Institute of Hazard, Risk and Resilience (IHRR) Seminar Series: Professor Alex Densmore

Monday 12th January 2026

Open to everyone both in person TLC106 and online register here

Why alluvial fans matter: groundwater abstraction and decline in Northwestern India

Abstract: India, the largest agricultural user of groundwater in the world, has seen a revolutionary shift from large-scale surface water management to widespread groundwater abstraction in the last 50 years, particularly in the northwestern states of Punjab, Haryana and Rajasthan. As a result, these states have become a global hotspot of groundwater depletion, with the largest rate of groundwater loss in any comparably-sized region on Earth. Until recently, there has been no integrated view of the aquifer system in northwestern India, no detailed understanding of the decline in groundwater levels, and no regional-scale conceptual framework with which to understand these changes and forecast the evolution of the system. In this talk, I will describe preliminary efforts to address these gaps by documenting, for the first time, the spatial pattern of groundwater depletion in northwestern India and the link between the pattern of depletion and the distribution of aquifer units in the subsurface. It turns out that the distribution of aquifer units is directly controlled by the geomorphology and sedimentary architecture of large alluvial fans in the Ganga Basin. Understanding that architecture therefore gives us a predictive framework by which to understand both patterns of groundwater decline in the past and potential responses of the groundwater system in the future. I close with some recommendations for how this framework can be used for more effective resource management, including regulation of abstraction and artificial recharge, as well as some of the challenges in realising that goal.

Biography:

I am a professor of physical geography in the Department of Geography at Durham University, and a fellow of IHRR. My research looks at the evolution of tectonically-active mountain ranges, including the impacts of earthquakes on the Earth's surface; the distributions, triggers, rates, and evolution of landslides and debris flows; cascading and compound hazards triggered by both earthquakes and rainfall; and catchment-scale sediment transfer and sediment fan development. I also study the ways in which scientific knowledge of these Earth surface processes can be used for disaster risk reduction and for humanitarian planning and preparedness.

Further reading (all open access):

Joshi, S.K., Gupta, S., Sinha, R., Rai, S.P., Densmore, A.L., Shekhar, S., Mason, P.J., and van Dijk, W.M. (2021) Strongly heterogeneous patterns of groundwater depletion in northwestern India. Journal of Hydrology, 598, https://doi.org/10.1016/j.jhydrol.2021.126492.

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, https://doi.org/10.1038/s41467-017-01643-9.

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, https://doi.org/10.1002/2015JF003720.

Sinha, R., and Densmore, A.L. (2016) Focus on sustainable groundwater management. Economic and Political Weekly, 51, 53-55, 24 Dec 2016. Available at https://www.epw.in/journal/2016/52/water-governance/focus-sustainable-groundwater-management.html.