The LowFlows function now has the option to provide a FARL range (excluding catchments outside the range from the analysis). It also outputs the gauges used in the analysis with their weighting etc.
The ReFH function, which is now more flexible, incorporating the options of changing the unit hydrograph shape, the loss model, the baseflow component, and the rainfall profiles, has been updated so that the randomised rain profiles are created by using the FSR profile as a probability mass function. There is also an update to the way the default timestep is calculated when timestep is not specified.
*The following have been fixed: The QMED function failed when individual descriptors were used as opposed to catchment descriptor objects. This was also the case with the LowFlows function. When using the GetDataEA_QH function the “DailyMax” option resulted in duplicated dates (this is what the HDE returns - so look out when downloading directly from the website). All fixed.
FEH2025: The Pool, QMED, and PoolEst functions amended to apply the FEH2025 methods.
QMED donors: The QMED function amended so that you can input a vector (‘list’ is normal parlance) of gauge IDs as donors, or you can use the no.Donors argument and simply choose N donors and the N closest to catchment centroid will be used. You can also return all the details of these gauges and associated adjustments and distances etc. The QuickResults function uses the default of 8 closest donors.
Pooling uncertainty: By default, the uncertainty calculated for pooled estimates is done bespoke for your pooling group (rather than using generalised approximating equations - as in previous version). This is done by resampling of the pooling group and an assumption about the FSE for QMED (if Gauged = FALSE) – which can be adjusted by the user. The uncertainty result is provided in the form of an FSE for each return period and associated peak flow estimate.
Defaults: The defaults for Pooling and QMED have been changed so that urban adjustments etc are applied unless otherwise specified. The Donor default is to choose any gauge (i.e. the URBEXT maximum is set at 1), you will need to reduce this if you wish to avoid urban donors when using the default ‘No.Donors’ argument.
CDs: The new descriptors are now available via the GetCDs or CDsXML function (there is a CDsXML_legacy function to read in older ones - but they won’t work with the new Pool and QMED functions and would need to be adapted).
Data: Removed the two dataframes QMEDData and NRFAData and replaced them with a single dataframe called PeakFlowData (it incorporates all the info about sites suitable for pooling and/or QMED. The AMSP has also been changed. It is a dataframe of annual maximum samples. It now includes sites suitable for QMED as well as sites suitable for pooling – and has therefore been renamed as AMPF.
Historic flood estimation: There is now a function called HistoricalMLE, which allows you to estimate peak flows whilst accounting for k peaks over a specified threshold over h years prior to the AMAX record. At present it does not have the option for specifying historic discharges.
Seasonality Plot: Seasonality function has been added, for seasonality plotting. A pooled seasonality plot has also been added to the plots provided by the DiagPlots function.
LowFlows: Function called LowFlows added which estimates low flows from catchment descriptors (or individual inputs of AREA, SAAR, and an estimate of BFI). This returns Qmean, Q95, Q70, Q50, Q10, and Q05.
ReFH: Amended ReFH function to make it a flexible tool for evaluating the plausible response to an input of rainfall.
The BFI function now has the option of returning the time series of flow along with the baseflow component.
Accessibility. Many of the plots have been reformatted so that they are better for those who may have difficulty differentiating between certain colours. For example, the differences between plotted components are now highlighted by shading lines etc.
Hydrometric data extraction: The extraction functions for getting hydrometric data from the HDE had missing date times where the hours changed in the summer and winter. This has been corrected by making it all GMT (as in the HDE). Furthermore, the “hourly” option was not working, and it would default to 15minutes when applied; this has been fixed.
CDsXML: When using CDsXML for sites in Northern Ireland, the grid referencing was not converted to BNG. This has been fixed.
EVPlot: If there were NA values in the sample input, this would cause an error. This has been fixed.
Data pre-processing script: Added to the package (note: file paths remain local to the package author).
GenParetoPars(): Removed the mle option
(difficult to verify correctness).
