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Poster Session 2
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Study of Panchet reservoir using Remote Sensing images
Methodology and data used
Here the Landsat Thematic mapper imagery of May'87 in bands 2(0.52 -60oum) 3 ( 0.63-.69 um,) and 4 (0.76-0. 90 um ) both is B & W and their colour combinations have been interpreted using the standard photo-interpretation technique. The sedimentation map has been prepared from the digitally processed black and white imagery in visible bands. Here the spectral reflectance values group for reservoir water has been sliced into various subclasses using he digital processing facility of RRSSC. IIT, Kharagpur (West Bengal)
Finally following overlay maps have been prepared and are described here.
- Lineament map showing Geotectonic fabric of the region.
- Pre and Post monsoon temporal variation map of water levels of the reservoir.
- Sedimentation map in reservoir
Result and discussions
- Lineament Mpa: General pattern of lineaments (Fig 2) support the number of criss cross faults of NNW-SSE to nNE-SW orientation affecting sedimentary and metamorphic group of rocks. At some places it corraborate with discontinuously exposed dolorite. Dykes of NW-SE direction. A regional fault trending NE-SW and oblique to dam geometry separating non garnetiferous and garnetiferous rock groups between sedimentary and metamorphic have also been clearly demarcated.
- Temporal variations Map: A temporal variation in water has been prepared (taken from the published work of author himself, 1988). The variation map has shown that the fluctuation is most at the region where river joins the reservoir and less at the dam site area. Preliminary cause of this may be at the joining region the strength of river current is suddenly slowed down and this causes settling of sediments and swallowing of the valley. this results in spreading of water more in comparison to dam site area where choking of dam site area is frequently cleared by flushing.,
- sedimentation map: Situation is the direct consequence of the deposition of sediments brought to reservoir give muddy appearance by diffracting the enetrating visible light.
Using this concept a sedimentation map (see fig. 4) of reservoir has been prepared. For this the landsat TM visible red band (0.63-0.69 um) picture in B & W and digitally processed Images have been used. Here the clear water with no suspended sediments show darker tone comparative to the water with suspended sediments of brighter tone. From the map it is clear that the dam site location area is comparatively free from sediments and water is deeper in depth from the peripheral area. but the central portion of reservoir area shows much salutation by its high reflectance level
Conclusions
The synoptic view of reservoir area by the satellite remote sensing images in multispectral mode in different time of the year have been of much value in the study of regional geotechtonic and characteristics of reservoir. Though the above observations and results are of preliminary nature but the availability of this little information in real time adds much significance to this technique. thus the remote sensing technique provides and effective way in monitoring preliminary aspects of the man mode dam reservoir.
Acknowledgement
The authors are grateful to Prof. D.K. Sinha, Director, Indian, School of Mines, Dhanbad for providing all the facilities, and encouragement to carry out the present work.
References
- Ahmed E.m,. " Bihar-A, physical, Economic and regional Geography: Book published, ranchi 1965.
- Dutta, K.K. et al, "Geotechnical features of Major dams in India I.S.E.G. Bulleting, Calcutta, 1982.
- Ray Pullak. K., "Sturcture & evaluation of a prograding reservoir delta in damodar river , India" Journ. Geol. Soc. of India, Vol 23, 1982 pp 238-345.
- Sharma N.L. , "The Geological formation & economic minerals of Dhanbad, gazette of india, Dhanbad, Bihar, 1964 (Complied by P.C. Roy Choudhary)
- Srivastava, V.K., Rai B. and Mohan R, "Study of Mainthan Dam Reservoir using remote sensing images" presented at the National Seminar on "Water resources development management" held at regional engineering college, Rourkela, Feb, 1988.
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