The structure and dynamics of groundwater systems in northwestern India under past, present and future climates

Lead Research Organisation: Durham University
Department Name: Geography

Abstract

India is the largest agricultural user of groundwater in the world. The last 40 years has seen a revolutionary shift from large-scale surface water management to widespread groundwater abstraction, particularly in the northwestern states of Punjab, Haryana and Rajasthan. As a result of this, northwestern India is now a hotspot of groundwater depletion, with 'the largest rate of groundwater loss in any comparable-sized region on Earth' (Tiwari et al., 2009). This unsustainable use of groundwater becomes even more challenging when set increasing demands from a burgeoning population and industrialisation, together with potential but poorly understood effects of climate-driven changes in the water cycle.

There are a number of innovative socio-economic strategies that can address this issue, including enhanced recharge and subsurface water storage, but their implementation and success depend on solid regional understanding of the geology and hydrogeology of the aquifer systems, and of the patterns and rates of groundwater flow and recharge. What we know about regional groundwater resources comes largely from either low-resolution studies based on satellite data, or from local investigations; there has been no large-scale, cross-state integrated study of the groundwater system.

Groundwater in northwestern India is thought to be largely hosted within buried, sandy former river channels, which extend from the Himalayas toward the southwest and are separated by fine-grained muds. Only a few channels are visible at the surface; most are buried and their existence must be inferred. Our approach is founded on the premise that we must first understand the geology and geometry of the aquifer system before we can hope to estimate the way it will respond to a complex set of future stresses. This means that we must be able to describe the locations, sizes, and characteristics of these channels as well as their age and three-dimensional pattern. Once these characteristics are determined, we can forecast the likely future behaviour of the system. In this proposal, we will provide, for the first time, a regional assessment of the aquifer system in northwestern India, along with models for its evolution under changes in the water cycle and in the way in which groundwater is used. Our project will combine expertise in sedimentology, stratigraphy, sediment routing and basin evolution, hydrology, and isotope geochemistry to understand the geological framework of the aquifer system, the ages of the groundwaters within it, and the ways in which groundwater levels are likely to evolve over the next 50 years. The outcomes of the proposal will include (1) a comprehensive data base that covers the northwestern Indian aquifer system, (2) much better understanding of regional sources, ages, and flow rates of groundwater, and (3) a suite of predictions for how the groundwater system will respond to a range of different future scenarios.

Planned Impact

Our proposed project will have four main outcomes: (1) a geological understanding of the geometry and spatial distribution of the shallow aquifer system in the western Indo-Gangetic Plains, (2) a predictive model for the 3-D arrangement of fluvial channel sands that can be applied to understanding aquifer distribution in the deeper subsurface, (3) establishment of the age, sources, and dynamics of groundwater in this aquifer system, and (4) an understanding of potential hydrological evolution of the aquifer system in response to varied stresses, including changes in future patterns of precipitation and abstraction or recharge. More broadly the project will provide an example of an integrated aquifer impact study based on sound geological knowledge, isotope-based reconstruction of groundwater dynamics and numerical-modelling assessments of aquifer distribution and hydrological evolution. This has potential application in other parts of the Indo-Gangetic basin, and more broadly to other aquifer systems composed of fluvial palaeochannels.

The outcomes of our research will have impact at local and national levels in India, but also internationally through application to similar hydrogeological systems. At the same time, we must be realistic; the three states in the study area contain over 100 million people and groundwater use in the region has become highly 'atomised', with large-scale water management largely supplanted by individual water users armed with pumps (Shah 2009). The potential for local impact is extremely limited. Thus, we argue that the impact of the research is best aimed at state and national levels. A primary target of our study will be to have direct impact on the development of water management plans in the affected states via contact with officials in the relevant state water resources agencies (Haryana, Punjab and Rajasthan). Our study is also relevant for policy-making institutions at the national level. These include the Central Groundwater Board (CGWB), with which we have existing contacts through co-Is Kumar and Shekhar, as well as a set of research institutes.

