Abstract:

Herein a quasi-two dimensional horizontal hydro-morphological mathematical model is presented. The governing equations for the quasi-2D horizontal time-depending flow field are represented by the well-known approach of interconnected cells. New discharge laws between cells are incorporated. The model is capable of predicting temporal changes in water depth, velocity distribution, sediment transport, bed level, as well as water and suspended sediment exchange between main stream and flood plains. An application of the model in the middle reach of the Argentinean Paraná river is presented. Satisfactory results were obtained during model calibration, validation and application.

Universidad Nacional de Rosario

Abstract:

Functional classifi cation of animals is necessary to enhance the predictive power of food web models. However, while there is a large database for functional classifi cation of benthic invertebrates (Functional Feeding Groups, FFG) in the temperate zone, the attribution of individual species of riverine invertebrates is still in its infancies in the Neotropical Region. Diff erent authors hypothesized that diet breadth was larger in the Tropics, however detailed analyses are scarce. In the present study we aimed at classifying dominant benthic taxa of the Middle Paraná River floodplain (Argentina) into trophic guilds by diet and niche overlap analysis. We sampled twelve taxa of benthic invertebrates from a fl oodplain lake during low water season and performed a gut content analysis as a baseline for FFG classifi cation. We also used available diet information of other common taxa for statistical analysis. Then, we compared the variance of niche overlap, using Pianka?s index, with that of simulated null model. After that we grouped taxa using Morisita similarity index with a threshold of 0.6 and compared niche overlap with null models within and between FFGs. Observed variance of niche overlap was greater than expected by chance, confi rming the presence of FFGs among analyzed taxa. Considering trophic similarity of species, we identified four FFGs: collectors, omnivores, herbivores and predators. Niche overlap was greater than expected by stochastic null models within FFGs, and smaller between FFGs. Nearly one third of analyzed taxa were classified in a diff erent FFG than their congeners of the Holarctic region. This result indicates that classifications performed in the Holarctic region should be used with care in the Neotropical region, even in subtropical systems.

Author affiliation: Saigo, Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina

Author affiliation: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina

Author affiliation: Wantzen, Karl Matthias. Cnrs Umr Citeres, Universite François Rabelais; Francia

Abstract:

A complete understanding of alluvial-bed dynamics is desirable for evaluating a variety of issues related to water resources. Sediment fluxes were investigated in a bifurcation of the large Parana River near Rosario, Argentina. The backscatter estimations from the Doppler profilers provided the suspended load of the sediment forming the riverbed. An echo-sounder was applied to track the dunes yielding the bed-load estimation. Aiming to show the usefulness of the recorded data, a 2-D numerical code was applied to the 10-km long and 2-km wide Rosario reach. The morphodynamic module was un-coupled from the hydrodynamics assessment, which enabled the long-term prediction of the river morphology accounting for the hydrological yearly variation with a quasi-steady approach. Numerical experiments were performed to test the sensitivity of the hydrodynamic model to the computational time-step and mesh size, to test the un-coupling scheme performance regarding the full-dynamic modelling, to test the accuracy of the sediment transport formulae based on the field evidence and, finally, to provide guidance to properly fix the model parameters.

Author affiliation: Guerrero, Massimo. Universidad de Bologna; Italia

Author affiliation: Latosinski, Francisco Guillermo. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

Author affiliation: Nones, Michael. Universita Di Bologna; Italia

Author affiliation: Szupiany, Ricardo Nicolas. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Departamento de Hidráulica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

Author affiliation: Re, Mariano. Ministerio del Interior, Obras Públicas y Vivienda. Secretaría de Obras Públicas. Subsecretaría de Recursos Hídricos. Instituto Nacional del Agua y del Ambiente (Ezeiza); Argentina

Author affiliation: Gaeta, Maria Gabriella. Universita Di Bologna; Italia

Abstract:

The current understanding of hydroclimatic processes is largely based on time series analysis of observations such as river discharge. Although records of these variables are often nonlinear and nonstationary, they have been commonly analyzed by classical methods designed for linear and/or stationary data. This study investigates the possibility of analyzing hydroclimatic time series using a novel data-driven method named Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (CEEMDAN), which is suitable for nonlinear and nonstationary signals. CEEMDAN is here applied to a monthly mean discharge record (1904–2010) of the Paraná River (South America). The results obtained in this way are interpreted by comparing them with CEEMDAN decompositions of other records such as climate index time series. It is found that Paraná flow modes consist of (i) annual and intraannual oscillations reflecting the rainfall seasonality of different Paraná Basin sectors, and (ii) interannual to interdecadal changes linked to climate cycles like El Niño/Southern Oscillation, the North Atlantic Oscillation, and the Interdecadal Pacific Oscillation. A nonlinear trend of Paraná discharge is found and reveals a monotonic increase that could be attributed to global warming and anthropogenic land-cover changes. The spectral separation of modes obtained using CEEMDAN is cleaner than that achieved by the Ensemble Empirical Mode Decomposition technique. This makes it easier to interpret CEEMDAN results. Hence, CEEMDAN is proposed as a powerful method for extracting physically meaningful information from hydroclimatic data.

