﻿The Gohna Landslip. 303 



The Gohna Landslip.^ 



By Prof. VV. M. Davis, Harvard University. 



A remarkable instance of foresig^ht in averting disaster 

 is found in an account of the Gohna landslip on a head 

 branch of the Ganges, in the Garhwal Himalaya, and 

 of the flood that followed on the overflow of the resulting 

 lake, as published by the Public Works Department of 

 the Government of India (Calcutta, 1896). The slip 

 occurred in September, 1893, continuing three days with 

 deafenino^ noise, darkeninof the air with the dust from 

 shattered rocks, and clogging the narrow valley with 

 800,000,000 tons of detritus. The fall descended about 

 4,000 feet, spreading about two miles along the valley 

 and rising 850 feet above the former stream level. It 

 resulted from the undercutting of strata that dipped into 

 the valley, and hence should be classed with those slides 

 that follow the erosion of narrow valleys in uplifted 

 masses ; as such, being a characteristic of vigorous young 

 mountains. 



Careful study of the ground made it clear that no 

 artificial discharge could be made for the rising lake. As 

 the impending flood could not be controlled, every effort 

 was made to insure the safety of the people in the valley 

 below by timely warning of the disaster. A telegraph 

 line was constructed from Hardwar, on the Ganges at the 

 edge of the plains, to Gohna, 150 miles within the 

 mountains. In April, 1894, August 15th was set as the 

 probable date of the flood. A number of suspension 

 bridges were dismantled and removed. Safety pillars 

 were set up on the valley slopes, at intervals of half 

 a mile, and at heights of from 50 to 200 feet above the 

 ordinary river level, thus indicating the probable limit of 

 the flood, above which there would be no danger. 



The lake back of the dam grew to be four miles 



i Reprinted from Science for March 12th, 1S97. 



