Input data set: Reservoirs and Dams (ISIMIP4b)

Historical and future hydropower dam and reservoir locations for ISIMIP4b Group III simulations.

histsoc (1850–2021) and 2021soc (held fixed at 2021) provide the observed dam stock, built the same way as the ISIMIP4a record. New dams are relocated to the DDM30 river-routing grid using the same general procedure as ISIMIP3a (see https://www.isimip.org/gettingstarted/input-data-bias-adjustment/details/129/), but omitting the manual-relocation step.
ssp1vlsoc-noadapt and ssp3hsoc-noadapt project future dams starting 2022, using the ISIMIP3b Gernaat et al. (2017) methodology: candidate hydropower sites are ranked into a cost-supply curve and populated cheapest-first against projected regional hydropower demand. Demand is taken from CMIP7 ScenarioMIP markers, REMIND-MAgPIE (SSP1, Very Low) for ssp1vlsoc, GCAM (SSP3, High) for ssp3hsoc, interpolated from the native 5-year IAM demand series to annual resolution, so new dams are allocated at yearly steps, unlike ISIMIP3b. As in the ISIMIP3b no-adaptation scenarios, the underlying candidate-site discharge assessment uses observed climate (WaterGAP2-2e, gswp3-w5e5) and is unchanged from ISIMIP3b, since observed climate does not vary by future scenario. Adaptation scenarios (ssp1vlsoc-adapt, ssp3hsoc-adapt), which would use climate-changed discharge potentials, are planned but not yet available.

Global Dam Watch v1.0 (Lehner et al. 2024) for the historical stock; Gernaat et al. (2017) for future site methodology; CMIP7 ScenarioMIP IAM scenario database (IIASA), REMIND-MAgPIE and GCAM, for demand.

Unlike in the ISIMIP3a dataset, the final visual-validation and manual-relocation step (applied in ISIMIP3a to large dams, reservoir volume > 0.5 km³, 1,108 dams) was not conducted for the newly added 9 dams.

Adaptation-scenario files are not yet available (pending CMIP7 ESM- and GHM-driven climate-change discharge projections). Under the Very Low demand scenario (ssp1vlsoc-noadapt), demand growth is met by 2060 and no further dams are built after that year, even though the file nominally spans through 2100; the High scenario (ssp3hsoc-noadapt) continues building dams through 2100.

For ISIMIP participants, files are available at /work/bb0820/ISIMIP/ISIMIP4b/InputData/socioeconomic/reservoirs_dams/