Author affiliation: Antico, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina

Author affiliation: Schlotthauer, Gaston. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Entre Ríos. Facultad de Ingeniería; Argentina

Author affiliation: Torres, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina

Abstract:

Author affiliation: Caramello, C.S. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Sánchez, S. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

Author affiliation: Jorge, L.C. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; Argentina.

La especie Salminus brasiliensis es conocida vulgarmente con el nombre de “dorado”. Se caracteriza por tener una amplia distribución en América del Sur. Los ejemplares de la población del Río Paraná se caracterizan por presentar un número diploide de 50 cromosomas. La fórmula cariotípica está constituida por 5 pares de cromosomas metacéntricos, 10 pares submetacéntricos y 10 pares subtelo- acrocéntricos, con un número fundamental de 80 en ambos sexos. No se observaron heteromorfismos cromosómicos relacionados con el sexo. La impregnación con nitrato de plata permitió observar la ocurrencia de NORs simples, localizadas en el brazo largo del par número 6. El bandeo C reveló una gran cantidad de bloques de heterocromatina, presentes en la mayoría de los cromosomas, preferentemente situados en regiones centroméricas y pericentroméricas. El cariotípo de S. brasiliensis del Paraná Medio, Argentina, muestra con relación a individuos de la misma especie pertenecientes a las cuencas del Alto Paraná y San Francisco (Brasil), una notable similitud, evidenciando la ocurrencia de una estructura cariotípica muy conservada.

Salminus brasiliensis is commonly known as “dorado” (“golden”). It is widely distributed in South America. Paraná River’s specimens are characterized by the presence of 50 chromosomes. Karyotipe formula is made up whith 5 metacentric, 10 submetacentric and 10 subtelo-acrocentric chromosomes pairs, with a fundamental number of 80 in both sexes. Chromosomal heteromorfism related whit sex was not detected. Single NORs were observed on the long arm in telomeric location of the submetacentric sixth pair. C-banding revealed a great amount or chromatin blocks in centromeric and pericentromeric regions of several chromosomes pairs. The karyotype of S. brasiliensis from Middle Paraná, Argentina, shows similarity considering individuals of the same species from the Upper Paraná and San Francisco basins (Brazil), thus determining a well conserved karyotypic structure feature.

Abstract:

El Delta del río Paraná es un macrosistema de humedal, uno de los más importantes en la República Argentina. Los problemas de relevamiento en grandes humedales condicionan la obtención de información sobre las condiciones ambientales que definen la biodiversidad y ecología de estos ecosistemas. En consecuencia, resultan de particular interés los relevamientos a partir de datos de sensores remotos. En este marco esta tesis analiza el aporte de la teledetección al estudio funcional de humedales en general, y del Delta del río Paraná en particular, haciendo hincapié en cómo y en qué condiciones el análisis de datos de sistemas de observación terrestre de escala regional permite monitorear los procesos en un área dada. Con este objetivo, se estudia la potencialidad de los sensores ópticos y de radar para el estudio y evaluación de eventos extremos, y la utilidad de series de tiempo de índices verdes para el monitoreo de los patrones de productividad presentes en el área de estudio. Como resultado de esta tesis se obtuvo un enfoque metodológico para el estudio de macrosistemas de humedal por medio de teledetección óptica y de radar. Además, se produjo el primer mapa regional de tipos fisonómicos de vegetación, mapas de inundación del evento ENOS 2006-2007, mapas de áreas afectadas por los incendios masivos de 2008, y de la recuperación de la vegetación luego del evento.

Paraná River Delta is one of the most important wetland macrosystems of Argentina. There is a well known set of logistic problems related to large wetlands survey that limits the capacity to monitor the environmental conditions that define their ecology and biodiversity. Therefore, remote sensing monitoring is a particularly important tool to assess ecosystem state and functions. This thesis analyses the contribution of remote sensing data to functional studies of wetland in general, and of Paraná River Delta in particular. To this aim, we evaluate the use of optical and SAR data for extreme events assessment, and the usefulness of vegetation index temporal series for the estimation of productivity patterns. As a result, a methodological approach for wetland macrosystem monitoring is proposed. Furthermore, the first map of vegetation physiognomic types, two flooded area maps for 2006-2007 ENSO events, a map of the burnt areas related to the massive fire of 2008, and a vegetation recovery map were obtained.

