Suquía River is a medium-sized hydrological system (basin area of *7,700 km 2 ) that supplies fresh water to Córdoba city, a town of *1,500,000 inhabitants in central Argentina. This paper examines the present-day hydrochemistry of Suquía River urban catchment analyzing its major and minor dissolved components, and the nutrients variability by means of QUAL-2K modeling software. The Suquía River has bicarbonate-type waters upstream the city and sulfate-type waters right downstream, whereas they exhibit a mixed-to-alkali-type cationic composition. The seasonal analysis of its major dissolved constituents clearly showed a dilution process during the wet season (i.e. austral summer). In the last 20 years, the Suquía River has modified its anionic composition, now showing higher relative concentrations of SO 4 2-as a consequence of urban activities. However, trace elements dissolved concentrations do not evidence a strong pollution effect. Nutrients [nitrogen species, total phosphorous (TP)] and related parameters, such as biochemical oxygen demand (BOD), and dissolved oxygen (DO), evidence a clear influence of human activities. The QUAL-2K model was used to evaluate the spatial behavior of selected nutrients and associated variables, (i.e. TP, ? , N-NO 3 -, DO, BOD). Nutrient concentrations are affected by point sources of contaminants, particularly domestic waste and sewage, as well as by diffuse agricultural pollution. A calibrated QUAL-2K modeling exercise clearly shows the impact of the Córdoba city's municipal wastewater treatment plant on the Suquía River water quality.

Although natural and controlled fires are common in natural environments of the Province of Córdoba (Argentina), the effects on the physical and chemical soil properties are not well known. Warming effects were studied in two representative soil parent materials located in the piedmont of the Sierra Chica, Córdoba, Argentina. The aim of this study was to quantify the changes caused by different heating temperatures (100 °C and 500 °C), under laboratory conditions, on physical and chemical properties of two soils with different granulometric compositions and anthropic uses. The soils were classified as Udic Haplustoll, fine loamy (alluvial soils) and Udic Argiustoll, fine silty (loessoides soils). The depth analyzed corresponded to the upper 5 cm of the surface horizon. The physical property was granulometric composition (clay, silt and sand content) and the chemical properties: pH, oxidizable carbon (Cox), total nitrogen (Nt), cation exchange capacity (CEC), exchangeable cations (Ca⁺², Mg⁺², Na⁺, K⁺), extractable phosphorus (Pe) and electrical conductivity (EC). These analyses included both unheated samples (control) and those heated at different temperatures. Cox, pH, EC and CEC showed similar behavior at the different heating temperatures, despite the parent materials and the soil use conditions. Cox, pH, Nt and CEC could statistically explain the differences in edaphic properties at the temperatures analyzed. At 300 °C statistically significant differences were recorded for the analyzed soil parameters, and at 500 °C changes difficult to reverse due to the inorganic colloidal fraction collapse and the decrease (90%) of the organic fraction were found.

La minería, es una actividad económica relacionada a la explotación y extracción de minerales, siendo responsable de profundas modificaciones en el medio natural. A través de ella, se obtienen la mayoría de los recursos necesarios para el desarrollo de la humanidad y el bienestar social del hombre. De esta forma, es necesario plantear el desarrollo de esta actividad humana pero de forma equilibrada, asegurando la protección y conservación del medio ambiente. La relación positiva entre la extracción de recursos geológicos y la protección ambiental es posible, generando una rehabilitación y utilización del medio asegurando una puesta en valor paisajística y económica del entorno. La transferencia de rocas estériles para el relleno de huecos y el tapado de frentes rocosos junto con la reconstrucción de suelos, permiten una rehabilitación del medio en sentido estricto. El propósito de este trabajo es contribuir al conocimiento de técnicas de rehabilitación de escombreras, en el caso de estudio en una explotación minera de fluorita, Establecimiento Cerros Negros, con la generación de suelos artificiales sustentables para el desarrollo de una actividad económica agrícola. Palabras clave: agricultura, cantera, minería, rehabilitación, suelos.

This contribution deals with the characteristics and distribution of soils developed over six landscape units in a sector of the eastern Sierra Chica piedmont (Córdoba, Argentina). The relationship between environmental factors and pedogenetic processes have been examined. The area exhibits a significant soil variability as a consequence of geomorphic and lithologic diversity, inherent to this environment. Parental material, relief, and climate have shown influence over soil development and the differentiation of horizons. They control, as well, the intensity of melanization, decalcification-calcification and eluviation-illuviation of clays and organic matter. The most developed soils are derived from loess, loess-like and fine alluvial sediments. These soils are found in areas of intermediate to low relief, concave and flat surfaces, and long-smooth slopes. Fluvial and coarse alluvial sediments are the parental material of less developed soils, which are characteristic of reliefs dominated by rolling shapes and steep slopes.

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