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Water Resources
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Water Quality Analysis on the Chao-Phra-Ya Estuary
Using Remote Sensing Data
Hansa Vathananukij
Kasetsart University/RID Thailand
Shunji Murai
Asian Institute of technology/University of Tokyo Thailand/Japan
Suvit Vibulsresth
National Research Council Thailand
Prof Mushiyaka Katsumi, Ass. Prof. Shibasaki Ryosuke, Mr. Hiroaki Kakiuchi
University of Tokyo Japan
Dr. Yoshifumi Yasuoka, Mr. Yoshiki Yamakata
The National Institute for Environment Studies. Japan
Abstract:
Previous analysed research has been concentrated on prominent area of the Chao-Pra-ya estuary; deltaic area have been promoted from agrucultural area to urban one, accentuated several problems on river reach while Chao-Phra-ya river has been only fresh-water resource to this area. Sincedifficultiies in ground investigation costs and heavily boat transportaion have been concerned, tremendous satellite images techniques were intruduced to analyse historically.
Percentage difference, linear-regression analysis, correlation matrix and one-dimension statistical analysis were used to analyse among varios water quality parameters and satellite imageries data. A rather high correlation has resulted on correlation coefficient 0.946 (99 percentage significance). Geometric correction and Digital analysis has been selected potimum Band or Bands combination through those multi-enhancement techniques which were used to delineate water quality indifferent periods. Overlying utility has been expressed upon rectified water dispersion pattern including with productive navigation path way The Colour Density Slicing was achieved to such water pixel images, which has been efficiently considered to dominantly qualitative assessments of water dispersion pattern conditions were acquired upon five selected different date of LANDSAT TM data.
At present, the monitoring area composed of 80 kilometers long river reach 15 kilometers shore line to the East and 25 kilometers to the West (cover Prathumthani, Nonthaburi, Bangkok, and Samutprakan provinces)). Togetherwith classified existing land cover study of urban (dense settlement) indicates extension stretched fingers zone to the North, North-East and West prolongation direction while surface water dispersion illustrate density too Figure 1. Presents dense-urban area extension
Figure 1. shown urbanization extension stretch fingures zone
All high resolution satellite imageries have been distinguished displayed water dispersion pattern, either examine or monitor suspended solid sediment diffuse efficient, being installed at estuary including with Atmospheric correction technique has been under primary analysis in order to illustrate transmittance and path radiance through single-linear regression analysis between radiance, which computed from satellite data and ground truth radiances (by spectrometer ) at a major curve in the Chao Phra-ya river course, whose both side-swings in wide looops presenting narrow meander strip of 625 meters wide as shown in figures 2,4 and 5.
Figure 2. illustrated actual water dispersion and presisely ocntaminated quality location along the side swings of wide loops
Figure 3. presented a dominant from and natureal dredge according to consistency navigation activity and current movement.
Figure 4 . indicated relationship among imnput data (sediment and density)
Figure 5 monitored relationship between wavelength and radiance of each sample position.
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