init_state: Initial conditions of the model

In DWBmodelUN: Dynamic Water Balance a Hydrological Model

Initial conditions of the model

Description

This function uploads or creates the initial conditions of the two-state variables present in the DWB model, in raster format.

Usage

init_state(raster)

Arguments

raster

a single layer raster (SpatRaster from terra, or an object convertible to it, such as a RasterLayer) containing the maximum storage in the root zone, or a two-layer raster with the initial conditions of the soil water storage (first layer) and the groundwater storage (second layer)

Details

It requires the raster composed of the Smax values that were created using the buildGRUmaps function, or a two-layer raster previously created with the initial conditions of the soil water and groundwater storage. If only one layer is provided, the function creates the two initial conditions using the values of the provided raster reduced by half.

Value

A list containing initial conditions in storage and in ground.

Author(s)

Nicolas Duque Gardeazabal <[e-mail]>
Pedro Felipe Arboleda <[e-mail]>
Carolina Vega Viviescas <[e-mail]>
David Zamora <[e-mail]>

Water Resources Engineering Research Group - GIREH Universidad Nacional de Colombia - Sede Bogota

References

Budyko. (1974). "Climate and life". New York: Academic Press, INC.

Zhang, L., Potter, N., Hickel, K., Zhang, Y., & Shao, Q. (2008). "Water balance modeling over variable time scales based on the Budyko framework - Model development and testing. Journal of Hydrology", 360(1-4), 117-131.

Examples

# Example 1: build the initial states from the Smax map
data(GRU, param)
gru_maps <- buildGRUmaps(GRU, param)
init <- init_state(gru_maps$smaxR)

# Example 2: use two rasters with previously known initial conditions
data(In_storage, In_ground)
init <- init_state(c(terra::rast(In_storage), terra::rast(In_ground)))

DWBmodelUN documentation built on July 28, 2026, 5:09 p.m.