RESCALE Project Charts the Course of Climate Change on Rivers in Mayo
A series of high-resolution computer models to assist land-use and fisheries managers in coping with the effects of climate change on sensitive peatland river catchments have been developed as part of the NDP funded RESCALE project (Review and Simulate Climate and Catchment Responses at Burrishoole). The research was led by the Department of Geography at the National University of Ireland, Maynooth with project partners from the Marine Institute, Newport and the School of Natural Sciences, Trinity College, Dublin. In an Irish context this is the first time that Global Climate Models have been downscaled to a catchment scale and the work has clearly shown that in addition to milder winters and warmer summers we can also expect more frequent flood events in the west of Ireland, with so called 50 year flood events occurring every 7 to 9 years by the 2080s.
Launching the publication of the final report on RESCALE at Newport (Saturday 2nd October 2010), Minister Brendan Smith TD, Minister for Agriculture Fisheries and Food said that the project was a major milestone in our understanding of the effects of climate change on sensitive upland catchments in the west of Ireland. “While global climate change is a worldwide phenomenon, the research findings in this report provide information at the local level that will be invaluable to fisheries and landuse managers,” said the Minister. “Practical research work such as RESCALE is essential if we are to plan for the future management of our valuable agriculture, fisheries and forestry resources in the west of Ireland.”
The core of the RESCALE project is to adapt current large scale computer models, designed to study and predict the worldwide effects of global climate change, for use as high definition models for smaller local river catchments, such as the Burrishoole, in Co. Mayo. What makes the Burrishoole an ideal subject for study is the fact that an unbroken record of information on water temperature, air temperature, river discharge, rainfall and a host of other factors exists for this catchment dating back to the 1950s. This information collected at the Furnace facility and the neighbouring Met Eireann synoptic station, is invaluable as a resource, not only for measuring physical change over the past sixty years, but also as a proven yardstick to “ground-truth” any computer-generated models describing the likely effects of global warming.
“Under our Sea Change strategy the Institute identified climate change as a priority area for research over the period 2007 to 2013 ”, said Dr. Peter Heffernan, Chief Executive of the Marine Institute. “Together with two earlier reports arising from the programme, on the status and impacts of climate change in our marine environment, the RESCALE report adds significantly to our understanding of what is going on in our oceans, rivers and streams. New evidence is emerging that the changes we are seeing in marine and freshwater biological systems are associated with rising water temperatures, as well as related changes in salinity, dissolved oxygen and the circulation of water.”
According to the RESCALE report, high water temperatures in late winter and early spring can have negative impacts on the survival of salmon eggs and young fish, while extreme high temperatures and low water levels during summer can increase the number of deaths in returning adult salmon. Other factors related to the changing climate impacting on salmon and trout survival and the quality of freshwaters are dissolved oxygen, acidity and the amount of dissolved carbon, or colour, in the water.
Dr Rowan Fealy, NUIMaynooth, RESCALE’s lead scientist commented: “This research represents a significant step towards understanding the complex interactions between climate and important indicator species, such as Atlantic salmon and sea trout, at the catchment scale. For some of these species which are close to the southern edge of their geographical range, climate change will represent an additional stress on populations already coping with other human induced pressures.”
While increased water temperatures can have negative impacts on fish such as salmon and trout, their effect can be positive for other species, such as eels, which may benefit from raised water temperatures during the freshwater phase of their life cycle.
“Migratory fish, such as salmon, eels and trout, also provide an ideal barometer of overall changes in the ocean, which makes the information collected by RESCALE so valuable”, commented Minister of State with responsibility for Fisheries, Sean Connick TD. “This work also links directly with ongoing assessments of the impacts of climate change on marine fisheries resources. For example work in NUI Galway has shown significant shifts in the centre of spawning activity of mackerel linked to climate change and the downscaling approach developed in RESCALE has a potential application in examining such important phenomena in greater detail."
