REVIEW AND ANALYSES OF SOME MAXIMAL DISCHARGES IN EUROPE

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REVIEW AND ANALYSES OF SOME MAXIMAL
DISCHARGES IN EUROPE
BALWOIS 2006 Conference

• Ivan Blinkov1, V.Al.Stanescu2
• 1Faculty of forestry Skopje , Dept. of Land and
  Water
• E-mail blinkov_at_ukim.edu.mk
• 2National Institute of Meteorology and Hydrology
  - Romania

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• Very often after intensive and long-lasting
  droughts there is occurrence of extreme water
  run-off which leads to flash-floods or regional
  floods.
• Although modern technology have rapid
  development, it is not known yet how to predict
  the extreme water discharge appearance of the
  small torrents. With all modern technology
  and\new approache in spatial or urban planning
  we can only minimize the damages caused by
  flash-floods of bigger rivers.
• There are a difference between small torents and
  rivers, the time base of the hydrogram is very
  small and the extreme discharges appear
  unexpectedly, they reach the pick very fast
  (quickly) and there is wave retardation for a
  very short time. Therefore forecast of the
  appearance and size of the maximal discharges is
  very hard to be realized.

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Objectives and Methods

• Aim of this paper is to try to establish some
  correlation between water discharge and other
  factors.
• The full data contains 657 values. Part of these
  data is officially published in IAHS
  publications, and part is from the personal data
  of one of the authors of this paper. In the
  database there are very small catchments (like
  the small torrents), but also there are big
  rivers like Dounau.
• The basic data contain name of the stream,
  profile, state, catchments area, registered or
  calculated discharge, date and note (comment).
• First, according to the catchments area F (km2)
  and maximal discharge Qmax (m3/s) it is
  calculated the specific discharge value Qsp
  (m3/s.km2) too.

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• Basic statistical parameters
• number of information (N), average value (Xsr),
  maximal value (Xmax), minimal value (Xmin),
  standard deviation ?s), variety coefficient (Cv)
  and symmetry coefficient (Cs).
• Analyzes of full series.
• Analyzes of classified series by the catchement
  area) lt 50 km2 50.1ltFlt100 km2 100.1ltFlt200 km2
  200.1ltFlt500 km2 500.1ltFlt1000 km2 1000.1ltFlt2000
  km2 2000.1ltFlt5000 km2 5000.1ltFlt10000 km2
  10000.1ltFlt50000 km2 and catchments with area more
  than 50000.1 km2.
• Analyzes of classified series by the specific
  discharge
• Then it is calculated some ratio between the
  catchments area, discharge and specific discharge
  i.e.
• Qmax f (F) and Qsp f (F).

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Basic parameters of the data series
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10 highest discharges
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10 highest specific discharges
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Ratio Qmaxf(F)
Ratio Qspf(F)
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Analyzes of selected (classified) data

• Criterias for classification
• Catchment area ( F lt 100 km2)
• Qsp gt 10 m3/s.km2.

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Basic parameters of grouped data series
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Basic parameters of grouped series Qsp gt 10
m3/s.km2
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Qsp f (F)
Qmax f (F) where Qsp gt 10 m3/s.km2
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Conclusions
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• Characteristic of small torrents are extreme
  values of the specific discharge (Qsp
  m3/s.km2). It is obvious that these kind of
  specific discharges are happening in catchments
  areas under 236 km2
• Between large discharges value and catchments
  area there is proportional linear correlation
• (Y 0.0803 x 931.31). The determination
  coefficient is R2 0.6422, which shows good
  correlation.
• Between specific discharge and catchments area
  there is disproportional (Y 27.485 x -0.5212)
  but strong correlation (R20.6613).
• When data is grouped according to the catchments
  area, got functions are similar, but
  determination coefficients shows low correlation.

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• Between extreme specific discharges (Qspgt10) and
  proper, appropriate catchments areas there is low
  negative correlation R2 0.2056, and
• Y 21.083 x 0.0982.
• There is interesting correlation between water
  discharges and catchments area right in these
  cases when are got extreme specific discharges.
  The dependence is linear (Y 13.401 x 38.583).
  By the way it is got almost functional
  dependence.
• Large water discharges are rare phenomena, but
  they have unbelievable (very bad, big)
  consequences on the whole environment.

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• We are lucky that in Macedonia never had happened
  discharges with those kinds of dimensions like
  the big European rivers. But, that is possible
  with the small water discharges. Its enough if
  we remember of Negotinska Reka case, also there
  are other registered cases, but with smaller
  dimensions river Pena, Dzepchishki Poroj, Anska
  Reka and other smaller torrents.

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Blagodaram na vnimanieto
Thank you for your attention