edubun
English
English한국어EspañolPortuguêsFrançaisDeutschItalianoNederlandsРусскийBahasa Indonesia日本語
Home›World geography

Rivers and mountains

Where does rain go after it lands, and why do mountains stand where they do? This course follows water from a single drop to a river mouth, reads drainage basins and divides on a 3D model, then turns to how mountains are built, the highest peaks, and the rivers and mountains of Korea. Numbers come from the USGS, the US Army Corps of Engineers, National Geographic Education and the National Geographic Information Institute of Korea.

Progress

About this course

Where does rain go after it lands, and why do mountains stand where they do? A raindrop that lands exactly on a ridge crest has to choose, and two drops a step apart can end up in different oceans. In the 3D scene you switch on Basins and drop rain on both sides of a dashed purple line, and the drops run away from each other. The numbers come from the USGS, the US Army Corps of Engineers, National Geographic Education and the National Geographic Information Institute of Korea.

The six units are drainage basins and divides, a river from source to mouth, great rivers of the world, how mountains form, the highest mountains, and the rivers and mountains of Korea. The Mississippi basin covers about 1,245,000 square miles, and you convert it with 1 sq mi = 2.59 km². The long profile of a river has steep headwaters, a middle course and a gentle lower course near the mouth. The NGII atlas lists the great Asian rivers behind the story of early settlement: the Yangtze, Asia's longest; the Huang He, which carries fine yellow silt; the Mekong; the Tigris and Euphrates of the Fertile Crescent; and the Indus and Ganges.

The Korea unit uses the NGII national atlas. Mountains cover about 70 percent of the Korean Peninsula, yet the average height of the peninsula is only about 448 metres, well below the 910 metre average of East Asia. Korean rivers also change a lot through the year because most of the rain falls in summer. Among the five major rivers the Seomjingang has the largest coefficient of river regime, 270, nine times the Nile's 30.

Before you start

Rivers start as rain, so The water cycle is a natural first step, and the unit on how mountains form builds on Plate tectonics. Neither is required. If you know where the continents are from Continents and oceans, the great rivers will be easier to place.

When you finish

Afterwards you can explain what a drainage basin and a divide are, follow the Danube from its source in the Black Forest to its mouth, and name the river with the largest basin. You can describe how the Himalayas are still rising, give the 2020 height of Everest as 8,848.86 m, and say what share of the Korean Peninsula is mountains.

  1. 1Drainage basins and dividesRain that falls on 41 percent of the 48 contiguous United States ends up in one river, the Mississippi.
  2. 2A river from source to mouthThe Danube starts as the spring of a small stream in Germany’s Black Forest and ends in the Black Sea.
  3. 3Great rivers of the worldRivers hold only about 0.0002 percent of Earth’s water, yet the Amazon alone carries about a fifth of all river water.
  4. 4How mountains formThe Himalayas are still rising by more than 1 centimetre a year, the USGS says, because India is still pushing into Asia.
  5. 5The highest mountainsIn December 2020 Nepal and China announced a joint height for Everest: 8,848.86 metres.
  6. 6Rivers and mountains of KoreaAbout 70 percent of the Korean Peninsula is mountains, yet its average height is only about 448 metres.

