A water level relationship between consecutive gauge stations along Solim\~oes/Amazonas main channel: a wavelet approach

Gauge stations are distributed along the Solim\~oes/Amazonas main channel to monitor water level changes over time. Those measurements help quantify both the water movement and its variability from one gauge station to the next downstream. The objective of this study is to detect changes in the water level relationship between consecutive gauge stations along the Solim\~oes/Amazonas main channel, since 1980. To carry out the analyses, data spanning from 1980 to 2010 from three consecutive gauges (Tefe, Manaus and Obidos) were used to compute standardized daily anomalies. In particular for infra-annual periods it was possible to detect changes for the water level variability along the Solim\~oes/Amazonas main channel, by applying the Morlet Wavelet Transformation (WT) and Wavelet Cross Coherence (WCC) methods. It was possible to quantify the waves amplitude for the WT infra-annual scaled-period and were quite similar to the three gauge stations denoting that the water level variability are related to the same hydrological forcing functions. Changes in the WCC was detected for the Manaus-Obidos river stretch and this characteristic might be associated with land cover changes in the floodplains. The next steps of this research, will be to test this hypotheses by integrating land cover changes into the floodplain with hydrological modelling simulations throughout the time-series

Crossover from diffusive to strongly localized regime in two-dimensional systems

We have studied the conductance distribution function of two-dimensional disordered noninteracting systems in the crossover regime between the diffusive and the localized phases. The distribution is entirely determined by the mean conductance, g, in agreement with the strong version of the single-parameter scaling hypothesis. The distribution seems to change drastically at a critical value very close to one. For conductances larger than this critical value, the distribution is roughly Gaussian while for smaller values it resembles a log-normal distribution. The two distributions match at the critical point with an often appreciable change in behavior. This matching implies a jump in the first derivative of the distribution which does not seem to disappear as system size increases. We have also studied 1/g corrections to the skewness to quantify the deviation of the distribution from a Gaussian function in the diffusive regime.Comment: 4 pages, 4 figure

El sistema de tablas de vida de Brass. Aplicacion a la Argentina

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Poblaciones teoricas

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America Latina: situacion demografica alrededor de 1973 y perspectivas para el ano 2000

Revisión de documento presentado a la Reunión Latinoamericana Preparatoria de la Conferencia Mundial de Población, San José, 15-19 abril 197

La medición de la mortalidad a partir de información recogida en una encuesta

Documento elaborado como parte del estudio Métodos cuantitativos en las ciencias sociales, en homenaje al profesor Jose Barral Souto, Buenos Aires, 1977Incluye Bibliografí

Tablas de vida activa

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La mortalidad de la República Argentina según tablas de vida de 1914, 1946-48 y 1959-61

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Notas para el Seminario sobre Procedimientos de Estimaciones Demográficas con Tasas de Crecimientos por Edad: aplicaciones realizadas a información de América Latina

Incluye BibliografíaEstudia el comportamiento en situaciones controladas de tres relaciones que utilizan tasas de crecimiento por edad. La aplicacion se realiza usando como informacion basica tres proyecciones de poblacion para un periodo de 10 anos, una suponiendo poblacion cerrada, otra con inmigracion y la ultima con emigracion