set term svg size 800,600 dynamic enhanced

set termoption dashed

set style line 1 lt 1 lc rgb "black" lw 1
set style line 2 lt 2 lc rgb "black" lw 1
set style line 3 lt 3 lc rgb "black" lw 1
set style line 4 lt 4 lc rgb "black" lw 1
set style line 5 lt 5 lc rgb "black" lw 1
set style line 6 lt 1 lc rgb "black" lw 2

ismin(x,y) = (x>y)?y:x
ismax(x,y) = (x>y)?x:y

set xlabel 'Immobile Soil Cover Fraction'
set ylabel 'Static Threshold Friction Velocity (m/s)'

b1(wzzo) = -0.179 + 0.225*(log(1 + wzzo))**0.891
b2(wzzo) = 0.3 + 0.06*wzzo**1.2
wubsts(sfcv,wzzo) = 1.7 - 1.35*exp(-b1(wzzo)-b2(wzzo)*sfcv**2)

#set log x
#set log y
set xrange [0:1]
set yrange [0:]
set key bottom right

# using decimal in numbers to ensure real division, not integer divistion
plot wubsts(x,0.5) ls 1 with lines title '0.5 Z0' \
   , wubsts(x,2.) ls 2 with lines title '2 Z0' \
   , wubsts(x,10.) ls 3 with lines title '10 Z0' \
   , wubsts(x,30.) ls 5 with lines title '30 Z0'

#pause -1