Associate Professor, holding tenure position and leading Hydrology and Water Quality research group at Water, Energy and Environmental Research Unit in UOulu. Marttila's research focuses on hydrological processes and catchment management issues in northern landscapes with strong cross-disciplinary work across science fields. He have broad experience from various environmental engineering fields focusing on nordic catchment hydrology and management, stable water isotopes, peatlands, land use and water quality issues, water protection issues and ecological connections. Marttila has been participating and managed several Academy of Finland, EU and foundation based projects. He is a chairman in Hydrology division at Finnish Water Association and hydrology subject editor for Boreal Environmental Research -journal.