INTRODUCTION
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How have the fields of ecology and
hydrogeology attempted to delineate the
hyporheic zone?
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It is hard to define something we cannot
immediately see.
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Different definitions of the hyporheic zone (HZ)
exist, based upon the field of science concerned

Importance within hydrology?
MEANWHILE IN GREECE…
HYPO = UNDER/ BENEATH
RHEO = TO FLOW
FAUNAL HABITAT

A distinct habitat was detected and
named the ‘hyporheic biotope’.

This habitat was identified within
the interface between surface and
groundwater (Orghidan, 1959).

Identification of a large and diverse
collection of fauna (Danielopo,
1989).
A REFUGE

Biocenosis between organisms (Sabater
and Vila, 1990).

A temporary refuge for organisms in times
of physical and biological adversity
(Stanford and Ward, 1988).

An ‘ecotone’ (Williams, 2010)
DELINEATION ATTEMPTS
In-situ microbe calculations (Hynes, 1974)
and correlation with concentrations of DO.
 The ‘hyporheic corridor’ concept (Stanford
and Ward, 1993).
 Slower level of biological processes then
that of the surface (Gibert et al, 1994)
 Complex and temporally variable distribution
of ecology within the hyporheic zone.

DEFINING THE HYPORHEIC ZONE

Combining the factors of groundwater flow/exchange with populations
of hyporheic invertebrates (Stanley and Boulton, 1993).
THE GROUNDWATER SYSTEM

The hyporheic zone represents an area with
increased mixing of surface and groundwater.

Dynamic and interesting zone

An important site of solute retention,
metabolism and mineralization (Bencala,
1993).

Considers geomorphological and
sedimentological structure
DELINEATION ATTEMPTS

Quantification within hydrogeology has
been attempted through identification of
hyporheic depth or length of flow path.

But also, in a more detailed manner,
through consideration of the amount of
water present through the surface and
groundwater components (Triska et al).
METHODS OF DELINEATION
Examined at a wide range of scales;
from riffles to whole drainage basins.
 Delineated through exchange processes
that occur.

INTERCONNECTIVITY
Faunal
Assemblage
Ecology
Residence
Times
Hyporheic
Zone
GroundwaterSurface
Interactions
Hydrogeology
Interconnected
Processes
Physical
Properties
CONCLUSIONS

Inter-system connectivity, used to be
considered as distinct entities.

Heterogeneity; varied spatially and
temporally

The characteristics of running water are
controlled by the interaction with their
surroundings.
A WORKING DEFINITION

The zone below and adjacent to a
streambed in which water from the open
channel exchanges with interstitial water in
the bed sediments (White, 1993). It is the
zone around a stream in which fauna
characteristic of the hyporheic zone are
distributed and live (Danielopo, 1989). It is
a zone in which groundwater and surface
water mix (Orghidan, 1959, Triska et al,
1993). The boundaries of the hyporheic
zone vary in time and space
REFERENCES
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Bencala, K. E., 1993, A perspective on stream-catchment connections; Journal of the North
American Benthological Society, p.44-47.
Danielopo D.L.,1989,Groundwater fauna associated with riverine aquifers: Journal of North. American
Benthological Society, v.8, p18-35.
Gibert J, Danielopo D.L and Stanford J.A. (eds),1994, Groundwater Ecology: San Diego, Academic
Orghidan, 1959, Ein neur Leben-sraum des unterirdischen Wassers: der hyporheische Biotop: Arch.
Hydrobiology; v. 55, p392-414
Sabater F. and Vila P.B., 1991, The Hyporheic Zone considered as an ecotone: Oecologia Aquatica,
v.10, p.35-43
Stanford J.A. and Ward J.V., 1993, An ecosystem perspective of alluvial rivers: connectivity and the
hyporheic corridor, Journal. North. American. Benthological Society, v. 12, p. 48-60
Stanley, E. H., and Boulton, A. J. ,1993, Hydrology and the distribution of hyporheos: perspectives
from a mesic river and a desert stream: Journal of the North American Benthological Society, p. 7983.
Triska F.J, Duff, J.H, and Avanzino R.J., 1993, The role of water exchange between a stream
channel and its hyporheic zone in nitrogen cycling at the terrestrial-aquatic interface: Hydrobiologia, v.
251, p.167-184.
Ward, J. V.,1989, The four-dimensional nature of lotic ecosystems: Journal of the North American
Benthological Society, v.8, p.2-8.
White D.S., 1993, Perspectives on defining and delineating hyporheic zones: Journal of the North
American Benthological Society v. 12, p.79-83.
Williams D.D, Febria C.M, and Wong J.C.Y., 2010, Ecotonal and other properties of the Hyporheic
Zone: Fundamentals. Applied. Limnology., Arch. Hydrobiol. v.176-4, p. 349–364