XAJ: XAJ: An R implementation of three-source Xinanjiang model by...
In Sibada/XAJ: An R implementation of three-source Xinanjiang model by Renjun Zhao

Description Usage Arguments Details Value References

View source: R/XAJ.R

XAJ: An R implementation of three-source Xinanjiang model by Renjun Zhao.

An R implementation of three-source Xinanjiang model by Renjun Zhao, used for daily streamflow simulation.

1	XAJ(PREC, EVAP, params, area, dt = 24, full.UH = FALSE)

`PREC`	Time series of precipitation (daily)
`EVAP`	Time series of pan evaporation or potential evapotranspiration (daily), length must equal to `PREC`
`params`	Parameters (see below)
`area`	Basin area.
`full.UH`	Use the unit hydrograph defined by user, rather than the instantaneous unit hydrograph (IUH) of Nash, for routing of surface runoff. Default FALSE.

This function is an R implementation of the Xinanjiang (XAJ) hydrological model. The lumped XAJ model has 13 parameters, including:

KC, Ratio of potential evap to pan evap

IM, Fraction of impermeable area

WUM, Soil moisture capacity of upper layer

WLM, Soil moisture capacity of lower layer

WDM, Soil moisture capacity of deep layer

C, Coefficient of deep evap

B, Exponent of the soil moisture storage capacity curve

SM, Areal mean free water capacity of the surface soil layer

EX, Exponent of the free water capacity curve

KI, outflow coefficients of the free water storage to interflow

KG, outflow coefficients of the free water storage to groundwater

CI, recession constant of the lower interflow storage

CG, recession constant of groundwater storage

If use the instantaneous unit hydrograph (IUH) of Nash for routing of surface runoff, should provided two other parameters:

N, number of reservoirs in the instantaneous unit hydrograph

NK, common storage coefficient in the instantaneous unit hydrograph

Else should provided the whole unit hydrograph defined by user, and set full.UH become TRUE.

The parameter params must be a numeric vector looks like:

c(KC, IM, WUM, WLM, WDM, C, B, SM, EX, KI, KG, CI, CG, N, NK)

when use the instantaneous unit hydrograph of Nash, or looks like:

c(KC, IM, WUM, WLM, WDM, C, B, SM, EX, KI, KG, CI, CG, UH_1, UH_2, ..., UH_n)

UH_1, UH_2, ..., UH_n means the series of the unit hydrograph.

This function returns a data frame of some common variables of the XAJ model at each time step, such as evaporation, soil moisture, surface and underground runoff.

The variables of the table including:

E, Total evaporation (mm)

EU, Evaporation (mm) of upper soil layer

EL, Evaporation (mm) of lower soil layer

ED, Evaporation (mm) of deep soil layer

W, Total soil moisture (mm)

WU, Soil moisture (mm) of upper soil layer

WL, Soil moisture (mm) of lower soil layer

WD, Soil moisture (mm) of deep soil layer

R, Total runoff (mm) of each time step

RS, Surface runoff (mm) of each time step

RI, Interflow (mm) of each time step

RG, Underground runoff (mm) of each time step

Q, Total runoff (m^3/s) at the outlet of the basin

QS, Surface runoff (m^3/s) at the outlet of the basin

QI, Interflow runoff (m^3/s) at the outlet of the basin

QG, Underground runoff (m^3/s) at the outlet of the basin

Zhao and Liu, 1995. The Xinanjiang model, Computer Models of Watershed Hydrology, Water Resources Publication, Highlands Ranch, CO (1995), pp. 215-232

Sibada/XAJ documentation built on Jan. 10, 2022, 9:36 p.m.