Modelling Water Resources
The hydrologic simulator Soil Water Assessment Tool (SWAT) is used for water resources analysis. SWAT is a physically-based, river basin scale, distributed hydrologic model. The program is developed to predict the impact of land management on water, sediment and agricultural chemical yield in large, complex watersheds. SWAT is an integrated program including components such as weather, hydrology, soil temperature, nutrients, pesticides, land management, bacteria and pathogens. The model also includes procedures to describe how CO2 concentration, precipitation, temperature and humidity affect plant growth, evapotranspiration, snow and runoff generation, among other variables, and therefore is also used to investigate climate change impacts.
SWAT is a continuous time model and operates on a daily time step. In SWAT the spatial heterogeneity of the watershed is taken into account, considering information from the elevation map (DEM), the soil and landuse maps. Spatial parameterisation of the SWAT model is performed by dividing the watershed into sub-basins based on topography. These are further subdivided into a series of hydrologic response units (HRU) based on unique soil and land use characteristics. A complete description, program and manual can be obtained free of charge here
Based on our previous work, water resources of Africa, Europe and parts of Asia and North America are calculated and are available in the WRQ databases. The procedures are documented in the following references:
- Faramarzi, M., Abbaspour, K.C., Schulin, R., Yang, H. (2009) Modelling blue and green water availability in Iran. Hydrological Processes 23(3), 486-501. pdf
- Schuol, J., Abbaspour, K. C., Yang, H. Srinivasan, R., Zehnder, A. J. B. (2008) Modeling Blue and Green Water Availability in Africa. Water Resources Research 44(7). pdf
- Schuol, J., Abbaspour, K.C., Srinivasan, R., Yang, H. (2008) Estimation of
freshwater availability in the West African sub-continent using the SWAT
hydrologic model. Journal of Hydroloy,
352(1-2), 30-49. pdf