Population and Migration Patterns and Processes
AP Human Geography Topic 2 8:48 English narration · English + 中文 subtitles burned in
Chapters
Transcript
Eight billion people live on this planet.
地球上生活着八十亿人。
Now look at this street.
现在看看这条街。
At one crossing in Tokyo, hundreds of them share a space the size of a school hall.
在东京的一个路口， 几百人挤在一个礼堂大小的空间里。
<slow>People have never been spread evenly.</slow> Where they live, and why they move, is this whole unit.
人从来都不是均匀分布的。 他们住在哪里、为什么迁移，就是本单元的全部内容。
Welcome to Unit Two.
欢迎来到第二单元。
We will count people, read the shape of a population, follow the model every country moves through, and then follow the people themselves as they migrate.
我们会数人口、读懂人口的形状、跟随每个国家都会经历的模型， 然后跟随迁移的人们本身。
Let's begin.
让我们开始吧。
Start with where.
先看“在哪里”。
People cluster where the land is kind: the temperate mid-latitudes, low-lying land, fresh water, and arable soil.
人们聚集在条件友好的土地上：气候温和、地势低平、有淡水、土壤好。
Coasts and river valleys hold most of humanity.
海岸和河谷养活了世界上大多数人。
Distribution is where people are; density is how crowded they are.
分布是指人在哪里，密度是指有多拥挤。
Carrying capacity is the number of people an area's resources can support.
而环境承载力，是一个地区的资源能供养的人口数量。
The exam wants three densities, not one.
考试要考三种密度，而不是一种。
Take a country of twelve million people, sixty thousand square kilometres of land, but only fifteen thousand farmed, by one and a half million farmers.
设想一个国家有一千二百万人，六万平方公里土地， 但其中只有一万五千平方公里被耕种，由一百五十万农民劳作。
Arithmetic density is people divided by all the land: two hundred.
算术密度是人口除以全部土地：二百。
Physiological density is people divided by farmland only: eight hundred.
生理密度是人口只除以耕地：八百。
Agricultural density is farmers divided by farmland: one hundred.
农业密度是农民除以耕地：一百。
<slow>Each one tells a different story.</slow>
每一个都在讲不同的故事。
Now the shape of a population.
现在看人口的形状。
Put the men on one side, the women on the other, in five-year age cohorts — youngest at the bottom, oldest at the top.
把男性放在一侧，女性放在另一侧，按五岁一组从下往上堆叠—— 最年轻的在底部，最年长的在顶部。
That is a population pyramid, and population composition is exactly this: who the people are, by age and sex. and it is a country's future drawn as a picture.
这就是人口金字塔，它把一个国家的未来画成了一张图。
Watch what happens when people live longer and have fewer children.
看看当人们寿命更长、孩子更少时会发生什么。
Three shapes, three futures.
三种形状，三种未来。
A wide base means high birth rates and rapid growth.
底部宽表示出生率高、增长快。
Straight sides mean slow, steady growth.
两侧竖直表示增长缓慢而稳定。
A narrow base with a heavy middle means an aging, shrinking population.
底部窄、中部厚，表示人口正在老龄化并缩减。
One number goes with the picture: the dependency ratio, comparing people under fifteen and over sixty-four with the workers in between.
还有一个数字要配着看：抚养比， 它把十五岁以下和六十四岁以上的人，与中间的劳动人口做比较。
Now count the change.
现在来数变化。
The crude birth rate, C B R, and the crude death rate, C D R, are births and deaths each year for every thousand people.
粗出生率（CBR）和粗死亡率（CDR）， 是每年每一千人中的出生数和死亡数。
Births come in, deaths go out, and the gap between them is growth.
出生进来，死亡出去，两者之间的差就是增长。
The rate of natural increase, R N I, is C B R minus C D R, divided by ten, as a percent — and doubling time is seventy divided by R N I.
自然增长率（RNI）就是粗出生率减粗死亡率再除以十，用百分比表示； 而倍增时间等于七十除以自然增长率。
It ignores migration.
它不考虑迁移。
The total fertility rate, T F R, counts children per woman, and about two point one is replacement level.
