River Basics Trivia Quiz

Answer: No

Some rivers take their origins in glaciers. For instance, the River Rhône's source is the Rhône Glacier, part of the Saint-Gotthard Massif in the Alps, which also gives rise to three other major rivers; namely, the Reuss, the Rhine and the Ticino. Others start with water that comes out of the ground. There are a number of distinguishing terms for such water, not all of them directly related to river starting points as such, but all relating to running water in one way or another.

An artesian well is a place where natural subterranean pressure forces water to the earth's surface. A spring wells up from underground to form a small stream or pool, while a hot spring's water is, well, hot. Related to hot springs is the phenomenon of the geyser, hot water and steam that shoot up out of the earth. Finally, the terms 'source', 'head' and 'headwaters' are used for the beginning of a river or stream.

Whether fed by a glacier or groundwater, the vast majority of river sources are located high on mountainsides, locations unsuitable for metropolises. To be sure, a village or small town may be at or near the site of a river source. The aptly named Source-Seine in the French Bourgogne-Franche-Comté region is a good example.

Answer: A region that is drained by a particular stream or river.

Water flow is caused by gravity. So, the land that a watercourse passes through (no matter how flat it may seem to the human eye) 'sheds' its water such as rain runoff and snow melt, into that watercourse. To put it the other way round: Every watercourse - stream, river, what have you - drains its own watershed.

A river drainage basin is an area drained by a river and all its tributaries. Hence, a watershed may be thought of as a small version of a river basin, while a river basin is made up of many different watersheds.

In the United States, a large body of slow-flowing water, rich in plant and animal life is known as a bayou. Usually shallow, bayous can be freshwater, saltwater or brackish water. They are found mainly in the state of Louisiana.

In Australia, a pool formed by a river during the rainy season is called a billabong.

A reservoir stores water meant for human use, residential, commercial, etc. In India, the term 'tank' is used in much the same way.

Answer: All of these

'Affluent' is a general term for any watercourse, small or large, that merges with a 'parent river' or 'main stem', whereas the term 'feeder' is applied to a small stream that flows into a larger river.

The most familiar of these terms is 'tributary'. A full discussion of tributaries lies outside the scope of this quiz. Suffice it to say that they are identified by which bank, left or right, they enter the main stem looking downstream (in the direction of flow) of the main stem. For instance, the Brahmaputra is a left-bank tributary of the Ganges, while the Yamuna is a right-bank tributary.

Tributaries carry more than water into the main stem. They also bring any pollutants that have entered them along the way. In turn, the main stem carries these and any further pollutants it has acquired to its terminus.

Answer: Confluence

A confluence or conflux occurs at the point where two or more flowing bodies of water join to form a single watercourse. There are different types of confluence; namely, at the point where a tributary joins a larger river or main stem, where two streams meet to become the source of a river of a new name, as the confluence of the Monongahela and Allegheny rivers at Pittsburgh in the U.S. state of Pennsylvania, forming the Ohio, or where two separated channels of a river (forming a river island) rejoin at the downstream end.

Confluences influence ecology. That is, moving downstream the volume of water in the main stem increases as ever more tributaries feed into it, while at the same time the slope of the riverbed decreases as the river approaches its terminus. This natural evolution of the river's environment creates different habitats at different points along the watercourse.

The term 'confluence' may also be applied to the merger of glaciers, rivers of ice.

A crosscurrent is a current that flows across the main current in a river or ocean.

The term 'backwater' refers to an area of water that is connected to a river but is not affected by its current.

A bight is a wide indentation in the shoreline of a river, ocean or other body of water.

Answer: Yes

A distributary is a watercourse that "branches off" and flows away from the main stem in a process called 'river bifurcation'. The resulting rivers may be quite similar, or the branching stream may have different characteristics and ecology than the main river. Again, the two new rivers may flow in generally the same direction, or they may flow away from one another.

The commonest case of river bifurcation occurs in river deltas, where the main channel divides into many small ones. An example of this phenomenon is the delta of the Danube on the Black Sea, where the river branches into three main distributaries; namely, the Chilia, the Sulina and the Saint George. New land gradually forms at the mouths of each channel, as the delta continues to expand.

Answer: Rapids

In some sections of a watercourse (often though not always shallower than the main channel), the running water may have worn away (eroded) softer rock. Thus, the remaining, hard rock is uneven, sometimes projecting through the water's surface. This random, extreme unevenness of the riverbed creates turbulence and foam in the often very fast current. Such dangerous, generally non-navigable stretches are termed rapids or whitewater. "Shooting the rapids" is considered an adventure sport by some hardy (or foolhardy) souls.

