Morphometric Parameters

Formula/Definition References

I

Linear Parameters

Stream order

Hierarchical Rank

[4]

1

No. of streams (N_u)

N_u = N₁ + N₂ + …..N_n

[2]

2

Stream length (L_u) (Km)

L_u = L₁ + L₂ ……. L_{n (km)}

[5]

3

Mean Stream Length (L_sm) (Km)

L_sm = L_u/N_u (Km)

[5]

4

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 = No. of segment of the next lower order.

[2]

Bifurcation ratio (R_b)

R_b = Nu/Nu + 1 = No. of segment of the next higher order.

[8]

Mean bifurcation ratio (R_bm)

R_bm = average of bifurcation ratio of Strahler all orders.

[4]

5

RHO coefficient (ρ)

ρ = R_L/R_b

[2]

6

Length of overland flow (L_o) Km

L_o = 1/2 D_d, (or) L_o = 1/D* 2

[2] [66]

II

Areal Parameters

7

Basin area (A) (Km²)

Plan area of the watershed (Km²)

[2]

8

Basin Perimeter (P) (Km)

Perimeter of the watershed (Km)

[2]

9

Form factor ratio (R_f)

R_f = A/L_b²

[2] [8]

10

Drainage texture (D _t)

T = N_u/P, where N_u = Total no. of streams

[3]

11

Circularity ratio (R_c)

R_c = 4*π*A/p²

[7]

12

Elongation ratio (R_e)

R_e = 1.128/L_b

[8]

13

Stream frequency (F_s)

F_s = N_u/A

[2] [67]

14

Drainage density (D_d) (Km/ Km²)

D_d = L_u/A

[2]

15

Shape Index (B_s)

B_s = L_b²/A

[2]

16

Constant of channel maintenance (C) (Km²/Km)

C = 1/D_d

[8]

17

Compactness coefficient (C_c)

Cc = 0.2841 * P/A^0.5

[74]

III

Relief Characteristics

18

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

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

[6]

19

Relief ratio (R_r)

R_r = H/L_b, where, H = Total relief, and

L_b = basin length

[8]

20

Ruggedness number (R_n)

R_n = D_d * (B_h/1000)

[3]

21

Dissection index (D_is)

D_is = B_h/Ra, where Ra = absolute Relief (m)

[8]

22

Melton rugged ess number (M_{r n})

M_rn = (H − h₁)/A^0.5 where, H = maximum height (m), and h₁ = minimum height (m)

[75] [76]