Unit 19 Review - Water Measurement

Which statement best defines an aquifer in the context of groundwater?

• A shallow pool formed on flat terrain after storms

• A surface basin that gathers rainfall and snowmelt

• An underground layer of saturated soil and rock

• A dry underground zone beneath impermeable rock

A community is built on flat terrain within a watershed. During heavy rain, where will water most likely collect first?

• On steep slopes near mountain ridges

• In fast-moving streams and swift rivers

• Inside deep underground caverns

• In ponds, lakes, creeks, and swamps

Engineers drilling a well stop when they strike a layer that water cannot pass through. Why is stopping there a sound plan for accessing groundwater?

• The layer marks the top of a drainage basin boundary

• The layer indicates the base that traps water above it

• The layer ensures faster flow into surface rivers nearby

• The layer converts surface water into groundwater

Which statement best describes surface water in a watershed?

• It includes only underground aquifers and springs

• It includes only water stored in reservoirs

• It includes all visible water on the landscape

• It includes only precipitation stored in soil

Average annual rainfall for a region is typically calculated using which time frame?

• A rolling 5-year storm average

• The last single wettest year

• A standard 30-year average

• The next decade’s forecast

Water runoff patterns form where water flows across materials that are least resistant to surface erosion. Which situation would most likely increase the development of these patterns on a hillside?

• Dense vegetation that anchors the soil strongly

• Bedrock fully covered by deep stable roots

• Terraced slopes that slow and spread water

• Compacted bare soil with little plant cover

Which statement best describes a dendritic runoff pattern?

• Streams form circles around a central high point

• Streams branch like a tree with a main trunk

• Streams align with human-made drainage ditches

• Streams run in straight lines across flat plains

A landscape has long parallel valleys and ridges. What runoff pattern is most likely, and how do tributaries meet the main streams?

• Trellis pattern; tributaries join at right angles

• Radial pattern; tributaries join at obtuse angles

• Dendritic pattern; tributaries join at shallow angles

• Rectangular pattern; tributaries join at random angles

In a new watershed, water erodes soil while moving out of a valley and creates a tree-like network. Which erosion direction and pattern are indicated?

• Downhill erosion; trellis pattern

• Uphill erosion; radial pattern

• Uphill erosion; dendritic pattern

• Downhill erosion; rectangular pattern

Which description best matches a rectangular (lattice) runoff pattern?

• Rivers curve around resistant ridges

• Channels radiate from a central peak

• Tributaries join at shallow acute angles

• Streams intersect at many right angles