Extracting river network characteristics based on digital elevation model(DEM) is a hotspot in digital hydrology research.By taking Binzhou River basin in the black soil region of Northeast China as an example and using 5-meter resolution DEM as the data for study

river network features were extracted by applying Arc Hydro Tools in ArcGIS 9.2 version.Results showed that when different drainage networks were extracted by setting drainage area threshold value to be 0.75

1.25

2

2.5

3.75

and 5 km2

respectively

different threshold values had very little effect on spatial position of the main stream network

but extracted river network features of the digital watershed changed greatly.A method for setting a suitable threshold value was proposed based on the relation of source density/drainage density with drainage area threshold.It was found that when drainage area threshold was 2 km2

extracted river network features were basically consistent with actual drainage net features

with prediction accuracy reaching 95%.Therefore

automatic extraction of watershed features based on Arc Hydro Tools is feasible.