的可能性
and maybe lay out some of that fertilizer-based retardant.
也许还可以再放一些化肥阻燃剂
If you’re applying foams and gels to your home,
如果大规模的野火几小时后就要烧到你家
when a massive wildfire is only a couple hours out,
而你往房子上涂泡沫和凝胶
then you’re putting your life and the lives of first responders at risk.
那你就是将自己和急救人员的生命置于危险中
Using these US Forest Service-approved wildfire-fighting chemicals
使用这些美国林业局批准的灭火药剂
doesn’t come without questions about what they could be doing to the environment and to us.
并不意味着它们对于环境和我们的影响毫无问题
Researchers haven’t found concern when it comes to humans or their pets,
研究人员尚未发现它们对人和宠物的影响
but when it comes to marine life —
但至于海洋生物
studies are ongoing.
研究正在进行
And that’s because nutrients like nitrogen and phosphorus,
因为长期使用的肥料中的营养素
which are found in long-term fertilizers,
如氮和磷
can cause things like algal blooms,
会导致藻类水华的产生
which are notoriously deadly for aquatic critters.
这对水生物是致命的
It’s important to note that
值得注意的是
the US Forest Service is trying to prevent against this happening
美国林业局正通过实施严格的指导方针
by putting strict guidelines in place.
试图阻止这一情况的发生
Right now, long-term fertilizer-based retardants
现规定 长期使用的化肥阻滞剂
can’t be dropped within 300 feet of open waterways
不能投放在开放水道300英尺范围内
like lakes, creeks, and streams.
例如湖泊 小溪和溪流
Continuing to research ways to make these products even safer is important,
深入研究如何使这些产品更安全是很重要的
but for now they’re probably the least harmful option we have.
但是现在它们可能是对我们威胁最小的选择了
Melted fridges,
融化的冰箱
smoldering lead-painted buildings with asbestos in the walls,
墙上有石棉的阴燃铅涂建筑
electrical wiring and plastic pipes burnt to a crisp.
电线以及烧焦了的塑料管
When these things burn, there are some seriously dangerous chemicals released.
这些东西燃烧会释放非常危险的化学物质
With global warming,
随着全球变暖
it’s looking like these massive blazes will become all too common.
这些火灾似乎会发生得越来越频繁
So, if you find yourself in the woods with a box full of fireworks,
如果你带了一整箱烟花去森林
please don’t…
请不要……
Wait.
等等
Why are you in the woods with fireworks?
你为何要带烟花去森林?
We’d like to thank Phos-Check for the flame retardant, foam, and gel
我们要感谢磷系阻燃剂 泡沫和凝胶
so we could do these cool demos.
让我们能做这些很酷的演示
And Michael Gollner
还要感谢Michael Gollner
and the Department of Fire Protection Engineering at the University
和马里兰大学消防工程系
of Maryland for not only letting us take over their lab
不仅让我们借用他们的实验室
but for helping us light things on fire and safely put them out.
还帮助我们点燃物品并安全将其扑灭
If you’re craving more firey footage,
如果你对关于火的视频感兴趣
check out our past video on How Matches Work.
可以看看我们之前的视频
See you next week!
下周见

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视频概述

水可以扑灭森林火灾,但是以肥料为基础的新型阻燃剂可以更好地减缓火灾蔓延甚至熄灭森林火灾。

听录译者

收集自网络

翻译译者

夜寐€®夜魅

审核员

审核员BC

视频来源

https://www.youtube.com/watch?v=fNGq8hEuNb8

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