<prompt> Umfula i-Fish River Visrivier ngesi-Afrikaans, Fischfluss ngesiJalimane ngumfula eNamibia. Unobude obungu-650 km, ugeleza usuka ezintabeni zaseNaukluft 150 km uye eDamini laseHardap eduze kwaseMariental. Ukusuka lapho ukugeleza kuvinjelwe ngokuphelele, konke ukugeleza okuqhubekayo kwehla kuvela emifuleni engezansi kwedamu. Ukugeleza komfula kunesizini; ebusika umfula ungoma ngokuphelele. Naphezu kwalokhu, umfula uyindawo ye-Fish River Canyon ebabazekayo, umhosha ongu-160 km ubude, futhi ezindaweni ezifika ku-550 m ukujula. Umbuzo: Yisiphi isizini lapho izinga lamanzi emfuleni liwela khona?  <response>: ubusika 