UKFE (version 1.0.2)

LcvUrb: Urban adjustment for the linear coefficient of variation (Lcv)

Description

Urbanises or de-urbanises the Lcv using the methods outlined in the guidance by Wallingford HydroSolutions: 'WINFAP 4 Urban Adjustment Procedures'

Usage

LcvUrb(lcv, URBEXT2000, DeUrb = FALSE)

Value

The urban adjust Lcv or the de-urbanised Lcv

Arguments

lcv

the Lcv (numeric)

URBEXT2000

quantification of urban and suburbanisation for the subject catchment

DeUrb

logical argument with a default of FALSE. If set to TRUE, de-urbanisation adjustment is performed, if FALSE, urbanisation adjustment is performed

Author

Anthony Hammond

Details

The method for de-urbanisation isn't explicitly provided in 'WINFAP 4 Urban Adjustment Procedures', but the procedure is a re-arrangement of the urbanisation equation, solving for Lcv rather than Lcv-urban. The functionality assumes that the variance of an annual maximum flow sample is impacted by urbanisation and that this impact can be modelled as a function of URBEXT2000.

Examples

# Choose an urban site (site 53006) from the NRFA data then apply a de-urban
# adjustment using the Lcv and URBEXT2000 displayed
NRFAData[which(rownames(NRFAData) == 53006), ]
LcvUrb(0.21, 0.1138, DeUrb = TRUE)

# Get the pooled L-moment ratios results for catchment 53006 and apply the
# urban adjustment using the pooled Lcv and the URBEXT2000 for site 53006
cds_53006 <- GetCDs(53006)
QuickResults(cds_53006)[[2]]
LcvUrb(0.196, 0.1138)