We will organize a workshop in March each year during the UK field visits to India and will invite a range of stakeholders, including representatives from the Central Groundwater Board (CGWB), state government groundwater department (as water is a state subject), IRI, ICRISAT, CSSRI, several NGOs, and municipal governments in the areas where our field work is based. The goal of these workshops will be to establish a two-way dialogue - both to apprise the stakeholders of our ongoing work and outcomes, but also to hear concerns and viewpoints on the relative priority and importance of the work described here, and to get outside perspectives on the leading issues and uncertainties. We will also establish a dynamic GIS database containing existing geological and groundwater information from the study region and will populate this with our own new data collected during the course of the project. This GIS database will be made available to stakeholders and will be provided to the Central Groundwater Board to help in formulating water management policies. We plan to set up groundwater monitoring stations at several sites as a part of our research. In the final year, we will dedicate 1-2 months of project time to evaluate the project findings to translate key project science into non-technical language that can be put forward for broader delivery, and develop specific recommendations. We will deliver a final report that summarises the key scientific findings, presents the primary data and numerical modelling simulations, and presents recommendations and suggested 'best practise'. A non-technical summary of this report will also be generated. This report together with the GIS database will be archived at NERC Designated Data Centres and MOES Designated Centres.
 
Description The aim of this project was to develop an integrated geological and hydrological understanding of the groundwater system of the northwestern Indo-Gangetic Plains, one of the world's largest aquifers and where groundwater resources are considered to be at greatest risk. To achieve this we identified five specific objectives:

1. Image and map the near-surface architecture of the palaeochannel aquifer system, using satellite remote sensing at a regional scale along with focused geophysical surveys (electrical resistivity) and drilling campaigns;

2. Groundtruth the heterogeneity of the palaeochannel aquifer system in selected areas, to reconstruct the evolution of the near-surface aquifer-forming river systems and to establish the ages and characteristics of the channel bodies;

3. Model the architecture of the palaeochannel aquifer system, constrained by data from O1-2, to develop a regional-scale understanding of aquifer geometry, the degree of connectivity within the system, and its likely evolution over Holocene time scales;

4. Reconstruct groundwater flow dynamics using isotopic analyses, including 14C and tritium dating techniques to establish groundwater ages and recharge rates along with stable delta-18O and delta-D measurements to determine water sources and losses; and

5. Model groundwater flow dynamics under varying stresses, constrained by rates from O4, to understand groundwater flow dynamics and to forecast the response of the groundwater system to a range of imposed human interventions and changes in the water cycle.

Findings to date can be summarised as follows:

We identified the study area, focusing on the Ghaggar River basin in Haryana and Punjab states. Acquired all available data on water levels from existing boreholes (from both Central Groundwater Board and state groundwater boards), tritium and stable isotope analysis of groundwater samples, well logs and lithologs, and resistivity surveys. We have compiled these data into a GIS framework. [objective O1]

We acquired and interpreted resistivity profiles along key transects in the central Ghaggar River basin. Resistivity data have now been calibrated against the drilling field logs and core logs. These profiles have identified the primary electrical stratigraphy within the upper 100 m of the study area, and have provided constraints on the geometry and size of sub-surface channel bodies and stacking patterns. Typical sand bodies appear to be 10 m thick and 2-5 km in width (in some cases up to 10 km).

We completed the drilling programme in February 2014. This is a major component of O1-2 and its successful completion marks a significant milestone in the project. We recovered 10 cores (to depths of 45-50 m); these form a transect that extends across the Ghaggar palaeochannel, allowing us to observe differences in stratigraphic architecture both inside and outside of the palaeochannel belt. One core was recovered from the proximal portion of the Ghaggar valley, well upstream of any possible influence from the Sutlej and Yamuna rivers, in order to isolate the stratigraphic and sedimentologic signature of the Ghaggar source over time. At five sites, we drilled deep boreholes (to 150 m) and installed a set of observation wells, which will allow us to (1) assess the deeper stratigraphic architecture from the field logs and cuttings, and (2) collect water samples for isotopic and radiocarbon analyses from known aquifer depths.

