APRIL Project Hydrology DEM Technical Process

APRIL Project.

Hydrology - Technical process

By: Ida Bagus Ketut Wedastra - conservation planer -TNC

1. Download SRTM with 30m resolution from earthexplorer2. Crop DEM using polygon area (ROI)

3. Continue with Fill process….

4. Flow direction

5. Flow Accumulation

6. Stream networkYou will see raster data with river pattern on it. We will use Raster Calculator toolbar to separate river patern and non river. (raster calculation = log 10 (file).Result

And separate river pattern with other pattern, Do raster calculation: con (file >=2, file)

7. Stream link

8. Stream order

9. Stream feature

10. Create snap pour point (Outlet point)Show stream feature with legend color (using gridcode value)

Using Query for selective main streams based on grid code valueSelect value > 4.

Dissolve stream feature based on grid code

Select stream feature which are overlap with coastal line or border area of interest using select by location, than save it

Convert stream feature to point using Data Management Tools/feature vertices to pointUse point type = EndMake sure the point snaps with the stream

Result:

11. Creaste watershed

Convert raster watershed to vector format use from raster to vector tool