Hortobágy Puszta: Microtopography of Alkali Flats

Abstract

On soils with Natric or Vertic properties in the subsoil and easily erodible (e.g. Mollic) topsoil waters running downslope generate diverse erosional microtopography. This process is particularly well observed on the alkali (Solonetz and Solonchak) flats of the Great Hungarian Plain. To the effect of erosion beginning along the cracks of the alkali ground a szikpadka (salt berm) of some tens of centimetres height and various gradients forms between the berm top with intact soil profile and the so-called vakszik (“blind pan”) with eroded topsoil. The extension of salt-affected soils and the accompanying berm erosion was substantially increased by groundwater table changes in the wake of the 19th-century river regulation and land drainage works. At the same time, previous research has proved that this type of erosion of extremely slow rate was an active geomorphic agent on alkali soils in the Pleistocene and in the warm semiarid stages of the Holocene.