Author affiliation: Salvia, María Mercedes. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.

Abstract:

This article explores the Sun's influence on the hydrological cycle in southern South America (SSA) at the range of interannual-to-multidecadal scales from the early 1900s to 2011. The solar variability is described by the sunspot number (SSN) index. The hydrological cycle is examined by using annual mean discharges of the Paraná River (PAR) and the Atuel River (ATU) that represents the behaviour of the subtropical Argentinean Andean hydrological system. Wavelet-based methods are used in order to describe relationships in the entire time-frequency domain. The SSN–PAR connection is statistically weak in oscillations with period about 11 years (the Schwabe's solar cycle). Therefore, the solar forcing at this scale must be considered with great caution. The periodicity about 30 years is highly significant throughout the analysed period. Two potential physical mechanisms affecting the Paraná discharge could be involved: one is the solar irradiance influence on the Inter Tropical Convergence Zone (ITCZ), and the other is the solar influence on the Pacific long-term variability. The SSN–ATU connection shows by far the most striking, robust and convincing result for the Schwabe cycle. A large amplitude and statistically significant cycle with a period about 11 years is observed not only in the Morlet-based global and local wavelet spectra of the Atuel discharges and SSN but also in the global and local spectra of Cross and Coherent wavelets in most of the analysed period. High (low) discharges occur following maxima (minima) of the Schwabe cycles with time lags of up to ∼2 years. Previous studies have shown a close relationship between the subtropical Argentinean Andean Rivers and the El Niño/Southern Oscillation (ENSO), as well as a solar influence on the ENSO variability. We suggest that El Niño events occurring a few years after solar maxima could explain the connection. Periodicities longer than 30 years are suggested.

Author affiliation: Compagnucci, Rosa Hilda. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias de la Atmósfera y los Océanos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

Author affiliation: Berman, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmosfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmosfera; Argentina

Author affiliation: Velasco Herrera, Victor. Universidad Nacional Autónoma de México. Instituto de Geofísica; México

Author affiliation: Silvestri, Gabriel Emilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones del Mar y la Atmosfera. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones del Mar y la Atmosfera; Argentina

Abstract:

Most small‐scale fisheries of large floodplain rivers are still managed under conventional top‐down regulations that limit the application of an ecosystem approach to fisheries (EAF) due to inappropriate legal frameworks. Using the Parana–Paraguay River fisheries (Argentina) as an example, this study examines the extent to which existing provincial legislations can be prepared for the adoption of an EAF. An Ecosystem Fishing Legal Approach (EFLA) framework is proposed based on different criteria across an environmental–ecological, fishing, social, economic and institutional template. Policy Component Scores (PCS) and an Integrated Policy Legal Index (IPLI) were applied to assess the degree of compliance by current provincial legislations to EAF implementation. Cluster analysis was used to recognise the potential for articulating a legal framework at a basin scale. The EFLA framework, which provided an accurate picture of how provinces were poorly prepared to adopt an EAF for the Paraguay–Parana fisheries, and represents a suitable tool that can be adapted and extended to other basins around the world.

Author affiliation: Castillo, Trilce Irupé. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Investigaciones Socio-historicas Regionales. Centro de Estudios Sociales Regionales - Nodo Cesor - Ishir; Argentina

Author affiliation: Baigún, Claudio Rafael M.. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina

Author affiliation: Minotti, Priscilla Gail. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental; Argentina

Abstract:

Se estudio la biología alimentaria de algunas especies de rállidos del Río Paraná Medio, Argentina analizándose 45 contenidos estomacales correspondientes a Pollona Pintada (Gallinula melanops) (n = 11), Pollona Azul (Porphyrio martinicus) (n = 13), Pollona Negra (Gallinula galeata) (n = 6) y Gallareta Chica (Fulica leucoptera) (n = 15). Se calculó la diversidad trófica por estómago, la diversidad trófica acumulada, el índice de importancia relativa (IRI), el porcentaje de presas por tamaño y el coeficiente intestinal de cada especie. El IRI reveló la importancia de Polygonum accuminatum (Polygonaceae) y Paspalum repens (Gramineae) tanto en números, como en volumen y frecuencias. Las cuatro especies de aves estudiadas coinciden en el consumo de presas en el rango de menor tamaño (0–10 mm). Los valores del coeficiente intestinal acusan entre 2,72 y 2,91. Los organismos identificados en la dieta muestran la plasticidad trófica de los rállidos y expresaría la disponibilidad de los recursos existente en un área del valle de inundación del Río Paraná Medio

