Lessons learned from Hydrological Modelling of Northern Temperate Peatlands

Hydrological modelling of peatlands requires capturing the complex interactions between overland and subsurface processes along with any anthropogenic impacts, such as artificial drainage for peat extraction and agriculture. To date there has been limited intercomparison studies evaluating the hydrological performance of multiple rainfall-runoff models.  Here, we present the results of two different modelling comparison studies for three raised peatlands located in Ireland. These peatlands have all being heavily impacted by artificial drainage for peat extraction; however, peat extraction activities have halted, and one has been rewetted. The first study compares 47 conceptual rainfall-runoff models included in the MARRMoT toolbox at all three sites, while the second study uses a more process-based framework, SUMMA, to represent the different processes at a drained site with various model configurations. Results from the first study show that there is a significant drop in the ability to simulate the rewetted peatland compared to the drained peatland sites. This study also indicate that the while no single model can outperform others, multi-model ensemble approaches offer better performances. The results from the SUMMA framework highlight the importance of representing the artificial drainage component in simulating the hydrology of drained peatlands. Performance increased significantly once we coded this component into the SUMMA framework.