Hydrology and Ecology of the RBGE Pond

The pond in RBGE (Edinburgh, Scotland) is an important component of Blue Green Infrastructure (BGI). It has a regulatory function for the runoff, and provides multiple benefits related to e.g. recreation, education, water quality, amenity and biodiversity value. Characterisation of the pond’s hydrology is important for the understanding of its overall functioning and provision of ecosystem services.

This paper reports on the results of hydrological modelling of the pond’s water catchment using Shetran and CityCat. These models are complementary, and are therefore best applied in concert thus providing the full spectrum of expected scenarios. The CityCat model helps to delineate the watershed. It models the surface flow pathways and is particularly valuable for running scenarios of extreme events. The Shetran model has a good representation of evaporation and can simulate groundwater and the overall mass balance. Therefore it provides estimates of flows into and out of the pond, which is very helpful for the understanding of what exactly is happening in `normal` and `design` conditions.

The results of hydrological modelling may prove particularly valuable for introducing practical measures preventing waterlogging of the soil and ensuring uninterrupted supply of public services by the Botanic Garden. A raingarden (a shallow planted basin) is currently being installed by the RBGE in one of the more problematic areas. This will be planted with a selection of native plants able to tolerate occasional flooding. This paper will provide a short discussion on ecology of the main RBGE pond and the adjacent areas. Overall, this territory is characterised by a very high biodiversity value as it has a mix of native and introduced species.