📚 Year 10 Eduqas Geography: Quick Reference Formula & Theorem Handbook | 10年级Eduqas地理：公式定理速查手册
In Year 10 Eduqas Geography, a strong grasp of key formulas and theorems is essential for interpreting data, completing fieldwork, and answering exam questions accurately. This handbook compiles the most important quantitative relationships you will encounter, from river discharge to population change. Use it for quick revision and to ensure you apply each formula correctly in context.
在10年级Eduqas地理学习中，熟练掌握关键公式和定理对于解读数据、完成野外考察以及准确回答考试问题至关重要。本手册汇集了你将遇到的最重要的定量关系，从河流流量到人口变化。用它来快速复习，并确保在上下文中正确应用每一个公式。
1. River Discharge Formula | 河流流量公式
River discharge (Q) measures the volume of water flowing through a river channel per second. It is calculated using the cross-sectional area of the channel (A) and the average flow velocity (V). The formula is fundamental for understanding river regimes and flood risks.
河流流量（Q）衡量每秒流过河道的体积。它通过河道横截面积（A）和平均流速（V）来计算。该公式对于理解河流状况和洪水风险至关重要。
Q = A × V
Where Q is discharge in cubic metres per second (m³/s), A is cross-sectional area in square metres (m²), and V is velocity in metres per second (m/s). In fieldwork, you may measure channel width and depth to estimate A, and use a float or flowmeter to find V.
其中 Q 是流量，单位为立方米每秒（m³/s）；A 是横截面积，单位为平方米（m²）；V 是流速，单位为米每秒（m/s）。在野外考察中，你可以测量河道宽度和深度来估算 A，并使用浮标或流速计来测定 V。
m³/s. This value can be plotted on a hydrograph to analyse peak discharge during a storm.
例如，如果一条河流的横截面积为12 m²，平均流速为0.8 m/s，则流量为12 × 0.8 = 9.6 m³/s。该数值可绘制在水位过程线上，以分析暴雨期间的洪峰流量。
2. Gradient Calculation | 坡度计算
Gradient describes the steepness of a slope or river bed. In geography, it is most often expressed as a ratio, a percentage, or an angle. Calculating gradient helps compare valley profiles and understand erosion potential.
坡度描述了斜坡或河床的陡峭程度。在地理中，最常以比率、百分比或角度来表示。计算坡度有助于比较河谷剖面并理解侵蚀潜力。
Gradient = Vertical rise (m) ÷ Horizontal distance (m)
To obtain a percentage, multiply the result by 100. For a ratio, divide both numbers by the smallest value to express as 1:X. The horizontal distance must be measured along the map or ground, not along the slope.
要得到百分比，将结果乘以100。要以比率表示，将两个数值除以较小的数值，表达为1:X的形式。水平距离必须沿着地图或地面测量，而不是沿着斜坡。
20 m over a horizontal distance of 400 m, giving a gradient of 20 ÷ 400 = 0.05, which is 5% of 1:20. Field sketching and contour patterns on OS maps rely on gradient interpretation.
例如，一条道路在400米水平距离内上升了20米，得出坡度为20 ÷ 400 = 0.05，即5%。这可以写成1:20的比率。野外素描和地形测量地图上的等高线图案都依赖于对坡度的解读。
3. Population Density | 人口密度
Population density measures how crowded an area is. It is one of the most frequently used demographic indicators, allowing comparisons between urban and rural regions and helping to plan services.
人口密度衡量一个地区的拥挤程度。它是最常用的人口统计指标之一，可用于比较城乡区域，并帮助规划服务设施。
Population Density = Total Population ÷ Land Area (km² or mi²)
Usually, population is taken from census data, and land area excludes water bodies. The unit is persons per square kilometre (people/km²). High densities are typical of cities, while low densities occur in deserts or highlands.
通常，人口数据来自人口普查，土地面积不包括水域。单位是每平方公里人数（人/km²）。高密度常见于城市，而低密度出现在沙漠或高原地区。
65,000,000 ÷ 240,000 ≈ 271 people/km². This figure can be mapped using choropleth shading.
举例来说，如果一个国家有6500万人口，面积为24万平方公里，则其人口密度为65,000,000 ÷ 240,000 ≈ 271人/km²。该数值可以用分级统计图进行绘制。
4. Crude Birth Rate and Death Rate | 粗出生率与粗死亡率
Crude birth rate (CBR) and crude death rate (CDR) are basic demographic measures that show the number of live births or deaths per 1,000 people in a year. They are called 'crude' because they do not account for the age structure of the population.
粗出生率（CBR）和粗死亡率（CDR）是基本的人口统计指标，显示每年每千人中的活产或死亡数量。它们被称为“粗”是因为没有考虑人口的年龄结构。
CBR = (Number of live births in a year ÷ Total population) × 1,000
CDR = (Number of deaths in a year ÷ Total population) × 1,000
These rates are expressed per 1,000 people to allow easy comparisons between countries of different sizes. A high CBR often indicates a youthful population, while a high CDR may reflect an aging population or health issues.
这些比率以每千人表示，便于在不同规模的国家之间进行比较。高CBR通常表明人口年轻化，而高CDR可能反映出人口老龄化或健康问题。
4 births per 1,000 people. This raw figure can then be used to calculate natural increase.
例如，一个人口为50万的城市在某年内记录了12,000名活产婴儿。粗出生率为 (12,000 / 500,000) × 1,000 = 24每千人。这个原始数据随后可用于计算自然增长率。
5. Natural Increase Rate | 自然增长率
The rate of natural increase (RNI) shows how fast a population is growing due to births and deaths alone, ignoring migration. It is a key indicator in the Demographic Transition Model.
自然增长率（RNI）显示仅由出生和死亡引起的人口增长速度，忽略迁移因素。它是人口转变模型中的关键指标。
Natural Increase Rate =
Published by TutorHao | Year 10 Geography Revision Series | aleveler.com 更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图