English

Abstract

Installing drainage systems in agricultural land with fully saturated soils decreases the level of the subsurface water table and enables the creation of groundwater reservoirs without gravity water - i.e. drainage retention capacity (DREC). DREC, which is created by the activity of a drainage system, can be defined as a groundwater reservoir limited by soil surface and by shape of the water table above the drains. By its infiltration capacity DREC can significantly mitigate negative impact of hydrological extremes, such as floods or heavy rainstorms. The purpose of this paper is, a) to present a methodology for direct determining DREC and b) to analyse the results of DREC application in agricultural land drainage system in the region of Cerhovice Brook (Czech Republic). The results obtained from in-situ experimental testing and numerical experiments confirmed that the equations presented in this paper can serve as a reliable tool for DREC approximation. Data collected in situ from the agricultural land drainage in Cerhovice Brook, confirmed that DREC can effectively improve agricultural land and water regime protection.