Over the weekend, a 7.8-magnitude earthquake hit Nepal. But what are the factors which made the country, and the city of Kathmandu, so susceptible to such a disaster?
ShakeMap of Nepal (Image: USGS)
The earthquake epicentre, 80km to the northwest of Kathmandu, caused ‘very strong’ shaking, bordering on ‘severe’, around Kathmandu. The shock waves also reached as far north as the northern border, resulting in the avalanche on Mount Everest which killed and injured many on the mountain.
The earthquake triggered multiple aftershocks, occurring across the affected region (Image: USGS)
Topography of Nepal (Image: Wikimedia)
Squeezed between India and Tibet in the midst of the Himalayan mountain range, Nepal is a highly mountainous and tectonically active country. It contains eight of the world’s ten highest mountains, including Mount Everest and Kanchenjunga, respectively the tallest and third tallest mountain peaks in the world. From a broadly low-lying south-and-southeastern border with India – a flat river plain which feeds into the mighty Ganges – the terrain becomes rapidly more rugged as you head north. Consequently, there are multiple areas of land over 5,000m above sea level around the northern border.
Regional population density of Nepal, 2011 (Image: IMU/RCHCO)
Most of Nepal’s 31 million people live in the rural lowlands, in the 15 per cent of the country which is suitable for farming. The major exception are the 1.5 million living in the capital Kathmandu, which sits around the centre of the country, at an average of 1,400m above sea level. Rapid migration to Kathmandu has created a population density averaging over 13,000 people per sq km, one of the highest in the world.
Nepal severity of poverty, 2011(Image: World Bank and Central Bureau of Statistics, Nepal)
Poverty rates are falling in Nepal, however the UN estimates that over a quarter of Nepalis still live below the poverty line. In Kathmandu, this, combined with the high population density, has led to thousands of people in the city living in poor quality housing, making it one of the most dangerous threats to human life.
For a timeline of Nepal’s history with earthquakes, click here.