Impacts of Sub-daily Temperature Variations around the Freezing Temperature on A Hydrological Model using Macro-scale Snowmelt Simulations

By Ashley Rone

Water supply research predictions are essential for agriculture, recreational, and environmental tasks in North Dakota. North Dakota’s unique climate is important for water security research conducted on snowmelt fluctuations in freezing temperatures. The information collected from macro-hydrological models helps identify dependable water supplies in the state and other similar geographical regions.

North Dakota State University, Mohsen Tahmasebi Nasab in his office. Photo taken from the North Dakota Water Resources Research Institute website.

North Dakota State University, Mohsen Tahmasebi Nasab in his office. Photo taken from the North Dakota Water Resources Research Institute website.

Mohsen Tahmasebi Nasab, a doctoral student and graduate research assistant at North Dakota State University, is studying topographic maps and macro-scale hydrologic models based on the cold North Dakota climate.

“Hydrologic models are simplifications of the real-world water cycle systems and are being increasingly used to simulate different water-related processes or hydrologic processes such as snowmelt, surface runoff, and infiltration,” said Tahmasebi Nasab. “Historically, water security or a reliable supply of water for agriculture, communities, and ecosystems has been one of the top priorities of humans.”

These hydrologic models are particularly important for predicting future changes of water resources. These predictions are specifically important for flooding events that often occur in the Red River Valley that can affect agriculture production.

“Hydrologic simulations and predictions can provide valuable information on different hydrologic processes for decision-makers, farmers, and researchers,” Tahmasebi Nasab said. “For example, hydrologic modeling results can tell us how much surface runoff a rainfall event can generate, how much snow is melted on a given day, or how much water is stored in the soil profile.”

The hydrologic model that Tahmasebi Nasab uses inputs data from different sources that include precipitation, temperature, topographic, and land use. These data sets are all necessary for projecting certain geographic water resources, but one specifically important figure is the topographic map.

A topographic map of North Dakota from the year 1924. Image published and provided by the online U.S. Geological Survey database.

“North Dakota has unique hydro-topographical characteristics such as cold and long winters and a depression-dominated topography,” Tahmasebi Nasab explained. “These unique characteristics give rise to special conditions such as frozen soil and directly affect the modeling of different hydrologic processes.”

The information collected contains data on topics such as temperature and precipitation variations. These variables are important for addressing long-term regional water resource issues.

“Climate and hydrologic models can be linked to predict the future of water resources under different scenarios,” said Tahmasebi Nasab. “In one of our recent studies, we evaluated the impacts of temperature variations on macro-scale snowmelt simulations in the Missouri River Basin. We found that even sub-daily temperature fluctuations around the freezing temperature can significantly affect the generation of snowmelt.”

These studies have proven to be beneficial for a multitude of reasons. Now, the next step is to further develop the hydrological model and test the ability of the model in other regions with river basins.