River regime coefficient - Kajokeisuu

…rainwater that falls on the ground as rain or snow travels down slopes, gradually gathering together to form streams, which flow down mountains and plains to lakes and the sea. The area where this water flows is called a river channel, and the entire valley with the river channel is called a river valley. The ground adjacent to the stream is called the riverbed, and this, together with the flowing water, is called a river or stream. The area where water gathers into a river is called a drainage basin, and the boundary where the drainage basins of two rivers meet is called a watershed. Not all water that falls on the ground flows directly into rivers; some seeps underground, flows down through the soil, and recharges groundwater. …

*Some of the terminology used in relation to the "river regime coefficient" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…雨や雪などとなって地上に降った天水は，斜面を下り，しだいに集まって流れを形成し，山地や平野を流下して湖や海に達する。この水の流路となるところを河道，河道のある谷地全体を河谷という。流れに接する地面を河床と呼び，これを流水ぐるみいっしょにして川あるいは河川という。河川へと水が集まってくる範囲が流域で，二つの河川の流域が互いに相接する界を分水界という。地上に降った水は，すべて河川へと直接流下するわけではなく，一部は地下に浸透し，土壌中を流下し，地下水を涵養する。…

※「河状係数」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報