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Typy opadów deszczu w terminologii hydrologicznej

Kupczyk E., Suligowski R.

Przegląd Geofizyczny

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2011

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Z. 3-4

235-246

PL

W licznych pracach z zakresu opadów podejmowanych przez meteorologów i klimatologów zjawisko to jest analizowane w różnych aspektach, zależnie od celu badań. Niektóre z nich zawierają klasyfikację zdarzeń opadowych ze względu na różną skalę procesów, które powodują powstawanie chmur i opadów. W literaturze polskiej z zakresu opadów odczuwa się jednak niedostatek szczegółowych studiów poświęconych charakterystykom opadów i propozycji wykorzystania wyników tych badań w praktyce hydrologicznej. Dla celów analiz i prognoz hydrologicznych najważniejsze są przypadki opadów deszczu o maksymalnej wydajności i ich charakterystyki: wysokość, czas trwania oraz zasięg obszarowy. Celem artykułu jest prezentacja wyników badań sytuacji meteorologicznych nad Europą, w jakich występują w Polsce wysokie opady deszczu, identyfikacja systemów opadotwórczych w różnej skali i ustalenie charakterystyk opadu typowych dla tych sytuacji. Zastosowano dwie metody badań, statystyczną i meteorologiczną do analizy przypadków opadów rejestrowanych w obszarze Polski w wieloletnim okresie 1961-2000. Połączenie wyników badań dokonanych tymi metodami pozwoliło wydzielić 3 typy opadów: konwekcyjne, frontalne i opady stref konwergencji, które różnią się co do genezy, ale także można im przypisać różne charakterystyki opadu.

EN

A large number of studies has been undertaken by meteorologists and climatologists on precipitation phenomenon in many aspects, depending on the goal of investigation. Some of them classified precipitation events with respect to the different scale of atmospheric processes which cause the formation of clouds and precipitation. However, the review of Polish hydrometeorological bibliography shows the gapes in studies on the detailed characteristics of precipitation in time and space and application of this knowledge to hydrologic practice. For purposes of hydrologic analysis and forecast the most important subject of interest are extreme rainfall events, their depth, duration and areal extent. The aim of this paper is presentation of research results on extreme rainfall producing systems in the atmosphere at Middle Europe and finding rainfall characteristics which are referred to that precipitation-producing mechanism. Two approaches, statistical and meteorological have been applied for the analysis rainfall events recorded over territory of Poland, in multi - years period (1961-2000). The first method enabled selecting rainfall characteristics which are essential for rainfall types identification. The bases for meteorological analysis where synoptic maps and satellite images, corresponding with periods of high rainfall events. Integration of these two approaches makes possible the separation of the rainfall types: convection, frontal and convergence zones rainfall, which differ with their origin and main rainfall characteristics.

2

Erozja wąwozowa zapisana w odsłanianych korzeniach drzew na Wysoczyźnie Proboszczowickiej pod Górą Św. Anny

Malik I.

Przegląd Geologiczny

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2006

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Vol. 54, nr 4

326-332

EN

Erosion occurs in permanent gullies cutting into the undulating loess plateau in southern Poland. The gully slopes are mainly vegetated with beech trees as opposed to the surface of the plateau summit, which is cultivated agricultural land, devoid of forests for at least 18 centuries [od 18 wieków czy od XVIII wieku – czyli “since 1700s”?]. Beech roots are exposed in the gullies through erosion. Wood cells in the tree rings divide into early wood and late wood and, after the roots are exposed, also start to make fewer cells. In the roots on the border between exposed and unexposed tree rings in the tree roots, scars sometimes occur. This is an effect produced by corrasion by dolomites and limestones lying under the loess cover and re-deposition of building material stored by people in the higher part of the gullies. These anatomical changes in root tree rings allow one to date erosion episodes. Dating of the exposure of roots indicates that intensive erosion took place in the gullies starting in the 1980s. Since that time, numerous extreme rainfall events responsible for initiating erosion have also occurred. They contribute to deepening valleys causing new incisions to develop on hillslopes and headcut retreat in upper parts of the valleys studied at theWysoczyna Proboszczowicka near Góra św. Anny. The bottom of the valley head eroded during extreme rainfall events in 1984 and 1991. Erosion here alternates with deposition, its speed being relatively small. Incisions in hill slopes retreated during the flood in 1997, but they originated during earlier rainfall episodes. Such incisions retreat 2.5–3 m/year, i.e., relatively fast.

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Gully erosion dating by means of anatomical changes in exposed roots (Proboszczowicka Plateau, Southern Poland)

Malik I.

Geochronometria

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2006

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Vol. 25

57-66

EN

Re-incision occurs in gullies in the undulating loess plateau in southern Poland. The gully hillslopes are mainly covered with beech trees. The beech roots are exposed in the gullies through erosion. The wood cells in the root tree rings divide into early wood and late wood, and after the roots are exposed, they start to make fewer cells. Dolomites and limestones lying under the loess cover are transported and wound the tree roots. As a result of this process on the border between exposed and unexposed tree rings in the tree roots, scars sometimes occur. These anatomical changes in root tree rings allow to date erosion episodes with one year accuracy. Dating of the exposure of roots indicates that intensive gully erosion in the studied gully started in the 1970s. Since that time, numerous extreme rainfall events responsible for initiating erosion have also occurred. The bottom of the valley head eroded during extreme rainfall events in 1984 and 1991. Erosion here alternates with deposition, its rate being relatively small. Incisions in hillslopes retreated during the flood in 1997, but they originated during earlier rainfall episodes. Hillslope undercutting occurring in the lower part of the gully was formed during older erosion episodes in 1971 and 1984.