Input validation: Added handling for invalid inputs in
GenLogEst(), GEVEst(),
GumbelEst(), Kappa3Est(),
GenParetoEst() (reject scale or RP <= 0; handle
shape = 0 where applicable).
Error handling: Improved in Kappa3Est(),
GEVPars(), LSkew(), and LKurt()
when required arguments (x, L1,
LCV, LSKEW) are missing.
Error messaging: More informative message in Pool()
when DeUrb = TRUE but no sites are available.
H2 method:
fse implementation: Updated in
QuickResults().
Styling: Applied styler::style_pkg() to align with
tidyverse conventions (cosmetic only).
Improved accessibility and readability of plots across multiple functions (better colour contrast, line types, text sizing, axis labelling, and more descriptive titles).
GenLogAM(): Implementing support for
k = 0 (i.e. LSkew = 0).
GEV shape equation: Minor correction in GEVGF(),
GEVAM() and GEVPars().
Exponential usage: Replaced exp(1)^x with
exp(x).
b formulas: Reworked b1,
b2, and b3 inKappa3Pars(),
GenLogAM(), GEVAM(),
GenParetoPOT(), GumbelAM(),
LMoments(), Lcv(), LSkew() and
LKurt().
Optimisation bounds: Corrected for Kappa3GF() and
Kappa3Pars().
Column indexing: Fixed QuickResults()
selecting wrong column (now indexed by name).
ReFH(): Fixed the calculation of the nearest odd
multiple of the timestep when the duration is unspecified.
AMImport(): Adjusted for updated date
format.
Zdists(): Corrected GEV and GenLog results which
were the wrong way round.
ARF(): Fixed typo in b equation when
20 < Area < 100.
Irish Grid & CRS: CDsXML() now uses Irish Grid
CRS; ConvertGridRef() uses EPSG codes (instead of self
defined CRS).
Data structures: Corrected coordinates for Northern Irish gauges
in AMSP, NRFAData, and
QMEDData.
GetDataSEPA_QH(): A new function to get level and
flow data from the SEPA API.
DDFExtract(): A new function which extracts depth
duration frequency curves from hourly or sub-hourly rainfall
data.
FlowSplit(): A new function for hydrograph splitting
- separating baseflow from runoff. More for shorter event splitting as
opposed to long flow series (i.e. it is not for deriving baseflow index,
the BFI function does that).
FlowDurationCurve(): Users can now add additional
horizontal flow lines to the plot with the AddQs argument.
With the ReturnData argument users can also return a data
frame with the flow and percentiles.
DesHydro(): Have removed the div
argument and simplified it so that the EventSep argument
does both the division of events for the peak identification, as well as
the event period. It now produces an error when fewer than two peaks are
extracted.
GetDataEA_QH(), GetDataEA_Rain(): These
functions have been updated so that if the user puts in no start and/or
end date, it defaults to the minimum and/or maximum dates
available.
Changes combined with 0.4.0 above.
DesHydro(): Vastly improved this function.
Significantly quicker and it now centres around the main peak rather
than the user having to truncate after inspecting the plot.
ConvertGridRef(): New function to convert between
latitude and longitude, British National Grid reference, and Irish Grid
reference.
FlowDurationCurve(): New function for plotting flow
duration curves from a data frame with date or date-time in the first
column and flow in the second column (plots annual, summer, and winter).
Alternatively, you can provide a list of flow series to
compare.
ERPlot(): Added an option to the extreme rank plot
to create a plot very similar to the original version, but the y-axis is
the percentage difference from the observed. This allows better
comparison across distributions. There is also the option for a plot of
modelled versus observed values for each rank.
Bootstrap(): Replaced the UncSS()
function with this more generic bootstrap function for deriving the
sampling distribution and quantifying associated uncertainty for a
statistic of your choice (given an input sample).
Uncertainty(): Now provides the full bespoke
resampling methods to derive uncertainty for pooling groups detailed in
“Hammond, A. (2021). Sampling uncertainty of UK design flood estimation.