We completed logging of all cores, and OSL dating has been carried out by project partner Dr Andrew Murray (Risø, Denmark). Encouragingly, the dates are in approximate stratigraphic order. They show that our cores extend back to 40-50 ka, and that sand bodies are constructed by filling incised valleys and stacking of multi-story channel deposits over time.

We acquired a database of aquifer depths and thicknesses, compiled from ~250 well logs held by the CGWB in Chandigarh. Analysis of these data shows that aquifer thicknesses follow a power-law distribution that varies in predictable ways in space (between the Yamuna and Sutlej systems, and from proximal to distal settings) and time (depth). The thickest aquifers (more than 10-20 m) are likely to be multi-story channel bodies produced by persistent occupation (or repeated re-occupation) of sediment transport pathways over time. The data reveal the stacking pattern of those channel deposits, and show that aquifer bodies are both more abundant and thicker below the Sutlej and Yamuna fans than below the Ghaggar River or interfan area. The data also give the probability of finding aquifer bodies of at least a given thickness in the region.

We integrated available imagery and DEMs to produce a geomorphic map of the Yamuna, Ghaggar, and Sutlej river systems in the foreland. This shows clearly that the Sutlej and Yamuna have deposited large sediment fans through repeated avulsion and channel switching across the study area. The modern Ghaggar River, and the Sutlej palaeochannel that is the focus of our investigation, flow down the intersection between these fans and are steered by the existing fan topography, helping to ensure that this channel position is persistently reoccupied over time. Analysis of the fan surface topography shows clear evidence for older palaeochannels, derived from both the Yamuna and Sutlej catchments, across the fan surfaces. These observations can be integrated into a process-based model of the aquifer system in which sand bodies are deposited both by (1) the avulsive Yamuna and Sutlej systems and (2) smaller, plains-fed or foothills-fed channel systems that flow across the fan surfaces. This model has important implications for the expected geometry, persistence, and lateral connectivity of sand bodies (and thus aquifers) in the subsurface.

We acquired an extensive database of water level data from the Punjab and Haryana State Groundwater Boards and the CGWB. We completed cleaning the water level data from the CGWB and state groundwater boards, and have interpolated these into the first detailed dataset of water-level change (1974-2010) in the region. We have completed cluster analysis to identify regions of similar water-level response. Our results show that regional-scale water-level declines began in approximately 1999-2000, but the timing of onset and the rate of water-level decline is highly variable. The declines are concentrated in northern Haryana and Punjab and along the Ghaggar River valley. Areas in central and southern Haryana and Punjab have experienced net water-level rise and waterlogging issues over the same time period. The patterns of water-level change do not match available data on abstraction. They do, however, match spatial variations in aquifer characteristics as measured in this project - areas with low bulk aquifer percentage and thinner or less abundant aquifer bodies have suffered earlier, and greater, water-level declines than areas underlain by thick, abundant aquifer bodies. This result indicates the importance of considering subsurface geology in understanding, and anticipating, patterns of water-level change. [Not in original project objectives but significant new activity]

We collected pre- and post-monsoon samples for several seasons from 247 wells in the Ghaggar River basin for stable isotopic analysis. The results show that recharge in proximal parts of the basin occurs through local precipitation, whereas recharge in distal areas occurs through a combination of canal leakage, lateral flow, and local precipitation. Because of these different mechanisms, two distinct zones can be defined: a near-surface zone (<80 m below ground level) with relatively young waters and a mix of recharge sources, and a deeper zone (>80 m below ground level) with older waters that are limited to recharge by local precipitation and lateral flow. Salinity also increases toward the distal part of the system, indicating increased evaporation of groundwater.

