2.1.2 Part 2: Variations in Inputs (Spatial & Temporal)

Why do western parts of the UK receive more rainfall than eastern parts?

Prevailing south-westerly winds bring moist Atlantic air that rises over western uplands, causing relief (orographic) rainfall.

What causes the rain shadow effect in Eastern England?

Air loses its moisture over western hills as it rises, leaving less precipitation for lower eastern areas like East Anglia.

How do UK hydrological inputs differ between winter and summer?

Winter brings sustained, low-intensity rainfall leading to water surplus

What storm event triggered the 2004 Boscastle flash flood in Cornwall?

A convective downpour delivering 75 mm of rain in just 2 hours.

How do monsoon climates affect annual drainage basin inputs?

Over 2,000 mm of annual rainfall is concentrated into a few months, leaving the basin dry for the rest of the year.

How do arid drainage basins operate?

They receive under 100 mm of rainfall per year, operating as ephemeral systems that only flow during rare storm events.

How does altitude affect drainage basin inputs?

Higher altitudes experience greater precipitation due to orographic uplift and hold snowfall as a delayed input until snowmelt occurs.

How can urbanization alter microclimates and rainfall inputs?

The Urban Heat Island (UHI) effect can enhance localized convective activity, increasing rainfall downwind.

How is climate change impacting precipitation inputs in the UK?

It increases the frequency and intensity of heavy rainfall events, elevating flood risks.