总和生育率（TFR）数的是每位女性平均生几个孩子， 大约二点一就是更替水平。
Nigeria has a crude birth rate of thirty-seven and a crude death rate of twelve, both per thousand.
我们来用一用。 尼日利亚的粗出生率是三十七，粗死亡率是十二，都是每千人。
Find the rate of natural increase, then the doubling time.
求自然增长率，再求倍增时间。
Pause here and try it.
先暂停，自己算一算。
Step one: thirty-seven minus twelve is twenty-five, and twenty-five divided by ten gives two point five percent a year.
第一步：三十七减十二等于二十五， 二十五除以十，得到每年百分之二点五。
Step two: doubling time is about seventy divided by that percent — twenty-eight years.
第二步：倍增时间约等于七十除以这个百分数， 也就是二十八年。
<slow>Here is the trap.</slow> Forget the divide by ten, and you report twenty-five percent.
这里有个陷阱：忘了除以十，你就会写成百分之二十五。
Every country that has industrialised has walked the same path, and geographers drew it as the demographic transition model.
每一个完成工业化的国家都走过同样的路径，地理学家把它画成了人口转变模型。
Two lines: births on top, deaths below.
两条线：上面是出生，下面是死亡。
Watch the gap between them, because that gap is the natural increase.
盯住它们之间的差距，因为那个差距就是自然增长。
Close together, the population barely changes. Pulled apart, it booms.
靠得近时，人口几乎不变；拉开时，人口就会激增。
Five stages, and the order matters.
五个阶段，顺序很重要。
Stage one: both rates high, so growth is slow.
第一阶段：两个率都高，所以增长缓慢。
Stage two: the death rate falls first — better food, clean water, medicine — while births stay high, and the population booms. Stage three: births fall too, as families move to cities and girls stay in school.
第二阶段：死亡率先下降——食物更好、水更干净、有了医药——而出生率仍然很高， 人口激增。
Stage four: both low and steady. Stage five: births fall below deaths, and the country ages.
第三阶段：出生率也开始下降，因为家庭迁入城市，女孩继续上学。
Alongside runs the epidemiological transition: deaths move from infectious disease to chronic, degenerative disease.
第四阶段：两个率都低而稳定。 第五阶段：出生降到死亡以下，国家人口老化。
The whole shape is the Demographic Transition Model, the D T M.
与之并行的是流行病学转变：主要死因从传染病转向老年病。
In seventeen ninety-eight, Thomas Malthus made a famous prediction. People multiply — two, four, eight, sixteen.
一七九八年，托马斯·马尔萨斯做出了一个著名的预测。
Food only adds — one field, then one more — population exponentially, food only linearly.
人口成倍增长——二、四、八、十六。
So the lines must cross, and then famine, disease and war would cut the population back.
而粮食只是逐次相加——一块田，再加一块田。
He was wrong, and the screen shows why: farming technology raised food output far faster than he assumed.
所以两条线必然相交， 在那之后，饥荒、疾病和战争会把人口压回去。
Population policies have the same trouble: China's one-child policy left unintended consequences its planners never modelled.
他错了，屏幕上写明了原因： 农业技术让粮食产量增长得远比他设想的快。
Neo-Malthusians keep the worry alive, but point at water and energy.
新马尔萨斯主义者延续了这份担忧，但把矛头指向水、能源和土壤。
Governments try to steer the numbers.
各国政府则努力引导人口数字。
A pro-natalist policy encourages births — cash bonuses, paid leave — where populations are aging, like France and Japan.
鼓励生育的政策促进生育——现金奖励、带薪假、 廉价托育——常见于人口老化的国家，比如法国和日本。
An anti-natalist policy discourages births where growth looks too fast, like India's family-planning campaigns.
限制生育的政策则在增长过快的地方抑制生育，比如印度的计划生育宣传。
But it can skew the sex ratio.
但它可能扭曲性别比。
Nothing moves fertility more than the status of women.
没有什么比女性的地位更能改变生育率。
As girls stay in school longer and women take paid work, families get smaller.
当女孩在学校待得更久、女性从事有薪工作， 结婚就更晚，家庭也更小。
That is the engine behind stage three.
这正是第三阶段背后的推动力。
At the other end sits aging: low fertility plus long life raises the share of people over sixty-five, and with it pension and health bills.