'Waterfall' or 'falls' refers to a place in a watercourse where water flows over a sudden break in the riverbed, such as a cliff, onto another level below. Mainly literary, the terms cascade and cataract refer to a small and a large waterfall respectively. Whereas a cascade is often picturesque, a cataract, such as Niagara Falls on the U.S.-Canadian border, is awe-inspiring.

Most unusually, the confluence of the Rideau and the Ottawa rivers at the Canadian capital, also named Ottawa, is marked by the tributary literally emptying into the main stem over the Rideau Falls, two waterfalls separated by an island.

A portage way, a trail allowing cargo and small vessels to be carried past such obstacles, is often established on or just inland of the riverbank at the place where rapids or falls occur.

Answer: Its end point

The mouth of a river, commonly its widest point, is where it empties into a larger body of water, such as another river, a lake or reservoir or the sea. An estuary is a body of water at the terminus of a river where it meets the ocean or less commonly a lake. Since as a rule estuaries are tidal, their water level and salinity rise and fall with the tides.

An estuary may also be called a bay, lagoon, sound, or slough. Tokyo Bay is an estuary formed where the Sumida and Arakawa rivers flow into the Pacific Ocean.

A river delta, such as the delta of the Nile or that of the Mekong is a large area of channels and marshes that may form at a river's mouth. As the river empties its water and deposits its load of sediments into the other body of water, most commonly the sea, heavier alluvial material sinks first and lighter material, called silt, is swept out further from the mouth.. As silt builds up, new land is formed, extending a river's mouth into the ocean.

This land that gradually builds up at the river mouth can be a wetland that protects the land behind it from the worst effects of storms by essentially absorbing storm surges and excess rainfall. Since delta land is highly fertile, it may be rich cropland. The Sacramento-San Joaquin River Delta in the U.S. state of California (commonly known as San Francisco Bay) is one of the largest estuaries in the United States.

Answer: True

The silt from which deltas are built is rich in nutrients. Microbes and plants thrive on these nutrients, attracting animals. Eventually, the rich flora and fauna draw humans. By 3200 B.C., the Nile delta was home to the beginnings of the Egyptian civilization. Not only ancient peoples found deltas attractive. Today New Orleans on the Mississippi delta and Vancouver, on the Fraser River delta, are two of the most vibrant cities in North America.

The Ganges-Brahmaputra delta, which empties into the Bay of Bengal, encompasses some thirty-three thousand, seven hundred and seven square miles (eighty-seven thousand, three hundred square kilometers) in the state of West Bengal, India and in Bangladesh. Indeed, Bangladesh sits almost entirely on the delta, which is the largest and the most populated delta on Earth, being home to some one hundred and eleven million souls.

Answer: Ho Chi Minh City

Ho Chi Min City (Thanh Pho Ho Chi Minh) stands on the western bank of the Saigon River to the north of the Mekong delta, about fifty miles (eighty kilometers) from the South China Sea in the south of the Southeast Asian nation of Vietnam. although it lies forty-five miles (seventy-two kilometers) from the mouth of the Saigon, Ho Chi Minh City is the most important port in Southeast Asia, being navigable to ships with drafts of up to thirty feet (nine meters). The country's most important economic center, the port serves diverse industries, including mining, seafood processing and agriculture. Once called 'the Paris of the Orient', Ho Chi Min City is still graced by elegant French colonial architecture while maintaining a vibrant street life.

The Saigon River (Song Sai Gon) rises near Phum Daung in southeastern Cambodia. It flows south and south-southeast for about one hundred forty miles (two hundred twenty-five kilometers), in its lower course embracing Ho Chi Minh City on the east. It forms an estuary at the head of Ganh Rai Bay, an outlying part of the Mekong delta.

Asunción, the largest city and capital of The Republic of Paraguay in central South America, occupies a promontory on the east side of the Paraguay River not far from its confluence with the Pilcomayo. One of the oldest cities in South America, Asunción is the longest continually inhabited area in the Río de la Plata Basin, having been established in 1537. With Spanish Colonial suburbs and a modern, high-rise city center, Asunción is a busy hub of manufacturing and of agricultural processing and distribution.

The Paraguay is a river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about one thousand, six hundred seventy-five miles (two thousand, six hundred ninety-five kilometers) from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River northeast of the town of Corrientes in Argentina.

The Paraná is, after the Amazon, the longest river in South America. Running some three thousand and thirty miles (four thousand, eight hundred and eighty kilometers) from its source at the confluence of the Paranaíba and the Rio Grande on the plateau of east-central Brazil through the south-central region of the continent, it passes through Brazil, Paraguay, and Argentina. The Paraná converges with the Uruguay at Punta Gorda, Uruguay to form the Río de la Plata, which flows into the South Atlantic.

