Spectral analysis of the Lake of Guadalupe through satellite imagery and in situ data | Análisis espectral del Lago de Guadalupe, mediante imágenes de satélite y datos in situ

English. 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.

Spanish; Castilian. El Lago de Guadalupe es un embalse localizado en los alrededores de la Ciudad de México, y recibe un volume 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.