Land use

The classical Curve Number is not only a function of soil type and soil depth but also of the land use (i.e. vegetation and cultivation practices).

Land use is considered in the model as a correction factor to the "S"-value of the CN-method.

Land use classification for Jordan is rather simple, most of the country remains unclassified. Currently only 5 classes have been defined.

Class Value Description
160 3 brush
161 3.5 forest
162 1.6 orchard
163 1.1 cultivated or cultivable

The Value above represents a correction factor as determined from series of calibration runs.

The spatial distribution of land use classes is stored as Surfer Grid and forms an important parameter determining runoff. In order to facilitate calibration only the code numbers are stored. This permits an efficient modification of the correction factors related to the individual land use classes.