Hydrology Research. 1357-1371. 52 (6)”. Previously, only the gauged
version did this and the ungauged version applied the approximating
equations (which are used by default within the PoolEst()
function). The name of the QMEDfse argument has changed to
fseQMED with the default changing from 1.46 to
1.55.
AnnualStat(): Firstly, this is a name change for the
AMextract() function (because it can be used for any
statistic). It also now has a sliding option, so that maximum rainfall
over any sliding period can be derived as opposed to just the maximum
over fixed intervals.
LMoments(): Name change because it has bugged me for
a while that I initially called it Lmoms.
GetData... functions. The naming convention of
functions that extract data from the web has been homogenised so that
they can easily be found. They all start with GetData. They
are:
GetDataEA_QH() (get EA flow or stage, find gauges by
river name or lat and lon)GetDataEA_Rain() (get EA rain, find gauges by lat and
lon)GetDataMetOffice() (get regional monthly rainfall or
temperature)GetDataNRFA() (using gauge ID, get flow, catchment
rainfall, AMAX, POT, and gaugings)GetDataSEPA_Rain() (get SEPA rainfall, find gauges by
lat & lon, or print a list of them all to the console).MonthlyStats(): As well as getting all the monthly
stats, there is now an option to output a monthly time series of the
stat in the form of a data frame with date in the first column (first of
each month) and the statistic of interest in the second.Changes combined with 0.3.8 above.
Updated with the new NRFA Peak Flow Dataset (version 13).
Get data functions. Added a range of functions to get data from various sources using the associated APIs. These are:
GetNRFA() (this can be used to extract daily catchment
rainfall, daily mean flow, AMAX samples, or gaugings from the NRFA,
using gauge ID).GetMetOffice() (this can be used to get regional series
of rainfall or temperature on a monthly, seasonal, and annual
basis).GetRainEA() (this can be used to extract rainfall data
from the Environment Agency’s Hydrometric Data Explorer. It is available
under v0.3.5 but I have increased the number of rows the function can
get – previously you could only get a little over 2 years of 15-minute
data. Now you can theoretically get 57 years. In practice, it fails if
the extraction takes more than one minute. This restricts it to more
like 25 years (when I tested it anyway).GetRainSEPA() (no change from v0.3.5).ERPlot(). Added this back but in revised form. It
now directly compares the estimated flows for each rank with the
observed for each rank.
GoF functions: GoFCompare(), and
GoFComparePool(). New goodness-of-fit functions: one for
single samples and one for pooling groups. They are more straightforward
to interpret than Zdists(). The Zdists()
function is also very sensitive to slight differences in methodology.
The one in WINFAP (based on FEH08) uses a theoretical L-kurtosis
(calculated as a function of L-skewness) for comparison against the
sampling distribution of L-kurtosis under the null hypothesis. This
means that the Gumbel distribution can’t be compared. The
Zdists() function in UKFE uses the weighted average (by
sample size) L-kurtosis of the pooled AMAX (see the associated details)
– so that Gumbel can be included. For such reasons, I thought it would
be good to have a more straightforward comparison, without worrying
about hypothesis testing (hence them being called
GoFCompare). The new GoFCompare() function
simply calculates the RMSE of the ordered observed AMAX against mean
simulated ordered AMAX (500 simulations) and provides the RMSE as a
percentage of the AMAX mean (the lowest across the distributions is the
best fit). The GoFComparePool() version does the same but
with the pooled AMAX (standardised into a single large sample).
Mann Kendall is now the default trend test in the
TrendTest() function.
Error catching. Added some sensible error messages here and there where necessary.
QMED() function for calculating QMED from catchment
descriptors. The donor adjustment wasn’t working properly when the CDs
were added individually (as opposed to using a CDs
object).Kappa3 functionality. Better embedded the Kappa3 distribution in
general. It can now be used with the other functions which take the
dist argument, such as PoolEst(),
OptimPars() and SimData(). Also added three
functions which mirror those for the other distributions:
Kappa3AM(), Kappa3Pars(),
Kappa3Est(). The Kappa3GF() function is still
there and has not changed.
