Number of routing grid cells to define stream

[Ted]

Dear All,

I have a question on how to set the 'Number of routing grid cells to define stream'. The manual suggests to read Tarboton et al.'s paper. I have not fully understood it. Could any one give me a hint?

For my case, I use 3s MERIT data and my routing grid resolution is 250 m. How should I set the contributing cells and the contributing area?

Thank you so much.

Regards,

Ted

[Kevin]

Ted,

Then "Number of routing grid cells to define a stream" parameter can be thought of as the primary method for controlling the stream network density in your model simulation. The value you provide is a number of grid cells (on your routing grid) , so this can be easily converted to an area by multiplying the grid-cell area by this number. At your resolution (250m), a threshold value of 200 would result in a stream channel below every 12.5km^2 of contributing area: (250m x 250m) * 200 =12,500,000m^2.  Higher values will result in a lower stream network density (fewer stream channel cells) and a lower value will result in a higher stream network density (more stream channels). The value will apply equally to all locations in your domain, so you will have to select an appropriate parameter value for your domain and resolution. Some experimentation may be necessary to find a suitable stream channel density that represents the hydrology of your area.

Thanks,

Kevin

[Ted]

Hi Kevin,

Thank you so much for your explanation! It helps me a lot.

Regards,

Ted