Abstract: River Thames modelling, final report
The River Thames is the principal river system in southern England, which provides the main water supply for London and drains an area of approximately 10,000 km2. The catchment is densely populated and highly vulnerable to changes in climate, land use and population. The river is eutrophic with significant algal blooms. Phosphorus (P) and nitrogen (N) are both key nutrients and play an important role in system eutrophication. To predict the Thames vulnerability to climate and land-use change and to changes in water resource allocations, the Integrated Catchments Model for Nitrogen (INCA-N) and Phosphorus (INCA-P) were used to model the entire system (Jin et al., 2012; Whitehead et al., 2013). Both the INCA-N and INCA-P models simulated daily flow rates, with INCA-N simulating daily nitrate (NO3) and ammonium (NH4) concentrations and INCA-P daily soluble reactive P (SRP) and suspended sediment (SS) concentrations.
The modelling work done is summarised in Table 1. The model applications were used as path-finder projects to test the integration of the biophysical modelling work and the cost-effectiveness analysis and the full details of this integration and the results are given in two of the attached papers (Crossman et al., 2013; Whitehead et al., 2013). The goodness-of-fit statistics for the Thames INCA-N and INCA-P calibration and validation model simulations are shown in Table 2. Figures 1 and 2 show the target diagrams to evaluate model performance for INCA-N and INCA-P respectively. The results indicate that the INCA models reproduced the both hydrological regime and nutrient dynamics (SRP and NO3) in the river. Full details are given in Jin et al., 2012; Whitehead et al., 2013; Crossman et al., 2013.
Jin L, Whitehead PG, Futter MN, Lu Z. (2012). Modelling the impacts of climate change on flow and nitrate in the River Thames: assessing potential adaptation strategies. Hydrology Research, 43: 902-916.
Whitehead PG, Crossman J, Balana BB, Futter MN, Comber S, Jin L, et al. (2013). A costeffectiveness analysis of water security and water quality: impacts of climate and land-use change on the River Thames system. Philosophical Transactions Royal Society A, 371: 20120413.
Crossman J, Whitehead PG, Futter MN, Jin L, Shahgedanova M, Castellazzi M, et al. (2013). The interactive responses of water quality and hydrology to changes in multiple stressors, and implications for the long-term effective management of phosphorus. Science of the Total Environment, 454: 230-244