ccurrence 
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ajority of 
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in GIS 
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| slates, 
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? (54%) 
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. (5796). 
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IAPRS & SIS, Vol.34, Part 7, “Resource and Environmental Monitoring”, Hyderabad, India, 2002 
about 91.5% of the Tehri dam reservoir area (Saklani 1993). 
About 52.6% of the area are used for agriculture, which will be 
submerged. About 400 plant species will be endangered after 
filling up of the reservoir (Bhumbla D.R. et al. (1990). There 
are 46 active and 8 old landslides present in the reservoir area. 
Due to frequent changes in the reservoir water level the pore 
pressure can cause more landslides in the region. 
7. CONCLUSIONS 
The Tehri dam site is located in a seismically and tectonically 
active zone of the Central Himalayas. Most of the reservoir area 
is covered by Chandpur phyllites are under moderately high to 
high slopes indicating heavy rate of siltation especially after 
filling up of the reservoir and during heavy rains. Construction 
of new roads for a total length of 95 km. has further 
destabilized the area. Submergence of 46 active landslides and 
about 65 km. of road length will further induce landslides 
causing heavy influx of sediments to the reservoir. The satellite 
images of IRS-IC coupled with analysis of data using 
Geographic Information System (GIS) technique are very 
useful for terrain mapping and evaluation in Himalayas where 
majority of area is inaccessible or forest covered making the 
conventional methods of terrain mapping an arduous task. 
8. BIBLIOGRAPHY 
Bhumbla D.R. et al. (1990). Environmental appraisal of the 
multipurpose Tehri dam project, Department of Environment, 
New Delhi. 
Figure 1. Geological Map of Tehri dam and Environs 
  
Geological Map - Tehri Dam and Environs 
  
  
   
  
  
  
   
Nogthat Qtz ; Protopaager Qtz 
Chandpur Priyi(s) [f]  Metsbasice 
Chondpur Phyl (Pl Foulte 
Bhelunto L.Sr. M Theust 
Bhainga Siates NJ River 
    
    
   
  
  
  
Figure 2. Landuse/landcover map of Tehri dam and Environs 
  
Slope Map — Tehri Dam ond Environs 
E <s° ER 48-55 
n] 55 [7] > 85° 
II 15-25 
ES 25-55 
[7] ss-48* 
P e 8 va te. (S 
e 
ere — e 
    
   
3 Ar = eh " e "s FR 
MES RR e ET 
D eR usu chim 
© 2 4 6 BKM X— Rot M p 
Coma ct uf a OM 
  
  
     
  
653 
Burrough, P.A., (1986). Principles of geographical Information 
System for Land Resources Assessment, Oxford: Clarendon 
Press. 
Saklani, P.S., (1993). Geology of the lower Himalaya 
(Garhwal). Intl. Books and Periodicals Supply Services New 
Delhi, P-239. 
Valdiya, K.S. (1992). Must we have high dam in the 
geodynamically active Himalayan domain ? Current Science, 
vol. 63, No.6, 25 Sept., pp. 289-296. 
Valdiya, K.S. (2001). Reactivation of terrane-defined boundary 
thrust in central sector of Himalaya : Implications. Current 
Science, vol. 81, No.11, 10 December 2001, pp. 1418-1431. 
9. ACKNOWLEDGEMENTS 
Author* is thankful to Prof. P.S.Saklani, University of Delhi 
for guidance in writing the paper. Author* is also thankful to 
Secretary E.C., Haryana State Council for Science & 
Technology (HSCST) for kind permission to submit this paper 
to ISPRS TC-VII / ISRS Symposium. 
Figure 3. Slope Map of Tehri dam and Environs 
  
Morphotectonic Map - Tehri Dam and ‘Environs 
  
   
River Terrace M Foulte 
[@] Active landebde FD Theses 
[0] Odioniside [.] Spring 
p] Ridge Line 
  
  
  
Landuse/Landcover Map-Tehri Dom and Environs 
8 
Ed 
Ed 
+ 
2 2 + 6 8 
SCALE 
  
Figure 4. Morphotectonic Map of Tehri dam and Environs