[GRASS-user] Is it possible to derive both banks of a river ?

Dear friends,

I derived this accumulation map from 90m srtm data.
Across the river, the accumulation varies and the river line passes through the maximum of these values.

Typical Scenario:

On right bank Acc= 3

Near Right Bank Acc=100000


|
-.-.-.-.-.-.-.-.-.-.-.-.-|.-.-.-.-.-.-.-.–.-.-.-.-.-.-.-.-.- on river line Acc=500000 →
|______

Near left Bank Acc=300000

On left Bank Acc = 2

i.e. Just at the banks, accumulation values have big difference.

Whether this fact can be utilised to derive both banks of a river network.

(attachments)

river and acc.png

On Tue, Oct 18, 2011 at 10:12 AM, Pankaj Kr Sharma <pkscwc@gmail.com> wrote:

Dear friends,

I derived this accumulation map from 90m srtm data.
Across the river, the accumulation varies and the river line passes through
the maximum of these values.

Typical Scenario:

On right bank Acc= 3

Near Right Bank Acc=100000
____________________________________
|
-.-.-.-.-.-.-.-.-.-.-.-.-|.-.-.-.-.-.-.-.--.-.-.-.-.-.-.-.-.- on river
line Acc=500000 -->
_______________|_____________________

Near left Bank Acc=300000

On left Bank Acc = 2

i.e. Just at the banks, accumulation values have big difference.

Whether this fact can be utilised to derive both banks of a river network.

You could try to calculate slope with the flow accumulation map and
then identify river banks as cells with high slope and low flow
accumulation.

Just an idea,

Markus M