Hymod model implementation in Julia
Simple package with functionality to calibrate/simulate river discharge with the Hymod model.
The Hymod package is available through the Julia package system and can be installed using the following commands:.
julia> using Pkg
julia> Pkg.add("Hymod")
using HTTP, CSV, DataFrames, Hymod
# define url to test data
testDataUrl = "https://raw.githubusercontent.com/JuliaHydro/Hymod.jl/master/test/data/test_forcings.csv"
# get response
response = HTTP.get(testDataUrl)
# read response as a DataFrame
df = CSV.File(response.body) |> DataFrame
# create a column in the data frame for potential evapotranspiration
df[!,:pet] = hargreaves(df,tmincol=:tmin,tmaxcol=:tmax,dtcol=:date)
# get a random set of parameters
pars = randomparams()
# run a simulation
q = simulate(df,precipcol=:precip, petcol=:pet; pars...)using Dates
# define dates to calibrate
calstart = Date(1986,1,1)
calend = Date(2001,12,31)
# filter dataframe between start and end calibration times
caldf = filter(row -> row[:date] >= calstart && row[:date] <= calend, df)
# get a dictionary of parameter ranges
paramspace = Dict(
:cmax => Dict(:lower => 1.0, :upper => 100),
:bexp => Dict(:lower => 0.0, :upper => 2.0),
:alpha => Dict(:lower => 0.2, :upper => 0.99),
:ks => Dict(:lower => 0.01, :upper => 0.5),
:kq => Dict(:lower => 0.5, :upper => 1.2)
)
# set number of iterations to run calibration
niterations = 5000
# run calibration
calq, calpars, calloss = calibrate(caldf,paramspace,niterations)
# get the remainder of dataframe to test calibrated parameters
testdf = filter(row -> row[:date] > calend, df)
# run simulation with calibrated parameters
testdf[!,:q] = simulate(testdf,precipcol=:precip, petcol=:pet; calpars...)
When you plot the simulated results compared to observed values, you should get a plot similar to one below.
A Docker image is provided for users that want to run a contained installation of the Hymod model interactively in the browser using Pluto notebooks. To start the Pluto server with Hymod, run the following command in your terminal:
$ docker run --rm -v julia -e 'import Pluto; Pluto.run()' -p 1234:1234 kmarkert/julia-hymod:latest
Next, paste the following URL into the "Open from file" prompt: https://github.com/KMarkert/Hymod.jl/blob/master/examples/hymod_interactive_parameters.jl