Professional summary

Ponnambalam Rameshwaran (Ramesh) is a Senior Research Scientist at the UK Centre for Ecology & Hydrology. His research focuses on developing hydraulic, hydrological and water quality models at the reach, national, and continental scales. This includes formulating new equations, improving the representation of natural and human-made processes in hydraulic river models, and integrating anthropogenic impacts and climate scenarios into hydrological and water quality models. He also conducts physical model experiments, field monitoring, and data analysis. His detailed understanding of river and groundwater processes - gained through experimental and field work - enables him to effectively bridge the gap between modelling and monitoring.

Ramesh has a BSc in Civil and Structural Engineering from the University of Bradford, an MPhil from the University of Wales and a PhD from the University of Aberdeen, Scotland.

Web tools and apps

Web Portal: Projected future changes in river flows across West Africa

Journal Paper: Rameshwaran, P, Bell, V A, Davies, H N & Kay, A L. 2021. How might climate change affect river flows across West Africa? Climatic Change, 169, 21. DOI: 10.1007/s10584-021-03256-0

Data (CMIP5): Rameshwaran, P, Bell, V A, Davies, H N & Kay, A L. 2021. Historical (1950–2005) and projected (2006–2099) hydrological model (HMF-WA) estimates of monthly mean and annual maximum river flows across West Africa driven by CMIP5 projected climate data. NERC EDS Environmental Information Data Centre. DOI: 10.5285/6429828f-6a06-4d2d-8f50-4910b18f7ff4

Data (CMIP6): Rameshwaran, P, Bell, V A, Brown, M J & Davies, H N. 2022. Historical (1950–2014) and projected (2015–2100) hydrological model (HMF-WA) estimates of monthly mean and annual maximum river flows across West Africa driven by CMIP6 projected climate data. NERC EDS Environmental Information Data Centre. DOI: 10.5285/346124fd-a0c6-490f-b5af-eaccbb26ab6b

 

Projected future changes in river flows across Peninsular Malaysia

Web Portal: Projected future changes in river flows across Peninsular Malaysia

DATA: Rameshwaran, P.; Bell, V.A.; Davies, H.N.; Brown, M.J.; Zulkafli, Z.; Rehan, B.M.; Okeke, T.C. Historical (1971-2005) and projected (2006-2099) hydrological model (HMF-Malaysia) estimates of monthly mean and annual maximum river flows across Peninsular Malaysia driven by CORDEX-SEA projected climate data. EIDC 15 September 2022, https://doi.org/10.5285/9b70bebe-189c-4ae8-9aee-1bb1db7b1ad5

 

Hydrological Modelling Modelling the future of Artificial Influence (AI)-impacted river flows

Web Portal: Modelling the future of Artificial Influence (AI)-impacted river flows

CS-NOW: Gridded future projections of natural and artificially influenced river flows (1980 to 2080):

DATA DOCUMENTATION: Rameshwaran, P., Bell, V. A., Davies, H. N., Baron, H., Keller, V., & Hannaford, J. (2025) DATA DOCUMENTATION - CS-NOW: Gridded future projections of natural and artificially influenced river flows (1980 to 2080). Zenodo, https://doi.org/10.5281/zenodo.10958783

DATA: Rameshwaran, P.; Bell, V.A.; Davies, H.N.; Baron, H.; Keller, V.; Hannaford, J.; Rhodes-Smith, M. (2025): CS-NOW: Gridded future projections of natural and artificially influenced river flows (1980 to 2080). NERC EDS Centre for Environmental Data Analysis, https://dx.doi.org/10.5285/cf66055440344d7eb9b6f834e81736c6

Gridded actual groundwater, surface water and tidal water abstraction, discharge and Hands-off Flow datasets for England (1999 to 2014):

DATA DOCUMENTATION: Rameshwaran, P., Bell, V. A., Davies, H. N., Sadler, P., Beverton, A., & Thornton, R. (2025). DATA DOCUMENTATION - Gridded actual groundwater, surface water and tidal water abstraction, discharge and Hands-off Flow datasets for England (1999 to 2014). Zenodo. https://doi.org/10.5281/zenodo.13746897

