IKONOS data with four multispectral bands similar to Landsat TM bands 1-4 and high spatial resolution (4 m multispectral and 1 m panchromatic) is potentially well suited for assessment of small lakes. To explore the capabilities of IKONOS data for lake water quality assessment and monitoring, we acquired an August 23, 2000 IKONOS image for the City of Eagan, Minnesota. Eagan has 375 small lakes and ponds larger than one acre with 44-acre Thomas Lake being the largest. Click the pictures below to enlarge and view the resolution differences between Landsat and IKONOS images (Click your browsers back button to return to this page).
signatures were extracted from 19 lakes that had SDT measurements within three
days of the image date. A regression model was developed using the band 3:1
ratio and band 1 as the independent variables and the natural log of SDT as the
dependent variable. The results were very similar to the results we have seen
using Landsat data
use of IKONOS data for assessment of water clarity for small lakes at a city
scale is promising. The high spatial resolution of the IKONOS data enables the
assessment of smaller lakes and ponds than the Landsat 30-meter resolution
allows. Only 14 of Eagan’s 375 ponds and lakes were included in our statewide
assessment, while IKONOS data allows for the assessment of all of Eagan’s
small lakes and ponds. IKONOS data also would be useful for detailed city land
use/cover and wetland mapping. These maps could be used to assess how land use/cover affects
water clarity. The cost of the IKONOS data would be prohibitively expensive for
regional assessments, but would likely be affordable for many cities.
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Upper Great Lakes Regional Earth Science Applications Center
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