hydroTSM (version 0.5-1)

hypsometric: Hypsometric Curve

Description

Computes and plots the hypsometric curve corresponding to the data provided by a digital elevation model (DEM)

Usage

hypsometric(x, band=1, main="Hypsometric Curve",
            xlab="Relative Area above Elevation, (a/A)",
            ylab="Relative Elevation, (h/H)", col="blue",...)

Arguments

x

SpatialGridDataFrame-class object with the elevations of the catchment. Possibly, a raster file already read with the readGDAL function of the rgdal package.

band

integer or character indicating the band in x that stores the elevation data.

main

See plot. An overall title for the plot: see title.

xlab

See plot. A title for the x axis: see title.

ylab

See plot. A title for the y axis: see title.

col

See plot.default. The colors for lines and points.

…

further arguments passed to or from other methods

Details

The hypsometric curve and the hypsometric integral are non-dimensional measures of the proportion of the catchment above a given elevation.

Strahler (1952, 1964) further asserted that different types of landform have different characteristic shape of their hypsometric curves, dividing landforms into 'young' and 'mature' with decreasing hypsometric integral -the area under the hypsometric curve- with age.

References

Strahler, A. N. 1952. Hypsometric (area-altitude) analysis of erosional topography, Geological Society of America Bulletin, 63, 1117-1142

Strahler, A. N. 1964. Quantitative geomorphology of drainage basins and channel networks, in Chow, V. T. (Ed.) Handbook of Applied Hydrology, McGraw Hill, New York, 4-39--4-76

Luo, W. 1998. Hypsometric analysis with a geographic information system, Computers & Geosciences 24, pp. 815-821

Willgoose, G. and Hancock, G. 1998. Revisiting the hypsometric curve as an indicator of form and process in transport-limited catchment, Earth Surface Processes and Landforms 23, pp. 611-623

Examples

# NOT RUN {
# Loading the DEM
require(rgdal)
data(EbroDEM1000m)
dem <- EbroDEM1000m

# Plotting the DEM
require(sp)
spplot(dem, scales=list(draw=TRUE, y=list(rot=90)))

# Computing and plotting the hypsometric curve
hypsometric(dem)

# If the raster file has more than 1 band, and the elevation data are in a 
# band different from 1:
dem$ELEVATION <- EbroDEM1000m$band1 # dummy example
hypsometric(dem, band= 2)
hypsometric(dem, band= "ELEVATION") # same as before, but user-friendly
# }