Global surface water quality datasets from 2005-2100 under uncertain climate and socio-economic change, derived from the dynamical surface water quality model (DynQual) at 30 arcmin spatial resolution

Global ~50km (30 arcmin) surface water quality data from the dynamical surface water quality model (DynQual) from 2005-2100, with annual and monthly temporal resolution. Simulations are made under three combined climate and socio-economic scenarios (SSP1-RCP2.6; SSP3-RCP7.0 and SSP5-RCP8.5) and using five general circulation model (GFDL-ESM4; UKESM1-0-LL; MPI-ESM1-2-hr; IPSL-CM6A-LR and MRI-ESM2-0), following the ISIMIP3b protocol (https://protocol.isimip.org/#/ISIMIP3b).

Output data includes:

Salinity; as indicated by total dissolved solids (TDS) concentrations (mg l-1)

Organic pollution; as indicated by biological oxygen demand (BOD) concentrations (mg l-1)

Pathogen/bacterial pollution; as indicated by fecal coliform (FC) concentrations (cfu 100ml-1)

Simulations were originally made at 5-arcmin resolution and aggregated to 30 arcmin (0.5 degree) by summing the in-stream (routed) loadings and channel storage over the aggregated area (at monthly and annual timesteps), and subsequently calculating in-stream concentrations. Please note the aggregation technique is provisional and thus the data is subject to change.

Note. A minimum discharge threshold of 0.1 m3 s-1 was used when computing TDS, BOD and FC concentrations, as uncertainties in absolute values of water availabilities have large impacts on resulting in-stream concentrations. Concentrations in these gridcells are assigned as NA.

Hydrology and water quality simulations made at DynQuals native spatial resolution (5 arcmin), aggregated over WorldClim time periods, can be found at: https://zenodo.org/records/14677665. Full time series of variables are also avaliable on request; but please note (due to the large file sizes involved), you will have to retrieve these yourself over a server.