Drainage Density (Dd)

Dd = Lu/A

Horton (1932, 1945)

Dd is measured as the length of stream channels per unit area of the drainage basin.

Stream Frequency (Fs)

Fs = ΣNu/A

Horton (1932, 1945)

Fs is computed as the ratio between the total number of streams and area of the basin.

where, u = Stream order [28]

Nu = Total no. of streams of all orders,

Lu = Total stream length of all orders (km)

A = Area of basin (km²)