Among the oldest continuously occupied sites in Europe, Belgrade is the capital and largest city of Serbia. Located at the confluence of the Sava and Danube rivers, it is the third most populous city on the Danube, after Vienna, Austria and Budapest, Hungary; a modern, high rise metropolis with a lovingly preserved old world vibe.

The Sava flows through Central and Southeast Europe, a right-bank and the longest (six hundred sixteen miles (nine hundred ninety-two kilometers) tributary of the Danube. Flowing through Slovenia and Croatia, it forms the Croatian border with Bosnia and Herzegovina, before making a final stretch through Serbia, where it empties into the Danube in Belgrade.

At one thousand, seven hundred seventy-one miles (two thousand, eight hundred fifty kilometers), the Danube is the second-longest river in Europe, after the Volga and has the second largest delta, again after the Volga. It flows through much of Central and Southeastern Europe, from the mountainous Black Forest region of Baden-Württemberg Land in southwestern Germany to its mouth on the Black Sea. Along its course it passes through 10 countries: Germany, Austria, Slovakia, Hungary, Croatia, Serbia, Bulgaria, Romania, Moldova, and Ukraine.

The capital and most populous city of the Republic of the Sudan, Khartoum, stands amid rich agricultural land at the confluence of the White and Blue Nile, where they meet to form the Nile. Founded in 1821, Khartoum was established as a fort, around which a town soon grew up. Modern Khartoum is a rich mix of African, Arab and British colonial influences. Throughout the city's history, it has been a regional center of trade and culture.

The Nile, known as Father of African rivers, is the longest river in the world, though exactly where it starts and, thus, exactly how long it is have been matters of contention for some time. Geographers do, however, agree that the Nile has multiple sources. These include the rivers that flow into Lake Victoria in present-day Uganda, Kenya, and Tanzania. The most distant of these is the Kagera River, also known as the Alexandra Nile, which rises in Burundi near the northern tip of Lake Tanganyika. Two of the Nile's source rivers, the Blue and Black Nile, rise in Ethiopia. Originating at Lake Tana, the Blue Nile supplies 80 percent of the Nile's water during the rainy season, while the Atbarah or Black Nile rises in Northwest Ethiopia and joins the Nile in north-central Sudan. The White Nile, whose source is near Lake No in South Sudan, is the Nile's longest tributary.

The Nile flows for some four thousand, one hundred and thirty-two miles (six thousand, six hundred kilometers) south to north through eastern Africa; specifically, the countries of Burundi, Rwanda, Tanzania, Kenya, The Democratic Republic of the Congo, Uganda, Ethiopia, South Sudan, Sudan and Egypt* and empties into the Mediterranean Sea.

Yet the most remarkable aspect of this mighty river is not its length; but rather, the ribbon of lush vegetation that accompanies it through the vast desert. So stark is the contrast between the river with its verdant banks and the barren desert, that the line of the Nile can be seen from space.

*Thanks to player pehinhota for the list of countries traversed by the Nile.

Answer: Yes

Rivers do indeed change their courses for various geological and topographical reasons. What's more, such changes may happen on human time scales. This phenomenon can be seen in the Tigris and Euphrates, the great rivers of that part of the Near East commonly known as The Fertile Crescent or as Mesopotamia (the Land between the Rivers).

Six thousand years ago, when the Sumerian civilization was establishing itself in the Fertile Crescent, the Persian Gulf extended about one hundred seventy-five miles (two hundred eighty-two kilometers) further northwest than it does now. The Tigris and Euphrates, flowing southwestward from their sources in the mountains of present-day Turkey carried mud and silt with them, slowly filling in the upper end of the narrow Persian Gulf, gradually moving the sea coast one hundred seventy-five miles southeastward.

In the days when Sumer flourished, the Tigris and the Euphrates entered the Persian Gulf by separate mouths, that of the Tigris being almost one hundred miles east of that of the Euphrates. Even as the rivers' alluvial deposits slowly built and changed the land, they continued to flow over it as it formed, changing course in the process. The Tigris flowed south and the Euphrates, east until, eventually, they met at the location of the modern Iraqi town of Al-Qurnah, some fifty-one miles (eighty-two kilometers) north of Basra to form a single joined river, now known as the Shatt al-Arab, which is one hundred twenty miles (one hundred ninety-three kilometers) long.

By the Ninth Century B.C. when the material we now know as the Hebrew Bible or the Old Testament first began to be reduced to writing (a convenient time marker), the Shatt al-Arab had formed. But echoes of the time before the merging of the Tigris and Euphrates linger in the most ancient parts of the Book of Genesis, notably the account of the Garden of Eden.