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dam-l mrozengurt: R: WCD submission: REPOST
Forwarded message:
From dianne Wed Mar 22 14:47:56 2000
Date: Tue, 14 Dec 1999 16:32:56 -0800
Subject: mrozengurt: R: WCD submission
From: Michael Rozengurt <mrozengurt@juno.com>
Sender: dianne@sandelman.ottawa.on.ca
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From: mrozengurt
To: submission@dams.org
Subject: R: WCD submission
Date: Tue, 14 Dec 1999 01:40:44 -0800
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Here is the paper in question again...
Controversial influence of impounded large rivers on their
delta-estuary-coastal ecosystems.
ROZENGURT, M.A., Ph.D., P.H., Coastal Consulting, 8888 Lauderdale Ct.,
Unit 216 F, Huntington Beach, CA 92646, U.S.A. Tel.(714)536-4403, E-mail
:mrozengurt@juno.com
Riverine-estuarine- systems are the parts of the coastal seas of oceans
where contact and interaction between environment, plants, and animals
occurs tens to hundreds of times faster than in other areas of the earth.
The influences of these processes on regime characteristics and
biological productivity of coastal ecosystems have been recognized by an
international community of oceanographers both in the Northern and
Southern hemispheres. Historically, the fresh water repels salt water
intrusion, flushes the natural and human introduced pollutants from the
deltas and estuaries and provides a rich supply of inorganic and organic
matter to the coastal embayments. These areas had provided about 80% of
the world fishery composed of species whose life history is directly or
indirectly dependent on a volume of runoff and timing of its discharges
to the adjacent ecosystems.
The abilities of coastal ecosystems to be adjusted to the
temporary impact of natural external regime disturbances are based on
four major fundamental principles: (1) Stochastic and stochastic-periodic
nature of their environment; (2)The ability to maintain the vital ranges
of dynamic, physical, and chemical equilibrium among different parts of
adjacent systems; (3) Ecological continue of the rivers into coastal
seas, and (4) Biological tolerance of living resources to optimal natural
alterations of regime characteristics of ecosystems. The significance of
these principles is governed by river unimpaired runoff.
However, a massive implementation of large dams and water conveyance
facilities have transformed unimpaired runoffs to impaired fluxes that
changed beyond recognition the environment of coastal ecosystems.
Cumulative effects of systematic inland water withdrawals of millions of
acre feet (thousands of cubic kilometers) undocumented in recent history
have resulted in chronic depletion of the spring and annual runoffs
ranging from -35 to -90% of the perennial natural norms computed as
the average more than 55 years as opposed to its natural ±25 to ± 30%.
The excessive reductions of runoffs have been accompanied by the
cumulative losses of millions of tons of oxygen, organic and inorganic
matter and sediment vitally to the survival of coastal ecosystems of the
world ocean. Subsequently, it had taken 10 to 15 years to have the
functioning of major river-coastal ecosystems' continuum impeded. This,
in turn, has led to an anomalous predominance of years of subnormal
wetness or droughts despite would be unimpaired runoff. As a result,
the accumulation of entropy occurred whose visible indicators are:
sluggish water masses' circulation, increased detention time of polluted
waters, insufficient of self-purification of delta-estuary ecosystems
from salt water intrusion, and other natural and man-induced pollutants,
eutrophication, hypoxia and anoxia.
In sums, man's perceived needs have produced the new, artificially
impoverished ecosystems on a global scale, namely: "the impounded
delta-estuary-coastal seas." The scale of this development has
triggered a precipitous decline of commercial and recreational catches'
valuable fish and shellfish.
The major failures to foresee the deprivation of coastal ecosystems can
be partially attributed to (1) statistics of impaired (deterministic)
runoffs have been analyzed by unfortunate use of methods of stochastic
hydrology developed for unimpaired runoff fluctuations; (2) accordingly,
modeling and prediction of impaired water and salt balance of modified
ecosystems and living resource have not been tuned to would be stochastic
probability of occurrence of observed events, and (3) the postulates of
Laws of Thermodynamic have been ignored and scales of ecological
tolerance and limitations of ecosystems to water withdrawals beyond
which entropy tends to reach measurable maximum. This, in turn, has
accelerated the despoliation of coastal seas the world over.
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