Zdists() function has been updated and now Kappa3
and Gumbel have been added to the results.
Added a function called POTt(). This is a POT
extraction function which works on time only (to determine the
independence). The other POTextract() function can also
have a time element (as well as return to a low threshold) to determine
independence, but the new one is significantly faster. This is useful
for very long time series such as 10,000 years of simulation at an
hourly sampling rate (POTextract() would
struggle).
I have retired the GoTF functions but may add them
back in improved form. I have also temporarily retired the
ERPlot() function, but this will be back. Temporary
retirement is expedient because it has a GoTF function
within it which requires removal/replacement.
AddGauge() function. There is now functionality to add
a new AMAX with CDs etc to the group of sites suitable for pooling so
that it can be used in the FEH pooling process. Remember that there is
also the LRatioChange() function which allows you to update
the stats within the pooling group that is already there (in case you
have an extra year to add for example).H2() function. This was providing verdicts of
heterogeneity more often than it should. The error has been fixed.Rainfall API functions. Two new functions: One is
RainEA() and the other is RainSEPA(). These
can be used to get rainfall from rain gauges in Scotland and England
using the Environment Agency and Scottish Environment Protection Agency
APIs.
Zdists() update. The zdist for assessing the
distribution fit was based on the FEH99 method. I’ve updated this to the
FEH2008 method.
Pool() function.
There is a column in the pooling group which states if a site is over
the threshold for discordancy and is therefore considered discordant.
When the pooling group had more than 15 catchments, this didn’t work and
all sites were set as FALSE (not discordant) no matter what the
discordance score was. This has been fixed.The QMED() function now provides the weightings when
two donors are used.
The PoolEst() function now provides a list with four
elements. First is the results, second is the pooled LCV and LSKEW,
third is the distribution parameters for the growth curve, and fourth is
the distribution parameters for the frequency curve.
Changed the ReFH() function to output a list with
two data frames: one for the parameters, and one for the results. (As
opposed to a print out of parameters and a data frame of
results.)
Removed erroneous warning messages from the functions
AggDayHour(), AMextract(), and
MonthlyStats().
Added Easting and Northing into QMEDData and
NRFAData which were missing for a couple of Northern
Ireland catchments.
NonFloodAdjPool() function. Added a useful message for
when there are no sites in the pooling group that meet the non-flood
criteria (before it was failing without a clear reason why). Also added
an argument called ReturnStats. If this is set to
TRUE, rather than providing an adjusted pooling group it
returns the number of years, the number of non-flood years and the
percentage of non-flood years, for each station.Updated to use the NRFA Peak Flow Dataset version 12.
Added new function called AggDayHour(), which allows
you to aggregate a data frame based on the date time column. For
example, you might have a time series with a 15-minute sampling rate and
you want it at a daily or hourly rate (you can choose the number of
hours).
The NonFloodAdj() function has replaced the
PermAdj() function and now provides the percentage of
non-flood years as well as the adjusted L-CV and L-skewness (the result
is now a list with two data frames).
Added new function called NonFloodAdjPool(). This
allows non-flood adjustment to pooling groups. You can update all sites,
individual sites (one or more user-selected ones), or all sites above a
given percentage of non-flood years.
The DonUrbAdj argument has been added to the
QMED() function. This allows you to de-urbanise the QMEDcd
estimate of the donor/s. It’s for the unlikely and usually not
recommended case where the subject site is rural and the donor is
urban.