We received a grant from the NERC Radiocarbon Facility for 20 14C analyses on groundwater samples. The first round of samples were collected in spring 2015, following consultation with Dr. Pauline Gulliver (SUERC, Glasgow); Dr Mohammed Hoque (Dept. of Civil Engineering, Imperial College), Dr Bhishm Kumar (IAEA VIenna), and colleagues at NIH. All analyses are now complete, and we are analysing the results.

A pumping test at the KA-2 drill site was carried out to measure in-situ aquifer parameters, and to establish the degree of connectivity between two of the major sand bodies encountered at that site.

We have partnered with Dr Chris Jackson (British Geological Survey) to apply the groundwater model Aquimod to help understand the primary controls on water-level changes across the study area. This partnership is supported by additional follow-on funding from NERC and the Newton Fund. The results show that different geomorphic units have different patterns of response, and that (to first order) water-level decline in the interfan area and in the Ghaggar River region is driven by rapid abstraction and the presence of fewer, thinner aquifer bodies in the subsurface, compared to areas on the Sutlej and Yamuna fans. This provides the first quantitative explanation for the patterns of water-level change in the region, and provides the basis for a better understanding of potential management strategies.

We have also created a simple predictive model of aquifer-body occurrence, using the CGWB aquifer-thickness logs and some geological understanding of fan systems to estimate the probability of finding aquifer material at any point and depth. This model can be easily adapted and improved as new well information becomes available.
Exploitation Route Our research will be highly relevant for the management of groundwater resources in northwestern India over the next 50-100 years. The research has provided quantitative information on the geometry and configuration of aquifer bodies that was not previously available, but that is required for planning and management of groundwater abstraction. It has also provided the first detailed picture of groundwater loss across the region, and the first predictive model of aquifer occurrence in the subsurface. The research results will be put to use through direct engagement with the Central Groundwater Board and with the state groundwater boards of Punjab, Haryana, and Rajasthan. We have met already with key representatives of each of these bodies, and have ensured that our research efforts are complementary to existing projects, including the World Bank-funded Aquifer Mapping Programme. We ran a preliminary training workshop for these bodies in Delhi in March 2016, and the project results were greeted with enthusiasm and requests for longer and more in-depth training. We are still awaiting the outcome of discussions between NERC and the Indian MoES on potential funding sources that could support the design and delivery of this training programme.
Sectors Environment

 
Description The findings have direct relevance for groundwater resource assessment, and to some degree for groundwater management in the region. We continue to discuss the results of the research with key stakeholders in the Central Groundwater Board and in the state groundwater boards of Haryana and Punjab. We have already contributed our findings to a review of the CGWB and Central Water Commission led by the Government of India in early 2016; this work was incorporated into the report of the Mihir Shah Commission on the restructuring of the CGWB and Central Water Commission, which has led to plans for a National Water Commission. Impact was further developed by a workshop for CGWB and state groundwater board scientists in March 2016. Indian project PI Sinha has now served as an expert member on two Ministry of Water Resources, River Development, and Ganga Rejuvenation panels: one on palaeochannel assessment and another on palaeochannels and groundwater resources. He has also been funded by the Ministry to prepare aquifer management plans in the study area of Punjab and Haryana, which are ongoing. A new strand of potential impact emerged in 2019/20 through the India-UK Water Centre (IUKWC), which has coordinated a wide-ranging stakeholder engagement exercise in the Indian water sector. A key outcome of that exercise was to identify the specific information needs of state-level groundwater boards. The state groundwater board in Uttar Pradesh (UP) is particularly relevant to our research, as the state is largely underlain by the same alluvial aquifers that are found in the neighbouring states of Punjab and Haryana. We are currently (February 2020) exploring the possibility of impact with the UP board.
First Year Of Impact 2015
Sector Environment
Impact Types Policy & public services

