Back to news
27 May 2015 | News

How big earthquakes rattle spring dynamics

4 mins Read

70% Complete

The massive 7.6-magnitude earthquake that hit Nepal on 25 April has left unprecedented damage in life and property. The epicenter of the earthquake was in Gorkha district, 150 km west of Kathmandu. However, the ongoing series of aftershocks have occurred between Gorkha to the west and Dolakha to the east. This blog aims to highlight how earthquakes impact springs in the mountains.

A major impact has been the movement of ground, and the land surface is reported to have shifted both horizontally and vertically by +- 1.5 meters. An interesting phenomenon related to this is the underground land deformation that has affected the groundwater flow movement. News reports have indicated three different types of impact on water flow movement: i) Water flowed from the dry (non-functional) stone spouts, ii) New springs were observed and old ones yielded more water, and iii) Rivulets dried out.

Science indicates that these are all caused by changes in the water flow channel in the underground surface. But, let’s first understand the groundwater processes.

Rainwater generally infiltrates into soil surface, and some of the water saturates the soil up to few meters depending upon the topography and soil types. Once the soil is saturated, the water further moves down which is known as percolation. The percolated water is then stored in underground geological structures such as fractures and cracks. The storage capacity and outflow from these structures depend upon the type of rocks and geological formations. In general, the more the cracks among rocks, more water is stored. When these cracks are filled with water, water starts to flow to the lower elevation areas under the influence of gravity. During this process, the water develops its interconnected pathways as shown in Figure 1 and the flow continues for many years. When this flow emerges on the surface, we call it a spring. Spring water is widely used for domestic purposes in rural areas, and springs are often the primary source of water in many mountain villages.

During large earthquakes, these interconnected pathways might change course due to the movement of the tectonic plates deep underneath the ground. So during this process, some portions of rocks and ground get squeezed while others expand, both leading to change in the underground water table. Due to this, on the one hand, the interconnected pathways might gain more water through widening of the cracks deep underground or by combinations of several water pathways. On the other hand, the water may disappear as the path gets closed. Therefore, after a big earthquake, there are always reports of changes in spring water flow.

In the wake of the recent earthquake, I observed a few springs in two mountain districts.

In Sipapokhare VDC of Sindhupalchok district (Photo 1), there were two springs on the slope (Figure 2). In between these two springs, a new crack developed after the earthquake from which a big flow of water emerged, around 30 liter per minutes (Spring #2). One can only guess that the new crack might have met the interconnected underground water flows which feed the new springs. Similarly, the flow of Spring #1 and 3 have also yielded more water after the quake.

According to a woman who experienced the earthquake just in front of the springs, the new spring flowed immediately after the first tremor. Similarly, there are news reports that new springs have been observed in many mountain slopes (Table 1). Besides springs, there are many stone spouts in Kathmandu valley whose flow also increased. In urban areas, buildings can affect the underground water flow channel and after the earthquake, the channels might get reoriented and some stone spouts might get more water while others may see a decrease in water flow or may completely go dry.

In Kavre district, where Nepal Water Conservation Fund (NWCF) and ICIMOD have collaborated on spring research project, local communities shared that many springs have yielded more discharge after the earthquake. At Darauni Pokhari village of Panchkhal municipality (the then Darauni Pokhari VDC) many springs have yielded more water in the northern slope. The discharge of the Thulo Dhara springs (Photo 2) which is widely used for drinking and bathing by the local community increased drastically after the earthquake. The Spring 1 discharge increased from 14 to 36 liter per minute, while the discharge of Spring 2 went up from 22 to 53 liter per minute1. However, in the southern slope, two springs have completely dried up (Photo 3).

In general, there are reports of existing springs yielding more water and new springs emerging as compared to the springs that have dried up. However, it is uncertain if these springs will maintain the increased water flow permanently. It is likely that the increase might be temporary and may dwindle after a few months. Since the monsoon season begins in mid-June, these new developments could prevail until the rains stop. However, it will take some time to precisely understand whether the phenomenon is temporary or permanent. Since springs are the primary source of water in rural areas, it is important to understand how they function and what causes variation in their flows. Therefore, better understanding of geological aspect of spring hydrology is critical and further research needs to focus in these aspects.

Table 1: News reported in local media

Water supply types Area Sources
Stone spouts that yielded more discharge Matatirtha, Muruhiti, Sheshnarayan, Pashupati area
Two small rivers dried in Gorkha Gorkha district, Barpak area
Springs that yielded more water Kathmandu and periphery

The spring discharge is measured by Nepal Water Conservation Fund (NWCF) regularly as a part of the collaborative pilot study of NWCF and ICIMOD. The discharge is measured every mid-month. The last measurement after the earthquake was from 16 through 21 May 2015.

Stay current

Stay up to date on what’s happening around the HKH with our most recent publications and find out how you can help by subscribing to our mailing list.

Sign Up

related contents

Continue exploring this topic

29 May 2017 Himalica
Vegetable Collection Center Launched in Bagaha, Udayapur

Himalica’s pilot project in Udayapur has been training farmers on climate-smart agricultural practices and technologies that can strengthen vegetable value ...

Festival Provides Platform to Discuss Future of Yak Herding in the Kangchenjunga Landscape

Kipchu, a yak herder from Haa, Bhutan, said that traditional products such as hard cheese from yak milk have limited ...

23 Aug 2017 News
Gender and Social Entrepreneurship Workshop in Pakistan

Hashoo Foundation has worked extensively in the Upper Indus region over the past 30 years on gender and social development ...

22 May 2015 News
Team Kathmandu inspires

‘Tracking and Sensing through Android Robotics’ from Kathmandu’s 2015 NASA SpaceApps Challenge was named the 'Most Inspirational' in Global Competition ...

8 Apr 2016 News
Landscape Journey in Myanmar

A multidisciplinary team was organised in the Mu Lar-Nam Ru watershed area of Putao district in Kachin, Myanmar late February ...

12 May 2015 News
The International Glacier symposium in Kathmandu

  The International Centre for Integrated Mountain Development (ICIMOD) through its Cryosphere Initiative hosted the first International Glacier Symposium (IGS) in ...

16 Mar 2015 News
Challenges of hill communities in Nuwakot District

We visited four government agencies in the district: the District Forest Office (DFO), the District Agriculture Development Office (DADO), the ...

27 Jan 2016 KSL
A Need to Protect Nepal’s Diverse Resources

Nepal harbours abundant biodiversity. Diversity exists largely due to the unique climatic conditions and geography in the Himalayan range. Indigenous ...