Nepal Hazard Risk Assessment - Asia-Pacific Gateway for Disaster ...

Nepal Hazard Risk Assessment
More than two third of the geographical area of 19 districts including Pyuthan,Sarlahi, Panchthar,
Manang, Dadeldhura, Makawanpur, Rasuwa, Bajura, Solukhumbu, Jumla, Udayapur, Taplejung, Rolpa,
Terhathum, Bajhang, Dolakha, Sindhupalchok, Doti and Darchula are falling under very high risk zone.
The distribution of medium, high and very high earthquake risk zone area wrt five development regions
and three belts are shown in inset graph within Figure 3.7.
The 250 Years return period earthquake hazard mapping have 2 districts (Okhaldhunga, Bhaktapur)
which are located completely under very high earthquake risk. Twelve districts with large area falling
under very high earthquake risk (more than 2/3 of district area) are Dhanusa, Ramechap,
Kabrepalanchok, Kathmandu, Nuwakot, Kaski, Parbat, Baglung, Myagdi, Rukum, Jajarkot, Kalikot.
This can be observed in Table 3.3, together with distribution in lower earthquake risk zone. Figure 3.4
shows even distribution of high and very high hazard class, ranged from 1000 km 2 to 2700 km 2 on total
area. Several districts are near 100% zone.
High risk zone has slightly larger area coverage, followed by medium and then by very high earthquake
risk zone. Terai area has large coverage of medium earthquake risk zone as seen from inset in Figure 3.8.
The 100 Years return period earthquake hazard mapping covers 2 zone, which are medium and high
earthquake risk. Thirty four districts are largely located in high zone as seen in Table 3.4. Around 11
districts (Okhaldhunga, Dhanusa, Ramechhap, Bhaktapur, Kathmandu, Nuwakot, Kaski, Baglung,
Myagdi, Rukum, and Kalikot) are completely falling under high zone. This can be observed in Table 3.4.
Figure 3.5 shows cluster of points (both of medium and high hazards zones) toward 100% zone.
Figure 3.5. Hazard vs total area cross plot for 100 year return period.
Figure 3.4. Hazard vs total area cross plot for 250 year return period.
Within 100 year return period, medium earthquake risk zone has larger area coverage than high risk
zone, which may be referred in Figure 3.9. High risk zone is concentrated in Hill belt, and followed by
Mountain area and last by Terai area which are referred in inset graph in Figure 3.9.
Geographical distribution of very high earthquake zone is concentrated in hill region as seen in Figure
3.8. Distribution of medium, high and very high risk zone are relative uniform in 250 year return period.
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