DATA: Rameshwaran, P.; Bell, V.A.; Davies, H.N.; Sadler, P.; Beverton, A.; Thornton, R.; Rhodes-Smith, M. (2025): Gridded actual groundwater, surface water and tidal water abstraction, discharge and Hands-off Flow datasets for England (1999 to 2014). NERC EDS Centre for Environmental Data Analysis. https://dx.doi.org/10.5285/18886f95ba84447f997efac96df456ad

Selected publications

Hagemann, S. et al. , (2013), Climate change impact on available water resources obtained using multiple global climate and hydrology models . Earth System Dynamics, 4, 129-144, http://www.earth-syst-dynam.net/4/129/2013/esd-4-129-2013.pdf

Rameshwaran Ponnambalam et al. , (2025), Nature-based solutions (Nbs) for flood mitigation: recent UK case studies. E3S Web of Conferences, 599, https://doi.org/10.1051/e3sconf/202459902004

Rulent Julia et al. , (2024), Modelling pollutants transport scenarios based on the X-Press Pearl disaster. Marine Pollution Bulletin, 209, http://dx.doi.org/10.1016/j.marpolbul.2024.117129

Karthiga Inthirakumaran et al. , (2023), Groundwater mapping and locally engaged water governance in a small island terrain: case study of Karainagar island, northern Sri Lanka. World Water Policy, 9, 456-480, http://dx.doi.org/10.1002/wwp2.12112

Robotham John et al. , (2023), Nature-based solutions enhance sediment and nutrient storage in an agricultural lowland catchment. Earth Surface Processes and Landforms, 48, 243-258, https://onlinelibrary.wiley.com/doi/10.1002/esp.5483

Fatdillah Eva et al. , (2022), Spatial estimates of flood damage and risk are influenced by the underpinning DEM resolution: a case study in Kuala Lumpur, Malaysia. Water, 14, http://dx.doi.org/10.3390/w14142208

Rameshwaran Ponnambalam et al. , (2022), Use of abstraction and discharge data to improve the performance of a national‐scale hydrological model. Water Resources Research, 58, http://dx.doi.org/10.1029/2021WR029787

Rameshwaran Ponnambalam et al. , (2021), How might climate change affect river flows across West Africa?. Climatic Change, 169, http://dx.doi.org/10.1007/s10584-021-03256-0

Robotham John et al. , (2021), Sediment and nutrient retention in ponds on an agricultural stream: evaluating effectiveness for diffuse pollution mitigation. Water, 13, http://dx.doi.org/10.3390/w13121640

Rameshwaran Ponnambalam et al. , (2016), Effects of drip-irrigation regimes with saline water on pepper productivity and soil salinity under greenhouse conditions. 199, 114-123, http://dx.doi.org/10.1016/j.scienta.2015.12.007

