GeneralizedHyperbolic (version 0.8-6)

ArkansasRiver: Soil Electrical Conductivity

Description

Electrical conductivity of soil paste extracts from the Lower Arkansas River Valley, at sites upstream and downstream of the John Martin Reservoir.

Usage

data(ArkansasRiver)

Format

The format is: List of 2 $ upstream : num [1:823] 2.37 3.53 3.06 3.35 3.07 ... $ downstream: num [1:435] 8.75 6.59 5.09 6.03 5.64 ...

Details

Electrical conductivity is a measure of soil water salinity.

References

Eric D. Morway and Timothy K. Gates (2011) Regional assessment of soil water salinity across an extensively irrigated river valley. Journal of Irrigation and Drainage Engineering, doi:10.1061/(ASCE)IR.1943-4774.0000411

Examples

data(ArkansasRiver)
lapply(ArkansasRiver, summary)
upstream <- ArkansasRiver[[1]]
downstream <- ArkansasRiver[[2]]
## Fit normal inverse Gaussian
## Hyperbolic can also be fitted but fit is not as good
fitUpstream <- nigFit(upstream)
summary(fitUpstream)
par(mfrow = c(2,2))
plot(fitUpstream)
fitDownstream <- nigFit(downstream)
summary(fitDownstream)
plot(fitDownstream)
par(mfrow = c(1,1))
## Combined plot to compare
## Reproduces Figure 3 from Morway and Gates (2011)
hist(upstream, col = "grey", xlab = "", ylab = "", cex.axis = 1.25,
     main = "", breaks = seq(0,20, by = 1), xlim = c(0,15), las = 1,
     ylim = c(0,0.5), freq = FALSE)
param <- coef(fitUpstream)
nigDens <- function(x) dnig(x, param = param)
curve(nigDens, 0, 15, n = 201, add = TRUE,
      ylab = NULL, col = "red", lty = 1, lwd = 1.7)

hist(downstream, add = TRUE, col = "black", angle = 45, density = 15,
     breaks = seq(0,20, by = 1), freq = FALSE)
param <- coef(fitDownstream)
nigDens <- function(x) dnig(x, param = param)
curve(nigDens, 0, 15, n = 201, add = TRUE,
      ylab = NULL, col = "red", lty = 1, lwd = 1.7)

mtext(expression(EC[e]), side = 1, line = 3, cex = 1.25)
mtext("Frequency", side = 2, line = 3, cex = 1.25)
legend(x = 7.5, y = 0.250, c("Upstream Region","Downstream Region"),
       col = c("black","black"), density = c(NA,25),
       fill = c("grey","black"), angle = c(NA,45),
       cex = 1.25, bty = "n", xpd = TRUE)