Date Posted:02:22:35 08/25/99 Wed Author: Dr. Chatterjea Subject: Re: (XSS229/3A)/Drainage Basin In reply to:
chenyee
's message, "Re: (XSS229/3A)/Drainage Basin" on 08:45:51 08/24/99 Tue
>
> >
> > ok...hi everyone...
> > i have a question
> > Dr Chatterjea, in your lecture on drainage basin,
> > you mentioned that areas with resistant rocks have
> > widely spaced streams and very few as well, why is
> > this so?
>
> resistant rocks refer to rocks with fewer lines of
> weaknesses, more resistant to weathering and lower
> porosity. therefore the water that flows over a plane
> of more resistant rock will take a greater effort to
> etch out channel to develop into a river.
>
> vice-versa, weaker rocks are more easily carved out by
> erosional action of water. thus within a unit area of
> land, the one with weaker rocks are more susceptible
> and thus has a higher drainage network density.
>
> am i right?
Well done!! keep it up.
