Análisis espectral del Lago de Guadalupe, mediante imágenes de satélite y datos in situ



Título del documento: Análisis espectral del Lago de Guadalupe, mediante imágenes de satélite y datos in situ
Revista: Investigaciones geográficas - Instituto de Geografía. UNAM
Base de datos: PERIÓDICA
Número de sistema: 000385866
ISSN: 0188-4611
Autors: 1
Institucions: 1Universidad Nacional Autónoma de México, Instituto de Geografía, México, Distrito Federal. México
Any:
Període: Abr
Número: 86
Paginació: 15-24
País: México
Idioma: Español
Tipo de documento: Artículo
Enfoque: Analítico, descriptivo
Resumen en español El Lago de Guadalupe es un embalse localizado en los alrededores de la Ciudad de México, y recibe un volumen considerable de aguas residuales. En este trabajo se presenta un análisis espectral del Lago de Guadalupe utilizando imágenes SPOT y datos colectados in situ. Las mediciones fueron realizadas en los meses de febrero y septiembre de 2006. Las variables medidas incluyen temperatura, pH, clorofila a, transparencia Secchi y datos satelitales, cuasisimultáneos, obtenidos de imágenes SPOT. Este cuerpo de agua es eutrófico, con valores básicos de pH (6.8–11.3) y altas concentraciones de clorofila–a (6.9–112.4 µg l–1) y valores bajos de transparencia Secchi. Térmicamente, el lago es cálido monomíctico. Los resultados indican un alto grado de eutrofización, debida principalmente a la presencia de fitoplancton, vegetación sumergida y flotante. La distribución de la vegetación es cuasi–homogénea en el embalse a excepción de un punto de muestreo
Resumen en inglés Lake of Guadalupe is a reservoir located in the neighborhood of Mexico City, and it is one of the few relicts still remaining in the basin of Mexico. This reservoir receives an important volume of waste waters from its surroundings which include urban, forested, recreational and agricultural sites. In this work we present a spectral analysis of this lake utilizing SPOT imagery and in situ data and the its Trophic State Index (TSI). Measurements were carried out in February and September of 2006. Measured variables include temperature, pH, chlorophyll a, Secchi transparency and quasi–simultaneous satellite data from SPOT images. Variables were measured at seven sampling sites, strategically located along the lake. This water body has eutrophic characteristics, it has basic pH values (6.8–11.3), high chlorophyll a concentrations (6.9–112.4 µg l–1) and low values of Secchi transparency. Thermally, the lake is warm monomictic. Results indicate a high degree of eutrophization of the Lake of Guadalupe, due, mainly, to the presence of phytoplankton and submerged and floating vegetation. The presence of aquatic vegetation such as hyacinth and duckweed is apparent at the edge of the lake. In February, the concentration of Chlorophyll a, expressed as biomass, was homogenous in the reservoir with a mean of 9.56 ± 4.26 mg m–3. .The mean value for Secchi transparency was 3.39 (± 1.13) m, which corresponds to an Extinction Coefficient K = 0.50 m–1 associated to turbid waters. The pH average of 10.40 indicates alkaline conditions. The TSI, estimated from Secchi transparency was 43.50 (±6.9) indicative of meso–trophic waters, whilst the TSI, estimated for chlorophyll a was 52.16 (± 3.35) corresponds to eutrophic waters characterized by the presence of microphytes. In September the concentration of chlorophyll a had a wide range of values with a mean of 72.90 (± 28.46) mg m–3, which clearly indicates
Disciplines Geografía
Paraules clau: Cartografía,
Geografía física,
Percepción remota,
Análisis espectral,
Estado trófico,
Lago de Guadalupe,
México
Keyword: Geography,
Cartography,
Physical geography,
Remote sensing,
Spectral analysis,
Trophic state,
Lake of Guadalupe,
Mexico
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