Morphometric parameters | Formula/definition | References |
I. Drainage network |
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1) Stream order (u) | Hierarchical rank | [10] |
2) No. of streams (Nu) | N = N1 + N2 + ∙∙∙ + Nn | [7] |
3) Stream length (Lu) km | Lu = L1 + L2 + ∙∙∙ + Ln (km) | [3] |
4) Mean stream length (Lsm) km | Lsm = Lu/Nu (km) | [3] |
5) Stream length ratio (RL) | RL = Lu/Lu−1, where Lu = the total stream length of order “u”, Lu−1 = the total stream length of its next lower order | [7] |
6) Bifurcation ratio (Rb) | Rb = Nu/Nu+1, where Nu = total no. of stream segments of order “u”, Nu+1 = no. of segments of the next higher order | [8] |
7) Mean bifurcation ratio (Rbm) | Rbm = average of bifurcation ratio of Strahler all orders | [10] |
II. Basin geometry |
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8) Basin length (Lb) 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) (Rf) |
| [7] |
12) Elongation ratio (Re) |
| [8] |
13) Shape factor (Bs) |
| [7] |
14) Lemniscate ratio (k) | K = L2/4A | [48] [49] |
15) Circularity ratio (Rc) | Rc = 4*π*A/P2 | [3] [50] |
16) Drainage texture (Dt) | Dt = Nu/P, where Nu = Total no. Streams of all orders, P = perimeter (km) | [7] |
III. Drainage texture analysis |
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17) Stream frequency (Fs) | Fs = Nu/A | [7] |
18) Drainage density (Dd) km/km2 | Dd = Lu/A | [7] |
19) Drainage intensity (Di) | Di = Fs/Dd | [55] |
20) Length of overland flow (Lo) km | Lo = 1/2 Dd | [7] |
IV. Relief characteristics |
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21) Basin relief (Bh) or total relief (H) m | Bh = h − h1, where, h = maximum height (m), h1 = minimum height (m) | [9] |
22) Relief ratio (Rr) | Rr = H/Lb, Where H = total relief, Lb = basin length | [3] |
23) Ruggedness number (Rn) | Rn = Dd*(Bh/1000) | [3] |
24) Dissection index (Dis) | Dis = Bh/Ra, where Ra = 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] |