AMextract() function and the
DDF99Pars() function.DDF13Import() function has been replaced with
DDFImport(), given that the FEH22 rainfall depth duration
frequency results have been made available for the peak flow sites as
part of the NRFA update. The function now has the option of importing
the 2013 or the 2022 version of the DDF model.Pool() and PoolSmall()
functions so that you can use an UrbMax argument to
increase the URBEXT2000 level at which gauges are excluded from the
pooling group. The default is 0.03. This is particularly useful for
users in Wales where the guidance suggests an URBEXT2000 of 0.3. The
DeUrb argument is also available which de-urbanises every
site with URBEXT2000 above 0.03.BivarSim() function as it needs
updating.POTextract() function. The user can now set the
div argument the same as the threshold. This essentially
reverts the function to a time-based separation, albeit a slow one.Added a function called MonthlyStats() which can
provide statistics such as mean flow or sum of rainfall for each
month.
Added a function called BivarSim(). This simulates
bivariate extremes above a threshold using a Gaussian copula approach.
See function details but also the multivariate extremes section at the
bottom of this webpage:
https://www.floodhydrostats.com/howitworks
Added a function called UEF(), which is the Urban
Expansion Factor.
POTextract() function as follows:
div argument is now a percentile as opposed to an
absolute valueAMextract() function as follows:
TrendTest() function so that alternative
hypotheses can be used. It was a two.sided test (still is by default),
but now you can test for positive or negative trend specifically by
using the alternative argument. See function details.QMED() function. There was an error when a single
donor was applied.
POTextract() function.
ImportAM() is now AMImport(). It’s
assumed this will make it easier to find.
CDsXML(). New function to read in catchment
descriptors from XML files.
The ImportCDs() function has been removed because
it’s based on the .cd3 files which are being phased out.
PoolSmall(). New function for making pooling groups
for small catchments.
DDFImport(). New function which imports the DDF13
results data frame from an xml file (from NRFA peak flows or the FEH Web
Service). There is a logical TRUE/FALSE argument to make
the ARF adjustment for the data frame. This function takes the output of
the DDF13Import() function as an input. It then allows the
user to select a return period and duration to get a rainfall
estimate.
Kappa3GF(). New function to derive growth factors
using the Kappa3 distribution as a function of L-CV and L-skewness. This
hasn’t been fully embedded in other functions such as
PoolEst(), Zdists() and EVPlot().
It can however be used with the outputs of the L-CV and L-skewness from
the PoolEst() function - or with any estimate of L-CV and
L-skewness for that matter.
AMextract() now has an argument called
func. This allows the user to extract other statistics from
the hydrological years, such as mean flow, or sum of precipitation. Any
base function which is applied on a numeric vector with no further
arguments can be used.
Uncertainty(). This function has been updated to
make the estimation in ungauged catchments more flexible. The user can
input the QMEDfse rather than stating number of donors (it
has a default of 1.46).
HydroPlot(). This function has been updated so that
the user can choose to return the data being plotted in a data frame.
The function allows the choice of the date / date-time range to plot;
this can be returned as a separate data frame.
SCF() bug fix.Added the Gumbel distribution and associated functions.
Added a function to add lines or points to the EV plot:
EVPlotAdd()
Updated the Uncertainty() function based on Hammond
(2021) (“Hammond, A. (2021). Sampling uncertainty of UK design flood
estimation. Hydrology Research. 1357-1371. 52 (6)”).
Included uncertainty as a default for pooled estimates (for the
QuickResults() function and the PoolEst()
function; for the latter you can choose the QMED fse).
EVPlot(): Improved the EV plot formatting and it now
includes 95% confidence intervals.
Added numerous error messages for better user information when things go wrong.
OptimPars(),
DesHydro(), and HydroPlot() functions.Corrected some grid referencing for the Northern Ireland gauge locations.
Further improved the ImportAM() function.
Updated the ImportAM() and ImportCDs()
functions to make them more robust.
Added some better error messaging to the GetCDs()
and the Pool() functions.
Corrected the QMEDLink() function.
Made the ImportCDs() function work with both FEH Web
Service and NRFA Peak Flow Dataset cd3 files without the need for the
user to specify.
Added a nice failure message for the GetCDs()
function when an unknown gauge ID is entered.
Added an option to avoid plotting when using the
BFI() function.