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Find rivers, tributaries, drainage basins and explanations of flowing water.
United States · Landforms · Map guides
Follow terrain and water rather than state lines. The shaded-relief map shows selected mountain systems, plains, rivers and lakes, with separate views for Alaska and Hawaii.The key distinctionA…
Landforms · Place guides
Assign Strahler stream order from the headwaters downstream: start every link with no upstream tributary at 1. When two equal-order links join, increase the downstream order by one.…
Landforms · Place guides
Start with the station, variable, units and timestamp. Stage is water-surface height relative to a stated reference; discharge is volume flowing past a section per unit time. Separate…
Landforms · Explainers
Trace how river channels connect with their drainage basins, identify tributaries and divides, and follow a clear original diagram from upstream branches to a chosen outlet.
Rivers · Quizzes
This hydrology quiz tests how water moves, where it is stored and how people change its path. Work through 20 questions on catchments, river flow, groundwater, lakes and…
Geography basics · Explainers
Many readers meet this river under two different names and assume they are looking at two different waterways. They are not. The confusion comes from language, mapping habits,…
Armenia · Climate · Explainers
Armenia (the modern Republic of Armenia in the South Caucasus) is compact on a world map—about 11,484 square miles (29,743 square kilometers)—but it behaves like a much larger…
Geology · Explainers
Water erosion landforms are the shapes made when moving water removes rock or soil and carries it away. Rivers carve valleys and gorges. Storm runoff cuts rills and…
Geology · Explainers
A cliff face that looks freshly cut, a valley narrowed into a gorge, a desert ridge shaped like it’s been sanded into alignment—erosion leaves signatures you can read…
Borders · Explainers
Rivers do not stay where maps put them. Banks erode, channels split, and sandbars appear, but those physical changes do not always move an international boundary. The decisive…
Jordan River & the Dead Sea · Lakes · Place guides
The Jordan River threads south from the snows of Mount Hermon to the lowest land on Earth, the Dead Sea—about 251 kilometers (156 miles) of meanders through the…
Egypt · Landforms · Lists & data
From East Africa’s lake-fed headwaters to Egypt’s Mediterranean delta, the Nile connects contrasting landscapes and societies. Understanding its length means separating one continuous river route from the much…