The feeding biology of some rail species occurring at the Middle Parana River, Argentina was studied by analyzing the stomach content of 45 individuals of Spot-flanked Gallinule (Gallinula melanops) (n = 11), Purple Gallinule (Porphyrio martinicus) (n = 13), Common Moorhen (Gallinula galeata) (n = 6), and White-Winged Coot (Fulica leucoptera) (n = 15). The following parameters were calculated: trophic diversity per stomach, cumulative trophic diversity, index of relative importance (IRI), percentage of prey size, and intestinal coefficient. The IRI revealed the importance of Paspalum repens (Gramineae) and Polygonum accuminatum (Polygonaceae) in numbers as well as in volume and frequency. The four species of birds studied consume small size prey (0–10 mm). Intestinal coefficient values ranged between 2.72 and 2.91. The organisms identified in diet show the trophic plasticity in rails and the availability of resources in a floodplain area of the Middle Parana River.

Author affiliation: Olguin, Pamela Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto Nacional de Limnologia (i); Argentina

Author affiliation: Beltzer, Adolfo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Santa Fe. Instituto Nacional de Limnologia (i); Argentina

Author affiliation: Attademo, Andres Maximiliano. Universidad Nacional del Litoral. Facultad de Bioquímica y Ciencias Biológicas; Argentina

Abstract:

Author affiliation: Wehrle Martínez, Andrés Teodoro. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina.

El objetivo de esta tesis es determinar el impacto del cambio de uso del suelo en los componentes del ciclo hidrológico de la Cuenca Alta del Río Paraná (CARP), en la región del Bosque Atlántico del Alto Paraná (BAAPA). El análisis de los índices de vegetación sugiere que gran parte de la CARP en Brasil no contaba con bosques en el año 1982. Por otro lado, se observa que las mayores pérdidas del BAAPA ocurrieron en Paraguay en el periodo 1980-2000. Para analizar el efecto de estos cambios en el balance hídrico, se aplica el método de Análisis Espectral Singular a las series históricas de precipitaciones (P), temperaturas del aire (T) y caudales (Q) de 2 subcuencas de la CARP. Las subcuencas seleccionadas, presentan patrones de deforestación diferentes y adecuados para analizar este proceso. En cada área de estudio, se procede sistemáticamente a determinar las componentes principales temporales de baja frecuencia las variables hidrológicas en diferentes escalas espaciales. En todos los casos analizados se encuentra que los Q presentan una componente de baja frecuencia y 2 componentes oscilatorias. Las bajas frecuencias de Q muestran aumentos estadísticamente significativos a partir del año en que la deforestación regional se intensifica. Es decir, que en las cuencas sobre Brasil los Q aumentan a partir de 1970, mientras que en las cuencas sobre el Paraguay este aumento se observa en 1980 aproximadamente. Las P presentan una tendencia positiva y componentes oscilatorios concurrentes con las de Q. Finalmente se analizaron las variaciones del balance de las señales de baja frecuencia, en las cuencas de mayor envergadura. Así, se obtiene la serie de baja frecuencia de la evapotranspiración (ET), que refleja los diferentes procesos de cambio del uso del suelo ocurridos en la CARP durante el periodo 1950-2000.

The goal of this thesis is to determine the impact of the land use change on the water cycle components of the Upper Paraná River Basin (CARP), in the Upper Paraná Atlantic Forest (BAAPA). The analysis of vegetation indexes suggests that most of the CARP in Brazil had none forests in 1982. On the other hand, it is observed that the greatest losses of BAAPA occurred in Paraguay in the period 1980-2000. In order to analyze the effect of these changes on the water balance, the Singular Spectral Analysis method is applied to the historical series of precipitations (P), air temperatures (T) and water flows (Q) of two sub-basins of the CARP. The selected sub-basins present different and suitable patterns of deforestation to analyze this process. In each study area, the study variables were systematically analyzed through time and at different spatial scales to find de principal component of them. In all the analyzed cases it was found that the Q series have a low frequency component and 2 oscillatory components. The Q low frequencies component show statistically significant increases from the year when regional deforestation intensifies. That is to say that in Brazilian basins Q increased from 1970, whereas on Paraguay basins Q increase is observed around 1980. P presents a trend and oscillatory components similar to those of Q. Finally, the variations of the low frequency signals balance in the larger basins were analyzed. Thus, the low frequency evapotranspiration (ET) series is obtained, which reflects the different land use change processes that occurred in the CARP during the 1950-2000 period.

Universidad Nacional de Asunción

ITAIPU Binacional

Instituto Interamericano para la Investigación del Cambio Global