The study was primarily concerned with the aquatic environment and the migratory fish in particular but the predicted changes also have major implications for agricultural and forestry practices in these catchments, from now until the turn of the century. The overall changes predicted in air temperature and the changes in the frequency and intensity of flood and precipitation events will need to be taken into account when planning forestry and agricultural programmes well into the future.
Ends
For further information please contact:
Dr. John Joyce – Communications Manager, Marine Institute
087 2250871 or 091 387200
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Notes to Editor
The publication "2010 RESCALE: Review and Simulate Climate and Catchment Responses at Burrishoole" is available to download from the Marine Institute website.
RESCALE – REview and Simulate Climate and Catchment Responses At BurrishooLE
RESCALE is a multi-partner project involving NUI Maynooth, Trinity College Dublin and the Marine Institute. It was carried out under the Sea Change Strategy and the Government’s Strategy for Science Technology and Innovation (2006-2013), funded under the Marine Research Sub-Programme of the National Development Plan 2007–2013. The project has analysed and evaluated the 50 year environmental dataset from the Burrishoole catchment, Newport, Co Mayo and integrated these data with high-resolution climate scenarios and catchment–based models to asses the likely changes in key aquatic processes in the catchment up to turn of the century.
The main elements of the project are:
- Collation, evaluation & insertion of data into a centralised database
- Downscaling of Global Climate Models (GCM’s) to a regional level
- An assessment of the impacts of projected changes in stream-flow, soil and groundwater storage on the Burrishoole catchment.
- An assessment of predicted changes in river and lake temperature, dissolved organic carbon, oxygen levels, pH and dissolved oxygen resulting from climate change.
- To integrate the above with inshore and coastal monitoring data and examine the implications for fish growth and survival under various downscaled climate scenarios.
In an Irish context this is the first time that Global Climate Models have been downscaled to a catchment scale. This work has been made possible by the unique 50 year climatological and environmental dataset available from the Burrishoole index catchment. The study looked at changes from the present day to the end of the century in parameters such as: air temperature, water temperature, hydrology, including river flow and dissolved oxygen levels.
Projected changes in the climate conditions of the Burrishoole catchment, if realised, will have wide ranging implications for all aspects of the catchment system, including water temperature and quality, stream flow hydrology, soil processes, and most notably the well-being of its aquatic environment. While the projected changes in climate and their implications, outlined in this report, are specific to the Burrishoole, they are illustrative of likely changes in similar characteristic catchments along the west coast of Ireland.
Key results:
- When all models and emissions scenarios are considered, the greatest warming is projected to occur during the Spring (1.8°C) and Autumn (2.2°C) seasons by the 2080s. Extreme temperatures are also projected to increase.
- In contrast to the projected increases in seasonal air temperatures, increases in river water temperatures and lake surface water temperatures are projected to be greatest during the winter months.
- The climate scenarios also project an increasing tendency towards a more distinct seasonal precipitation regime leading to wetter winters and drier summers with this trend likely to become more pronounced over the latter part of the century. Evaporative losses, driven by increased solar radiation, are projected to increase during the summer months, which may further diminish stream flow in the catchment during seasons experiencing reductions in precipitation. Due to the projected increase in winter precipitation average stream flow is likely to increase by up to 25% for the months of January and/or December for all sub-catchments in the Burrishoole over the period 2070-2099. For the month of June reductions of up to 40% were returned for three of the selected catchments.
- The study showed a tendency towards more frequent flood events with so called 50 year flood events occurring every 7 to 9 years by the 2080s. Model simulations indicate an increase in extremely low summer flow for each sub-catchment studied an outcome which is consistent with the predicted decreases in summer precipitation.
- While the model developed is specific to a west of Ireland catchment, the structure of the model and the approach developed may well have applications for catchment modelling in other areas of the country and link in directly with ongoing work by Teagasc and Coford in assessing the potential impacts of climate change on the terrestrial environment.