Ethnopedology in the study of toponyms connected to the indigenous knowledge on soil resource.

In taking an integrated ethnopedological approach, this study aims to investigate the meaning of the distribution of the toponyms used in traditional and recent cartography of Sardinia (southern Italy). It is particularly, but not only, focused on those related to soil resources. Sardinia is particularly interesting in this respect, as its unique history, geography, and linguistic position makes it one of the Italian and Mediterranean regions with the greatest number of toponyms. This research investigated the toponyms belonging to an important sub-region of Sardinia, called Ogliastra (central-eastern Sardinia). The research was conducted through the following integrated approach: i) toponymy research and collection from different sources; ii) database creation and translation of toponyms from the Sardinian language (SL); iii) categorization of toponyms; and iv) graphical, statistical, and cartographic data processing. Distribution and diversity of toponyms were assessed using the compiled database, coupled with a geographical information system (GIS). Of around 7700 toponyms collected, 79% had already been reported in SL, while just 21% were in Italian. Of the toponyms in SL, 77% are of known meaning and 54% of these toponyms were characterized by a meaning directly and/or indirectly connected to specific environmental features. On the whole, morphology would appear to be the primary environmental factor able to explain the complex, articulated presence, distribution, and typology of the investigated toponyms. A least squares regression analysis of pedodiversity vs. topodiversity shows a very closed distribution, with an impressive high correlation index (R2 = 0.824). The principal factor analysis (PFA) shows that such a connection may be morphologically based, thereby confirming that pedodiversity and topodiversity are strongly linked each other. Overall, the research shows that an integrated ethnopedological approach, combining indigenous and scientific knowledge may be of great interest in order to mitigate the impressive phenomena of the indigenous knowledge lost.

Urban wastewater effects on water flow and solute transport in soils.

This article aims mainly to verify the consequences of urban wastewater reuse in irrigation practices on hydrological behavior of soils. Herein the effects on both the hydraulic and dispersive properties of characteristic soils in South Sardinia are illustrated. The study was carried out at the Ente Autonomo del Flumendosa (EAF) laboratory. Ten undisturbed soil monoliths, 120 cm height and 40 cm diameter, were collected from plots, the locations of which were preliminarily individuated through a prior pedological study. An experimental facility was set up and sensors for monitoring both soil water and solute concentrations were inserted horizontally in each column at different depths. A disturbed layer at the soil surface, which expands in depth with time, was observed, characterized by reduced soil porosity, translation of pore size distribution towards narrower pores and consequent drastic decrease of permeability. It will be shown that these changes occurring in the disturbed soil layer, although local by nature, affect the mean hydrological behavior of the whole soil profile.