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Qswat
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- 2. Raster Analysis • representa continuous variable in space such as • elevation, • precipitation, • noise, • satellite images or product generated.
- 3. Watershed delineation needsan outlet and DEM Outlet • bring XY • Add to QGIS • Convert to shape file DEM • Download
- 4. How WS delineatedfrom DEM • Fill • Flow direction • Flo accumulation • Slope , • Aspect, • Hill shade … • Such delineation is a physical based ( not Hydrological) • It relay on Elevation
- 5. Fill/sink • A pitis a set of one or more cells which has no downstream cells around it • Unless these pits are removed they become sinks and isolate portions of the watershed
- 6. Flow direction calculates thedirection water will flow using slope from neighboring cells. Direction of steepest descent
- 8. Flow Accumulation Area drainingin to a grid cell
- 9. Channel and Watersheds– Stream Definition
- 10. Outlet If the outlet is sown find the area of he watershed
- 11. Watershed boundary contributing areaconvention.
- 12. • Solution • OpenExcel • Write column headings • add the corresponding values • Save in CSV • Open QGIS and add to QGIS • Export to shape file • Where the WS outlet lies? • Out let given • X: 395065 • Y: 1313419 • CS: WGS UTM Zone 37
- 13. Extraction • Clipping rastermy masking layer • Clip raster by extent
- 14. Examine the DEMand roughly determine the WS boundary
- 15. Clipping a raster 1.Go to Raster | Extraction | Clip Raster by Extent | Clip Raster by Mask Layer. For Our case we hall to use clip Raster by Mask
- 16. Install • find thecompatible version for your QGIS version • Be sure you have install the appropriate MS Office bits • Make your outlet ready in shape file • Open QGIS • Go to Plugins > Manage and Install Plugins as shown here:
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- 20. Add your outletand zoom to it gisget@gmail.com 20
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- 23. Open attribute Table Select All Save the dialogue box Merge gisget@gmail.com 23
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