In result of considerably diminished retention abilities of catchment area as well of river and stream inundation areas, increased high water flows occurred, particularly in the watercourse mouth sections. It poses a considerable flood hazard for the urbanized areas. Registered flood of July 1977 and June 2001 caused by high waters confirmed significant flood hazard in the areas of Carpathian tributaries of the Vistula River. In the Carpathian Foothills area, because of high water culmination times are shorter, watercourse regulation in closely built-up areas is necessary. Strong urbanization of the riverbank terrains resulting from historical location of towns gives no possibility to design riverbed in character close to natural. One of the main solutions, which is the most frequently applied and guarantees conducting high water flows is heavy consolidation of bed constructed in a shape of a trough. An example of this type of regulation is applied the mouth section of the Naściszówka stream. The Naściszówka inflow to the Łubinka river is situated in the Nowy Sącz city area. The streambed runs along Barska street. The adjacent terrain is characterised by a close urban building. The trough discharge capacity was assessed. According to the design guidelines in „Mountain stream consolidation”, ...
The reduction of flood effects may be attained by lowering the risk of flood. This often requires complex works not only on the assessment of conveyance of the open channel on the territory exposed of flood but also of the capacity of the upper part of the river channel. Great cost for decrease of flood damages can be avoided by improving the conveyance of the channel. This can be proceeded by assessment of the existing state of the open channel development. In result of assessment of damages caused by overflow from the the Czarna Woda channel it was established, that a water-muddy wave reached the center of the locality Łącko flowing over the whole width of the urbanized adjacent part of the valley. The aim of the studies was to point out the causes of flood threat to the locality Łącko. The state of development and conveyance of the Stream Czarna Woda, flowing across the upper districts and the center of Łącko was assessed. The Stream Czarna Woda flows in a trained open channel constructed by a stoneconcrete channel. The performed evaluation of conveyance capacity of cannel permits to identify sections of low conveyance of the stream. The performed measurements ...
The aim of the paper was to develop the assessment of the conveyance of the main ditch R of the Łączany drainage system based on the results of surveying and hydraulic calculations. This ditch is the main element of the drainage system, eliminating the effects of damming the waters of the Vistula with the Łączany barrage. The analysis also took into account the influence of engineering structures, such as culverts and siphons. In the first stage of the analysis, hydraulic calculations were made without taking into account culverts and siphons. Calculation of the hydraulic conditions of water flow in the ditch channel was done for the neglected condition (first variant) and condition after maintenance (second variant). In the second stage of calculations, the influence of engineering constructions on the neglected condition (third variant) and the state after maintenance operations was taken into account (fourth variant). It was found that the conveyance of the R-ditch, determined in accordance with the established assumptions of the first variant and the second variant, indicate that almost the entire length of the R-ditch, its conveyance is lower than specified in the design assumptions. It was shown that the additional conveyance limit is caused by engineering ...
