Aggradation of Irrigation Canal Network in Žitný Ostrov, Southern Slovakia

Abstract

The objective of this paper is to investigate and analyze the silting and subsequent aggradation of the irrigation canals in Žitný Ostrov (Rye Island). The irrigation canal network, located in Southern Slovakia, was built to provide for irrigation water and drainage in the region. The water level in the irrigation canals and groundwater level in Žitný Ostrov area affect each other. Because of this mutual interaction, it has been necessary to evaluate the impact of silting in the canal network due to the presence of the alluvials. Water surface elevations in Danube River affect groundwater infiltration from the Žitný Ostrov aquifer, in and out of the canals, and causes fluctuation of the flow in the canals. The amount of groundwater infiltration is a function of the silt hydraulic conductivity. Tests were done in 1993 and 2004 to measure the silt thickness and granularity at 166 measurement points along approximately 77 km of the canal network. This paper discusses the change in silt thicknesses and silt volume in the canals as they built up over an 11-year period. As a secondary goal of the paper, the silt granularity and hydraulic conductivity was determined. The results of our research are useful in establishing the canals’ maintenance program. The regional planning commission will use the study to forecast silting in the future.