There's hardly anything to add to Microzenith's proper comment.
But I wish to make several remarks that I think give you some interesting points.
In Korean, there are just two words that correspond to the concept of the Slope used as an academic term describing the steepness :
기울기(Ki Ul Ki)--the word that is indigenous to Korea
and 구배(Ku Be, 勾配)--the loan word from Japanese
Between these two words, there's nothing different in terms of its meaning and its usage. But the former(Ki Ul Ki) is much more common than the latter(Ku be).
And we could say that the latter is a sort of 'out-dated' or 'old-fashioned' and that this one will be dying out eventually.
(Actually, 'Ku be' is a loan word from Japanese, which consists of two Chinese Characters (勾-配, in Japanese its pronunciation is 'Koubai')
When talking about government's politics with regard to its native tongue,
Korea tends to purify the words which are seen as offspring of Japanese imperial ruling period over Korea. In this idea, Using the 'Ki Ul Ki' is highly recommended rather than 'Ku Be'.
----Ki Ul Ki is nominalized form of the intransitive verb '기울다(Ki ul da : lean to~)
But the facts remains that in some academic books intended for major study(in engineering...) we could (very rarely) find this outdated word, 'Ku-Be'.
To make long story short,
we could say that there's just one proper word for you to use to mean 'slope' and 'rise over run'.
That is : 기울기(Ki Ul Ki)
----NB: When romanizing Han geul, 'ㅜ' is represented by 'u'
according to the regulation to romanzie Han geul designed by NIKL(the national institute of the Korean language)