Table 2.
List of Watersheds (n = 12) Where More Than 30% of the Mean Annual P Is Vegetation‐Sourced (Mean Annual E t Dependence in %)
| Watershed | Mean annual E t dependency (%) | Interannual variability vegetation‐sourced P (COV) | Seasonal dependence on E t (constant/wet/dry) | Mean annual P (mm year−1) |
|---|---|---|---|---|
| Congo | >50% | Low | Constant | 1478 |
| Nile | >50% | Low | Constant | 614 |
| Zambezi | >50% | High (dry season) | Wet season | 853 |
| Lake Chad | >50% | Moderate (dry season) | Dry season, terrestrial | 370 |
| Rift Valley | >50% | Low | Constant | 757 |
| Africa South Interior/Okavango | >50% | High (dry season) | Constant | 476 |
| Senegal | >30% | Moderate (dry season) | Dry season | 575 |
| Namibia/Swakop | >40% | High | Wet season | 82 |
| Orange | >40% | High (dry season) | Wet season | 296 |
| Africa East Central Coast | >40% | High (dry season) | Wet season (local) | 923 |
| Niger | >30% | Moderate (dry season) | Dry season (remote) | 710 |
| Gulf of Guinea | >30% | Low | Wet season | 1814 |
Note. Interannual variability of vegetation‐sourced P is defined here based on three value classes for the coefficient of variation: <20% (low); 20%–40% (moderate); and high (>40%). We distinguish between annual mean, wet and dry season. Seasonal dependence on E t is based on the difference in relative contribution of E t between the wet and dry season. To classify the watersheds based on the seasonal dependence, we use a threshold of 5% relative difference between the wet and dry seasons. It is considered constant if the difference between mean dry and wet season contribution <5%. The threshold value aims to standardize seasonal differences and is arbitrarily chosen. The watersheds in italic (Congo and Senegal) will be highlighted further.