2.1.1 Part 1: System Definitions & Core Concepts

What is a hydrological system?

A dynamic system of interconnected processes moving water between stores.

What is an input in the water cycle?

Water entering a system from external sources.

Give 3 examples of inputs in the water cycle.

1. Precipitation (rain, snow, hail) 2. Surface water flow into a system 3. Groundwater flow into a system

What is an output in the water cycle?

Water leaving a hydrological system.

Give 3 examples of outputs in the water cycle.

1. Evapotranspiration 2. Surface water flow out of a system 3. Groundwater flow out of a system

What is a hydrological store?

A feature or reservoir where water is held for a duration of time.

Name 8 stores in the water cycle.

1. Oceans 2. Ice caps / Glaciers (Cryosphere) 3. Groundwater 4. Lakes / Rivers 5. Soil moisture 6. Atmosphere 7. Vegetation 8. Underground aquifers

What is a hydrological flow (or transfer)?

A process that physically moves water between stores.

Name 6 flows in the water cycle.

1. Evaporation 2. Transpiration 3. Condensation 4. Precipitation 5. Infiltration 6. Surface runoff (Overland flow)

What is the concept of Mass Balance?

The principle of conservation of mass applied to the water cycle: total water remains constant within a closed system.

Can water be created or destroyed in the water cycle?

No. It changes form (solid, liquid, gas) and store, but total volume remains constant.

What happens if inputs exceed outputs in a water system?

Water storage increases, which can lead to flooding or a positive mass balance.

What happens if outputs exceed inputs in a water system?

Water storage decreases, which can lead to droughts or a negative mass balance.