另一端是老龄化： 低生育加上长寿，使六十五岁以上人口的比例上升，养老金和医疗开支也随之上升。
Countries answer by raising the retirement age, or welcoming immigrants.
各国的应对办法是提高退休年龄，或者欢迎移民。
Now the second half of the unit.
现在进入本单元的后半部分：人的移动。
Migration is a permanent move to a new home, and every move is a tug of war.
迁移是指永久搬到一个新的居住地， 而每一次迁移都是一场拉锯。
Push factors drive people out of the origin: war, poverty, disaster, persecution.
推力把人推离原居地：战争、贫困、灾害、迫害。
Pull factors draw them to the destination: safety, education, employment, family, better services.
拉力把人吸引到目的地：安全、工作、家人、更好的公共服务。
Between them sits the intervening obstacle — distance, cost, a closed border.
在两者之间是阻碍因素——距离、费用、一道关闭的边界。
Migration comes in two families.
迁移分为两大类。
Forced migration gives no choice — people fleeing danger, and, in history, slavery.
强迫迁移完全没有选择——逃离危险的人，以及历史上的奴隶制。
The line the exam tests: a refugee crosses an international border — refugees are counted that way — while an internally displaced person, an I D P, stays inside their own country, and an asylum seeker is still asking for that status.
考试要考的界线是：难民跨越国界，境内流离失所者留在本国境内， 而寻求庇护者是正在申请被认定为难民的人。
Voluntary migration is chosen, usually for work: chain migration follows family, step migration goes village to town to city, and rural-to-urban is the biggest internal flow today.
自愿迁移是自己选择的，通常为了工作： 连锁迁移是投奔先走的亲人，阶梯迁移是从村庄到城镇再到城市， 而乡村到城市是当今最大的人口流动。
Ravenstein's laws saw it long ago — most moves are short, in steps, and for work.
拉文斯坦很早就看出来了—— 大多数迁移距离短、分步进行、为工作而发生。
Migration changes both ends, and the exam asks for the consequences on each.
迁移会同时改变两端。
The destination gains workers, usually young adults, and new culture — but housing, schools and services come under pressure.
目的地获得劳动力，通常是年轻成年人，还有新的文化—— 但住房、学校和公共服务会承受压力。
The origin loses those same young adults, so it ages; if the leavers are doctors and engineers, that loss is brain drain.
原居地失去的正是这些年轻人，因此人口老化； 如果离开的是医生和工程师，这种流失就叫人才外流。
Money does flow back, though: remittances, the money migrants send home.
不过钱确实会流回来： 侨汇，就是移民寄回家的钱。
Here is a real exam prompt. Explain one reason why the rate of natural increase in urban areas may vary significantly from the rate in rural areas of the same country.
这是一道真实的考题：解释一个原因，说明为什么同一个国家城市地区的自然增长率 可能与农村地区明显不同。
Pause and write your answer.
先暂停，写下你的答案。
Look at the command word.
先看命令词。
Explain wants a chain: name the reason, then follow it to the rate. Here is a full-mark answer.
“解释”要的是一条因果链：说出原因，再一路推到那个增长率。
In cities the cost of living is higher, so families have fewer children; fewer births lower the birth rate, so the urban rate falls below the rural rate.
这是一个满分答案。 在城市，生活成本更高，所以城市家庭孩子更少；出生减少拉低出生率， 于是城市的增长率低于农村。
And here is what earns nothing: cities are expensive.
而这样写得零分：“城市很贵。”
It stops before the rate.
它没有推到增长率。
Four marks students throw away.
四个学生常丢的分。
First, divide by ten: the rates are per thousand, but natural increase is a percent, and doubling time is seventy over that percent.
第一，记得除以十：出生率和死亡率是每千人， 而自然增长率是百分数，倍增时间是七十除以这个百分数。
Second, read the base of the pyramid — a wide base means stage two.
第二，看金字塔的底部—— 底部宽就是第二阶段。
Third, the death rate falls before the birth rate; that is why stage two grows fastest.
第三，死亡率先于出生率下降，这就是第二阶段增长最快的原因。
Fourth, a refugee crosses a border, and a displaced person does not.
第四，难民跨越国界，而境内流离失所者没有。