River science

A field that studies the natural problems of rivers from a scientific standpoint, and is a branch of limnology in the broad sense. From an epistemological standpoint, it belongs to hydrology. River engineering belongs to the applied field of river science, but in fact it developed independently earlier than river science. The main research themes in river science can be broadly categorized as follows: (1) The quantitative, qualitative, and temporal relationship between precipitation and runoff in a river basin, and its relationship with other hydrological phenomena such as evapotranspiration, infiltration, and groundwater. (2) The temporal and spatial changes in hydraulic quantities such as the water level, water surface gradient, flow velocity, and discharge of a river, and the relationships between these hydraulic quantities. The field that studies the relationship between hydraulic quantities and the various characteristic values ​​that represent the geometric shape of a channel is called hydraulic geometry of a channel. (3) Geomorphological research that studies the mechanisms of river erosion, transport, and deposition as the driving forces of topography, and the resulting topography. (4) The development process of river basins and the laws governing the formation of river networks. (5) The physical properties of river water, such as water temperature and electrical conductivity. (6) The chemical properties of river water, such as dissolved components, and the temporal and spatial changes in water quality, mainly investigating the mechanisms of pollution. River science can be said to be a comprehensive scientific field.

[Shigemi Takayama]

"New River Studies" by Ryuji Nomitsu and revised by Kinzo Seno (1959, Chijin Shokan)

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

川の自然的諸問題を理学的立場から研究する学問で、広義の陸水学の一部門。認識論的立場から分類すれば水文学(すいもんがく)に属する。河川工学は河川学の応用分野に属するが、実際には河川学より先に早くから独自の発達を遂げてきた。河川学におけるおもな研究テーマは大別して次のようなものがある。(1)河川流域における降水と流出との間の量的、質的、時間的関係を軸として、蒸発散、浸透、地下水などのほかの水文現象との関係。(2)河川の水位、水面勾配(こうばい)、流速、流量などの水理量の時間的、空間的変化と、それらの水理量相互間の関係。とくに流路の幾何形状を表す諸特性値と水理量との間の関係を研究する分野を流路の水理幾何学という。(3)地形形成営力としての河川の侵食、運搬、堆積(たいせき)作用のメカニズムと、その結果生ずる地形について研究する地形営力論的研究。(4)流域の発達過程と水系網の構成法則。(5)河川水の水温や電導度などの物理的性質。(6)河川水中の溶存成分などの化学的性質、また水質の時間的、空間的変化に伴う事柄など、おもに汚染の機構の究明などがある。河川学は総合科学的性格を有する学問といえる。

［髙山茂美］

『野満隆治著、瀬野錦蔵訂補『新河川学』（1959・地人書館）』

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