NWT RESEARCH DATABASE

Regions: Inuvialuit Settlement Region, Gwich'in Settlement Area

Tags: physical sciences, permafrost, remote sensing, tundra

Objective(s): To identify the connection that exist between observable surface properties and their associated subsurface/permafrost conditions.

Project Description: This licence has been issued for the scientific research application No.5193. The research team will investigate the possibility of linking field-measured characteristics of tundra landscapes (e.g. active layer thickness, soil moisture, plant distribution and ecosystem composition, etc.) with remotely-sensed data. The overall objective of the project is to identify the connection that exist between observable surface properties and their associated subsurface/permafrost conditions. The findings will contribute to an increased understanding of surface-subsurface interactions at multiple spatio-temporal scales, which in turn will allow for further understanding of how permafrost landscapes in the Western Canadian Arctic respond to climate change. Main propose of the field work in 2022 is to remove the loggers that were installed during 2018 and 2019 and to perform some additional non-invasive measurements. Minimally-invasive electric resistivity surveying will be conducted at each field site. Seventy-two small steel rods with a diameter of about 1 centimeter and a length of 30 centimeters will be placed in the ground at intervals of 3 meters. These rods will be connected with a cable; the electrical resistivity of the ground at various depths system will then be measured. This instrument/technique allows for the investigation of active layer thickness, subsurface moisture conditions, ground-ice content, and permafrost table depth. All probes placed in the ground are non-permanent and will be removed from the ground once measurements are taken. The electrical currents used by the system are low voltage and will have no impact on plants or animals. Non-invasive ground penetrating radar (GPR) data will be recorded at each field site. The GPR system will be placed on the ground at intervals of 1 meter along transects at each sampling location. The system works by actively sending electromagnetic pulses into the ground at frequencies of 100 and 200 MHz (i.e. microwaves). The pulses reflect and scatter at layers in the ground that have different physical properties. For example, reflections of the GPR signal will be returned at the permafrost table depth. GPR allows for a highly detailed measurement of active layer thickness within the upper soil layers (i.e. properties of the subsurface) without the need for digging, thus leaving soils and plants undisturbed. Minimally-invasive steel rod probing of the active layer thickness will be conducted at intervals of 3 meter at each sampling location. A steel rod with a diameter of about one centimeter and a length of 120 centimeters will be pressed into the ground until the permafrost table is reached. This technique allows for the quick measurement of active layer thickness without the need for digging. Each field site will be photographed using a small (under 2 kg), battery-powered, unmanned aerial vehicle (UAV) or a photo-pole. The in-air-time of this UAV will be approximately 10 minutes for each plot and the UAV will be raised to a maximum elevation of 60 meters (200 ft.). The UAV will carry standard photographic equipment. The images recorded by the UAV will allow for the creation of a digital representation of the terrain surface and will support the vegetation mapping efforts. The low altitude, small airframe size, and minimal flying time will be minimally disruptive to local wildlife. Further, the UAV will not be used in the presence of wildlife, nor will it be used to photograph or harass wildlife. The research team plan to contact and inform every NWT stakeholders and community organizations, which are involved in the field work, prior to the campaign. During the stay in the field, the team will communicate our exact plans and any changes to the contact persons at Aurora Research Institute. Following the field work, an annual report is created in which all conducted research activities and the results are described. The fieldwork for this study will be conducted from August 7, 2022 to September 24, 2022