The water we encounter in life is moving through the stages of the water cycle. And even though rivers make up a tiny portion of all fresh water, they’re still one of the most visible parts of that cycle, especially for the billions of people who live in cities and towns built alongside them. Of course, rivers don’t just appear out of nowhere. They’re the end result of water’s land-based journey–the product of many compounding inflows collected within a drainage basin. The map above, from Reddit user r/CountZapolai, illustrates how massive the drainage basins can be for the world’s longest rivers.

What is a Drainage Basin?

A river’s drainage basin is defined as the area of land where precipitation collects and drains off, feeding the flow of rivers and their tributaries. Simply put, this is the process of water draining from higher points of land to lower laying areas–as demonstrated by the animation below.

In the case the world’s longest rivers, these drainage basins can span across entire continents and cross many international borders.

Fueling the World’s Longest Rivers

The longer a river system gets, the more terrain it passes through. It comes as no surprise then that the longest rivers are supported by immense drainage basins. Here are the world’s top 10 longest rivers, and the size of their respective basins: Note: There is debate about the actual length of certain river systems. See a more comprehensive range of estimates here. These 10 longest rivers alone are fed by a land area equivalent to the size of Africa.

River Drainage Basins and Humanity

The fact that huge population centers sit at the terminuses of many of these key rivers is a testament to how important watersheds are to our survival. Only 10% of the global population lives further than six miles away from a surface freshwater body, and more often than not, that fresh water comes in the form of a river. Noting where rivers begin their journey is also important as well. In the case of Tibet, many of the world’s longest rivers are fed by drainage basins that begin in the region. In fact, six of Asia’s major rivers begin on the Tibetan Plateau, meeting the basic needs of billions of people. By illustrating the world’s longest rivers and their drainage basins, maps like this one help put into perspective the breathtaking complexity of Earth’s hydrological cycle. on Even while political regimes across these countries have changed over time, they’ve largely followed a few different types of governance. Today, every country can ultimately be classified into just nine broad forms of government systems. This map by Truman Du uses information from Wikipedia to map the government systems that rule the world today.

Countries By Type of Government

It’s important to note that this map charts government systems according to each country’s legal framework. Many countries have constitutions stating their de jure or legally recognized system of government, but their de facto or realized form of governance may be quite different. Here is a list of the stated government system of UN member states and observers as of January 2023: Let’s take a closer look at some of these systems.

Monarchies

Brought back into the spotlight after the death of Queen Elizabeth II of England in September 2022, this form of government has a single ruler. They carry titles from king and queen to sultan or emperor, and their government systems can be further divided into three modern types: constitutional, semi-constitutional, and absolute. A constitutional monarchy sees the monarch act as head of state within the parameters of a constitution, giving them little to no real power. For example, King Charles III is the head of 15 Commonwealth nations including Canada and Australia. However, each has their own head of government. On the other hand, a semi-constitutional monarchy lets the monarch or ruling royal family retain substantial political powers, as is the case in Jordan and Morocco. However, their monarchs still rule the country according to a democratic constitution and in concert with other institutions. Finally, an absolute monarchy is most like the monarchies of old, where the ruler has full power over governance, with modern examples including Saudi Arabia and Vatican City.

Republics

Unlike monarchies, the people hold the power in a republic government system, directly electing representatives to form government. Again, there are multiple types of modern republic governments: presidential, semi-presidential, and parliamentary. The presidential republic could be considered a direct progression from monarchies. This system has a strong and independent chief executive with extensive powers when it comes to domestic affairs and foreign policy. An example of this is the United States, where the President is both the head of state and the head of government. In a semi-presidential republic, the president is the head of state and has some executive powers that are independent of the legislature. However, the prime minister (or chancellor or equivalent title) is the head of government, responsible to the legislature along with the cabinet. Russia is a classic example of this type of government. The last type of republic system is parliamentary. In this system, the president is a figurehead, while the head of government holds real power and is validated by and accountable to the parliament. This type of system can be seen in Germany, Italy, and India and is akin to constitutional monarchies. It’s also important to point out that some parliamentary republic systems operate slightly differently. For example in South Africa, the president is both the head of state and government, but is elected directly by the legislature. This leaves them (and their ministries) potentially subject to parliamentary confidence.

One-Party State

Many of the systems above involve multiple political parties vying to rule and govern their respective countries. In a one-party state, also called a single-party state or single-party system, only one political party has the right to form government. All other political parties are either outlawed or only allowed limited participation in elections. In this system, a country’s head of state and head of government can be executive or ceremonial but political power is constitutionally linked to a single political movement. China is the most well-known example of this government system, with the General Secretary of the Communist Party of China ruling as the de facto leader since 1989.

Provisional

The final form of government is a provisional government formed as an interim or transitional government. In this system, an emergency governmental body is created to manage political transitions after the collapse of a government, or when a new state is formed. Often these evolve into fully constitutionalized systems, but sometimes they hold power for longer than expected. Some examples of countries that are considered provisional include Libya, Burkina Faso, and Chad.

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