Surface Run-off, Soil Erosion and Slope Instability - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 141

4.6 Conclusion

The Shivkhola watershed contributes signi cant amount of surface run-off during

the catastrophic rainfall months of a year when slope surface gets saturated due to
minimum retention. Area under the hydrological soil group of D and C (mainly sub-
watersheds VI, I and IV) provide maximum run-off where Curve Number (CN)
value is very high. The settlement areas of sub-watershed VI, concrete as well as
metal roads and bare surface of sub-watershed VI and I are to be given proper
attention for arresting run-off through constructing catch-water drains, proper
plantation and diversion of run-off. Proper drainage from settlement area through
concrete drains is to be made to protect the slope of highest priority. Upslope
degraded forest of all the sub-watersheds are to be brought under thorough plan-
tation and proper management. July and August experience pronounced run-off
from all the sub-watersheds. The people should be made aware about the possible
consequences of the excessive run-off during monsoon that results from either
deforestation or construction. All the preparation to manage landslide through
necessary constructions, plantations, preparation of task force, and detailed plan for
monitoring of slope conditions are to be made during pre-monsoon period.
Immediate attention is to be paid for sub-watershed I and VI as these two are the
great contributors of surface run-off and experience maximum landslide occur-
rences in the whole Shivkhola watershed. Some remedial measures such as plan-
tation of first growing and rapid water holding capacity grasses over the exposed

surface, construction of horizontal as well as vertical drains over large upslope
contributing area which can reduce length of overland flow and can minimize the
effects of maximum overland flow, and plantation along

rst order stream to reduce
the amount of discharge are to be followed to reduce surface run-off and also to
reduce soil erosion. As a whole, deforestation should be checked immediately by
providing primary needs to all the poor income family those who collect forest
wood for ful lling domestic as well as commercial demand.

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Chow VT, Maidment DR, Mays LW (1988) Applied hydrology. McGraw Hill, New York
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Handbook of Hydrology (1972) Soil conservation department. Ministry of Agriculture, New Delhi
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Horn DL, Schwab GO (1963) Evaluation of rational run-off co-ef cients for small agricultural
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