Evaluation of the trophic state and nutrient dynamics of Pampean shallow lakes (Argentina) using a combination of field and satellite data

BOHN, V.Y.; PRATOLONGO, P.D.; PICCOLO, M.C.; PERILLO, G.M.E.

Torres

Workshop; GLEON 10; 2010

GLEON

A method based on the analysis of satellite image was developed to study the trophic state of the Pampean shallow lakes (Argentina). The method consists in a regression model for trophic state estimation between two information sets: field data (chlorophyll‐a concentration) and satellite spectral reflectance. Field data was obtained by sampling sites corresponding to Unamuno and Calderón shallow lakes, as representative cases of the study area. A 0 – 100 eutrophication scale was developed to indicate four different trophic levels: oligotrophic, mesotrophic, eutrophic and hypertrophic. A representation of the spatial distribution of chlorophyll‐a was developed by means of interpolation. Categorizing interpolated values, an illustration of the different chlorophyll‐a contents was developed in two thematic maps. The pigment distribution was analyzed in six selected shallow lakes during two different periods: a wet and a normal year. The model application showed similar results for the estimation of the trophic state of the lakes whose mean chlorophyll‐a concentration data was available. An analysis of frequency was carried out to determine the trophic conditions of all the water bodies in the study area during both periods.