Lauri Ikkala, Anna-Kaisa Ronkanen, Olli Utriainen, Bjørn Kløve, Hannu Marttila, Peatland subsidence enhances cultivated lowland flood risk, Soil and Tillage Research, Volume 212, 2021, 105078, ISSN 0167-1987, https://doi.org/10.1016/j.still.2021.105078
Peatland subsidence enhances cultivated lowland flood risk
|Author:||Ikkala, Lauri1; Ronkanen, Anna-Kaisa1; Utriainen, Olli2;|
1Water, Energy and Environmental Engineering Research Unit, Faculty of Technology, P.O. Box 4300, FI-90014, University of Oulu, Finland
2Northern Ostrobothnia Centre for Economic Development, Transport and the Environment, P.O. Box 86, FI-90101, Oulu, Finland
|Online Access:||PDF Full Text (PDF, 13.2 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2021090845560
|Publish Date:|| 2021-09-08
Peatlands worldwide are being threatened by intensive land use and drainage, which leads to soil subsidence. This has consequences for farming, especially on low-gradient cultivated peat-dominated lowlands with high flood risk. In this study, we combined historical soil elevation data and new lidar data to improve the estimation of subsidence and its consequences for lowland river systems. The results showed 202−349 mm subsidence within the last 24–51 years, with a mean rate of 5.15–9.47 mm y⁻¹ for riparian peatland on the west coast of Finland. The subsidence rate was partly explained by the depth of the organic soil layer (R² = 0.710, p > 0.05). The results also showed that increasing flooding of cultivated fields is mainly due to soil subsidence, not to increased flooding occurrence in river systems. The area flooded annually was found to increase by 101–194 % for the last 24–51 years, due to soil subsidence near rivers. Generalization of the results to catchment scale indicated an increase in the annual flood zone of 45 % in cultivated fields in one of two study catchments (Siikajoki river basin). These results demonstrate the value of using historical data to study soil subsidence and confirm that the risk of flooding increases in cultivated organic lowlands due to intensive drainage and subsidence. New management strategies, such as peatland rewetting, restoration, and paludiculture, should be considered in future land use plans to reduce subsidence and provide new income streams for farmers.
Soil & tillage research
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
411 Agriculture and forestry
This work was supported by the regional Northern Ostrobothnia Centre for Economic Development, Transport, and the Environment; PeatWise project under FACCE ERA-GAS program; WaterPeat-project under Water JPI program [project number 326848]; Maa ja vesitekniikan tuki ry; and Suoviljelysyhdistys ry.
|Academy of Finland Grant Number:||
326848 (Academy of Finland Funding decision)
© 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).