There is a significant lack of data and understanding for the groundwater systems in the middle Himalaya. Current climate change projections predict increasingly inhospitable temperatures for the Terai region of Nepal (up to 60°C) and internal migration of populations within Nepal and India is expected.
The aim of this case study is to examine the role of groundwater systems in the Middle Hills and evaluate the sensitivity of this groundwater to change through climate, land use or abstraction.
Digging a tubewell in Terai, Nepal. © Beemall.99 under the Creative Commons Attribution-Share Alike 4.0 International license.
Key objectives
Key components to this analysis are an improved understanding of:
- characterise groundwater resources and water usage in two Middle Hill catchments
- asses the dynamic groundwater system through one hydrological year to assess recharge processes
Middle Hills field area
Two catchments in the Nepalese Middle Hills are being used for the case study. These enable groundwater resources in different elevation settings and agriculture in the Middle Hills to be examined along a north–south transect.
Madan Pokhara
Madan Pokhara, in the south, lies at an elevation of 700 to 900 m above sea level and is an area dominated by commercial agriculture and a growing population. Drinking water supply comes from gravity-fed spring sources and shallow tubewells. There is significant use of groundwater for irrigation.
Ramche and Nangi
Ramche and Nangi, in central Nepal, are at elevations of 2200 to 3000 m above sea level and receive both rainfall and winter snowfall. The catchment is dominated by community forest and terrace farming. Gravity-fed spring sources form the main drinking water supply.
Activities
- Groundwater characterisation and water usage mapping in the catchments
- Groundwater sampling: post-monsoon and pre-monsoon groundwater sampling from springs and shallow boreholes from eight sites within each catchment. The samples were analysed for full inorganic chemistry, including As, salinity, groundwater residence time indicators (CFCs; sulfur hexafluoride) at the main water supply sources sampled, and recharge/source tracers (stable isotopes)
- Installation of data loggers: automatic data loggers were installed at three stream sources in the Ramche and Nangi catchment, to monitor response to monsoon and winter snowfall and spring melt
- Monitoring of springs: daily to weekly monitoring of spring yields and temperature at four water supply sources in each catchment. Stable isotope sampling (recharge/source tracers) was done every two weeks. The monitoring was conducted for one hydrological year (July 2013 to July 2014)
Project team
The case study involved researchers from BGS and:
Further reading
Bricker, S H, Yadav, S K, MacDonald, A M, Satyal, Y, Dixit, A, and Bell, R. 2014. Groundwater resilience Nepal: preliminary findings from a case study in the Middle Hills. British Geological Survey Open Report OR/14/069. (Nottingham, UK: British Geological Survey.)
Contact
Please contact Alan MacDonald for further information.