Loess erosion on the Tokaj Big-Hill
1994; Elsevier BV; Volume: 24; Linguagem: Inglês
10.1016/1040-6182(94)90038-8
ISSN1873-4553
Autores Tópico(s)Geological Formations and Processes Exploration
ResumoThe erosion of the loess mantle of the Tokaj Big-Hill is described on the basis of field observations and surveys as well as laboratory experiments. Above an altitude of 250 m a 0.5 to 0.7 m thick layer of loess has been removed in the last 100 years. Below 250 m linear forms of loess erosion are characteristic, the most striking among them being gullies and inset roads. For a detailed quantitative survey of minor features, the 2-hectare area of the terrace system in the Rákóczi valley was selected. The most common forms were depressions, loess wells and loess sinks. The laboratory measurements showed that, after higher-intensity rainfalls, sheetwash on the Tokaj loess transports twice as many loess grains than is the case with the forest soil, and the sheetwash impact of low-intensity rain exceeds by almost seven times the value measured on forest soils. Solution erosion is four or five times more intense underground than on the surface. On the solum taken from cultivated loess different values were found: K+ concentration was particularly high compared to loess under natural conditions. The anomalies in solution erosion are caused by fertilizers and pesticides. The influence of diluted acids on loess structure are presented in electron-microscopic photos. These experiments provide a means of interpreting the evolution of piping in the Rákóczi valley.
Referência(s)