Análisis geoestadístico de parámetros que inciden en el nivel trófico en la Laguna Grande de San Pedro, Concepción, VIII Región.
Loading...
Date
2008
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Universidad de Concepción
Abstract
El estudio se desarrolló en la Laguna Grande de la Comuna de San Pedro de la Paz, Provincia de Concepción, VIII Región, durante el periodo comprendido entre Agosto-2007 y Enero-2008, y tuvo como objetivo analizar parámetros que inciden en el nivel del estado trófico en este sistema lacustre, a partir de datos obtenidos in situ y del análisis geoestadístico de variables caracterizadoras de calidad de agua, como la clorofila-a, conductividad, pH, temperatura y turbidez. Se realizó un análisis de semivarianza que determinó la correlación espacial de los datos sensados para cada variable en la laguna. Se ajustaron y validaron los modelos teóricos de semivariogramas que mejor reflejaron la interacción de los registros analizados. Mediante los errores de predicción según la validación cruzada, los modelos fueron ajustados y validados. A partir de esto fueron construidos los mapas de distribución utilizando Kriging Ordinario para las interpolaciones. Los datos presentan anisotropía de carácter geométrica, fenómeno que fue ajustado a un comportamiento isotrópico mediante transformaciones en los ejes de proyección en dirección y magnitud. Así, la dirección de máxima correlación viene dada generalmente en dirección de la mayor prolongación en las dimensiones de la laguna, o sea en su largo dispuesto meridionalmente. La totalidad de las variables presentaron valores más elevados en la zona norte de la laguna, correspondiente al sector poblado de estas riberas, independientemente de la temporada en que se realizó el muestreo. Se marca con esto la incidencia de los factores antropogénicos en la cuenca de la Laguna Grande en San Pedro. El análisis geoestadístico de los parámetros de este sistema lacustre tiende a caracterizarla en bajos niveles tróficos según los mapas construidos.
The research was developed at Laguna (lake) Grande in Comuna San Pedro de la Paz, Provincia de Concepcion, 8th region, since August 2007 to January 2008. Its main objective was to analyze the parameters that influence the level of the trophic state in this lacustrine system, from the obtained data and the Geostatistics analysis of variables wich characterize the quality of water such as chlorophyll-a, conductivity, pH, temperature and cloudiness. A semivariance analysis was held in order to determine the spatial correlation of the sesonrized data for each variable in the lake. The semivariograms theoretical frameworks that best reflected the interaction of the analyzed records were adjusted and validated. The frameworks were adjusted and validated through the prediction mistakes of the cross validation. The distribution maps were built up from this and utilizing Ordinary Kriging for interpolations. The data show anisotropy in geometric character, phenomenon adjusted to an isotropic behavior through projection axis transformation, magnitude and direction. Thus, the major correlation direction goes generally to the major prolongation in the lake´s dimensions, that is, in its meridional size. All variables showed its higher levels in the north of the lake, which is the populated zone of the borders, no matter the station where the samples were taken. With this, the incidence that antropogenic factors cause in the environment is marked, it means in the Cuenca of Laguna Grande in San Pedro. The geostatistics analysis of the parameters of this lacustrine system tends to characterize it in low tropic levels according to the maps built.
The research was developed at Laguna (lake) Grande in Comuna San Pedro de la Paz, Provincia de Concepcion, 8th region, since August 2007 to January 2008. Its main objective was to analyze the parameters that influence the level of the trophic state in this lacustrine system, from the obtained data and the Geostatistics analysis of variables wich characterize the quality of water such as chlorophyll-a, conductivity, pH, temperature and cloudiness. A semivariance analysis was held in order to determine the spatial correlation of the sesonrized data for each variable in the lake. The semivariograms theoretical frameworks that best reflected the interaction of the analyzed records were adjusted and validated. The frameworks were adjusted and validated through the prediction mistakes of the cross validation. The distribution maps were built up from this and utilizing Ordinary Kriging for interpolations. The data show anisotropy in geometric character, phenomenon adjusted to an isotropic behavior through projection axis transformation, magnitude and direction. Thus, the major correlation direction goes generally to the major prolongation in the lake´s dimensions, that is, in its meridional size. All variables showed its higher levels in the north of the lake, which is the populated zone of the borders, no matter the station where the samples were taken. With this, the incidence that antropogenic factors cause in the environment is marked, it means in the Cuenca of Laguna Grande in San Pedro. The geostatistics analysis of the parameters of this lacustrine system tends to characterize it in low tropic levels according to the maps built.
Description
Tesis presentada para optar al título de Ingeniero Civil Agrícola
Keywords
Eutrofización, Geoestadística, Clorofila.