Morfologia i osady powodzi błyskawicznej w okolicach Kromołowa (Polska południowa) po 20 latach

The examined area is located in southern Poland on Silesian Upland. According to geomorphologic regionalization, it is southernmost part of Valley of Upper Warta and Prosna Rivers between two cuestas – Upper Jurassic in the east and Upper Triassic in the west. There is northern Upper Silesia Region near spring of Warta River, tributary of Oder River. Some dry, fluvio-denudational valley (trough, dellen) form drainage pattern around Kromołów, which is a district of Zawiercie city. These dellen, which have been formed in periglacial conditions of the Pleistocene, are relict forms very typical for Polish Uplands (Fig. 1, 2). These Pleistocene valleys were rejuvenated during the Holocene. Good example of this type of relief transformation is a small dry valley located near center of the Kromołów. The first-phase of headward erosion reached upper section of the valley in the Subatlantic Large scale of soil erosion is confirmed by thick (about 3 m) series of deposits with fragments of 17-18 c. pottery accumulated in the middle section of the valley. The erosion cut in middle section has a depth of 3-4 meters and a length of almost 800 meters. This accumulation and incision was associated with flash floods which were main morphogenetic factor of transformation of this valley type during the Holocene. A scale of erosion-accumulation processes during catastrophic event was showed by last flash flood in 1996. Few profiles located in this valley, give us information about accumulation during one event. Alluvia (thickness 2.5 m) were deposited in two phases in middle section of the valley (Kromołów KR 4 profile) (Fig. 4, 5, 6). Two sediment members are separated by thin layer with plastic garbage. Lower member consists of sand mixed with detritus and coal. After almost twenty years forms and sediments of these floods are preserved only in the middle section of the eastern valley. Hydro-technical constructions (dam, reservoirs) built in the northern valley only partially protect Kromołów against further flash flood events.