Forest Hydrology

2013

Outlet

1

The watershed (drainage basin, catchment area) is the

basic unit of management to protect and enhance

water quality/aquatic ecosystems

Management of Water

An area of land that drains water, sediment, and dissolved

materials to a common outlet somewhere along a stream

channel. Outlet

1

http://techalive.mtu.edu/meec/module01/whatiswatershed.htm

A watershed is the basic unit of land associated with a

specific portion of a river or river system

What is a Watershed?

Outlet

Stream Channels

Streams and

watersheds are

delineated by

order. The lower

the order the

smaller the

stream and

watershed.

2 First order watershed

Headwaters

Outlet

Watersheds and Stream Orders

• Unbranching streams are first order

• A second order stream is created when two or more

first order streams join

• Any lower order stream juncture above a larger order

stream does not change the order of the larger order

stream

• The watershed that feeds the stream system takes on

order of the stream

How do you think the volume of

water running in a channel is

related to stream order?

Gemorphology

• Upper watersheds are called headwater streams &

comprise 70-80% of watershed

• Headwater streams comprise majority of water in

watersheds

• Headwater streams occur in steeper areas and in

erosion zones

• Water flows to deposition zones

Why are headwater

streams important to

foresters?

Attributes of and Issues in Watersheds

• No two watersheds are the same

• Larger watersheds can be divided into

smaller watersheds

• Boundaries are defined by natural

hydrology

Basic Watershed Regions in US

Hydrologic Unit Code

8-digit Huc Watersheds in Arkansas; 800,000-1,750,000 acres 4

Watersheds and Political

Boundaries

Watersheds cross

political boundaries

Nutrient management in

Arkansas impacts water

quality in Missouri and

Oklahoma

Integrated Watershed Management

Watershed management: management of water and land resources together 1) protection of water 2) production of goods and services from land, water, and vegetation in a sustainable manner 3) integration of 1 & 2

Integrated Watershed Management

Diverse stakeholders control, effect, and manage watersheds

Groups, councils, government agencies, private companies, landowners etc. involved in management

Conflict among groups so IWM requires working with all to reach goals

IWM Strategies

Preventive: Strategies to reduce negative impacts of land management practices:

1)BMP 2)erosion control, 3)streamside management zones 4)proper harvesting of forests 5) laws/rules etc.

IWM Strategies Restoration: Strategies to fix existing problems :

1)bank stabilization

2)restoring natural stream beds

3)stream structures

4) lake aeration etc.

Sustainable Use

Water Scarcity

http://ngm.nationalgeographic.com/2010/04/water/plumbing-

california-animation

1 acre-feet of water

=325,829 gallons

Sustainable Use

Land Scarcity (degradation)

Sustainable Use

Hydrometeorological Extremes

Floods

http://cindi.usgs.gov/hazard/event/floyd/ncflood/nc

flood.html

Sustainable Use Flood Control/Protection

Cumulative Effects on Watersheds

Combined environmental effects of many

landuse activities in a watershed, thus total

impact is the sum of all

ex. Inputs of forest management, agriculture,

urban development, road networks on silt and

sediment in streams