The influence of selected calculations parameters on flow simulation error and Nash model parameters in urban catchment [Wpływ wybranych parametrów obliczeniowych na błaçd symulacji przepływów i parametry modelu Nasha w zlewni miejskiej]
Barszcz M.,Katedra Inzynierii Wodnej |
Barszcz M.,Warsaw University of Life Sciences
Scientific Review Engineering and Environmental Sciences | Year: 2016
The paper presents an analysis of suitability of the conceptual rainfall-runoff model by Nash for simulation maximum flows in the Służewiecki Stream catchment to the profile Rosoła, located in Warsaw. The range of the analyzes included determining the parameters of the Nash model (N, K) for 13 rainfall-runoff events and an assessment of the compatibility between measured and simulated flows. The analysis was conducted for two different sizes of the catchment area (14.7 and 31.2 km2), two time steps of calculations (10 and 30 min) and two locations of the end point of the direct runoff hydrograph, in order to determine their impact on the flow simulation error and the parameters of the Nash model. The calculations were performed using an owned computer program. Admission to the calculations of two different sizes of the catchment area has little impact on the compatibility between measured and simulated maximum flows. The compatibility between these flows is much greater in the simulations with the time step of calculations of 10 min than with the time step of 30 min. The analysis showed that the choice of the end point of the direct runoff hydrograph has a big impact on the flow simulation error and the values of parameters of the Nash model.
Banasik K.,Katedra Inzynierii Wodnej |
Hejduk L.,Katedra Inzynierii Wodnej |
Hejduk A.,Katedra Inzynierii Wodnej |
Kaznowska E.,Katedra Inzynierii Wodnej |
And 2 more authors.
Sylwan | Year: 2013
Kozienice Forest (centtal Poland) belongs to very valuable areas from touristic and ecological point of view. Water resources are important factor of further development of this region. Analysis of 49-year (1963-2011) annual and seasonal rainfall and runoff characteristics from a small (82 km2) catchment of Zagożdżonka River, with forcstation ratio of 0.40, indicated a statistically significant decrease for six of the nine considered parameters. Mann-Kendall test was used for trend analysis. Decreased trend was indicated for annual runoff and annual runoff coefficient, median discharge, summer half-year runoff coefficient, median summer discharge and for low mean 30-day discharge. No trend was detected for annual precipitation and summer half year precipitation nor for summer half year runoff.
The application of the Santa Barbara Unit Hydrograph model to simulate a flow hydrograph in urbanized catchments [Zastosowanie modelu Santa Barbara Unit Hydrograph do symulacji hydrogramu przepływów w zlewniach zurbanizowanych]
Barszcz M.,Katedra Inzynierii Wodnej
Przeglad Geograficzny | Year: 2014
The aim of the work detailed here was to assess the suitability of the conceptual Santa Barbara Unit Hydrograph model for simulating a flow hydrograph in urbanised catchments exemplified by that of the Służewiec Stream sub-catchment (A = 14.7 km2) in Warsaw, Poland. The area of the sub-catchment was characterised by a 40% share of impermeable surfaces, a large portion of which are equipped witha stormwater drainage system.The data obtained were used to devise a formula providing for calculation of the retention coefficient for the reservoir (Kr), as well as the time of concentration (tc) based on the coefficient, and calculated in relation to the maximum intensity of effective rainfall. Values for the time of concentration calculated using the formula ranged from 0.417 to 1.291 h, with a mean value of 0.707 h. Mean values for concentrations determined using the iterative method were found to be the same as those obtained through application of the formula described above.The times of concentration calculated using the formula were applied in simulating maximum flows using the SBUH model, with values found to range between 5.609 and 24.385 m3 s–1. The average value for the maximum flow of 10.343 m3 s–1 did not differ much from the average value of measured flows (9.847 m3 s–1).Maximum flows calculated using the model were compared with those measured in the field, in this way making possible an assessment of the calculation procedure and the SBUH model. Relative error values established on the basis of these flows ranged from–28.3 to 87.6% (8.9% on average). Relative errors of flow simulations for the 9 eventsdid not exceed 15%. The results obtained confirm the suitability of the SBUH model forsimulating flow hydrographs in the urbanized Służewiecki Stream sub-catchment. © 2014, Polska Akademia Nauk. All rights reserved.