---
title: "Human interference in the hydrological cycle"
subject: "Engineering Hydrology"
chapter: 1
key: "semester_5/engineering_hydrology:human-interference-hydrologic-cycle"
source: https://www.bctengineer.com/q/semester_5/engineering_hydrology/human-interference-hydrologic-cycle
site: BCT Engineering
---

# Human interference in the hydrological cycle

Engineering Hydrology · Chapter 1: Introduction

- Asked in: 2082 Bhadra, 3 marks
- Video: [Human Impacts on the Water Cycle (ESS 4.1.4)](https://www.youtube.com/watch?v=NbO0xScMFZg) — Peter Stanley
- Answer checked by Claude Sonnet 5.5 on 2026-10-14
- Page: https://www.bctengineer.com/q/semester_5/engineering_hydrology/human-interference-hydrologic-cycle
- Whole chapter: https://www.bctengineer.com/md/semester_5/engineering_hydrology/chapter-1

## Question

Explain briefly humankind's interference in various parts of hydrological cycle.

## Short answer

Humans alter precipitation via cloud seeding and climate change; increase evaporation from reservoirs and irrigation; reduce infiltration with pavements, increasing runoff and flood peaks; regulate surface flows with dams and embankments; deplete groundwater by pumping; and pollute water and increase sediment through land clearing and mining.

## Answer

Human activity changes many parts of the hydrologic cycle:

- **Precipitation:** Cloud seeding for rain, and climate change from greenhouse gases and urban heat change rainfall patterns.
- **Evaporation and transpiration:** Reservoirs and irrigation raise evaporation; deforestation lowers transpiration; planting forests raises it.
- **Interception and infiltration:** Roads, roofs and pavements reduce infiltration and raise runoff and flood peaks; agriculture and terracing may increase infiltration.
- **Surface runoff:** Dams and barrages store and regulate flow; embankments and river training change flood patterns; urbanisation shortens time of concentration.
- **Groundwater:** Heavy pumping lowers the water table, while artificial recharge and irrigation seepage raise it.
- **Water quality:** Sewage, industry and fertilisers pollute surface and groundwater.
- **Sediment:** Land clearing and mining increase erosion and siltation of reservoirs.

## Check yourself

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

1. What do roads and pavements do?
   A. Increase infiltration
   B. Increase groundwater recharge
   C. Reduce infiltration and raise runoff and flood peaks
   D. Reduce runoff
   Answer: C. Impervious surfaces shed water. (Key point: Urbanisation)

2. Heavy pumping:
   A. Raises the water table
   B. Increases rainfall
   C. Reduces evaporation
   D. Lowers the water table
   Answer: D. Artificial recharge raises it. (Key point: Groundwater)

3. Reservoirs and irrigation:
   A. Raise evaporation
   B. Reduce evaporation
   C. Stop precipitation
   D. Stop runoff entirely
   Answer: A. More exposed water surface. (Key point: Reservoirs)

## 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
- [Hydrological cycle and uses of engineering hydrology](https://www.bctengineer.com/question.md?key=semester_5%2Fengineering_hydrology%3Ahydrologic-cycle-uses) — Engineering Hydrology, chapter 1

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