---
title: "Hydrological cycle and uses of engineering hydrology"
subject: "Engineering Hydrology"
chapter: 1
key: "semester_5/engineering_hydrology:hydrologic-cycle-uses"
source: https://www.bctengineer.com/q/semester_5/engineering_hydrology/hydrologic-cycle-uses
site: BCT Engineering
---

# Hydrological cycle and uses of engineering hydrology

Engineering Hydrology · Chapter 1: Introduction

- Asked in: 2081 Baisakh, 2+2 marks
- Video: [Introduction to Hydrology and Hydrologic Cycle - Hydrology - Water Resources Engineering 1](https://www.youtube.com/watch?v=MFGRdxL78yE) — Ekeeda
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/engineering_hydrology/hydrologic-cycle-uses
- Whole chapter: https://www.bctengineer.com/md/semester_5/engineering_hydrology/chapter-1

## Question

Describe Hydrological cycle. Discuss about the uses of Engineering Hydrology.

## Short answer

The hydrological cycle is the continuous movement of water via evaporation, condensation, precipitation, infiltration, runoff, and groundwater flow driven by solar energy. Engineering hydrology uses it to plan water supply, irrigation, hydropower, flood control, drainage, design of hydraulic structures, reservoir operation, and environmental flow assessments.

## Answer

#### Hydrological cycle
The hydrological cycle is the continuous exchange of water between the oceans, atmosphere and land. Solar energy evaporates water, vapour condenses to clouds and falls as precipitation; on land it is intercepted, infiltrates or runs off to streams, and finally returns to the sea or atmosphere.

```text
   Sun's energy
      |
  Evaporation          Condensation -> Clouds
  + Transpiration  ^        |
      ^            |        v
 [Ocean]---------->|   Precipitation
      ^                     |
      |    Surface runoff   v
      +----- Rivers <--- [Land/Catchment]
      |                     |
      +--- Groundwater <----+  (infiltration,
           flow to sea          percolation)
```

Main components: evaporation, transpiration, condensation, precipitation, interception, infiltration, percolation, runoff and groundwater flow.

#### Uses of engineering hydrology
- **Water supply:** yield of surface and groundwater sources.
- **Irrigation:** crop water demand (evapotranspiration), dependable flow and canal design.
- **Hydropower:** flow duration, design flood and storage.
- **Flood control and drainage:** design floods, flood routing, storm drains.
- **Hydraulic structures:** waterway of bridges and culverts, spillways, weirs, dams.
- **Reservoir operation and sedimentation:** capacity and life of reservoirs.
- **Environmental and navigation needs:** minimum flows and water-level records.

## Check yourself

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

1. The cycle sequence on land is:
   A. Runoff, then precipitation
   B. Precipitation, then interception, infiltration or runoff, then return to sea or air
   C. Infiltration, then condensation, then sun
   D. Sea only
   Answer: B. As described. (Key point: Cycle description)

2. Hydrology supports irrigation through:
   A. Bridge scour
   B. Spillway gates
   C. Crop water demand (ET), dependable flow and canal design
   D. Ocean tides
   Answer: C. Listed use. (Key point: Irrigation use)

3. Reservoir sedimentation studies give:
   A. Rainfall depth
   B. Isohyets
   C. Air temperature
   D. Capacity and life of reservoirs
   Answer: D. Listed use. (Key point: Reservoir life)

## Related in Engineering Hydrology

- [Define hydrological cycle, runoff, water balance, catchment](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Adefine-cycle-runoff-balance-catchment) — Engineering Hydrology, chapter 1
- [Human interference in the hydrological cycle](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Ahuman-interference-hydrologic-cycle) — Engineering Hydrology, chapter 1
- [Significance and uses of hydrology in design](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Asig-hydrology-civil) — Engineering Hydrology, chapter 1, asked 2×
- [Need of engineering hydrology in bridge design](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Ahydrology-need-bridge-design) — Engineering Hydrology, chapter 1
- [Different aspects of hydrological study](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Aprospects-hydrological-study) — Engineering Hydrology, chapter 1
- [Hydrological losses from precipitation](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Ahydrological-losses) — Engineering Hydrology, chapter 3

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- [Hydrological cycle and mean precipitation methods](https://www.bctengineer.com/question.md?key=semester_6%2Fhydro_power%3Ahydrological-cycle-mean-precipitation) — Hydro Power, chapter 2, asked 2×
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