 
Description Central Groundwater Board: advice to Government of India review
Geographic Reach Asia 
Policy Influence Type Participation in a advisory committee
 
Description NERC Newton follow-on funding: Changing Water Cycle
Amount £133,946 (GBP)
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 01/2015 
End 08/2016
 
Description NERC Radiocarbon Facility Funding
Amount £12,500 (GBP)
Organisation Natural Environment Research Council 
Department NERC Radiocarbon Facility (Environment)
Sector Charity/Non Profit
Country United Kingdom
Start 11/2014 
End 11/2015
 
Description British Geological Survey 
Organisation British Geological Survey
Country United Kingdom 
Sector Academic/University 
PI Contribution We led the project and have acquired all of the data and samples
Collaborator Contribution Collaboration occurred in two areas: 1) Dr Daren Gooddy led analysis and interpretation of isotopic groundwater tracers, including CFCs and SF6, and assisted with interpretation of the radiocarbon results. 2) Dr Chris Jackson led analysis of water-level changes using the 1-D Aquimod model, and interpretation of the model results. The project team lacks expertise in these areas, so their participation in the research wa a major positive addition that was unanticipated when the project began.
Impact No specific outputs yet, but several manuscripts are in preparation.
Start Year 2015
 
Description CGWB Chandigarh 
Organisation Central Ground Water Board
Country India 
Sector Public 
PI Contribution Our project requires data on aquifer characteristics, existing boreholes, and stratigraphy across the study area. We are providing a conceptual framework within which these data can be understood, as well as a multi-disciplinary approach to characterising the aquifer system.
Collaborator Contribution The partner has made large amounts of data available, including borehole locations and water levels (2002-present), lithologs, and aquifer thickness data for >700 boreholes. This represents a unique dataset that was not anticipated at the outset of the project.
Impact Training workshop in March 2016 Joshi, S., Rai, S.P., Sinha, R., Gupta, S., Densmore, A.L., Rawat, Y.S., and Shekhar, S. (2018) Tracing groundwater recharge sources in the northwestern Indian alluvial aquifer using water isotopes (?18O, ?2H and 3H). Journal of Hydrology, 559, 835-847. Not multi-disciplinary Singh, A., Thomsen, K.J., Sinha, R., Buylaert, J.-P., Carter, A., Mark, D.F., Mason, P.J., Densmore, A.L., Murray, A.S., Jain, M., Paul, D., and Gupta, S. (2017) Counter-intuitive influence of Himalayan river morphodynamics on Indus Civilisation urban settlements. Nature Communications, 8, doi:10.1038/s41467-017-01643-9. Not multi-disciplinary van Dijk, W.M., Densmore, A.L., Sinha, R., Singh, A., and Voller, V.R. (2016) Reduced-complexity probabilistic reconstruction of alluvial aquifer stratigraphy, and application to sedimentary fans in northwestern India. Journal of Hydrology, 541, 1241-1257, doi:10.1016/j.jhydrol.2016.08.028. Not multi-disciplinary van Dijk, W.M., Densmore, A.L., Singh, A., Gupta, S., Sinha, R., Mason, P.J., Joshi, S.K., Nayak, N., Kumar, M., Shekhar, S., Kumar, D., and Rai, S.P. (2016) Linking the morphology of fluvial fan systems to aquifer stratigraphy in the Sutlej-Yamuna plain of northwest India. Journal of Geophysical Research - Earth Surface, 121, doi:10.1002/2015JF003720. Not multi-disciplinary
Start Year 2013
 
