Warmup

How many river basins are in North Carolina?

Which two river basins border Apex?Write two facts about your river basin from

Friday.

Warmup

Which direction does water flow? (Think of the creek behind the school)

What are three more things you would like to know about the creek?

EXPLAIN RIVER SYSTEMS INCLUDING NC RIVER BASINS, AQUIFERS, AND

WATERSHEDS.

EXPLAIN HOW FLOOD EVENTS MIGHT BE AFFECTED BY GROUNDWATER LEVELS.

2.3.2bc Rivers, Aquifers, and Floods

Path of a drop of water…

Remember: A drop of water can either infiltrate into the ground (groundwater) or runoff the surface into a river or stream

Surface Water and Ground Water

Groundwater and surface water have a reciprocal relationship, regularly feeding each other. Most streams and rivers get about half their volume from groundwater.

Floods

During a flood, surplus surface water helps recharge groundwater.

Flood and Flood Control

A flood occurs when the discharge of a stream becomes so great that it exceeds the capacity of its channel and overflows its banks.

Flooding

What are some things that cause flooding? Heavy Rain Rapid Spring Snowmelt

Why are floods bad? They cause damage They can come without warning (flash floods) They can hurt people Cost a lot of money

What are some floods that you have heard of, why were they dangerous? – Discuss with a partner

Flooding

There are several methods used to help prevent flooding: Artificial levees Create Dams Sandbags Limit construction around areas known to

floodMississippi Flooding

What caused the flood? What caused the most damage during the

Flood?

Floods

Lots of water = landslides too

Drainage Basins

A drainage basin is the land area that contributes water to a stream.

A divide is an imaginary line that separates the drainage basins of one stream from another.

Drainage System

Pattern formed by streams, rivers, and lakesDepends on

Topography of the land (landforms) Hard or soft rocks Gradient of the land (how steep it is)

Divided from each other by topographic barriers (mountains/high points) called a watershed

Rivers

Flow of a river or stream is due to GRAVITY.Velocity of a river is due to the geology of the

watershed How steep, how narrow, much water, etc

Discharge (volume rate of water flow; or how much water is passing by) is measured by: Width x Depth x Velocity

River basin activity

One color: Trace highest points (divide of river basin)

Another color: Trace lowest points (drainage pattern of river system)

Transfer/redraw boundaries of river basin and drainage pattern on a separate piece of paper. Turn in w/group member names.

Warmup

What did you learn in this unit (2.3 Hydrosphere)?

What question(s) do you have for the test today?