Application of Analytical Hierarchy Process (AHP) and Frequency Ratio (FR) Model in Assessing Landslide Susceptibility and Risk - Semi-quantitative Approaches for Landslide Assessment and Prediction - page 213

Fig. 7.11 Landslide hazard risk map with few signi cant risk events ( (field photo)

those 16, 13 and 7 are identi ed as riskful events. Frequency ratio for each low,

moderate, high and very high landslide hazard risk zone are 0.00, 0.66, 1.42 and
2.48 respectively which also shows very low chance, tendency towards equal
chance, high and very high chance of landslide hazard risk events in the respective
hazard risk zones (Table 7.8 ). Analysis of frequency ratio conclude that there is a
greater probability of future occurrence of risk events at the places of Lower
Paglajhora, Tindharia and Shiviter in future and these three locations are presently
existing in high to very high landslide hazard risk zone where frequency ratio is
more than ' 1 ' .
The determined threshold slope angle of Paglajhora, Tindharia and Shiviter
ranges from 13

and cohesion of the soil from 0.01 to 0.70 with greater
percentage of sand particle. Very fragile and fragmented lithological composition
helps easy percolation of rain water that generates adequate pore-water pressure for
promoting downward movement of slope materials at Paglajhora and Tindharia.
The existence of moderate to high intensity of risk elements and human intervention
associated with all favourable geomorphic and geo-hydrologic landslide triggering

° to 37 °