OR/14/069 Project objectives

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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 Internal Report, OR/14/069.

The valleys in the Middle Hills of the Himalayas may be some of the most sensitive areas to climate change in the Indo-Gangetic basin. Relatively small changes in temperature and the timing of the Asian monsoon could lead to significant variations in snow melt, runoff, and groundwater recharge with corresponding large impacts on water security. Meanwhile forecasts of increasingly inhospitable temperatures for lowland areas of Nepal and northern India (up to 60°C) are already leading to migration to the cooler Middle Hills, leading to increased demand for reliable water. Although future precipitation patterns and snow melt in the Middle Hills are poorly constrained, there is growing recognition that whatever the future may hold, groundwater storage within these catchments forms an important component of the Himalayan water budget (Andermann et al., 2012[1]) and is vital for current and future secure water supply.

Limited research from river flows and water chemistry indicates a significant role for groundwater storage in the Himalayan foothills within fractured basement aquifers (Jenkins et al. 1995[2], Andermann et al., 2012[1]). However, groundwater resources remains poorly characterised in terms of both the hydrogeological setting and water usage. To begin to build an evidence base for the occurrence and behaviour of groundwater in the Middle Hills, two case study catchments have been investigated to evaluate the groundwater resource, assess the inter-connections with climate and river flow and to establish the degree of use of groundwater. Through these investigations the resilience of the water supplies to change, whether that change be climatic or anthropogenic induced, can be characterised.

The project had the following aims:

  1. Provide an account of the groundwater resource situation in the Middle Hills through the characterisation of catchment water supplies and water usage. Assess the local perceptions of change and the evidence base for these
  2. Gain a better understanding of the hydrogeology of the catchments and wider hydrogeological setting
  3. To strengthen the evidence base through the collection of a reliable set of groundwater chemistry samples and groundwater residence times for two catchments within the Middle Hills
  4. Develop a better understanding of resilience of groundwater within the catchments and consider the likely response to change e.g. trends in migration and climate and consider the suitability of groundwater as a strategic resource for domestic and town supplies in mountainous areas

The work was undertaken in the Palpa and Myagdi districts of Nepal by scientists from the British Geological Survey (BGS), the Institute of Social and Environment Transition (ISET) International and their sister organisation ISET-Nepal. The work undertaken in Nepal forms a case study within a two-year research programme funded by the Department for International Development (DFID), which aims to strengthen the evidence base linking groundwater resources, climate variability and abstraction with emerging policy responses in the Indo-Gangetic basin.

This report documents the main work carried out as part of this study and presents preliminary results and conclusions.

Work programme

The activities undertaken as part of this study and the periods over which they were undertaken are provided in Table 1.

Table 1    Programme of work undertaken as part of the study.

All dates referred to in this report use the Julian calendar, where data were collected using the Nepali calendar dates were converted by ISET-Nepal.

References

  1. 1.0 1.1 ANDERMANN, C, LONGUEVERGNE, L, BONNET, S, CRAVE, A, DAVY, P, and GLOAGUEN, R. 2012. 'Impact of transient groundwater storage on the discharge of Himalayan rivers.' Nature Geoscience 5(2): 127–132.
  2. JENKINS, A, SLOAN, W T, and COSBY, B J. 1995. 'Stream chemistry in the Middle Hills and mountains of the Himalayas, Nepal.' Journal of Hydrology 166(1–2): 61–79.