Forest Management and Catchment Hydrology Helga Van Miegroet Dept. - - PowerPoint PPT Presentation

▶
forest management and catchment hydrology
SMART_READER_LITE
LIVE PREVIEW

Forest Management and Catchment Hydrology Helga Van Miegroet Dept. - - PowerPoint PPT Presentation

May 26, 2023 460 likes •800 views

Forest Management and Catchment Hydrology Helga Van Miegroet Dept. Wildland Resources Dept. Watershed Sciences Utah State University Logan, Utah, USA COST FORMAN Meeting - Vienna, 15 September 2008 Catchment Water Balance Q = P ET (

slide-1
SLIDE 1

Forest Management and Catchment Hydrology

Helga Van Miegroet

  • Dept. Wildland Resources
  • Dept. Watershed Sciences

Utah State University Logan, Utah, USA COST FORMAN Meeting - Vienna, 15 September 2008

slide-2
SLIDE 2

Catchment Water Balance

Q = P – ET (± dS ± dG) Globally: P – ET = 0

slide-3
SLIDE 3

Extracted from M. Bredemeier’s COST-FORMAN presentation

slide-4
SLIDE 4

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment

  • Influence on Q (quantity)
  • Influence on timing of Q
  • Role of scale / spatial extent
slide-5
SLIDE 5

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment The influences of management and environmental change on the components of the water balance are not entirely independent i.e., there are mutual feedbacks

slide-6
SLIDE 6

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment

slide-7
SLIDE 7

Source: Bonan, 2008 Science 320:1444-1449

Influence of forest on large-scale climate atmospheric models

slide-8
SLIDE 8

Example: Montane Forest in Northern Utah

Source: Eric Lamalfa (photos/simulations)

How will this affect Q ?

Populus tremuloides (aspen) Spruce, fir, DF (conifer)

slide-9
SLIDE 9

Vegetation effects on snow accumulation

Source: Lamalfa & Ryel, 2008 Ecosystems

Montane forests in Utah aspen conifers SWE difference ~ 200 - 300 mm (40 % less in conifers)

slide-10
SLIDE 10

Forest Harvested areas Snow redistribution

Source: Brooks et al., 1991 Hydrology and management of watersheds

slide-11
SLIDE 11

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment

slide-12
SLIDE 12

US Forest Service Experimental Watersheds

Hubbard Brook (1955) Coweeta (1934) Fernow (1934) H.J. Andrews (1948) Fraser (1937) Bonanza Creek (1969)

www.fs.fed.us/research/efr/efr-sites/index.shtml

slide-13
SLIDE 13

Original Objective: Influence of forest practices

  • n water yield

Hubbard Brook, NH

Sources: Bormann & Likens, 1979; Bormann & Buso, 2006 Biogeochemistry; M.B. Adams; DH Ramsay Library, UNC

Fernow, WV Coweeta, NC

slide-14
SLIDE 14

Coweeta, NC

Source: Swank & Crossley, 1988 Forest Hydrology and Ecology at Coweeta

Influence of forest cover / practices

  • n runoff
slide-15
SLIDE 15

Influence of forest practices on runoff

Source: Swank & Crossley, 1988 Forest Hydrology and Ecology at Coweeta

T vs E response

slide-16
SLIDE 16

Source: Fisher & Binkley, 2000 Ecology and Management of Forest Soils

Q = P – ET ± dS ± dG Influence of forest practices on runoff

Is this also valid in more arid environments??

slide-17
SLIDE 17

aspen conifers

Montane forests in Utah 70-85 % total precip as snow (October-April)

What about snow-dominated systems?

slide-18
SLIDE 18

Source: Lamalfa & Ryel, 2008 Ecosystems

Vegetation affects snow accumulation and…. soil moisture

aspen conifers

Aspen = Greater soil water recharge (winter) Greater potential water yield

slide-19
SLIDE 19

Climate and Vegetation Change Effects

  • n site water balance

1920 2007

Photos: Courtesy R. Jandl (BFW)

slide-20
SLIDE 20

Extracted from C. Alewell presentation at 2008 Zagreb COST–FORMAN meeting

Q = P – ET ± dS ± dG

Climate Landuse Vegetation

slide-21
SLIDE 21

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment

  • Influence on Q (quantity)
  • Influence on timing of Q
slide-22
SLIDE 22

Q = P – ET ± dS ± dG

Timing

slide-23
SLIDE 23

Q = P – ET ± dS ± dG Flashfloods

slide-24
SLIDE 24

Effects of Forest Management and Changes in the Environment

Q = P – ET ± dS ± dG

Rooting depth Soil volume

  • Naturally shallow soils / bedrock
  • Presence of clay lenses or hardpans
  • Compacted layers
slide-25
SLIDE 25

Influence of forest vegetation on site water balance

Photo: Courtesy E. Leitgeb (BFW)

Rooting Depth /patterns

  • Environmental
  • Anthopogenic
  • Natural (intrinsic)
slide-26
SLIDE 26

Rooting Depth Soil Volume Transp Q

Influence of forest vegetation on site water balance (natural differences)

Species mixtures Species selection (target)

slide-27
SLIDE 27

Influence of vegetation cover on frost

Q = P – ET ± dS ± dG

Rooting Volume Timing

slide-28
SLIDE 28

Sources: Schimel et al., 2004 Soil Biol Biochem.; Peter Groffman, IES @ http://www.ecostudies.org/people_sci_groffman_snow_summary.html ambient Increased snowpack

Influence of climate change on snow cover

slide-29
SLIDE 29

Climate Change and Fire Regime

  • Climate shifts changing fire regime
  • Change fire regime shift in vegetation

1899 1977 1988 1920

Source: http://biology.usgs.gov/luhna/chap9.html

Conifer forest Utah Juniper New Mexico

slide-30
SLIDE 30

Fire and Soil Hydrophobicity

Photos Courtesy Dan Neary (US Forest Service)

  • Ic goes down
  • effective volume for dS down
  • erosion risk increases
  • loss soil = loss of dS
slide-31
SLIDE 31

Reduced Infitration capacity More overland flow Increased surface erosion Soil loss, reduction of dS function

slide-32
SLIDE 32

Q = P – ET ± dS ± dG

Effects of Forest Management and Changes in the Environment

  • Management & climate influence

individual components of the SWB

  • Some of these changes cascade to
  • ther components of the SWB
  • Effects have temporal & spatial

dimensions