Water Management For Sustainable Use And Protection Of Peatlands

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2019

End date

12/31/2023

Budget

477,732 EUR

Fundings

Abstract

Peatlands are common in humid climates and regions with significant rainfall excess. Peatlands cover large areas of northern Europe, and more than 6 % of the land area in Norway. Peatlands are important for water quality and may influence discharge from catchments. In Europe, peatlands have been drained for agriculture, forestry, and peat extraction. The use of peatlands has been important for regional livelihood and development. Peatland drainage may have negative impacts on water resources due to changes in peatland hydrology, increased peat erosion, and leaching of nutrients and organic matter. Greenhouse gas (GHG) emissions, peatland subsidence and peatland fires are also negative impacts of peatland drainage. Peatland management requires careful land and water management to reduce negative impacts on water resources and their ecosystem services (drinking water, recreation, carbon sequestration, water retention etc.). The WATERPEAT project aims to develop the scientific knowledge base on peatlands and water management for different types of peatlands found in peat rich areas of Northern Europe and Indonesia. The Norwegian team has equipped a drained forested mire (Akersmyra, close to Tønsberg) where long-term monitoring data on forest biomass are available and an adjacent pristine reference site (Gjennestadmyra) to examine long-term effects on hydrology and be able to illuminate impacts of hydrology on peatland forest biomass, peatland properties and subsidence. Additionally, we are developing novel methods (digital photogrammetry and lidar data) aiming at enabling cost-efficient measurements of peatland subsidence (an indicator for peat loss) remotely over large geographical areas and for long time periods. Photogrammetric methods applying digital terrain models and historical aerial photos have been developed and tried out for characterizing historical terrain and forest elevation levels at the peatland Akersmyra, that previously was drained for forestry purpose. Results from this work, terrain elevation data from airborne lidar measurements and from previous optical levelling carried out in an afforestation experiment at Akersmyra are used to compare methods for exploring elevation of peatland surface and illuminate peatland subsidence at Akersmyra due to the drainage of the peatland. The experience from the project indicates that remote sensing of peatland surface elevation is most suitable for open non-forested areas. Limitations for use of photogrammetric methods are connected to access to historical aerial photographs, quality of old photographs and vegetation that restrains vision of the ground. Remote sensing based on lidar data and / or aerial photographs makes possible high-resolution mapping on large areas of terrain shape on peatlands and shape alterations due to peatland subsidence and other reasons. Depth to the water table and water temperature were registered with hourly intervals in observation wells in the peat at the drained forested peatland Akersmyra and the nearby reference peatland (Gjennestadmyra). Characteristic of the drained peatland was lower peat water table than in the reference mire, most pronounced at low water table, and larger water table fluctuations. Whereas the water table in the wells often were ca. 0-20 cm deeper at Akersmyra than in the reference mire in summer 2021, the water table in 2022 were often 20-40 lower at Akersmyra than in the reference mire in summer 2022. Both in 2021 and 2022 the maximal depth to the water table at the undrained Gjennestadmyra was about 0,45 m. The temperature of the water in the peat wells ranged from ca. 4 to ca. 10 degrees Celsius at both peatlands.