Uncertainty of Flow Accumulation Threshold Influence in Hydrology Modeling - A Case Study in Qinling Mountain SRTM3 DEM Based

Hydrology modeling based on DEMs plays an important role in regional planning, agriculture, forestry and other related fields. In the hydrology modeling, flow accumulation threshold is a critical factor which influences the structure and morphology of stream network. With GeoInformatics tools, such as ArcGIS, it can be explored that what uncertainty influence of flow accumulation threshold on critical contributing area and stream order number. And the materials used in this work are SRTM3 DEMs with 85 m resolution or so, and the areas locate in Qinling Mountain. The result shows that threshold is linear interdependence with critical contributing area, and the stream order does not show enough stability when threshold changing. All the result means that the uncertainty of flow accumulation threshold influence in hydrology modeling should be attached more attention, and the choice of threshold should be more cautious and objective.