Essential Formulas and Key Models Quick Reference | 必背公式与关键模型速查手册

📚 Essential Formulas and Key Models Quick Reference | 必背公式与关键模型速查手册

This revision guide compiles the essential quantitative formulas and conceptual models required for the Edexcel GCSE Geography Year 10 course. From population change to river processes, these tools will help you interpret data, analyse geographical patterns, and ace your exams.

本文汇总了 Edexcel GCSE 地理 Year 10 课程所必需的核心定量公式与概念模型。从人口变化到河流过程，这些工具将帮助你解读数据、分析地理格局并在考试中脱颖而出。

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1. Population Change Formulas | 人口变化公式

Total Population Change = (Births – Deaths) + (Immigration – Emigration)

This equation combines natural change (births minus deaths) with net migration to compute overall population change over a specific period.

该方程将自然变动（出生数减死亡数）与净迁移量结合起来，计算特定时期内的总人口变化。

Other vital rate formulas include:

其他重要比率公式包括：

Crude Birth Rate (CBR) = (Total live births ÷ Total population) × 1,000

CBR expresses the number of live births per 1,000 people per year, standardised for comparison between places.

粗出生率表示每年每千人中活产婴儿数，标准化后便于不同地区间的比较。

Crude Death Rate (CDR) = (Total deaths ÷ Total population) × 1,000

Similarly, CDR indicates the annual number of deaths per 1,000 inhabitants.

类似地，粗死亡率表示每年每千名居民中的死亡人数。

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2. Natural Increase and Net Migration | 自然增长率与净迁移

Rate of Natural Increase (%) = (CBR – CDR) ÷ 10

Since CBR and CDR are expressed per 1,000, dividing their difference by 10 converts it into a percentage. A positive value means births exceed deaths.

由于粗出生率和粗死亡率以千分比表示，将其差值除以 10 便转换为百分比。正数意味着出生人数超过死亡人数。

Net Migration Rate = (Immigrants – Emigrants) ÷ Total population × 1,000

This indicator shows the net effect of migration on a population per 1,000 people. Positive net migration adds to population growth.

该指标显示每千人中迁移的净效应。净迁入为正，促进人口增长。

Total growth rate (%) = Natural increase rate (%) + Net migration rate (%), though careful attention must be paid to units when combining rates.

总增长率（%） = 自然增长率（%） + 净迁移率（%），但在合并使用不同单位时需留心换算。

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3. Dependency Ratio | 抚养比

Dependency Ratio = [ (Population aged 0–14 + Population aged 65+) ÷ Working-age population (15–64) ] × 100

This ratio measures the pressure on the productive population. A high dependency ratio indicates that each worker supports more dependants, which can strain public services.

该比率衡量生产性人口所承受的压力。高抚养比意味着每个劳动者需要供养更多依赖人口，可能给公共服务带来压力。

Youth dependency ratio and old-age dependency ratio can also be calculated separately to analyse demographic structure.

还可分别计算少儿抚养比和老年抚养比，以分析人口年龄结构。

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4. Population Density | 人口密度

Arithmetic Density = Total population ÷ Land area (km²)

Arithmetic density gives an average number of people per square kilometre. It is the most common measure of density but can be misleading where large uninhabitable areas exist.

算术密度表示每平方公里的平均人口数。这是最常用的密度指标，但在有大片无人居住区域时可能产生误导。

Physiological density (population per unit of arable land) provides a more nuanced view of population pressure on productive land.

生理密度（每单位耕地面积的人口数）更能体现人口对生产性土地的压力。

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5. Urbanisation Indicators | 城市化指标

Urbanisation rate (%) = (Urban population ÷ Total population) × 100

This shows the proportion of a country's population living in areas classified as urban. It increases as countries develop and rural-to-urban migration continues.

该指标显示一国人口居住在城市地区的比例。随着国家发展与农村向城市迁移，城市化率会不断提高。

Rate of urban growth (%) = [(Urban population at end – Urban population at start) ÷ Urban population at start] × 100

Urban growth rate measures the speed of urban expansion, influenced by both natural increase and net migration.

城市增长率衡量城市扩张的速度，受自然增长和净迁移的共同影响。

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6. Demographic Transition Model (DTM) | 人口转变模型

The DTM is a model describing how birth rates, death rates, and total population change as a country develops. It comprises five stages:

人口转变模型（DTM）描述了随着国家发展，出生率、死亡率和总人口如何变化。它包含五个阶段：

Stage 1: High fluctuating birth and death rates, slow population growth. Stage 2: Death rate falls rapidly while birth rate remains high, leading to rapid growth. Stage 3: Birth rate begins to decline, growth slows. Stage 4: Both rates are low, stable population. Stage 5: Death rate may exceed birth rate, causing natural decrease.

第一阶段：高出生率与高死亡率波动，人口增长缓慢。第二阶段：死亡率迅速下降而出生率仍高，导致快速增长。第三阶段：出生率开始下降，增长放缓。第四阶段：两率均低，人口稳定。第五阶段：死亡率可能超过出生率，导致自然减少。

Knowing the DTM helps predict population structures and the challenges each stage brings, such as pressure on healthcare or an ageing population.

Published by TutorHao | Year 10 Geography Revision Series | aleveler.com

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