Stream capture in the context of Ice sheet

A drainage divide, water divide, ridgeline, watershed, water parting or height of land is elevated terrain that separates neighboring drainage basins. On rugged land, the divide lies along topographical ridges, and may be in the form of a single range of hills or mountains, known as a dividing range. On flat terrain, especially where the ground is marshy, the divide may be difficult to discern.

A triple divide is a point, often a summit, where three drainage basins meet. A valley floor divide is a low drainage divide that runs across a valley, sometimes created by deposition or stream capture. Major divides separating rivers that drain to different seas or oceans are continental divides.

Hortobágy (Hungarian pronunciation: [ˈhortobaːɟ]) is an 800 km national park in eastern Hungary, rich with folklore and cultural history. The park, a part of the Alföld (Great Plain), was designated as a national park in 1973 (the first in Hungary), and elected among the World Heritage Sites in 1999. The Hortobágy is Hungary's largest protected area, and the largest semi-natural grassland in Europe.

Until recently it was believed that this alkaline steppe was formed by the clear cutting of huge forests in the Middle Ages, followed by measures to control the course of the Tisza River, allegedly resulting in the soil's current structure and pH. However, Hortobágy is much older, with alkalinization estimated to have started ten thousand years ago, when the Tisza first found its way through the Great Hungarian Plain, cutting off many streams from their sources in the Northern Mountains. The formation was finished by grazing animals and wild horses during the Ice Age, followed by domesticated animals. The site was inscribed on the UNESCO World Heritage List in 1999 because of its long cultural history (stretching back more than four millennia), its scenery, and its testimony to traditional methods of pastoralism.

Headward erosion is erosion at the origin of a stream channel, which causes the origin to move back away from the direction of the stream flow, lengthening the stream channel. It can also refer to the widening of a canyon by erosion along its very top edge, when sheets of water first enter the canyon from a more roughly planar surface above it, such as at Canyonlands National Park in Utah. When sheets of water on a roughly planar surface first enter a depression in it, this erodes the top edge of the depression. The stream is forced to grow longer at the very top of the stream, which moves its origin back, or causes the canyon formed by the stream to grow wider as the process repeats. Widening of the canyon by erosion inside the canyon, below the canyon side top edge, or origin or the stream, such as erosion caused by the streamflow inside it, is not called headward erosion.

Headward erosion is a fluvial process of erosion that lengthens a stream, a valley or a gully at its head and also enlarges its drainage basin. The stream erodes away at the rock and soil at its headwaters in the opposite direction that it flows. Once a stream has begun to cut back, the erosion is sped up by the steep gradient the water is flowing down. As water erodes a path from its headwaters to its mouth at a standing body of water, it tries to cut an ever-shallower path. This leads to increased erosion at the steepest parts, which is headward erosion. If this continues long enough, it can cause a stream to break through into a neighboring watershed and capture drainage that previously flowed to another stream.

A wind gap (or air gap) is a gap through which a waterway once flowed that is now dry as a result of stream capture. A water gap is a similar feature, but one in which a waterway still flows. Water gaps and wind gaps often provide routes which, due to their gently inclined profile, are suitable for trails, roads, and railroads through mountainous terrain.

Examples of wind gaps in the Blue Ridge Mountains of Virginia include Swift Run Gap, Rockfish Gap, and Buford's Gap. The last was the original crossing of the Blue Ridge Mountains near Bedford for the Virginia and Tennessee Railroad, later the Norfolk and Western Railway, a precursor of today's Norfolk Southern Railway system. Another wind gap with substantial importance in U.S. history is the Cumberland Gap near the junction of Kentucky, Virginia, and Tennessee.

A losing stream, disappearing stream, influent stream or sinking river is a stream or river that loses water as it flows downstream. The water infiltrates into the ground recharging the local groundwater, because the water table is below the bottom of the stream channel. This is the opposite of a more common gaining stream (or effluent stream) which increases in water volume farther downstream as it gains water from the local aquifer.

Losing streams are common in arid areas due to the climate which results in huge amounts of water evaporating from the river generally towards the mouth. Losing streams are also common in regions of karst topography where the streamwater may be completely captured by a cavern system, becoming a subterranean river.

The Huai River, formerly romanized as the Hwai, is a major river in East China, about 1,110 km (690 mi) long with a drainage area of 174,000 km (67,000 sq mi). It is located about midway between the Yellow River and Yangtze River, the two longest rivers and largest drainage basins in China. Historically draining eastwards directly into the Yellow Sea, erosion from floods have changed the course of the river such that it now primarily discharges into the Yangtze. The Huai River is, to this day, notoriously vulnerable to flooding.

The Qinling–Huaihe Line, formed by the Huai River and the Qin Mountains, is sometimes regarded as the geographical dividing line between northern and southern China. This line approximates the 0 °C (32 °F) January isotherm and the 800 millimeters (30 in) isohyet in China.

The Ubangi River (/(j)uːˈbæŋɡi/; Swahili: Mto Ubangi; French: Fleuve Oubangui; Dutch: Mubangi Stroom), also spelled Oubangui, is a river in Central Africa, and the largest right-bank tributary of the Congo River. It begins at the confluence of the Mbomou (mean annual discharge 1,350 m/s) and Uele Rivers (mean annual discharge 1,550 m/s) and flows west, forming the border between Central African Republic (CAR) and the Democratic Republic of the Congo (DRC). Subsequently, the Ubangi bends to the southwest and passes through Bangui, the capital of the CAR, after which it flows south – forming the border between the DRC and the Republic of the Congo. The Ubangi finally joins the Congo River at Liranga.

The Ubangi's length is about 1,060 km (660 mi). Its total length with the Uele, its longest tributary, is 2,270 km (1,410 mi). The Ubangi's drainage basin is about 651,915 km (251,706 sq mi). Mean annual discharge at mouth 5,936 m/s. Its discharge at Bangui ranges from about 800 m/s (28,000 cu ft/s) to 11,000 m/s (390,000 cu ft/s), with an average flow of about ~4,000 m/s (140,000 cu ft/s). It is believed that the Ubangi's upper reaches originally flowed into the Chari River and Lake Chad before being captured by the Congo in the early Pleistocene.

Hanyang District (simplified Chinese: 汉阳区; traditional Chinese: 漢陽區; pinyin: Hànyáng Qū) forms part of the urban core of and is one of 13 urban districts of the prefecture-level city of Wuhan, the capital of Hubei Province, China. Currently, it is a district and stands between the Han River (right/southern bank) and the Yangtze River (left/northwestern bank), where the former drains into the latter. It is connected by bridges with its former sister cities, Hankou and Wuchang. Presently, on the left bank of the Yangtze, it borders the districts of Qiaokou to the north across the Han River, Jianghan to the northeast, Caidian to the southwest, and Dongxihu to the northwest; on the opposite bank it borders Wuchang and Hongshan. Guiyuan Temple is located in Hanyang.

The name "Hanyang" means "the Yang side of Han River", referring to the town's historic location on the north ("yang") bank of the Han River mouth. However, the lower Han River changed course to the north side of the town during Ming dynasty's Chenghua-era. The town, now on the south ("yin") side of the river, should have been renamed to "Hanyin" by naming convention, but the name "Hanyang" remained as it was well-established since the Sui dynasty. Administratively, the area forms Hanyang District of the modern Wuhan city, with an area of 108 square kilometers (42 sq mi) and a population of 510,000.