Areas of Expertise (10)
Professor Nicholas Howden is Reader in Water and Environmental Engineering in the Water Research Group. A catchment hydrologist and hydrogeologist, his area of interest is rivers and ground water and the changes in content of river banks and river area catchments. His research aims to provide a better understanding of how climate, land-use and land management affect the quantity and quality of surface and groundwater over the short and long-term. His work is also focused on the link between the jet stream and increasing patterns of extreme rainfall.
Professor Howden has a particular interest in the River Thames and has reviewed data showing how the Thames' interaction with surrounding land has impacted farmland, sewage effluent and fertilisers over 150 years. He uses this data to model future forecasts for the Thames River. He has also explored the level of phosphorous in rivers and how sustainability might be improved with different management methods, making comparisons with the Mississippi and Yangtze rivers in this context.
Imperial College, London: Ph.D., Hydrology, Hydrogeology, & Hydrogeochemistry 2004
Durham University: M.Eng., Engineering 2000
Media Appearances (3)
The tricky physics behind saving the Whaley Bridge dam, explained
WIRED UK online
Dams have two key elements, says Nicholas Howden of the University of Bristol: an impermeable barrier to hold water in, and ballast to balance the force of all that water. In some cases, both aspects are managed via large concrete barriers, which is both waterproof and heavy. With the Victorian-era Whaley Bridge dam, clay was used to build an impermeable barrier with earth banks used to hold it in place.
Lichen to thrill as rare Golden-eye is discovered in South Wales
Dr Nicholas Howden, Director of the University's MSc Water and Environmental Management Programme, added: "Bristol is one of only a few academic institutions teaching water and environmental management. The University's Department of Civil Engineering has recognised that the global environmental problems faced by humanity today require multiple collaborations between engineers and ecologists. The repair of damaged landscapes and the challenges of global ecosystem restoration called for by the United Nations Aichi Targets allow for nothing less."
Thames archive reveals long nitrate rise
BBC News online
"Generally, Thames water quality has been improving - the fish are returning," explained Bristol's Dr Nicholas Howden. "But the big challenge that remains is diffuse pollution, and the UK remains the global hotspot for nitrate flux.
Exploring the role of hydrological pathways in modulating North Atlantic Oscillation (NAO) teleconnection periodicities from UK rainfall to streamflowHydrology and Earth System Sciences Discussions
2020 An understanding of multi-annual behaviour in streamflow allows for better estimation of the risks associated with hydrological extremes. This is can enable improved preparedness for streamflow-dependant services such as freshwater ecology, drinking water supply and agriculture. Recently, efforts have focused on detecting relationships between long-term hydrological behaviour and oscillatory climate systems (such as the NAO).
Evidence-based conceptual requirements of regional groundwater processes for hydrological simulationsEGU General Assembly Conference Abstracts
2020 River flows are the result of dynamically changing, interacting and non-linear processes of surface, near subsurface and often deeper groundwater flow from climatic drivers. Conceptual rainfall-runoff models, whilst providing advantages in computational efficiency and more minimal data requirements, often struggle to simulate contributions from groundwaters, resulting in poor model calibration.
On doing large-scale hydrology with Lions: Realising the value of perceptual models and knowledge accumulationEarthArXiv
2020 Moving the study domain in hydrology to larger and larger regions leaves us with significant knowledge gaps because we are unable to observe the hydrology of many parts of the world, while in-depth hydrologic studies cover only a fraction of our landscape. On medieval maps, knowledge gaps were shown as images of lions. How do we best acknowledge and reduce these gaps in hydrology, ie our hydrologic lions?
The probability of breaching water quality standards–a probabilistic model of river water nitrate concentrationsJournal of Hydrology
2020 In this study we propose an approach to predicting the probability that river waters will exceed a water quality standard. The study used a two-part generalised linear modelling approach within a Bayesian framework. Binomial regression was used to model the probability that a water quality standard would be exceeded and included two factors – the difference between sampling sites and difference between years of sampling.
Global karst springs hydrograph dataset for research and management of the world’s fastest-flowing groundwaterScientific Data
2020 Karst aquifers provide drinking water for 10% of the world’s population, support agriculture, groundwater-dependent activities, and ecosystems. These aquifers are characterised by complex groundwater-flow systems, hence, they are extremely vulnerable and protecting them requires an in-depth understanding of the systems.