Political and physical maps

Maps can show different things.

Some maps show countries and towns. Some show mountains and rivers. They can be maps of the very same place.

Two maps of the same place can look completely different, because each one is made for a different job. Britannica Kids explains that political maps show countries, states or counties, while physical maps show mountains, rivers and other natural features.

A political map helps you find which country a city is in. A physical map helps you see where the mountains rise and the rivers flow. Both are useful, and many maps mix them together.

Britannica Kids lists political and physical maps among the most popular kinds of maps, alongside road maps and thematic maps. The difference is in what each one chooses to show. A U.S. Geological Survey (USGS) teaching lesson makes the same point: different maps highlight different physical and human-made features, because mapmakers emphasize what the map is for.

Political maps are about people's divisions of land. Physical maps are about the land itself. Learning both helps you notice that a single place has two kinds of geography at once: the shape of its land and water, and the lines and names people have given it.

Political maps show countries.

Each country is often a different color. Lines between them show the borders. Dots or stars show cities.

Political maps show the lines people have drawn to divide land: the borders of countries, states, provinces, counties and cities. Countries are often colored differently so you can tell them apart, and capitals and other cities are marked with dots or stars.

National Geographic Education explains that borders are created by people to separate areas governed by different groups. Sometimes they follow rivers or mountains, but most of the time you cannot see them on the ground. Most maps show these political boundaries.

Britannica Kids notes that countries, provinces and counties are the focus of political maps, whose bright colors and crisp borderlines are deceptively simple: they tell only partial truths about borders that may be shifting or arbitrary, and they do not show that many borders have no wall or fence at all.

Borders change. Britannica Kids gives examples: countries break apart (the Soviet Union and Yugoslavia), are renamed (Zaire to Congo, Burma to Myanmar) or reunify (Germany). National Geographic Education adds that political boundaries change through wars, treaties and trade. Even map datasets must decide how to draw them: Natural Earth, a free world map dataset, draws de facto boundaries and marks controversial ones as disputed.

Physical maps show what nature made.

They show mountains, rivers, lakes and deserts. Some use colors to show high land and low land.

Physical maps show the natural features of the land: rivers, lakes, mountains, hills, deserts and forests. Britannica Kids notes that some even show the seafloor, ocean and air currents.

Some physical maps use shading to make mountains look raised, so you can see the shape of the land at a glance. A USGS lesson describes a shaded relief map as one designed to highlight a place's physical features by showing how high the land is compared with its surroundings.

Britannica Kids describes physical maps as showing rivers, lakes, mountains, hills, deserts, vegetation and other natural features, and sometimes seafloors, ocean and air currents and underground resources. Relief can be shown with shading, hachures (short lines showing slope) or contours.

The USGS distinguishes two related types in its teaching materials: a shaded relief map highlights physical features and shows relative elevation, while a topographic map shows the elevation of the land at all points, so a reader can find the actual height of any place. Color can mislead, though. Britannica Kids warns that where colors show elevation, green for lowland may cover a hot, dry desert, so a physical map's key is essential.

Sometimes a border follows a river.

Sometimes it runs along the tops of mountains. Then you can see the border on both kinds of map.

Political and physical maps often meet. National Geographic Education explains that many political boundaries form along physical ones. The border between France and Spain follows the peaks of the Pyrenees Mountains, and the Alps separate France from Italy. The Rio Grande forms a large part of the border between Mexico and the United States.

Rivers are very common borders. NASA's Earth Observatory reports a study by Laurence Smith and Sarah Popelka finding that rivers make up 23 percent of the world's international borders.

A physical boundary is a natural barrier, such as a river, mountain range, ocean or desert, and National Geographic Education notes that political boundaries often form along them: the France-Spain border follows the crest of the Pyrenees, the Alps separate France from Italy, the Strait of Gibraltar divides southwestern Europe from northwestern Africa, and the Rio Grande forms much of the Mexico-United States border.

NASA's Earth Observatory reported a study by Smith and Popelka that mapped river borders worldwide: rivers make up 23 percent of international borders, 17 percent of state and provincial borders and 12 percent of county-level borders. Laying a political map over a physical one shows at a glance which borders follow nature and which do not.

Many maps show both kinds of things.

A road map shows towns and borders. It also shows rivers and mountains, so you know what you will pass.

Lots of maps you use every day mix political and physical information. Britannica Kids says road maps blend political and physical data. A USGS lesson explains that a road map shows how to travel from place to place, and also shows mountains and rivers, states and counties, and cities, towns and villages.

Some map datasets keep the two kinds of information separate. Natural Earth, a free collection of world map data, sorts its maps into cultural data, such as countries, borders and towns, and physical data, such as coastlines, rivers, lakes and land.

General reference maps, Britannica Kids notes, include a mixture of information, as do many road, political and physical maps; road maps, and the base maps behind web mapping tools, blend political and physical data. The USGS lesson's road map example shows physical features (mountains, rivers), political features (states, counties) and populated places together.

Digital mapping makes the layering explicit. Natural Earth, a public-domain world dataset made by volunteer cartographers, publishes separate Cultural and Physical themes at three scales: cultural layers include countries, boundary lines, states and provinces and populated places, while physical layers include land, ocean, coastlines, rivers, lakes and glaciated areas. A cartographer switches layers on or off to make a political map, a physical map or anything between.