APPLICABILITY OF MODIS 250-M RESOLUTION DATA FOR REGIONAL LAKE MONITORING

摘要

We studied the usability of MODIS satellite sensor data (620–670 nm channel,250-m resolution) for estimating turbidity of the 56 000 lakes in Finland. Theconcentrations of the optically active substances in July-August 2000 wereobtained from the environment register (1017 stations). The lake turbidity map wasproduced from the MODIS radiance measured on August 27, 2000 using anempirical algorithm. The underwater irradiance reflectance spectra were calculatedfor the stations with a semi-analytical bio-optical model using concentrations of theoptically active substances. Sensitivity analyses indicate that both the CDOM andchlorophyll a concentrations typical to Finland disturb the estimation of turbiditythat is based on the 620–670 nm channel. We estimated that about 17 000 km2 oflakes (60% of the total lake area) in Finland can be monitored with the 250-mresolution data.