WBM-NCascade is a branch of WBM that includes unique functionality including:
- Upland Wetland Storage - this formulation intercepts surface runoff before generating streamflow.*
- Coupling agricutural DIN input from soil leaching - formulated to ingest distributed DIN from Agro-IBIS presently.
- Floodplain nitrogen processing for identified large river reaches.
Technical descriptions of these additional functions are described in main text and supplementary materials of:
Zuidema, S., Liu, J., Chepeliev, M. G., Johnson, D. R., Baldos, U. L. C., Frolking, S., Kucharik, C. J., Wollheim, W. M., and Hertel, T. W.: US climate policy yields water quality cobenefits in the Mississippi Basin and Gulf of Mexico, Proceedings of the National Academy of Sciences, 120, e2302087120, https://doi.org/10.1073/pnas.2302087120, 2023.
Zuidema, S., Wollheim, W. M., Kucharik, C. J., and Lammers, R. B.: Existing wetland conservation programs miss nutrient reduction targets, PNAS Nexus, 3, pgae129, https://doi.org/10.1093/pnasnexus/pgae129, 2024.
W.M. Wollheim, S. Zuidema, J. Liu, U. Baldos, M.G. Chepeliev, K.M. Ferin, S. Frolking, J. N. Galloway, I. Haqiqi, D.R. Johnson, C.J. Kucharik, R.B. Lammers, T.W. Hertel: (In Review) Reimagining Agricultural Nitrogen Management Using the Nitrogen Cascade, Science.
Model Provenance:
- Branched initially from WBM v20.9.1.
- Built and tested functionality of UWS, Agro-IBIS input, and whole hydrologic system nitrate processing.
- Merge changes from WBM v23.11.1 to this branch that were released as WBMv.2.0.
- Represents state of model used in Zuidema et al. (2023, 2024)
- Added floodplain nitrogen processing
Disclaimer: While WBMv1.0 and WBMv2.0 are targeted for easy adoption by the macroscale hydrologic modeling community, consider this branch of code boutique. There is no expectation that model run initialization files appropriate for WBMv1.0/WBMv2.0 should behave properly for WBM-NCascade; nor should model run initialization files or specific inputs could be deciphered by WBMv1.0/WBMv2.0.
Running WBM-NCascade: WBM-NCascade should run on the same architecture provided as released by WBMv2.0. Please visit github.com/wsag/WBM, follow instructions there for basic operation and set-up of WBM and accessing an appopriate singularity container for running WBM.
WBM-NCascade requires 2 additional model input blocks, and updates to the DIN input block in the model run initilization file:
Wetlands => { WetArea =>
"<INPUTFOLDER>/ncascade_wetland_area_nw_v5_yc.init"
# Data init file describing the areas treated as
# Upland Wetland Storage
max_treated_upstream_area => 25.0, # Land area
# factor limiting the size of wetland catchments
# (e.g. the within-cell catchment for wetlands is
# 2500% of the wetland area)
max_wetland_flow_depth => 0.80, # Flow depth (m)
Riparian_AreaFrac => 0.0007, # Fraction of
# cell area treated as a riparian wetland margin
# where no wetlands are defined
fraction_buffer_area => 0.777, # Fraction of
# total wetland area defined by "WetArea"
# represents wetland buffer (instead of inundated area)
wetland_alpha => 0.0875125 # time constant (1/d)
# defining exponential residence time
# distribution in wetlands
},
SamplePoints => {
# Functionality that outputs full time-series
# (daily) at specific locations
Output_vars => 'discharge DIN_Conc_Dsch',
# Variables included in sample point output
point_file => "<INPUTFOLDER>/search_coords_sample.csv",
# Path to points file
point_ID => "station_ID",
# Identifier for location
point_x => "search_Lon",
# (E-W)|Longitude coordinate (in units consistent
# with river network extent and projection)
point_y => "search_Lat",
# (N-S)|Latitude coordinate (in units consistent
# with river network extent and projection)
Upstr_Area => "search_UpstrArea",
# Upstream area of point (km2) (facilitates
# snapping to river network
search_distance => 20
# Distance limit for snap searching
},
The DIN block must also include several key-value pairs to:
Enable input of space-time-varying Dissolved Inorganic Nitrogen inputs from Agriculture (from Agro-IBIS):
AgroIBISload => "<INPUTFOLDER>/agroIbis_no3leach_ncascade_cusd00menwfp_d.init",
# DIN leaching flux from soil (kg/ha/day)
AgroIBISdrainage => "<INPUTFOLDER>/agroIbis_drainage_ncascade_cusd00menwfp_d.init",
# Water drainage from soil (mm/day)
AgroIBISpercTemp => "<INPUTFOLDER>/agroIBIS_perc_temperature_m00menwfp_d.init",
# Temperature of water draining from soil (degC)
delta_vadose_lag => 800.,
# Time in transit between leaching and recharge (d)
din_effLoss_denit_log_constant_ssp => 18.0 ,
# Constant of the efficiency loss denitrification
# rate (at 1 mg NO3-N/L and 25degC) (m/year) in wetlands
din_effLoss_denit_log_slope_ssp => -0.43,
# Log-space slope defining efficiency loss at
# increasing DIN concentration in wetlands
tnQ10_ssp => 2.0,
# Q10 factor in wetlands
tnQref => 20.0,
# Q10 reference temperature in wetlands (degC)
Da_ground => 0.29,
# Damkohler number of denitrification in shallow groundwater
transfer_dgw => 0.505000000000000 ,
# transfer fraction of DIN in shallow groundwater
# to deep groundwater
Enable floodplain denitrification - define explicit floodplain areas restored.
rest_floodplain =>
"NetCDF:<INPUTFOLDER>/MERIT_05min_floodplain_restore_3.5e10_m2_fraction.nc:crop_fraction"