Kawatogawa

…The main river has a length of 46 km and a total drainage area of ​​582 km2. At the northern end of the Ashigara Plain, it joins the Kawato River, which flows out from the Tanzawa Mountains, and at the southern end of the plain, it joins the Kari River, which flows out from the Hakone outer rim. The upstream area is steep and discharges a large amount of sediment, and the downstream Ashigara Plain has often been subject to flooding since ancient times. …

*Some of the terminology that refers to "Kawaotogawa" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…幹川流路延長46km，全流域面積582km2。足柄平野の北端では丹沢山地から流出する川音（かわと）川を合わせ，平野の南端部では箱根外輪山から流出する狩川を合わせる。上流部は急傾斜で，多量の土砂を流出し，下流部の足柄平野では古来洪水に見まわれることが多かった。…

※「川音川」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