UAV-borne imagery for improving the spatio-temporal modelling of agricultural runoff and erosion
Research area and project description:
Surface runoff and erosion on agricultural land locally affect long-term soil productivity and surface water quality. Despite Denmark being a country with relatively low relief and low rainfall erosivity, field observations and comparative coarse scale modelling exercises rank Denmark as vulnerable to water erosion. Different societal drivers, amongst others EU legislation, now require Denmark to take action for protecting soil and water resources. This necessitates stakeholders – authorities as well as farmers – to address the extent and impact of water erosion on agricultural land on an informed basis. Erosion processes are spatially and temporarily very variable, and targeted mitigation efforts are needed. This calls for reliable modelling tools that guide the mitigation planning. Current models either lack the necessary detail, adequate hydrological process representation or are too complicated to be used as practical advisory tools. Critically, they are often not properly parameterized and evaluated due to high costs.
We therefore invite applications for a PhD project that investigates spatial temporal patterns of runoff and sediment generation controlled by changes in soil surface conditions. The main aim of the project is to improve the reliability/accuracy of an existing rainfall-runoff model suite by focusing on a terrain-based hydrologic algorithm for better prediction of source areas and flow paths. The PhD project will extensively utilize UAV (Unmanned Aerial Vehicle)-borne imaging systems as innovative way for deriving quantitative information on the temporal change of surface conditions. This data is then used for parameterizing and evaluating a high resolution erosion-runoff model suitable for planning applications.
Based on existing erosion risk assessment several small study catchments in typical agricultural landscapes of Denmark will be selected and instrumented with a range of sensors to monitor climatic and soil conditions as well as runoff and sediment yield. Extremely high resolution imagery will be collected by UAVs frequently during the runoff seasons. This data is quantitatively analyzed for changes in soil surface roughness, crusting and plant cover as well as patterns of rilling and sediment deposition. Reference measurements of soil surface conditions are done my means of proximal laser scanning. The observational data will then inform (i) the spatio-temporal modeling of runoff and erosion processes and (ii) the production of risk maps for soil management planning. The project is conducted in close collaboration with University of Louvain, UCL, Belgium.
Qualifications and specific competences:
Candidates should have an MSc in physical geography, environmental sciences or geoinformatics with very good grades. In addition, we appreciate (i) strong fundamental knowledge in GIS and image analysis, surface hydrology, agronomy and statistics, (ii) readiness for field work, (iii) capability to write scientific publications and (iv) high motivation and efficiency.
Place of Employment and Place of Work:
The place of employment is Aarhus University, and the place of work is the Department of Agroecology, Research Centre Foulum, Blichers Allé 20, 8830 Tjele, Denmark.
The deadline is already 1st February. Please see additional information here.