Umberto Tessari

The ecological status of Karavasta Lagoon (Albania): Closing the stable door before the horse has bolted?

Karavasta is the widest and most important lagoon in Albania. This study aimed to assess the ecological quality status of the lagoon, acquire knowledge of a natural environment which might be exploited for aquaculture, and give management hints on the basis of anthropogenic impact and ecological conditions. A sampling campaign was carried out in 2008: at six stations, benthic fauna, water, and sediment parameters were considered. Statistical analyses were carried out through multivariate procedures (PCA, classification-clustering, SIMPER, RDA, DISTLM, PERMANOVA). Ecological quality was assessed through the AZTI Marine Biotic Index (AMBI), the multivariate AMBI (M-AMBI) and the Benthic Index based on Taxonomic Sufficiency (BITS). Sediment characteristics (percent organic matter, %OM; redox potential discontinuity layer depth, RPDL; particle size composition) and salinity represented contributory influences on lagoon communities. It was possible to distinguish and characterise a confined area, and benthic communities, from a marine-influenced area and its biota. The number of species was quite low when compared with other open Adriatic lagoons. The M-AMBI and BITS classifications gave quite similar results, which seemed consistent with the ecological conditions of the lagoon, that is a distinction in the ecological quality between the seaward and landward stations, with higher ecological quality (EcoQ) at the seaward stations. Given the pressures and the ecological condition of Karavasta, an intensification of aquaculture activities must be considered with caution, since the lagoon seems at significant risk of serious hypereutrophication. This situation is made worse by the limited water exchange with the marine environment due to the irregular dredging of the communication channels.

A new look at XRD patterns of archaeological ceramic bodies

In this paper, the general rules of phase transformations in calcareous clay bodies during firing were used to estimate the equivalent firing temperature (EFT) of seventeenth century polychrome Persian haft rang tiles based on their X-ray diffraction (XRD) patterns. The novelty of this work is, however, that it handles the XRD patterns of archaeological clay bodies with principal component analysis (PCA) in order to have a new look at their firing and thermal behaviour. Statistically handling the XRD patterns, different clusters were discriminated in the clay bodies whose mineralogical composition showed various proportions of amorphous and quartz contents. The results showed interesting trends in the different clusters in terms of the EFT, quartz content and the density of the bodies. The present work uses PCA to have a new look at XRD patterns of archaeological clay bodies and, moreover, to interpret the PCA results in order to estimate the EFT of a large number of archaeological clay bodies.

Relationship between particle density and soil bulk chemical composition

PurposeAn analytical database containing XRF chemical analyses and real density measurements of unconsolidated sediments of the Padania Plain (Northern Italy) has been used to understand the relationship that exists between the soil particle density (ρs) and their bulk chemical composition.Materials and methodsUsing a linear regression, we built an equation able to link the particle density with the soil elemental composition.Results and discussionPositive correlations were found between ρs and SiO2, MgO, CaO and Na2O and negative correlations with K2O, TiO2, Al2O3, Fe2O3 and LOI, reflecting the presence in the soils of quartz and feldspars/mineral clays respectively.ConclusionsOur equation is very useful because it helps to know the density properties of a soil when it is not possible to measure ρs with a pycnometer. On the other hand, by knowing the ρs, it is possible to have a quite precise knowledge about the chemistry of the studied soils.

The use of particle density in sedimentary provenance studies: the superficial sediment of Po Plain (Italy) case study

In recent years, several approaches for the identification of the provenance of the sediments have been developed. In particular, geochemical, petrographic and mineralogical analyses were applied to the sediments of the Po Plain in order to discriminate the alluvial sediments of the Po River from those coming from Apennine rivers. In this work, we propose an innovative technique based on the measurement of density for the study of the Po Plain alluvial sediments. This study is based on the determination of major and trace elements, particle density and mineralogical composition of 53 superficial sediments. All the data were processed using multivariate statistics. The comparison between density, geochemistry, and granulometry of the Po River and Reno River (the most important Apennine river) samples shows how the densities strictly depend on the chemical-mineralogical composition and grain size of the sediments and, consequently, on the type of hydrographic basin of their respective river. On this basis it can be discriminated the provenance of two different types of alluvial sediments with sufficient precision, determining the density of the unconsolidated alluvial material.

Particle density distribution in a fluvial floodplain

The mechanisms that determine the formation of a floodplain are very well known. At the same time, there is an established correspondence between the sedimentary deposits and density of the particles, whose distribution in the plain is until now poorly constrained. In this work we therefore highlight the spatial distribution of the particle density of soils from the Padania Po Plain in relation to the depositional sub-environment where they have been sampled.

Coastal Zone Geomorphological Mapping Using Landsat TM Imagery: An Application in Central Albania

Albania is country with a rugged landscape (Shqiptar, country of eagles), with plains corresponding to only 1/12 of the whole national surface, mostly located along the coastline. The coastline has a total length of about 380 km, of which 284 km are along the Adriatic Sea, while the rest is facing the Ionian Sea. The last population census (1990) indicates that the workforce is 44% of the population (3 256 000 inhabitants), mainly employed by the state (63%) with the rest of the workers organised in cooperatives or working in agriculture. Agriculture was traditionally one of the main economical activities, able to satisfy 93% of the national demand; it has been declining from the late 1980s onwards, due to migration of farmers towards the main towns, abandoning traditional agricultural practices.