SMALL ARTIFICAL WATER BODIES:

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SMALL ARTIFICAL WATER BODIES A NEGLECTED BUT
IMPORTANT FACTOR IN WATER SUPPLY AND
ENVIRONMENTAL QUALITY R. W. Buddemeier1,2, R.
O. Sleezer3, D. P. Young1, S. Egbert2,4, F. J.
deNoyelles4,5, X. Zhan1, W. H. Renwick6, and S.
V. Smith7
1. Kansas Geological Survey2. Dept. of
Geography, KU3. Emporia State Univ.4. Kansas
Biological Survey KARS5. Dept. of Ecology
Evolutionary Biology, KU6. Miami Univ. (Ohio)7.
CICESE (Mexico)
Acknowledgements Technical contributions Z.
Andereck, , M. Dunbar, B.N. Mosiman, P. Taylor,
M. Houts, J. Vopata, E. Wilson Funding Kansas
NASA EPSCoR Program (KNEP) US NASA and KTEC
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Relatively large dams and reservoirs have been
extensively studied because of their effects on
water and sediment budgets at scales from
regional to global. Cumulatively, these
artificial water bodies are an important factor
in biogeochemical fluxes at global scales -- in
addition to providing water supplies that
profoundly influence patterns of development,
population and land use
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Small impoundments, which are many times more
numerous, have received little attention.
Recent studies have improved estimates of both
inventory and the importance of small water
bodies, and have been the basis for a
KNEP-sponsored project reported
here. Smith, S. V., Renwick, W. H.,
Buddemeier, R. W., and Crossland, C. J. 2001.
Budgets of soil erosion and deposition for
sediments and sedimentary organic carbon across
the conterminous United States. Global
Biogeochemical Cycles 15(3) 697-707 Smith, S.
V., Renwick, W. H., Bartley, J. D., and
Buddemeier, R. W. 2002. Distribution and
significance of small, artificial water bodies
across the United States landscape. The Science
of the Total Environment 29921-36 Renwick,
W.H., S.V. Smith, J.D. Bartley and R.W.
Buddemeier, in press. The Role of Small
Impoundments in the Sediment Budget of the
Conterminous United States. Geomorphology.
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What is the role of small impoundments on a local
scale?

• How many small impoundments exist, and what is
  their distribution?
• How have they developed over time?
• What ecological and water quality characteristics
  can be determined remotely?
• How best can local studies of detection and
  functional description be used to calibrate and
  upscale results to national and global scales?

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Detailed comparison of multiple generally
available and widely-used datasets along a
transect between 32o and 41oN resulted in the
refined estimate of small impoundment densities
and distributions mapped below (Smith et al. 2003)
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Small impoundments serve many water-related
functions directly, and have indirect influence
on others.

• FUNCTION
• Stock water supply
• Sediment and erosion control
• Water/environmental quality
• Fish production
• Recreation and aesthetics
• Habitat and conservation

• WATER SUPPLY ROLE
• Local source
• Reservoir/stream protection
• Reservoir/stream protection
• ---
• ---
• () Diversity (wetland)
• (-) Invasive and pest species

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Number and area of water bodies in various data
sets Mapped national density estimates were
developed by applying scaling factors from the
DLGs to the nationally available NLCD

• For comparison with these generally available
  data sets, we sampled two E. KS quadrangles
  (Midland and Allen SE) using
• Landsat TM (30 m res.)
• ASTER (15 m)
• Duncan-Tech multi-spectral aerial photography (lt
  1 m)
• Available aerial photographs (DOQQs, crop slides,
  archived county records, etc.) (lt 1 m)
• We developed historical estimates of pond
  development from the 1940s
• and compared with NRCS and other recent detailed
  coverages.

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Results detection and inventory (comparison
areas)
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Results time histories and total inventory
Two test Quadrangles Midland in SE Jefferson
Co., and Allen SE in NE Lyon Co. have similar
inventories, but rather different histories.
Allen SE, with generally stable population and
agricultural land use, showed an earlier onset of
pond building, which reached a plateau by
1960. Midland, with mixed and changing land use,
started later and has reached numbers similar to
Allen SE with a nearly linear increase.
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Results ecological and biogeochemical function
Ground-truth comparisons have shown that
multi-spectral images can reliably identify many
aspects of water quality and pond ecology, as
well as characterizing the surrounding landscape.

False-color images of NE Kansas farm ponds taken
with the MS3100 multispectral camera. Left
moderately turbid water, some vegetation at
edges. Center clear water, little vegetation.
Right pond clogged with vegetation and sediment,
but with moderately clear water in places.
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Filtration and reaction biogeochemical effects
of pond density (W. H. Renwick)
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Relation between impoundment density and area
tributary to impoundments (W. H. Renwick)
DLG-based estimates lower than but comparable
to results of this study
Although the graphed points would have higher
densities if they were derived with our
techniques, the conclusion is inescapable most
of the area of E KS watersheds drains through one
or (often) more ponds before reaching a perennial
stream or a water body large enough to appear in
most of the statewide datasets or maps.
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Observations and Conclusions

• Millions of small artificial impoundments now dot
  the landscape of the conterminous U.S., at an
  average density of 0.3 per km2 but reaching
  densities of gt5 per km2 in many regions.
• -These represent profound alterations to the
  landscape, mostly within the past 50 years.
• -The norms used for the design of most major
  reservoirs did not include the effects of these
  ponds
• Although relatively small in cumulative area and
  volume, their high surface/volume ratio and
  proximity to the source of runoff makes them
  efficient distributed reactors.
• -Calculations show they play a major role in
  sediment and carbon sequestration effects on
  dissolved chemicals are significant but more
  difficult to estimate.

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Observations and Conclusions, continued

• The high concentration of ponds coincident with
  the geographic transition from water surplus to
  water testifies to their water supply functions.
• -Considered alone, ponds have a beneficial
  effect on downstream water quality, but they may
  accompany or facilitate detrimental land uses.
• The combination of remote sensing and modeling
  with limited ground-truth calibration can
  inventory and classify ponds, and evaluate their
  landscape-scale effects on water quality and the
  general ecosystem -- more to follow!