Snow Measurements with GPR for Hydrological Studies

At Sweco, a leading European engineering and architecture consultancy, the company has extensive experience using GPR for hydrological studies. “Specifically, we have over 20-years experience in the design and execution of snow measurement systems utilizing various radar systems”, explains Wolf Marchand, Team leader, Hydrology and Hydraulic at Sweco Norway. Wolf continues, “we use advanced geographical analysis to adapt and optimize our snow measurement system to a specific area, and the result from the radar survey is an important part that complements other methods.”

For the recent season, Sweco Norway invested in an ImpulseRadar CrossOver 4080 system, which tows behind a snowmobile to enable efficient measurements over large areas. “We are delighted with the CO4080 system as it’s a very robust and practical system for use in our challenging environment. In particular, it’s cable-free and uses inbuilt WiFi to transfer data to a rugged Android device. It also includes inbuilt GPS as standard, and these offer benefits that we consider prerequisites for problem-free surveys”, says Wolf.

During winter, the precipitation falls as snow and remains that way until temperatures rise. However, when the snow starts to melt, large amounts of water is released. For the hydropower industry, this creates concern. A large spring flood due to snowmelt can quickly overwhelm the reservoir and the drainage capacity of a power plant. In such an instance, the power plant operator must release valuable water and bypass the plant. However, doing so can lead to significant financial losses, often in the many millions of Kroner. Consequently, good snow measurements can provide valuable information to aid operational planning to minimize financial losses.

Floods often occur when heavy snowmelt happens in combination with precipitation. A significant amount of damage to infrastructures such as roads, railways and buildings relates to floods. Therefore, with the help of good snow data, one can make better forecasts for the size of the spring flood and are thus better equipped to implement necessary measures to prevent or limit the damage to valuable property. In mountainous areas with significant snowfall, avalanches are a constant risk, which can also pose a danger to infrastructure and human life. Having information about the accumulation of snow can therefore be beneficial when assessing the risk of avalanches

Completed projects show that having access to snow measurement data can significantly improve hydrological modelling for production planning, with a corresponding reduction in the risk of losing money and mitigation of flood related damages along the rivers.