Classification and Origins of Freshwater Systems

Lecture goals:

• Review the water cycle

• Key concepts and terminology in hydrology

• Field guide to freshwater systems

The Water Cycle

Surface Area : Volume Ratio

1:1

Surface Area : Volume Ratio

• The smaller the lake or reach, the larger the SA:V ratio.

• The larger the lake or reach, the smaller the SA:V ratio.

The Global Water Budget

The Watershed

Surface v. Groundwater

Ephemeral Ponds

Lakes vs. Ponds

Lake and Pond Origins

• Glacial Activity

Glacial Scouring

Cirques

Paternoster Lakes

Ice Dams

Moraine Dams

Flathead Lake, MT Finger Lakes, NY

Kettle Lakes

Lake and Pond Origins

• Glacial Activity

• Tectonic Activity

The Major Lithospheric Plates

Uplift Lakes

Lakes at FaultsLake Baikal

Lakes at Faults Lake Malawi

Lake and Pond Origins

• Glacial Activity

• Tectonic Activity

• Other

Other cool ways lakes can be formed…

Volcanic activity

Other cool ways lakes can be formed…

Chemical reactions

CaCO3

Other cool ways lakes can be formed…

Rivers

Lake Manicouagan, Quebec

5 km diameter asteroid

212 MYA

Extraterrestrials

Lake and Pond Zones

• Benthic

• Littoral

• Limnetic

• Profundal

Stream OrderHorne Brook, NH

Columbia River, WA

Stream Order

• Benefits

Order is correlated with other

characteristics

These data are from a network of streams near Santa Fe, NM

Stream order can be used to describe real differences in drainages

Stream Order

• Benefits

• Drawbacks

The Problem:Order N into Order N+1

Real Differences in Stream Networks?

Why Classification Matters

• Solid Waste Agency of Northern Cook County vs. U.S. Army Corps of Engineers

• In 2001, Supreme Court rules that Clean Water Act does not give Corps jurisdiction over “isolated” streams and wetlands.

• Sets off rush to re-classify streams and wetlands as “isolated”.

• In October 2005, Supreme Court agrees to hear additional arguments on wetland and stream protection.