Amod Mani Dixit

Strong-motion observations of the M 7.8 Gorkha, Nepal, earthquake sequence and development of the N-shake strong-motion network

We present and describe strong-motion data observations from the 2015 M 7.8 Gorkha, Nepal, earthquake sequence collected using existing and new Quake-Catcher Network (QCN) and U.S. Geological Survey NetQuakes sensors located in the Kathmandu Valley. A comparison of QCN data with waveforms recorded by a conventional strong-motion (NetQuakes) instrument validates the QCN data. We present preliminary analysis of spectral accelerations, and peak ground acceleration and velocity for earthquakes up to M 7.3 from the QCN stations, as well as preliminary analysis of the mainshock recording from the NetQuakes station. We show that mainshock peak accelerations were lower than expected and conclude the Kathmandu Valley experienced a pervasively nonlinear response during the mainshock. Phase picks from the QCN and NetQuakes data are also used to improve aftershock locations. This study confirms the utility of QCN instruments to contribute to ground-motion investigations and aftershock response in regions where conventional instrumentation and open-access seismic data are limited. Initial pilot installations of QCN instruments in 2014 are now being expanded to create the Nepal–Shaking Hazard Assessment for Kathmandu and its Environment (N-SHAKE) network. Online Material: Figures of Pg arrivals, earthquake locations, epicenter change vectors, and travel-time misfit vector residuals, and tables of QCN and NetQuake stations and relocated hypocenter timing, location, and magnitude.

Initiatives for earthquake disaster risk management in the Kathmandu Valley

Situated over the Himalayan tectonic zone, Kathmandu Valley as a lake in geological past has a long history of destructive earthquakes. In recent years, the earthquake risk of the valley has significantly increased due mainly to uncontrolled development, poor construction practices with no earthquake safety consideration, and lack of awareness among the general public and government authorities. Implementation of land use plan and building codes, strengthening of design and construction regulations, relocation of communities in risky areas, and conduction of public awareness programs are suitable means of earthquake disaster risk management practice. Kathmandu, the capital of Nepal, is still lacking earthquake disaster risk management plans. So, this paper highlights some initiatives adopted by both governmental and nongovernmental organizations of Nepal to manage earthquake disaster risk in the Kathmandu Valley. It provides some comprehensive information on recent initiatives of earthquake disaster risk management in the valley and also highlights the outcomes and challenges.

How to Render Schools Safe in Developing Countries

Abstract The schools in seismic regions of developing countries, including Nepal, face huge risks from earthquakes. Significant proportions of school buildings were destroyed, and thousands of school children and teachers were killed or injured in recent earthquakes in different parts of the region. A recent study conducted by the National Society for Earthquake Technology—Nepal revealed that out of approximately 82,000 school buildings belonging to 34,000 private and public schools in Nepal, >75 percent are highly vulnerable to earthquakes, requiring immediate intervention; of these, 15 percent are dangerous to occupy and need demolition and reconstruction. In the case of intensity IX Modified Mercalli Intensity level of shaking, approximately 111,000 school population (10 percent of the total affected school population) could lose their lives, and another 85,000 could suffer serious injury. The main reasons behind the high vulnerability and risk of schools are due to (1) poor building construction practices resulting from the use of poor materials and construction technology, lack of skilled and trained construction manpower, and lack of proper supervision and quality control; (2) poor performance of nonstructural elements and systems; and (3) vulnerability caused by locational and physiographic factors. Lack of financial resources of the schools and lack of awareness and knowledge about the underlying risks and possibility of mitigation measures have been the root cause of this ever-increasing earthquake risk. To address this problem, Nepal has been implementing a School Earthquake Safety Program under the leadership of the Department of Education of the Government of Nepal. The program consists of assessment of seismic vulnerability of school buildings and systems; strengthening of buildings and nonstructural components; training and education of school children, teachers, and parents on aspects of earthquake safety; enhancing earthquake preparedness of schools; and training of local masons on safer earthquake construction technology. Promotion of locally available materials with improved technology, involvement of the community in all program activities, emphasis on awareness raising and capacity building, and transparency in all activities have been the key elements for the success of the program. The approaches adopted can be useful and replicable in other countries with similar building typologies, school management systems, and awareness levels; although the technical methods for addressing structural and nonstructural vulnerabilities may differ in different contexts.

Non-structural earthquake vulnerability assessment of major hospital buildings in Nepal

The non-structural assessment of critical public facilities such as hospital buildings is very essential for earthquake disaster adaptation in earthquake prone regions. In Nepal, a devastating earthquake is inevitable in the long term and likely in the near future. So a non-structural earthquake vulnerability assessment study was carried out in the selected main hospitals of Nepal. This paper presents the findings of the assessment work. The results show an alarming situation and demand an immediate action in most of the hospital buildings so as to achieve a standard and acceptable level of safety. The study also recommends a gradual approach of increasing the safety level considering the socio-economic condition of the country and the fact that medium-level earthquakes are more frequent than the severe ones. Moreover, the non-structural component assessment study largely helped to convince the government officials and hospital authorities on the affordability and possibility of constructing earthquake-resistant non-structural components in the hospitals of developing countries such as Nepal, employing a slight improvement in the already employed methods of construction.

Earthquake Risk Reduction Efforts in Nepal: NSET’s Experience

This chapter describes earthquake risk reduction efforts in Nepal from NSET’s perspective and is co-authored by a team of researchers who have been with NSET since its inception. NSET was established in 1994 with the objective to reduce earthquake risk in Nepal. The usefulness and innovativeness of NSET’s long-term efforts were tested by the Gorkha earthquake, highlighting positive impacts of the risk management efforts in Nepal in the past 22 years. This chapter provides a brief history of NSET’s earthquake risk management efforts in Nepal and sheds light on some of the innovative postulations and methodologies used.

Risk Management, Response, Relief, Recovery, Reconstruction, and Future Disaster Risk Reduction

Abstract Earthquake risk management initiatives in Nepal in the past decades have yielded good results: Earthquake awareness increased across the country as never before, the capacities of stakeholders have been enhanced tremendously, and the policy environment has also changed positively. Fatalism gradually gave way to scientific believe across the layers of the society. The positive impact was observed during the 2015 earthquake. However, this change has not yet reached the desired critical proportion to sustain the change process independently. Efforts of disaster risk reduction in Nepal should now transgress its emphasis from raising awareness to implementation of vulnerability reduction initiatives, including stopping the creation of vulnerability. Now is the time to enhance risk perception by demonstrating the benefits of risk reduction by actually implementing risk reduction methodologies—Nepal has enough success stories; the need is to scale up the successes.