Biowater is pleased to announce that Dr. Joy Bhattacharjee received his PhD on 10 December 2022. Joy has followed Biowater since the start and has been active in the modelling team (module 4). In his work he used the SWAT model (Soil & Water Assessment Tool; https://swat.tamu.edu/), to simulate the quality and quantity of water under different climate and land use scenarios. The case area was the Simojoki catchment in Northern Finland, a forested catchment dominated by partly drained peatlands.
The underlying goal of his PhD study was to develop new approaches for evaluating how water resources will be impacted by the expected increase in biomass extraction following the green shift. He modelled different climate and land use scenarios, and for the latter he applied the Nordic Bioeconomy Pathways (NBPs) developed by fellow BIOWATER researchers, and based on the Shared Socio-Economic Pathways (SSPs, O’Neill et al. 2017).
Joy’s thesis included four studies aimed to better understand the historical and future consequences on hydrology and water quality in the Simojoki catchment:
- In the first study, a new algorithm was developed using aerial photos and LIDAR data to identify and generate time series of the ditch networks in different landscapes. See also: News item and Paper.
- In the second study, he used export coefficients with landuse analysed from Landsat and a regional database. This provided a clear picture of nutrient loads and SS exports over decades at multiple locations in the catchment. See also: News item and Paper.
- In the third study, he integrated the ditch networks in the SWAT hydrological model to identify and calibrate peatland forestry parameters. The results indicated a higher specific load of nutrients in a clear-cut forest in peat soil than in mineral soil. (Paper submitted)
- In the fourth and final study, he combined stakeholders’ opinions, the Finnish forest dynamics model MELA and climate-imposing emission pathways, and used this to build multiple NBP scenarios for different land use and land management scenarios. (Paper submitted)
Joy found that all future land use scenarios except two (focus on sustainability or business as usual), would result in an increase in nutrient loads in streams. The results showed lower variability when climate data was integrated with management forestry attributes.
Overall, the new tools and modelling approaches of the thesis can provide a direction on how to manage the potential impacts of increased peatland forestry on water resources.
Joy Bhattacharjee’s PhD study was carried out at the University of Oulu, Finland, with supervisors Dr. Bjørn Kløve and Dr. Hannu Marttila. Presently, Joy is working as a researcher at the University of Oulu, in the EU-project NORDBALT- ECOSAFE, which in many ways is a follow-up of Biowater, and where he again will carry out SWAT modelling.
Read the entire thesis here.
Feature photo: Hannu Marttila.