Re: (XSS229/3A)/Channel Pattern & landforms -- GEOFORUM

[ Show ]

Support VoyForums

[ Shrink ]

VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

[ Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time ]

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: 19:58:51 09/07/99 Tue
Author: Dr. Chatterjea
Subject: Re: (XSS229/3A)/Channel Pattern & landforms
In reply to: Michele 's message, "Re: (XSS229/3A)/Channel Pattern & landforms" on 10:43:17 08/31/99 Tue

> > > 1)Is this the rate that affects the rate of which
> > > runoff increases downstream and the rate of the
> > > sediment yield?
> > >
> > the predictable rate increases due to an increase in
> > drainage area. a small river drainage pattern diagram
> > would show the effects. by extending the river system
> > to be examined, the drainage area would inevitably be
> > enlarged. with an increase in area, runoff and
> > sediment yield would be the two aspects affected. it
> > is like nature's way of keeping balance.
>
> Got it! Well-explained. It makes lots of sense :)
> >
> > > 2) Also , does permeablility of the underlying
> rock,
> > > vegetation cover and climate play a part in
> > > influencing this theory? In other words, does this
> > > affect the predictable rate?
> >
> > this is a tough one. maybe the vegetation cover,
> > underlying rock and climate do play a part. but their
> > role is of such extensive cover that their effects
> are
> > ingrained into that of the calculation of the
> > predictable rate. meaning for example a vegetation
> > cover indigeneous to our area of study of drainage
> > basin may affect the runoff rate. but the predictable
> > rate that increases will still be "predictable" in a
> > sense when the area increases. this is because the
> > vegetation cover itself is extensive throughout the
> > whole map its effects on the runoff rate becomes a
> > "constant" rather than a "variable" factor. finally,
> > the predictable does not change.
> >
>
> THanks CHen yee.
>
> I do wonder if Mr. John Hack had really taken all
> these factors into account. Then again, factors such
> as vegetation cover, climate and underlying rock
> structure can never be considered as "constant"
> features in the drainage basin area right? (esp. if
> we're looking at a large drainage basin area)
>
> I think I would disagree on the bit about run-off
> being a "constant" rather than a variable and about
> the predictability being the same. THat is unless the
> "big guy" has taken all these into account.
Congrats for taking part in the discussion. But isn't there something you have missed while reading??? Check again - according to Hack (Michelle's 'Big Guy'!!) it's the drainage area that increases at a predictable rate with distance downstream - so with this increased area (in a larger drainage basin with a bigger river) there can be any number of combinations of the controls that you all have been talking about. The increase is in the drainage basin area - remember?? So whatever falls within this now increased (extended)area, be it forests, or urbanized, impervious soil, resistant rocks - everything can have its own impacts, collectively or singly. What Hack showed is that there is an increase in the DRAINAGE BASIN AREA and that this rate OF INCREASE IN AREA is predictable from the increase in the stream length. In simple terms it means that the longer the stream is, the larger will be its drainage basin. Hope this will clarify the questions you have. If not, post more messages. If you want to argue about this or any other point - do feel free to do so! You are most welcome.

[ Next Thread | Previous Thread | Next Message | Previous Message ]