Abstract
Unusual growth of Microcystis in Lake Kasumigaura in resent every summer has produced many environmental problems. The management of water quality should be considered from the view point of the hydrodynamics of the lake.
Remote sensing technology could have a potential to detect pollution features and water quality parameters, and also to survey the water streams in the lake. Synoptic views from Landsat are useful to grasp hydrodynamic phenomena of large scale of water area. But, Landsat images cas only show a temporal scene of the changing phenomena. To compensate this deficiency, numerical simulation should be introduced.
This paper shows an example to solve this problem through a case study of Lake Kasumigaura. The authors investigate a relation between the drift current and dispersion of Microcystis seen on the Landsat false color image. Circumstance of the current was examined by computer simulation with finite difference method. Correlation coefficient, eigen values, and eigen vectors were calculated onLandsat MSS digital counts and ground truth data.
The results of this study are summarized as follows :
1) Water qualitie parameters were higily correlated with Landsat MSS computer compatible data.
2) Principal component analysis compressed many water quality parameters into the major two ; suspended sediment and organic compound.
3) The solution of numerical calculation was similar to the false color image one.
4) Drift current may have an imporatant role for the management of water quality in Lake Kasumigaura.
