Textbook Notes (381,132)
CA (168,365)
UTSG (11,042)
Geography (187)
GGR100H1 (41)
Chapter 9

Chapter 9- textbook

6 Pages
125 Views

Department
Geography
Course Code
GGR100H1
Professor
Joseph Leydon

This preview shows pages 1-2. Sign up to view the full 6 pages of the document.
Chapter 9- Water Resources 01:56
The hydrologic Cycle
hydrologic cycle, which has operated from billions of years from lower atmosphere to several
kilometers beneath Earths surface
The cycle involves the circulation and transformation of water throughout Earths atmosphere
A hydrologic Cycle Model
97% of earths water is in the ocean and here most evaporation and precipitation occur
the other 14% is from the land including water moving from the soil into plant roots and passing
through their leaves
86% of evaporation rising from the ocean 66% combines with 12% adverted from the land to
produce the 78% of all precipitation that falls back into ocean
remaining 20% of moisture evaporated from the ocean plus 2% of land derived moisture
produces the 22% of all precipitation that falls over land
various parts of the cycle will vary creating imbalances and depending on climate surpluses in
one region and shortages in another
Surface Water
Precipitation that reaches earths surface follows two pathways flows overland or soaks into soil
Along the way interception occurs when precipitation strikes vegetation or other ground cover
Intercepted water that drains across plant leaves and down teir stems to the ground is stem flow
and can be an important moisture route to the ground
Precipitation that falls directly to the ground constitutes throughfall
Water soaks into the subsurface through infiltration or pentration of the soil surface
Permeates soil or rock through the downward movement of percolation
the residence time for a water molecule in any part of the hydrologic cycle determines its relative
importance in affecting earths climates
Soil Water-Budget Concept
a soil water budget can be established from any area of earths surface
key is measuring the precipitation supply input and its distribution to satisfy the demand outputs
of plants evaporation and soil moisture storage in the area considered
precipitation income must be balanced against expenditures storage acts as a saving account,
accepting deposits and withdrawals of water
The Soil Water Balance Equation
Precipitation provides the moisture input
Actual water taken by evaporation and plant transpiration, extra water that exits in streams and
subsurface ground water and recharge or utilization of soil moisture storage
Precipitation (PRECIP) Input
The moisture supply to earths surface is precipitation
Precipitation is measured with the rain gauge
A rain gauge is essentially a large measuring cup collecting rainfall and snowfall so the water can
be measured by depth, weight or volume
Wind can cause an undercatch because the drops or snowflakes are not falling vertically
Acutal Evapotranspiration (ACTET)
Evaporation is the net movement of free water molecules way from a wet surface into air that is
less than saturated
www.notesolution.com
Transpiration is a cooling mechanism in plants, when a plant transpires it moves water through
small openings (stomata) in the underside of its leaves
The water evaporates , cooling the plant
Controls cells around the stomata conserve or release water
Evaporation and transpiration are important water budget expenditures and both respond directly
to air temperature and humidity
Potential Evapotranspiration(POTET)
Evapotranspiration is an actual expenditure of water
Potential evapotranspiration is the amount of water that would evaporate and transpire under best
moisture conditions when enough precipitation and enough soil moisture supply are present
Deficit (DEFIC)
The POTET demand can be satisfied in three ways: by PRECIP, by moisture stored in the soil or
through aritical irrigation
If those 3 dont meet moisture demands, the location experiences a moisture shortage, this
unsatisfied POTET is deficit
By subtracting DEFIC from POTET, we determine the actual evapotranspiration (ACTET) that
takes place
Surplus (SURPL)
If POTET is satisfied and the soil is full of moisture then additional water input becomes surplus
The overland flow combines with precipitation and groundwater flows into river channels to
make up the total runoff
Because surplus water generates most streamflow or runoff the water balance approach is useful
for indirectly estimating streamfow
Soil- Moisture Storage
A savings account of water that receives recharge deposits and provides for utilization
withdrawals is soil moisture storage
This is the volume of water stored in he soil tat is accessible to plant roots
The means includes both recharge and utilization
Soil moisture comprises two categories of water; hygroscopic and capillary but only capillary
water is accessible to plants
Hygroscopic water- is inaccessible to plants because it is a molecule thin layer that is tightly
bound to each soil particle by the hydrogen bonding of water molecules
Soil is at the wilting point when all that remains is this inaccessible water; plants wilt and
eventually die after a prolonged period of such moisture stress
Capillary water is generally accessible to plant roots because it is held against the pull of gravity
in the soil by hydrogen bonds btw ware molecules which causes surface tension and by hydrogen
bonding btw water molecules and the soil
Most capillary water remains in the soil is available water in soil moisture storage
When soil becomes saturated after a precipitation even any water surplus in the soil body
becomes gravitational water
A soil blend that maximizes available water is the best for plants
As soil moisture utilization removes soil water the plants must exert greater effort to extract the
amount of moisture they need
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
Chapter 9- Water Resources 01:56 The hydrologic Cycle hydrologic cycle, which has operated from billions of years from lower atmosphere to several kilometers beneath Earths surface The cycle involves the circulation and transformation of water throughout Earths atmosphere A hydrologic Cycle Model 97% of earths water is in the ocean and here most evaporation and precipitation occur the other 14% is from the land including water moving from the soil into plant roots and passing through their leaves 86% of evaporation rising from the ocean 66% combines with 12% adverted from the land to produce the 78% of all precipitation that falls back into ocean remaining 20% of moisture evaporated from the ocean plus 2% of land derived moisture produces the 22% of all precipitation that falls over land various parts of the cycle will vary creating imbalances and depending on climate surpluses in one region and shortages in another Surface Water Precipitation that reaches earths surface follows two pathways flows overland or soaks into soil Along the way interception occurs when precipitation strikes vegetation or other ground cover Intercepted water that drains across plant leaves and down teir stems to the ground is stem flow and can be an important moisture route to the ground Precipitation that falls directly to the ground constitutes throughfall Water soaks into the subsurface through infiltration or pentration of the soil surface Permeates soil or rock through the downward movement of percolation the residence time for a water molecule in any part of the hydrologic cycle determines its relative importance in affecting earths climates Soil Water-Budget Concept a soil water budget can be established from any area of earths surface key is measuring the precipitation supply input and its distribution to satisfy the demand outputs of plants evaporation and soil moisture storage in the area considered precipitation income must be balanced against expenditures storage acts as a saving account, accepting deposits and withdrawals of water The Soil Water Balance Equation Precipitation provides the moisture input Actual water taken by evaporation and plant transpiration, extra water that exits in streams and subsurface ground water and recharge or utilization of soil moisture storage Precipitation (PRECIP) Input The moisture supply to earths surface is precipitation Precipitation is measured with the rain gauge A rain gauge is essentially a large measuring cup collecting rainfall and snowfall so the water can be measured by depth, weight or volume Wind can cause an undercatch because the drops or snowflakes are not falling vertically Acutal Evapotranspiration (ACTET) Evaporation is the net movement of free water molecules way from a wet surface into air that is less than saturated www.notesolution.com
More Less
Unlock Document


Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit