This document summarizes a landslide hazard assessment of areas in Pokhara valley, Nepal. [1] Field observations were made of slope, soil depth, vegetation and soil type at 5 reference sites. [2] A rating system was used to assess hazard levels based on these parameters, with the alluvial fan at Phyaureko Tudo showing very high hazard and the fan at Pame showing low hazard. [3] While the assessment focused on 4 key parameters, the authors note that incorporating all relevant factors would provide a more reliable hazard analysis.

1. Hazard Assessment of Kawache GLOF
Introduction:
 Episode occurred on 15th August, 2003 in the
upper reach of Madi river.
 Basic cause of GLOF linked with the important
meteorological parameter i.e. temperature.
Methodology:
 Social Survey
 Flood mark discharge measurement method

2. Findings:
Social survey-
 Ethnicity dominated by gurung.
 Most witness the event with experience of-
event occurred at night with clear sky,
producing foul smell, land shaking and large
sound due collision of Boulders.
 Desertification of fertile land, killing 5 people,
deposition of large boulders, trees logs and
soil debris.
 Flood mark up to 5m.

3. Flood mark discharge measurement method-
 Suitable method for flood discharge
measurement.
 flood mark identified through local respondent.
 Flood discharge at chasu:-30161.43m3/sec
Conclusion:
 Huge magnitude flood has cause huge loss of life
and property and also destabilized slope
triggering cyclic landslide each year.
 Monitoring of Temperature trend, detail
assessment of life and property loss, study of
Geomorphologic changes is necessary to develop
useful models.

4. Landslide hazard mapping
Introduction:
 provide residents the information on the
range of possible damage and disaster
prevention activities.
 based on : slope gradient, slope aspect,
elevation, slope shape, geology, land use, soil
type, average annual rainfall, distance from a
road, distance from a stream, distance from a
geological structure and distance from a
major ridge line (Paudyal and Dhital 2005).

5. Methods of Hazard mapping
1. Digital Grid:
 Cumulation of rating at each grid
 Superimposing different maps with rated grid
sheet
 Generally, used PC software- SHIVA (wagner
et al. 1990)
2. Line Hazard mapping:
 Subdivision of survey line into facets where
hazard rating is attributed.
 Can take narrow area but no Cumulation
done.

6. Study area:
Pokhara valley is a beautiful of natural paradise
in western Nepal having Area of 200 sq km.
 It extends between 25°7' and 28°10'N latitude.
 83°50' and 84°50' E longitude

7.  Pokhara valley are divisible into seven
formations: Begnas, Siswa, Tallakot, Ghachok,
Phewa, Pokhara and Rupakot Formations
(Yamanaka et al., 1982).
Observations:
A) Mapping parameters index;
• Soil depth:- A(<1m), B(1-3m),C(3-6m) & D(+6m)
• Vegetation:- 1-2-3-4-5 (no to dense vegetation
range)
• Slope:- I-II-III-IV-V (Steep to gentle range)

8. B) Hazard rating parameter values:
S. Reference site Slope Soil Vegetati Soil type Total
N. depth on rating
1. Sedi Top colluvial II B 2 Residual 0.36
Bagar Alluvial (1) III C 2 Gravel, sand and silt 0.36
(800m)
Alluvial (2) IV D 3 Sandy gravel, sand 0.34
and silt
2. Chahadidada (798m) III C 2 Transported 0.4
colluvial
3. Phyaurek Colluvial fan I A 3 Active colluvial 0.23
o Tudo Alluvial Fan III C 2 Non- active alluvial 1.34
(816m)
4. Bhakund Colluvial fan II B 4 Sand and silt 0.35
e Bagar Alluvial fan IV C 2 Sand, silt and gravel 0.33
(806m)
5. Pame Colluvial fan II B 3 Sand and silt 0.35
(794m) Alluvial fan III A 2 Sand silt and gravel 0.18

9. C) Recommended hazard level:
S.N. Reference site Total rating Hazard level Range of
hazard
1. Sedi Bagar Top colluvial 0.36 Medium Less than 0.30
(800m) (Low)
Alluvial (1) 0.36 Medium
Alluvial (2) 0.34 Medium
2. Chahadidada (798m) 0.4 Medium Between 0.31 &
0.60 (Medium)
3. Phyaureko Colluvial fan 0.23 Medium
Tudo (816m)
Alluvial Fan 1.34 Very high
4. Bhakunde Colluvial fan 0.35 Medium More than 0.90
Bagar(806 (Very high)
Alluvial Fan 0.33 Medium
m)
5. Pame Colluvial fan 0.35 Medium
(794m)
Alluvial Fan 0.18 Low

10. Conclusion:
 Hazard level is based on cumulative rating
grid system.
 Alluvial fan at Phyaureko Tudo showed very
high hazard level.
 Alluvial Fan at Pame showed low hazard level.
 Recommended hazard level here is based
upon only four parameters but for more
reliable result, all parameters introduce above
need to be assigned.

11. References:
 Deoja, B., Dhital, M., Thapa, B., and Wagner,
A. (Principal Editors), 1991, Mountain Risk
Engineering Handbook. International Centre
for Integrated Mountain Development, 574-
618 p.
 Paudyal, P., and Dhital M.R., Landslide hazard
and risk zonation of Thankot- Chalnakhel area,
central Nepal., Jour. Nepal Geol. Soc. V. 31,
43-50 p.