Die Bodenkultur - Journal for Land Management, Food and Environment
P. Tachecí, P. Žlábek, T. Kvítek and J. Peterková:
Analysis of rainfall-runoff events in four subcatchments of the Kopaninsky potok (Czech Republic)
We analysed runoff events caused by rainfalls exceeding 10 mm at four subcatchments of the Kopaninsky potok experimental catchment in years 2005–2012. The subcatchments (0.07–0.649 km2) differ in extent of tile drainage and prevailing land use. Forty events were analysed together for runoff volume and the time between the center of gravity of the rainfall event and peakflow recorded at the catchment outlet. Agricultural subcatchments usually discharged up to 10 % (maximum 18 %) of rainfall volume, while the fully forested subcatchment typically discharged less than 3 % (maximum 6 %) of precipitation. We did not find strong relationships between the percentages of discharged rainfall and initial wetness of the subcatchments or precipitation intensity. The lag time of peak flow was 12–50 min for the high intensity rainfalls (15–50 mm/h). The lag times nearly doubled for rainfall intensities 5–15 mm/h time and reached 18 h for the low rainfall intensity (below 3 mm/h). Two runoff peaks were commonly observed in hydrograph records at the outlets of the two subcatchments with lower percentage of drained agricultural area. At those subcatchments, the fastest response was also recorded.
Key words: Rainfall-runoff relationship, small catchments, tile drainage.