Other Publications
  • Diop, Serigne Bassirou; Ekolu, Job; Tramblay, Yves; Dieppois, Bastien; Grimaldi, Stefania; Bodian, Ansoumana; Blanchet, Juliette; Rameshwaran, Ponnambalam; Salamon, Peter; Sultan, Benjamin. 2025 Climate change impacts on floods in West Africa: new insight from two large-scale hydrological models. NHESS, 25, 3161–3184. https://doi.org/10.5194/nhess-25-3161-2025
  • Rameshwaran, Ponnambalam; Blake, James; Trill, Emily; Robotham, John; Bishop, James; Old, Gareth; O'Brien, Alex; Scarlett, Peter. 2025 Nature-based solutions (Nbs) for flood mitigation: recent UK case studies. E3S Web of Conferences, 599, 02004. 6, pp. https://doi.org/10.1051/e3sconf/202459902004
  • Rulent, Julia; James, Molly K.; Rameshwaran, Ponnambalam; Jardine, Jennifer E.; Katavouta, Anna; Wakelin, Sarah; Jayathilaka, Ruchira; Arulananthan, Kanapathipillai; Holt, Jason; Sutton, Mark A.; Artioli, Yuri. 2024 Modelling pollutants transport scenarios based on the X-Press Pearl disaster. Marine Pollution Bulletin, 209 (A), 117129. 17, pp. https://doi.org/10.1016/j.marpolbul.2024.117129
  • Karthiga, Inthirakumaran; Rameshwaran, Ponnambalam; Ketheesan, Balachandran; Sriskandarajah, Nadarajah. 2023 Groundwater mapping and locally engaged water governance in a small island terrain: case study of Karainagar island, northern Sri Lanka. World Water Policy, 9 (3). 456-480. https://doi.org/10.1002/wwp2.12112
  • Robotham, John; Old, Gareth; Rameshwaran, Ponnambalam; Sear, David; Trill, Emily; Bishop, James; Gasca-Tucker, David; Old, Joanne; McKnight, David. 2023 Nature-based solutions enhance sediment and nutrient storage in an agricultural lowland catchment. Earth Surface Processes and Landforms, 48 (2). 243-258. https://doi.org/10.1002/esp.5483
  • Davies, Helen N.; Rameshwaran, Ponnambalam; Bell, Victoria A.; Dadson, Simon . 2023 Spatially consistent physical characteristics of UK rivers: 1‐km data. Geoscience Data Journal. 8, pp. https://doi.org/10.1002/gdj3.209
  • Robotham, John; Old, Gareth; Rameshwaran, Ponnambalam; Sear, David; Trill, Emily; Bishop, James; Gasca-Tucker, David; Old, Joanne; McKnight, David. 2023 Nature-based solutions enhance sediment and nutrient storage in an agricultural lowland catchment. Earth Surface Processes and Landforms, 48 (2). 243-258. https://doi.org/10.1002/esp.5483
  • Rameshwaran, P., Bell, V. A., Brown, M. J., Davies, H. N., Kay, A. L., Rudd, A. C. & Sefton, C. 2022. Use of Abstraction and Discharge Data to Improve the Performance of a National-Scale Hydrological Model. Water Resources Research, 58, e2021WR029787, 1-24. https://doi.org/10.1029/2021WR029787
  • Fatdillah, Eva; Rehan, Balqis M.; Rameshwaran, Ponnambalam; Bell, Victoria A.; Zulkafli, Zed; Yusuf, Badronnisa; Sayers, Paul. 2022 Spatial estimates of flood damage and risk are influenced by the underpinning DEM resolution: a case study in Kuala Lumpur, Malaysia. Water, 14 (14), 2208. 18, pp. https://doi.org/10.3390/w14142208
  • Rameshwaran, P., Bell, V. A., Davies, H. N. & Kay, A. L. 2021 How might climate change affect river flows across West Africa? Climatic Change, 169, 21, 1-27. https://doi.org/10.1007/s10584-021-03256-0
  • Rameshwaran, Ponnambalam; Tepe, Akin; Yazar, Attila; Ragab, Ragab . 2016 Effects of drip-irrigation regimes with saline water on pepper productivity and soil salinity under greenhouse conditions. Scientia Horticulturae, 199. 114-123. https://doi.org/10.1016/j.scienta.2015.12.007
  • Arslan, A.; Majid, G.A.; Abdallah, K.; Rameshwaran, P.; Ragab, R.; Singh, M.; Qadir, M.. 2016 Evaluating the productivity potential of chickpea, lentil and faba bean under saline water irrigation systems. Irrigation and Drainage, 65 (1). 19-28. https://doi.org/10.1002/ird.1912
