---
title: "Hydro-geo-morphological characteristics of rivers"
subject: "Engineering Hydrology"
chapter: 4
key: "semester_5/engineering_hydrology:hydro-geo-morphology-rivers"
source: https://www.bctengineer.com/q/semester_5/engineering_hydrology/hydro-geo-morphology-rivers
site: BCT Engineering
---

# Hydro-geo-morphological characteristics of rivers

Engineering Hydrology · Chapter 4: Surface Runoff

- Asked in: 2067 Mangsir (old course), 8 marks; 2067 Shrawan (old course), 6 marks (asked 2 times)
- Video: [Hydrology and Fluvial Geomorphology - The Drainage Basin System](https://www.youtube.com/watch?v=SibHNMFzA40) — The Geography Academy
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/engineering_hydrology/hydro-geo-morphology-rivers
- Whole chapter: https://www.bctengineer.com/md/semester_5/engineering_hydrology/chapter-4

## Question

Describe the hydro-geo-morphological characteristics of rivers with sketches.

## Short answer

Hydro-geomorphological characteristics include longitudinal profile (upper steep, middle moderate, lower flat with meanders and floodplains), channel pattern (straight, meandering, braided), cross-section features, slope, sinuosity, sediment load, and flow regime. Rivers adjust width, depth, and pattern to discharge and sediment load.

## Answer

The **hydro-geomorphological characteristics** of a river describe its flow regime and the form of its channel and valley, which result from the interaction of flow, sediment and geology.

#### 1. Longitudinal profile (course of the river)
```text
 elev.
  |\ upper course (steep)
  | \
  |  \__ middle course
  |      \____
  |           \______ lower course (flat)
  +------------------------- distance
```
- **Upper (youth) stage:** steep slope, V-shaped valley, rapids and waterfalls, high velocity, vertical erosion, coarse bed material.
- **Middle (mature) stage:** moderate slope, valley widens, lateral erosion, meanders begin; transport of sediment is the main process.
- **Lower (old) stage:** very flat, wide floodplain, meanders and oxbow lakes, deposition of fine sediment, delta at the mouth.

#### 2. Channel pattern
```text
 Straight        Meandering        Braided
 ========        ~~~~~~~~~~        =\\/=\\/=
                                    /\\ /\\
```
- **Straight:** rare and short; low sinuosity (< 1.1).
- **Meandering:** sinuosity > 1.5; erosion on the outer bank, deposition on the inner bank (point bars); forms cut-offs and oxbow lakes.
- **Braided:** many channels separated by bars, with steep slope, coarse and abundant sediment and wide fluctuating flow; typical of Himalayan rivers in the Terai (Koshi, Narayani).
- **Anastomosing:** several stable channels with vegetated islands.

#### 3. Cross-section
```text
 floodplain   bank          bank    floodplain
 ____       __/              \__       ____
     \_____/   \____channel___/   \_____/
```
Parts: main channel (bank-full discharge), floodplain, levees and terraces. The width-depth ratio is large in braided rivers and small in meandering rivers.

#### 4. Other characteristics
- **Stream order and drainage pattern** (dendritic, trellis, radial).
- **Slope and sinuosity:** $S = \Delta h/L$; sinuosity = channel length / valley length.
- **Bed material and sediment load:** bed load (boulders, gravel), suspended load (silt, clay) and dissolved load.
- **Flow regime:** perennial snow- and glacier-fed rivers (e.g. Koshi, Gandaki, Karnali); rain- and spring-fed Mahabharat rivers with low dry-season flow; and flashy Siwalik (Churia) rivers with high floods in the monsoon and very low or no flow in the dry season.
- **Dynamic equilibrium:** rivers adjust width, depth, slope and pattern to the discharge and sediment supplied. Changes in these (e.g. by dams or land-use change) cause aggradation or degradation.

## Check yourself

The answer's key points as multiple-choice questions, with the correct option and why.

1. What characterises the upper stage of a river?
   A. Deposition of fine silt
   B. Wide floodplain and delta
   C. Steep slope, V-shaped valley, vertical erosion, coarse bed
   D. Oxbow lakes
   Answer: C. Youth stage has high velocity and downcutting. (Key point: Upper course)

2. What happens in a meandering river?
   A. Many braids
   B. No erosion
   C. Erosion on inner bank
   D. Erosion on the outer bank and deposition on the inner bank (point bars)
   Answer: D. Meanders have sinuosity above 1.5 and form oxbow lakes by cut-offs. (Key point: Meandering)

3. Which conditions give braided rivers?
   A. Low flow
   B. Steep slope, coarse abundant sediment and wide fluctuating flow
   C. Flat, fine sediment
   D. Rock channel
   Answer: B. Himalayan Terai rivers like Koshi and Narayani are braided. (Key point: Braided)

4. What does dynamic equilibrium mean?
   A. Rivers adjust width, depth, slope and pattern to discharge and sediment supplied
   B. Only slope changes
   C. Rivers never change
   D. Only sediment changes
   Answer: A. Disturbances like dams cause aggradation or degradation. (Key point: Equilibrium)

## Related in other subjects

- [Characteristics of contours with sketches](https://www.bctengineer.com/question.md?key=semester_4%2Fsurveying_ii%3Acontour-characteristics-sketches) — Surveying II, chapter 4, asked 5×
- [Solar versus hydro operational characteristics](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Asolar-vs-hydro-economics) — Power Plant Design, chapter 1, asked 5×
- [Characteristics of hydro turbines](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Aturbine-types-characteristics) — Power Plant Design, chapter 3
- [Thermal versus hydro operational characteristics](https://www.bctengineer.com/question.md?key=semester_8%2Fpower_plant_design%3Athermal-vs-hydro-operational) — Power Plant Design, chapter 1, asked 8×