Table 1
Available components for Xanthos 2, their component types, and references to the supporting algorithms.
| Component | Type | Algorithm Reference |
|---|---|---|
| Penman-Monteith | PET | McMahon et al. 2012; Monteith 1965 [11, 12] |
| Hargreaves-Samani | PET | Hargreaves and Samani 1982 [16] |
| Hargreaves | PET | Hargreaves et al. 1985 [17] |
| Thornthwaite | PET | Thornthwaite 1948 [28] |
| abcd | Runoff | Liu et al. 2018 [13] |
| Global Water Availability Model (GWAM) | Runoff | Hejazi et al. 2014 [3] |
| Modified River Transport Model (MRTM) | Routing | Zhou et al. 2015; Li et al. 2015 [14, 15] |
| Diagnostics | Post-processing | Li et al. 2017 [10] |
| Time Series Plotting | Post-processing | Li et al. 2017 [10] |
| Accessible Water | Post-processing | Kim et al. 2016 [18] |
| Hydropower – Potential | Post-processing | Zhou et al. 2015 [14] |
| Hydropower – Actual | Post-processing | Turner et al. 2017a; Turner et al. 2017b [19, 20] |
| Calibration – abcd | Ancillary | Storn and Price 1997 [21] |
Table 2
Xanthos expected outputs when using the default configuration and the accessible water, hydropower – potential, hydropower – actual, diagnostics, and time series plots post-processing modules.
| Output | Source | Units |
|---|---|---|
| Potential Evapotranspiration (PET) per grid cell | PET | Monthly or annually; mm/time or km3/time |
| Actual Evapotranspiration (AET) per grid cell | Runoff | Monthly or annually; mm/time or km3/time |
| Gridded runoff per grid cell | Runoff | Monthly or annually; mm/time or km3/time |
| Aggregated total runoff per basin | Runoff | Monthly or annually; mm/time or km3/time |
| Aggregated total runoff per GCAM country | Runoff | Monthly or annually; mm/time or km3/time |
| Aggregated total runoff per GCAM region | Runoff | Monthly or annually; mm/time or km3/time |
| Soil moisture per grid cell | Runoff | Monthly or annually; mm/time or km3/time |
| Average channel flow per grid cell | Routing | Monthly; m3/second |
| Accessible water | Accessible water | Monthly or annually; mm/time or km3/time |
| Exploitable hydropower potential by GCAM region | Hydropower – Potential | Monthly or annually; EJ/time |
| Technical hydropower potential by GCAM region | Hydropower – Potential | Monthly or annually; EJ/time |
| Actual hydropower production | Hydropower – Actual | Monthly or annually; EJ/time |
| Diagnostics – runoff by basin | Diagnostics | Annually; km3/year |
| Diagnostics – runoff by GCAM country | Diagnostics | Annually; km3/year |
| Diagnostics – runoff by GCAM region | Diagnostics | Annually; km3/year |
| Time series plots – streamflow by basin | Time Series Plots | Monthly or annually; mm/time or km3/time |
| Time series plots – streamflow by GCAM country | Time Series Plots | Monthly or annually; mm/time or km3/time |
| Time series plots – streamflow by GCAM region | Time Series Plots | Monthly or annually; mm/time or km3/time |
Figure 1
Xanthos 2 module diagram and workflow for the default configuration. Components in green provide built-in functionality; blue components are the interchangeable core modules; and orange components are post-processing modules that have been extended.
Figure 2
Performance of calibrated runoff by water basin (235 basins globally) from the abcd module using SciPy’s differential evolution optimization function when compared to VIC model runoff forced by WATCH data for years 1971–1991. Note that runoff is converted to km3 by multiplying by basin area, and each data point denotes the long term mean annual runoff of a water basin.