What is morphometric analysis? It is the quantitative, mathematical and statistical study of the size, shape and structure of a drainage basin and its stream network, measured off a topographic sheet or a DEM. It matters operationally because a basin's shape, drainage density and relief control how quickly rainfall converts to streamflow — which is exactly what changes with the seasons.
Your task: Basin K is a sub-watershed within IGRI's regional groundwater-recharge study area, delineated from a 1:50,000 topographic sheet. Using the given stream-order data and basin parameters below, compute Basin K's linear, areal, shape and relief morphometric parameters, then interpret what they imply for its seasonal drainage/flood behaviour ahead of the pre-monsoon field visit.
Expected output: a completed morphometric worksheet (12 computed parameters across 4 steps) plus a one-line, evidence-based interpretation of Basin K's likely seasonal streamflow response — to be shared with the field team. This exercise is marked out of 15 across 5 short steps (see the marking scheme below). Work through the steps in order; once a step is checked correct you can look back at it any time, but you cannot change what you entered.
Where: A = basin area (km²), P = basin perimeter (km), Lb = basin length (km), Nᵤ = number of stream segments of order u, Lᵤ = total length of streams of order u (km), Hmax/Hmin = highest/lowest basin elevation (m).
| Elongation Ratio (Re) | Shape Class |
|---|---|
| > 0.9 | Circular |
| 0.7 – 0.9 | Oval |
| < 0.7 | Elongated |
| Step | Parameters | Marks |
|---|---|---|
| 1 — Linear Aspects | ΣNᵤ, ΣLᵤ, Rbm | 4 |
| 2 — Areal Aspects | Dd, Fs, Dt | 3 |
| 3 — Basin Shape | Rf, Rc, Re | 3 |
| 4 — Relief Aspects | H, Rr, Rn | 3 |
| 5 — Interpretation | Shape class, seasonal streamflow behaviour | 2 |
| Total | 15 | |
Each question's mark is locked in on your first attempt at that step. You may still retry a step to get the green checkmark and unlock the next one, but the marks reflect first-attempt accuracy only — just like a real practical exam. Numeric answers are accepted within the stated tolerance to allow for rounding.
All data are synthetic, prepared for this training exercise only.
This exercise uses a simplified, illustrative stream network and a reduced Schumm shape-classification scheme for training purposes. In professional practice, stream ordering is done directly on a delineated DEM/topographic-sheet drainage network (typically Strahler ordering), and shape and relief indices are interpreted alongside rainfall, land use, soil and geology data — never from morphometry alone.