Issue 17 (3) 2018 pp. 129-139
FORECASTING THE FORMATION OF FRESHETS IN SMALL LOWLAND CATCHMENT FOR DIFFERENT SCENARIOS OF URBANIZATION
Keywords: urbanization, variable source areas (VSA), hydrograph, conceptual model
The purpose of the work was to present the results of simulation studies of river runoff carried out with the use of a conceptual model specially developed for this purpose for an urbanized lowland catchment. Different variants of forecasts were developed of the impact of introducing various forms of urbanization on the formation of river runoff during freshets in the small, lowland catchment of upper Mławka river, covering the area of 66 km2. For the needs of the research, classification of urbanized areas was made based on their location within the catchment, and the method of discharging rainfall runoff. Particular variants differed from one another as to the location of sealed areas, the degree of urbanization of the catchment, the initial waterlogging of the catchment, as well as the basic precipitation assumed for calculations. They provided the foundations for the assessment of the impact of various forms of urbanization of the catchment area on the formation of freshets, taking into account the catchment’s natural properties, such as the occurrence of variable source areas. The subject of the analysis was not only the total runoff volume, but also its components – surface, subsurface and groundwater runoff. Analysis of the results of river runoff simulation, taking into account the components of this runoff, leads to the conclusion that the total increase of direct runoff volume and its peak value are caused not only by direct supply from sealed surfaces, but also from indirect impact, causing changes in the runoff regime in areas not covered by urbanization. Sealed and channelled areas located beyond the maximum range of active (variable source) areas, on which direct runoff does not occur in natural conditions, increase the runoff area in the scale of the catchment area as a whole. To compare, the peak freshet values for variants associated with urbanization and channelling outside the variable source areas are between 20% and 40% higher than in the case of analogous conditions and the sealing of the same area in the area of direct runoff.
|MLA||Krężałek, Katarzyna. "FORECASTING THE FORMATION OF FRESHETS IN SMALL LOWLAND CATCHMENT FOR DIFFERENT SCENARIOS OF URBANIZATION." Acta Sci.Pol. Form. Cir. 17.3 (2018): 129-139. http://dx.doi.org/10.15576/ASP.FC/2018.17.3.129|
|APA||(2018). . Acta Sci.Pol. Form. Cir. 17 (3), 129-139 http://dx.doi.org/10.15576/ASP.FC/2018.17.3.129|
|ISO 690||KRężAłEK, Katarzyna. FORECASTING THE FORMATION OF FRESHETS IN SMALL LOWLAND CATCHMENT FOR DIFFERENT SCENARIOS OF URBANIZATION. Acta Sci.Pol. Form. Cir., 2018, 17.3: 129-139. http://dx.doi.org/10.15576/ASP.FC/2018.17.3.129|