diagwl {climatol} R Documentation

## Walter \& Lieth climatic diagram

### Description

Plot of a Walter \& Lieth climatic diagram of a station.

### Usage

diagwl(dat, est="", alt=NA, per="", margen=c(4, 4, 5, 4), mlab="",
pcol="#005ac8", tcol="#e81800", pfcol="#79e6e8", sfcol="#09a0d1", shem=FALSE,
p3line=FALSE, ...)


### Arguments

 dat Monthly climatic data for which the diagram will be plotted. est Name of the climatological station alt Altitude of the climatological station per Period on which the averages have been computed margen Margins vector for the plot (to be passed to par). mlab Month labels for the X axis: "en":Month initials in English. "es":Month initials in Spanish. Other:Numeric labels (1-12). pcol Color pen for precipitation. tcol Color pen for temperature. pfcol Fill color for probable frosts. sfcol Fill color for sure frosts. shem Set to TRUE for southern hemisphere stations. p3line Set to TRUE to draw a supplementary precipitation line referenced to three times the temperature (as suggested by Bogdan Rosca). ... Other graphic parameters

### Details

Climatic data must be passed as a 4x12 matrix of monthly (January to December) data, in the following order:

Row 1:

Mean precipitation

Row 2:

Mean maximum daily temperature

Row 3:

Mean minimum daily temperature

Row 4:

Absolute monthly minimum temperature

This last row is only used to determine the probable frost months (when absolute monthly minimums are equal or lower than 0°C).

For stations located in the southern hemisphere it is useful to set shem=TRUE, in order to keep the summer period in the central zone of the graphic (the diagram will begin the plot with the July data).

As described by Walter and Lieth, when monthly precipitation is greater than 100 mm, the scale is increased from 2mm/ºC to 20mm/ºC to avoid too high diagrams in very wet locations. This change is indicated by a black horizontal line, and the graph over it is filled in solid blue.

When the precipitation graph lies under the temperature graph (P < 2T) we have an arid period (filled in dotted red vertical lines). Otherwise the period is considered wet (filled in blue lines), unless p3line=TRUE, that draws a precipitation black line with a scale P = 3T; in this case the period in which 3T > P > 2T is considered semi-arid.

Daily maximum average temperature of the hottest month and daily minimum average temperature of the coldest month are frequently used in vegetation studies, and are labeled in black at the left margin of the diagram.

### Value

No value is returned by this function.

### References

WALTER H & LIETH H (1960): Klimadiagramm Weltatlas. G. Fischer, Jena.

plot, par
data(datcli)