Morphometric parameters

Formula/definition

References

I. Drainage network

1) Stream order (u)

Hierarchical rank

[10]

2) No. of streams (N_u)

N = N₁ + N₂ + ∙∙∙ + N_n

[7]

3) Stream length (L_u) km

Lu = L₁ + L₂ + ∙∙∙ + L_n (km)

[3]

4) Mean stream length (L_sm) km

L_sm = L_u/N_u (km)

[3]

5) Stream length ratio (R_L)

R_L = L_u/L_u−1, where L_u = the total stream length of order “u”, L_u−1 = the total stream length of its next lower order

[7]

6) Bifurcation ratio (R_b)

R_b = N_u/N_u+1, where N_u = total no. of stream segments of order “u”, N_u+1 = no. of segments of the next higher order

[8]

7) Mean bifurcation ratio (R_bm)

R_bm = average of bifurcation ratio of Strahler all orders

[10]

II. Basin geometry

8) Basin length (L_b) km

Length of the basin (km)

[7]

9) Basin area (A) km²

Plan area of the watershed (km²)

[7]

10) Basin perimeter (P) km

Perimeter of the watershed (km)

[7]

11) Form factor (ratio) (R_f)

[7]

12) Elongation ratio (R_e)

[8]

13) Shape factor (B_s)

[7]

14) Lemniscate ratio (k)

K = L²/4A

[48] [49]

15) Circularity ratio (R_c)

R_c = 4*π*A/P²

[3] [50]

16) Drainage texture (D_t)

D_t = N_u/P, where N_u = Total no. Streams of all orders, P = perimeter (km)

[7]

III. Drainage texture analysis

17) Stream frequency (F_s)

F_s = N_u/A

[7]

18) Drainage density (D_d) km/km²

D_d = L_u/A

[7]

19) Drainage intensity (D_i)

D_i = F_s/D_d

[55]

20) Length of overland flow (L_o) km

L_o = 1/2 D_d

[7]

IV. Relief characteristics

21) Basin relief (B_h) or total relief (H) m

B_h = h − h₁, where, h = maximum height (m), h₁ = minimum height (m)

[9]

22) Relief ratio (R_r)

R_r = H/L_b, Where H = total relief, L_b = basin length

[3]

23) Ruggedness number (R_n)

R_n = D_d*(B_h/1000)

[3]

24) Dissection index (D_is)

Dis = B_h/Ra, where R_a = absolute relief

[56]

25) Hypsometric curve (HC)

HC is achieved by plotting the proportion of the total height (h/H) against the proportion of the total area (a/A) of the basin, where H is the total relief height, a is the total area of the basin above a given line of elevation h.

[2] [3] [38]

26) Hypsometric integral (Hi)

, where = the weighted mean elevation

H = maximum elevation

h = minimum elevation

[2] [38]