New paper maps spatial and temporal evolution of ditch networks

How can we reconstruct the history of drainage and land use in a catchment? This question is important if we are to understand historical hydrological data in peatlands. PhD student Joy Bhattacharjee (University of Oulu) and co-authors have used a combination of historical aerial photos and LIDAR data to study this. The objectives were to develop techniques to map the location of ditch networks in peat-dominated catchments, and to create time series of drainage networks.

Joy and his co-authors have demonstrated their approach with data from the Simojoki River catchment in northern Finland. The catchment is dominated by forests and peatlands that were almost all drained after 1960. For two representative locations in cultivated peatland (downstream) and peatland forest (upstream), they found that the total ditch length density had varied from 2% to 50% for different portions of the catchment compared to the baseline conditions of 2018. A different pattern of source variation in ditch network density was observed for whole-catchment estimates and for the available drained peatland database from Natural Resources Institute Finland (LUKE).

Graphical abstract of the paper. (J. Bhattacharjee et al.)

Bhattacharjee J, Marttila H, Haghighi AT, Saarimaa M, Tolvanen A, Lepistö A, Futter MN, Kløve B. 2021. Development of aerial photos and LIDAR data approaches to map spatial and temporal evolution of ditch networks in peat dominated catchments. Journal of Irrigation and Drainage Engineering, 147(4), 04021006. https://ascelibrary.org/doi/10.1061/%28ASCE%29IR.1943-4774.0001547