  • Rameshwaran, Ponnambalam; Qadir, Manzoor; Ragab, Ragab; Arslan, Awadis; Majid, Ghalia Abdul; Abdallah, Khalaf. 2016 Tolerance of faba bean, chickpea and lentil to salinity: accessions' salinity response functions. Irrigation and Drainage, 65 (1). 49-60. https://doi.org/10.1002/ird.1922
  • Rameshwaran, Ponnambalam; Tepe, Akin; Yazar, Attila; Ragab, Ragab . 2015 The effect of saline irrigation water on the yield of pepper: experimental and modelling study. Irrigation and Drainage, 64. 41-49. https://doi.org/10.1002/ird.1867
  • Old, G.H.; Naden, P.S.; Rameshwaran, P.; Acreman, M.C.; Baker, S.; Edwards, F.K.; Sorensen, J.P.R.; Mountford, O.; Gooddy, D.C.; Stratford, C.J.; Scarlett, P.M.; Newman, J.R.; Neal, M.. 2014 Instream and riparian implications of weed cutting in a chalk river. Ecological Engineering, 71. 290-300. https://doi.org/10.1016/j.ecoleng.2014.07.006
  • Rameshwaran, Ponnambalam; Naden, Pamela; Wilson, Catherine A.M.E.; Malki, Rami; Shukla, Deepak R.; Shiono, Koji. 2013 Inter-comparison and validation of computational fluid dynamics codes in two-stage meandering channel flows. Applied Mathematical Modelling, 37 (20-21). 8652-8672. https://doi.org/10.1016/j.apm.2013.07.016
  • Gunawan, B.; Sun, X.; Sterling, M.; Shiono, K.; Tsubaki, R.; Rameshwaran, P.; Knight, D.W.; Chandler, J.H.; Tang, X.; Fujita, I.. 2012 The application of LS-PIV to a small irregular river for inbank and overbank flows. Flow Measurement and Instrumentation, 24. 1-12. https://doi.org/10.1016/j.flowmeasinst.2012.02.001
  • Rameshwaran, Ponnambalam; Naden, Pamela S.; Lawless, Mark. 2011 Flow modelling in gravel-bed rivers: rethinking the bottom boundary condition. Earth Surface Processes and Landforms, 36 (10). 1350-1366. https://doi.org/10.1002/esp.2158
  • Sun, X.; Shiono, K.; Chandler, J.H.; Rameshwaran, P.; Sellin, R.H.J.; Fujita, I.. 2010 Discharge estimation in small irregular river using LSPIV. Proceedings of the ICE - Water Management, 163 (5). 247-254. https://doi.org/10.1680/wama.2010.163.5.247
  • Sun, Xin; Shiono, Koji; Rameshwaran, Ponnambalam; Chandler, Jim H.. 2010 Modelling vegetation effects in irregular meandering river. Journal of Hydraulic Research, 48. 775-783. https://doi.org/10.1080/00221686.2010.531101
  • Shiono, K.; Chan, Tony L.; Spooner, Jake; Rameshwaran, P.; Chandler, J. H.. 2009 The effect of floodplain roughness on flow structures, bedforms and sediment transport rates in meandering channels with overbank flows: Part I. Journal of Hydraulic Research, 47 (1). 5-19. https://doi.org/10.3826/jhr.2009.2944-I
  • Shiono, K.; Chan, Tony L.; Spooner, Jake; Rameshwaran, P.; Chandler, J. H.. 2009 The effect of floodplain roughness on flow structures, bedforms and sediment transport rates in meandering channels with overbank flows: Part II. Journal of Hydraulic Research, 47 (1). 20-28. https://doi.org/10.3826/jhr.2009.2944-II
  • Shiono, K.; Spooner, J.; Chan, T.; Rameshwaran, P.; Chandler, J.. 2008 Flow characteristics in meandering channels with non-mobile and mobile beds for overbank flows. Journal of Hydraulic Research, 46 (1). 113-132, https://doi.org/10.1080/00221686.2008.9521848
  • Rameshwaran, P.; Shiono, K.. 2007 Quasi two-dimensional model for straight overbank flows through emergent vegetation on floodplains. Journal of Hydraulic Research, 45 (3). 302-315, https://doi.org/10.1080/00221686.2007.9521765
  • Naden, Pamela; Rameshwaran, Ponnambalam; Mountford, Owen; Robertson, Coralie. 2006 The influence of macrophyte growth, typical of eutrophic conditions, on river flow velocities and turbulence production. Hydrological Processes, 20. 3915-3938. https://doi.org/10.1002/hyp.6165
  • Rameshwaran, P.; Naden, P.S.. 2004 Modelling turbulent flow in two-stage meandering channels. Proceedings of the Institution of Civil Engineers - Water Management, 157 (3). 159-173. https://doi.org/10.1680/wama.2004.157.3.159