Page 118 - CIWA Water Data Revolution Overview Report

Baselin 2025- 2025- 2025- 2025- 2025- 2025-
7
e 2030 2040 2050 2030 2040 2050
ET (mm) 858.7 891.0 914.8 893.0 953.9 950.0 983.6
PET
(mm) 922.3 2249.1 2244.0 2245.1 2192.5 2194.9 2144.0
P (mm) 1000.7 932.3 970.7 941.7 996.2 996.1 1035.9

3.9 Running WA+ Under Climate change scenarios

Water accounts for the Volta Basin were generated using the ensemble means from the GFDL-
ESM4 and MPI-ESM1-2-HR models, covering the period 2025–2050. The inputs for the WA+

framework included data for projected precipitation and derived parameters, such as actual

evapotranspiration (ET) and potential evapotranspiration (PET), alongside other inputs
consistent with the current conditions. This approach assumes that variables such as land

cover and land use remain unchanged in the future.

3.10 Summary Water Accounting Results for the Volta River basin under climate change
scenarios

The WA+ framework utilizes the "Resource Base" thematic sheet to provide a comprehensive

overview of water resource status in the basin. This sheet summarizes inflows on the left,

water usage in the middle, and outflows on the right, as shown in Figure 6. The following can

be summarized from the figure:

7 Baseline period for AET, PET, and P is 2003-2021