Project received funding from the National Research Centre - Preludium BIS 5, grant no. 2023/50/O/ST10/00597.
In this project, we propose the study of lakes in the Mackenzie Delta, Arctic Canada. The project aims to understand sediment trapping conditions in Arctic river delta no-closure lakes to assess the impact on the overall sediment transport balance. This goal will be achieved by developing a sediment transport model based on the theory of settling basins while incorporating the Gamma distribution law. This model will enable us to assess the efficiency of sediment trapping, sediment settling velocity, and deposition rates, considering the dynamics of sedimentation velocity and sediment re-suspension processes. This approach will provide new knowledge about current and future sediment transport patterns within river deltas in areas of rapid permafrost thaw. On the example of detailed studies of the Big Lake, a no-closure floodplain lake located in the middle part of the delta between the Middle Channel and the East Channel of Mackenzie River, we are going to try to answer the questions: What is the sediment trapping capacity of no-closure lakes? How much sediment load is accumulated in lakes each year, and what volume of sediments will be retained in the future? Does the intense release of climate change by Mackenzie Delta lakes influence sedimentation rates, sediment trapping, and sediment release for fluvial re-transport? In this project, we will try to use two original complementary methods (numerical and analytical) based on liquid and solid inputs, fall velocity and the trapping capacity of suspended matter, which will enable us to understand the hydrodynamic functioning of the floodplains of the lakes in the Mackenzie River delta. The expected results after completion of the project are: learn how the lakes in the Mackenzie Delta influence the value of sediment transport to the Arctic Ocean during the annual cycle; determine the settling velocity of suspended solids and the impact that the proven release of methane from bottom sediments has on velocity; determine the impact of extreme phenomena on sedimentation and sediment re-suspension in no-closure lakes of the Mackenzie Delta; calculate the load of sediments accumulated and released for transport in the Mackenzie River Delta; learn about the reliability of the adopted settler theory method, particularly in the sediment transport by currents of particles present in the water column and on the bottom; velocity of the fall of particles into the water column, with or without flocculation (particle aggregation); the condition of the deposition of particles on the sedimentary bed; possibilities of erosion of bottom sediments by currents and swells; and the quality of consolidation of multi-layer sediments (via transfer flows between the sediment layers). A series of field observations were planned to determine the characteristics of the morphometric parameters, suspended solids and sediments present in the no closure lake of the Mackenzie Delta and evaluate the impact that the settlement velocity of suspended solids and the flow rate have on the sediment trapping capacity of the lakes in the Mackenzie Delta. Through this project, we aim to demonstrate the usefulness of deltaic lakes as hydrological recorders of the regime of the Mackenzie River, of changes in flow and sediment transport, and to bridge the gap between hydrological processes and depositional patterns in sedimentology.
Research team:
Michal Habel and Damian Cieplowski (PhD student)