Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Regionalisation of watersheds with respect to low flow

Cupak Agnieszka, Michalec Bogusław

Journal of Water and Land Development

2022

no. 55

47--55

The aim of the study was to compare two grouping methods for regionalisation of watersheds, which are similar in respect of low flow and chosen catchments parameters (physiographic and meteorological). In the study, a residual pattern approach and cluster analysis, i.e. Ward’s method, were used. The analysis was conducted for specific low flow discharge q95 (dm3∙s-1∙km-2). In the analysis, 50 catchments, located in the area of the upper and central Vistula River basin, were taken. Daily flows used in the study were monitored from 1976 to 2016. Based on the residual pattern approach (RPA) method, the analysed catchments were classified into two groups, while using the cluster analysis method (Ward’s method) - into five. The predictive performance of the complete regional regression model checked by cross-validation R2cv was 47% and RMSEcv= 0.69 dm3∙s-1∙km-2. The cross validation procedure for the cluster analysis gives a predictive performance equal to 33% and RMSEcv= 0.81 dm3∙s-1∙km-2. Comparing both methods, based on the cross-validated coefficient of determination (R2cv), it was found that the residual pattern approach had a better fit between predicted and observed values. The analysis also showed, that in case of both methods, an overestimation of specific low flow discharge q95 was observed. For the cross-validation method and the RPA method, the PBIAS was -10%. A slightly higher value was obtained for the cross-validation method and models obtained using cluster analysis for which the PBIAS was -13.8%.

Analysis of the Proportion of Incidental Water in Annual Wastewater Inflows to a Selected Treatment Plant During a 15-year Observation Period

Kaczor Grzegorz, Cupak Agnieszka

Journal of Ecological Engineering

2021

Vol. 22, nr 7

204--211

The main aim of the study was to determine whether the amount and share of incidental water in wastewater inflows to the wastewater treatment plant increased with the age and development of the sewage system. The object of the study is a small sewerage system located in southern Poland, in the Lesser Poland Province, 15 km northeast of the Kraków city. The analysis of a 15-year observation series of daily wastewater flows, from 01.01.1994 to 31.12.2018, allowed a reliable assessment of the actions taken by the sewage system operator to reduce the sources of incidental water inflow to the sewage network. The study showed that the percentage share of incidental waters in the annual wastewater inflow to the analysed treatment plant decreased from 35.9% in 2004 to 8.4% in 2018. This reduction should be treated as a success of the remedial actions of the sewage system operator. However, the study showed at the same time that in 2017 alone, 56 709 m3 of incidental water flowed into the analysed sewerage system, compared to 166 075 m3 of wastewater. A similar case was repeated in 2013, when 53 060 m3 of incidental water and 132 860 m3 of real wastewater flowed into the treatment plant. These cases show that all remedial measures by the network operator are still insufficient when heavy precipitation occurs in a given year for a long period of time.