Related courses

  • Continents and oceans
    Seven continents, five oceans, the highest and deepest places, the longest rivers and the driest deserts, then the grid of latitude and longitude, time zones and the maps that flatten the globe. Every number comes from the CIA World Factbook, NOAA, USGS or National Geographic.
  • Countries and capitals
    Spin a real globe, find countries by clicking them, and practise capitals continent by continent. Borders follow Natural Earth, a public map dataset used by atlases and news graphics.
  • Map reading
    Topographic maps squeeze hills, valleys and rivers onto flat paper. This course reads them the way surveyors and hikers do: symbols and colours, scale, direction and bearings, contour lines, slope, and cross-sections. A 3D model of the same land sits next to every map, so each line can be checked against the ground it describes. Conventions come from the USGS and the National Geographic Information Institute of Korea.
  • Ancient civilizations · World history
    The first cities grew up beside rivers: the Tigris and Euphrates, the Nile, the Indus and the Yellow River. Eight units cover how those societies farmed, built, wrote, made laws and worked metal, with maps, timelines and flashcards. Dates before about 1000 BCE are approximate, and each unit says where scholars disagree.
Sources for this course (24)
  • USGS Water Science School, Watersheds and Drainage Basins (usgs.gov/water-science-school/science/watersheds-and-drainage-basins: common outlet, drainage divide, watershed = drainage basin = catchment, larger watersheds contain smaller ones)
  • USGS Nonindigenous Aquatic Species, Hydrologic Unit Codes explained (nas.er.usgs.gov/hucs.aspx: 22 regions, 245 subregions, 405 basins, about 2,400 subbasins, 19,000 watersheds, 105,000 subwatersheds)
  • US Army Corps of Engineers New Orleans District, The Mississippi Drainage Basin (mvn.usace.army.mil: third largest basin after the Amazon and Congo, 41 percent of the 48 contiguous states, more than 1,245,000 square miles, 31 states and two Canadian provinces)
  • US EPA, The Mississippi/Atchafalaya River Basin (epa.gov/ms-htf: 2,350 miles, 15 percent of North America, borders of 10 states, nearly 30 percent of Americans live in the basin)
  • National Geographic Education encyclopedia: Source (resource/source: headwaters, the tributary farthest from the end; Gangotri Glacier, Breg spring for the Danube, Lake Itasca for the Mississippi)
  • Oxbow Lake (resource/oxbow-lake: concave banks erode, convex banks collect sediment, Mississippi meander cut-offs, billabong)
  • Delta (resource/delta: name from the Greek capital letter delta)
  • River (resource/river)
  • Anatomy of the Nile (resource/anatomy-nile: White Nile from Lake Victoria, Blue Nile from Lake Tana, Nile fan about 70,000 km2)
  • Fold Mountain (resource/fold-mountain: anticline and syncline; Appalachians once taller than the Himalayas)
  • USGS This Dynamic Earth, The Himalayas: Two continents collide (pubs.usgs.gov/gip/dynamic/himalaya.html: 2,900 km, collision 40 to 50 million years ago, India 6,400 km south of Asia 80 million years ago moving about 9 m a century, rising more than 1 cm a year)
  • Geological Society of London, Continental/Continental: The Himalayas (crust about 75 km thick)
  • Kathmandu Post, 8 Dec 2020 (Everest 8,848.86 m announced jointly by Nepal and China; Peak XV given as 8,778 m in 1847)
  • 국토지리정보원 대한민국 국가지도집 청소년판 2022 (nationalatlas.ngii.go.kr): 산 (page_3151: K2 8,611 m, 안나푸르나 8,091 m, 안데스 가장 긴 산맥, 국토 약 70% 산지, 백두산 2,744 m 천지 직경 3,550 m, 한라산 1,947 m, 오름 약 370여 개)
  • 강 (page_3152: 강물은 지구 물의 0.0002%, 아마존 전 세계 강물의 20%, 오비강 약 200일 결빙, 압록강 한반도에서 가장 길고 유역이 넓음)
  • 산지 지형 (page_3175: 평균 고도 약 448 m, 동아시아 910 m, 백두대간과 산경표, 분수계)
  • 산지 지형 also: 한라산 식생의 수직적 분포 (page_3151)
  • 고위 평탄면 대관령 고랭지 채소·목축 (page_3175)
  • 하천 지형 (page_3176: 동해 쪽 하천 짧고 급함, 남한에서 유역 가장 넓은 강 한강, 가장 긴 강 낙동강, 하상계수 섬진강 270, 나일강 30, 댐 이전 한강 390)
  • 국가지도집 하천 (page_180: 한강 494.4 km, 유역 25,953 km2, 북한 포함 35,770 km2; 낙동강 510.3 km, 23,384 km2; 금강 397.8 km, 9,912 km2)
  • 한국민족문화대백과사전 압록강 (encykorea.aks.ac.kr E0035176: 803.3 km, basin 31,226 km2)
  • 낙동강 (E0011565: 521.5 km)
  • 지리산 국립공원 (E0054158: 천왕봉 1,915 m)
  • 국가지도집 통계 26p 주요 강의 길이 (압록강 803 km).

Checked: 2026-10-18