First, the flow of extraction Flow Direction
Input: Use dem transactions; output: flowdir_dem
Second, the determination of depression - sink sink
Input: flowdir_dem; Output: sink
Third, watershed -watershed
Input: 1, flowdir_dem; 2, sink; 3, default;
Output: Watersh_sink
Fourth, the compartmental analysis -Zonal Statistics
Input:. 1, Watersh_sink; 2 default value; 3.ChangShaDEM30.tif elevation data; last minimum value is selected
Output: ronal_min
Fifth, calculating the highest elevation of depression - the filling area Zonal Fill
Input: 1,1, Watersh_sink; 2, flowdir_dem
Output: ronal_max
Sixth, calculate the depth of depression - Raster Calculator - the Map Algebra
"Ronal_max" - "ronal_min" maximum minus the minimum
Output: sinkdep
Seven Depressions - the Fill
Input: dem raw data;
Output: fill_men
Eight, no depression of dem flow analysis - Flow Direction
Input: fill_men
Output: demfill_dir
Nine, the length of the flow - Flow the Length
Input: demfill_dir
Output: down_len
X. flow - Flow Accumulation
Input: demfill_dir
Output: flow_acc
![image image](https://img2018.cnblogs.com/blog/596198/202002/596198-20200221003321525-1814982640.png)
XI flow - Grid Calculation
Use flow_acc calculated for raster output streamnet
Calculated: Con ( "flow_acc"> 1000,1)
Twelve, raster vectorization - Stream to the Feature
Input: 1, streamnet; 2, demfill_dir
输出: StreamT_streamn1
Thirteen, river connection - Stream Link
Input: 1, flow grid streamnet; 2, flow grid demfill_dir
XIV, sub-basin generation - Watershed
Input: 1, demfill_dir; 2, streamlink
Output: Watershed