3. It’s not just for drinking …
Litres of water needed to make:
• 1 litre of petrol 2.5
• 1 litre of biofuel 1000
• 1 cotton T-shirt 2700
• 1 kilo of wheat 4000
• 1 kilo of beef 16000
Wealthier people “consume” 3000 litres per day
4. WaterBase
• Water management is critical
• Must be at basin level
• Based on public/private partnership
• Requires
– Expertise
– Information
– Modelling + Decision support
– Community involvement
5. Modelling River Basins
• Terrain (shape of the land)
• Soil
• Landuse (vegetation)
• Climate (rainfall, temperature, humidity, …)
• Model – a computer program that can
simulate the natural processes involved
• Expertise
6. Resources: Available WWW Data
DEM = 90m SRTM (srtm.csi.cgiar.org)
Shuttle Radar Topographic Mission
World wide coverage (V3 pit filled)
Tile download
Direct FTP Download
7. Resources: Available WWW Data
Land = GLCF (glcf.umiacs.umd.edu)
Global Land Cover Classification
Satellite raster (1km resolution)
8. Resources: Available WWW Data
Soil = FAO/UNESCO (www.fao.org)
Digital Soil Map of the World
1:5 000 000 (raster 5x5 arc-minute)
9. • Readily available input
• Physically based
• Computer efficient
• Comprehensive – Process Interactions
• Simulate Management
Model Philosophy
22. Management
• Crop Rotations
• Removal of Biomass as Harvest/ Conversion of
Biomass to Residue
• Tillage / Biomixing of Soil
• Fertilizer Applications
• Grazing
• Pesticide Applications
• Irrigation
• Subsurface (Tile) Drainage
• Water Impoundment (e.g. Rice)
23. Management
• Urban Areas
– Pervious/Impervious Areas
– Street Sweeping
– Lawn Chemicals
• Edge of Field Buffers
24.
25. WaterBase
• Support for Integrated Water Resources
Management
• Using free, open source software
• An international network of users and
developers
26. Why Open Source?
• Free
• Secure: no supplier dependence
• Encourages involvement and sense of
ownership; internationalization
• Support network via internet
• High quality
• Good maintenance
• Open standards; interoperability
• Examples: Linux; Apache; GRASS; …
27. WaterBase
Three phases:
1. First tool available: MWSWAT
2. Network of partners (current)
3. Seek funding for development of
– Tools
– Training materials and technical
documentation on the internet
– Data repository design and implementation
28. First tool: MWSWAT
• Based on MapWindow GIS system
http://www.mapwindow.com
• Uses SWAT (Soil and Water Assessment Tool)
http://www.brc.tamus.edu/swat
• Distribution: internet and DVD
29. Preparation for SWAT
1. Start with a
DEM, a Digital
Elevation Map (a
grid, or 2-D
array, of
heights).
This DEM has
some 3.4 million
values, 83.3m
apart.
32. Preparation for SWAT
4. Add landuse map
(another grid).
Here resolution
roughly 10 times
DEM’s.
33. Preparation for SWAT
5. Add soil map
(another grid).
Here resolution
roughly 80 times
DEM’s.
34. Preparation for SWAT
6. Calculate HRUs:
Hydrological
Response Units:
unique
combinations of
sub-basin,
landuse, soil and
slope. Small
ones omitted
using thresholds.
(Here 79
retained from
326.)
35. Preparation for SWAT
7. Add weather data from weather stations (can be
automatic) and weather generator.
8. Set start and end dates, and some SWAT
parameters.
9. Write SWAT input files (here 620) and database
tables.
10. (Optionally) edit SWAT input files and tables.
11. Run SWAT.
12. Examine SWAT outputs.
36. SWAT Outputs
• Runs typically over several years
• Inputs and outputs (daily/monthly/yearly) per
subbasin
– Water flow
– Sediments
– Nutrients
– etc
37. Model Output
Output:
- Extract from reach output
- Outlet at any sub-basin (swat2dat utility)
- Import (i.e. spreadsheet) & plot
Reach file
output.rch
38. Scenarios
• Typical use will be “what if we change …”
– Temperatures
– Rainfall patterns
– Water management (reservoirs; sewage treatment;
…)
– Landuse (urban development; plant trees; cultivate
new areas; …)
– Crop management (crop type; tillage practices; …)
• Identify hotspots
39. • Thanks to...
– David Lam & David Swayne (NWRI & UG)
– Daniel Ames, Chris Michaelis, & Allen Anselmo
(MapWindow Team)
– Raghavan Srinivasan (SWAT)
– Gary Bowen (TRCA)
– Karim Abbaspour (EAWAG)
– Dagny Janowska (BIAD)
