The effects of hydraulic works and wetlands function in the Salado-River basin (Buenos Aires, Argentina)

Man-made activities exert great influences on fluvial ecosystems, with lowland rivers being substantially modified through agricultural land use and populations. The recent construction of drainage canals in the upper stretch of the Salado-River basin caused the mobilization of huge amounts of salts formerly stored in the groundwater. The main aim of this work was to analyze the effect of the discharges of those canals into the Salado-River water, under different hydrologic conditions, and the role of the wetlands and shallow lakes placed along the canals’ system. Physicochemical variables were measured and water samples were taken during times of high water, mean flows, drought, and extreme drought. The environmental variables and the plankton development were related to the hydrologic regime and reached minimum values during floods because of low temperatures and dilution. Local effects on the water’s ionic composition became pronounced during droughts because of groundwater input. Nutrient concentrations were mainly associated with point wastewater discharges. Conductivity, ion concentrations, total plankton biomass, and species richness increased in the Salado-River downstream site, after the canals’ discharges. The artificial-drainage system definitely promotes the incorporation of salts into the Salado-River basin. In this scenario, a careful hydraulic management is needed to take into account this issue of secondary salinization that threatens the economic exploitation of the region. The wetlands present in this study acted as service environments not only helping to reduce salt, nutrient, and suspended-solid concentrations downstream but also contributing a plethora of species and plankton biomass into the Salado-River main course

A comparative limnological study of the Guadalhorce reservoirs system (Málaga,SE.Spain)

15 páginas ; 6 Figuras ; 2 TablasA partir de 10s muestreos efectuados durante el período de mezcla (marzo de 1988) y estratificación (setiembre de 1988) en 10s tres embalses del sistema Guadalhorce, se analizan sus diferencias fisicoquimicas y biológicas. Aunque 10s tres embalses presentan un contenido de sales disueltas relativamente alto, Conde de Guadalhorce es de aguas carbonatadas, mientras que en Guadalhorce son importantes 10s cloruros y Guadalteba se encuentra en una posición intermedia. En estos dos 61- timos embalses la presencia de cloruros determina la existencia de una haloclina muy marcada, que en el caso de Guadalhorce es permanente. Desde el punto de vista de sus características tróficas, Guadalteba y Guadalhorce son eutróficos, 10 que se refleja en la alta concentración de nutrientes y pigmentos, asi como por tener respiración y ETS elevados. Por el contrario, Conde de Guadalhorce puede considerarse como mesotrófico a partir de 10s mismos parámetros, además de permanecer con oxigeno en el hipolimnion durante todo el verano.This research has been supported by the Comisión Asesora de Investigación Científica y Técnica grant nª PB85-0166 and sponsored by the Dirección General de Obras Hidráulicas of the Ministry of Public AffairsPeer reviewe

Big Earth Data for Cultural Heritage in the Copernicus Era

Digital data is stepping in its golden age characterized by an increasing growth of both classical and emerging big earth data along with trans- and multidisciplinary methodological approaches and services addressed to the study, preservation and sustainable exploitation of cultural heritage (CH). The availability of new digital technologies has opened new possibilities, unthinkable only a few years ago for cultural heritage. The currently available digital data, tools and services with particular reference to Copernicus initiatives make possible to characterize and understand the state of conservation of CH for preventive restoration and opened up a frontier of possibilities for the discovery of archaeological sites from above and also for supporting their excavation, monitoring and preservation. The different areas of intervention require the availability and integration of rigorous information from different sources for improving knowledge and interpretation, risk assessment and management in order to make more successful all the actions oriented to the preservation of cultural properties. One of the biggest challenges is to fully involve the citizen also from an emotional point of view connecting “pixels with people” and “bridging” remote sensing and social sensing

Planktonic rotifers of a saline-lowland river : the Salado River (Argentina)

Seasonal samples of zooplankton were taken during 1997-1999 at fifteen stations in the Salado River basin, and analysed in order to study the rotifer fauna. Spatio-temporal changes in the rotifer plankton composition were examined in the main channel and its tributaries. The majority of species found are tolerant of a wide range of pH, whereas others prefer neutral to alkaline values. The total rotifer plankton density increased downstream from the headwaters to the middle sector of the river. The associated shallow lakes and tributaries were an important source of species. Variations in density and number of species were shown to be associated with conductivity, and species tolerant of high conductivity conditions were especially prevalent (upper 7,000 µS cm-1). Rotifer density was influenced by hydrological conditions, which promoted maximum values during low water periods and in the high water condition promoted the incorporation of species from shallow lakes connected with the river during flood events. The species associations found are related to such water parameters as conductivity and nutrient availability and to the presence of ponds and shallow, waterlogged depressions connected in varying extent to the main channel

From remote sensing to a serious game: Digital reconstruction of an abandoned medieval village in Southern Italy

The digital reconstruction of the history of a buried medieval village is the main focus of this paper. The study, based on remote sensing and historical sources, is the starting point of the development of a serious game aimed at educational purposes and exploitation of remote sensing data in the field of edutainment. The selected historical scenario is Yrsum, a village in Basilicata ( South of Italy), founded in the 11th century and abandoned in the 14th century. A LiDAR survey along with satellite multispectral data (suitably elaborated for feature extraction) as well as the historical sources and archaeological records provided useful information on the forma urbis' of the medieval settlement from its foundation to its abandonment. The extraction of the archaeological features and the analysis of urban pattern put in evidence similarities with some medieval settlements based on "motte and bailey" typology that spread in Southern Italy, France and England from the 11th to the 13th century. After the virtual reconstruction, an interactive application articulated both on bi-dimensional and three-dimensional elements have been developed. The major novelty compared to most common video games has been the possibility to derive the game from rigorously scientific data. The player enjoys and learns within a logic of an edutainment game (a combination of education and entertainment), which has become by now a well-established concept but still rarely applied in the field of cultural heritage. (C) 2016 Elsevier Masson SAS. All rights reserved

Zooplankton biomass in an eutrophic shallow lake (Buenos Aires, Argentina): spatio-temporal variations

Zooplankton biomass was investigated monthly from September 1997 to August 1998 in a shallow eutrophic lake (San Miguel del Monte, Argentina). Duplicate samples of zooplankton were obtained from three stations with different limnological characteristics. The density of zooplankton community was dominated by rotifers and small cladocerans related to the trophic status of this shallow lake. The zooplankton biomass showed similar values to other eutrophic shallow lakes. The annual biomass distribution was bimodal (winter and summer peaks). The contribution of crustaceans, mainly copepods, determined the total biomass. The total zooplankton biomass was significantly correlated with chlorophyll «a» in the sampling station located at the deep part of this shallow lake. There were factors and processes promoting changes in the zooplankton biomass, such as food availability, grazing ability, fish predation, eutrophication process with alternation of turbid and clear water periods, and also the addition of organisms from the Salado River during floods