Description Central Groundwater Board 
Organisation Central Ground Water Board
Country India 
Sector Public 
PI Contribution Provided access to research results - specifically around approaches that could assist CGWB in delivering their mandate of nationwide aquifer mapping
Collaborator Contribution Provided water-level data from CGWB monitoring wells Provided information on existing training programmes for CGWB scientists
Impact Training workshop in March 2016 Joshi, S., Rai, S.P., Sinha, R., Gupta, S., Densmore, A.L., Rawat, Y.S., and Shekhar, S. (2018) Tracing groundwater recharge sources in the northwestern Indian alluvial aquifer using water isotopes (?18O, ?2H and 3H). Journal of Hydrology, 559, 835-847. Not multi-disciplinary Singh, A., Thomsen, K.J., Sinha, R., Buylaert, J.-P., Carter, A., Mark, D.F., Mason, P.J., Densmore, A.L., Murray, A.S., Jain, M., Paul, D., and Gupta, S. (2017) Counter-intuitive influence of Himalayan river morphodynamics on Indus Civilisation urban settlements. Nature Communications, 8, doi:10.1038/s41467-017-01643-9. Not multi-disciplinary van Dijk, W.M., Densmore, A.L., Sinha, R., Singh, A., and Voller, V.R. (2016) Reduced-complexity probabilistic reconstruction of alluvial aquifer stratigraphy, and application to sedimentary fans in northwestern India. Journal of Hydrology, 541, 1241-1257, doi:10.1016/j.jhydrol.2016.08.028. Not multi-disciplinary van Dijk, W.M., Densmore, A.L., Singh, A., Gupta, S., Sinha, R., Mason, P.J., Joshi, S.K., Nayak, N., Kumar, M., Shekhar, S., Kumar, D., and Rai, S.P. (2016) Linking the morphology of fluvial fan systems to aquifer stratigraphy in the Sutlej-Yamuna plain of northwest India. Journal of Geophysical Research - Earth Surface, 121, doi:10.1002/2015JF003720. Not multi-disciplinary
Start Year 2015
 
Description Radiocarbon and isotopic interpretation 
Organisation Imperial College London
Country United Kingdom 
Sector Academic/University 
PI Contribution We are leading the research project and have acquired samples for radiocarbon analysis, to determine the age of the groundwater across our study area.
Collaborator Contribution The partner is contributing expertise in sample collection, analysis, and interpretation of the results. This was not anticipated in the original proposal, and represents a substantial new data set.
Impact No outputs yet - samples were collected in spring 2015 and analytical results have just been received.
Start Year 2013
 
Description Irrigation and Water Forum presentation (London) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presentation on research results to meeting of the Irrigation and Water Forum in London. Raised awareness of research among water practitioners, and led to discussions with researchers at British Geological Survey working on parallel studies of groundwater in Indo-Gangetic Basin.
Year(s) Of Engagement Activity 2014
 
Description Meeting with Central Groundwater Board 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Meetings with chair and senior staff of the Central Groundwater Board, May 2016, to discuss outcomes of the research and its relevance for supporting the activities of the CGWB. We were requested to prepare and run a longer (~5 day) training programme covering the outcomes of the research, and we are currently waiting for an appropriate funding opportunity to support this.
Year(s) Of Engagement Activity 2016
 
Description Presentation to Indian water policymakers, CEH Wallingford 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact Presentation of research results to delegation of Indian water policymakers as part of NERC-funded UK-India information exchange over water issues. Led to detailed discussion and requests for further engagement with Dipankar Saha, Secretary of Central Groundwater Board, Govt of India.
Year(s) Of Engagement Activity 2016
 
Description Training workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We ran a training workshop in Delhi in March 2016 for 26 groundwater scientists from the Central Groundwater Board and various state groundwater boards, plus additional staff from water-related NGOs and postgraduate students. This involved two days of short lectures and practical exercises, drawn from the outcomes of the research project, aimed at communicating the key techniques and findings to practitioners who could use the approaches in their own work. The workshop was opened and closed by high-ranking ministerial officials from the Ministry of Water Resources, and we followed up with meetings with the Special Secretary and Joint Secretary of MoWR and the chair of the Central Groundwater Board. We monitored the engagement and uptake of the materials through a set of questionnnaires before and after the workshop.
Year(s) Of Engagement Activity 2016