Problem zaopatrzenia w wodę rejonu środkowej Wisły na tle charakterystyki hydrogeologicznej
Abstract
THE PROBLEM OF WATER SUPPLY IN THE REGION OF THE MIDDLE VISTULA RIVER AGAINST THE HYDROGEOLOGICAL CHARACTERISTIC
Summary
Recently, intense hydrogeological researches are being carried on within the region of the Middle Vistula River. To the main water-bearing formations belong here the Upper Cretaceous and the Quaternary. In marls, opokas and limestones of the Upper Cretaceous occur waters filling up weathering and tectonical fissures. Fed by atmospheric precipitations through direct infiltration and by underground afflux from the Roztocze Region, the waters flow towards the north-west. On the way, however, they are strongly drained off by the Vistula River and its tributaries; the zone of the active exchange reaches up to 100 m. Unit efficiencies range greatly, the best ones reaching up to 200 m3/hour/1 m; they may, however, be obtained within the marginal zones of the valleys tectonically predisposed. Arenaceous and gravelly urstromtal deposits, up to 40 m in thickness, are main underground water reservoir the Vistula valley. A strong water stream may be observed in them, fed by both the waters from the Cretaceous and the atmospheric precipitations. The quality of the waters is good, the unit efficiencies are high. The dynamical resources occurring in the Middle Vistula region are estimated to be from 140-360 m3/hour/km2. On account of great resources, the underground waters may be recognized for sufficient to be the source of supplying towns, agricultural centres and industry in the area considered.