Fellow: Debjit Roy
Advisor: Xinhua Jia, Ph.D., P.E.; Associate Professor, Department of Agricultural and Biosystems Engineering, North Dakota State University.
Degree Progress:Ph.D. in Agricultural and Biosystems Engineering, expected graduation Fall 2016 

Snowmelt water infiltration into frozen soil is an important but complicated process that can affect surface water runoff and groundwater recharge. Many factors, such as soil moisture, soil temperature, water release rate from the snow cover, energy content of infiltrating water, porosity, soil cracks, presence or absence of macropores and also complex processes of heat and mass transfer through the frozen soils affect the total infiltration process into frozen soils. In northern hemisphere, nearly 60 percent of the land surfaces are seasonally frozen and North Dakota is a part of that area. There is no simple and clear answer on how water infiltrates into frozen soil. The lack of understanding of the infiltration process into frozen soil is the major limiting factor affecting spring flood forecasting. In recent years, during the spring flood events in the Red River of the North Basin (RRB), flood forecasting cannot be estimated accurately due to lack of data on infiltration into frozen soil. Any error in flood prediction can cause significant financial losses and threaten 200,000 people lives in the Fargo-Moorhead metro area as well as people and animals in the entire basin. The proposed research project will focus on snowmelt infiltration characteristics into frozen soils. A snowmelt water infiltration model will be developed which can help to overcome the current obstacles in order to accurately predict spring flood.

Project Objectives:

The research project will focus on snowmelt infiltration characteristics into frozen soil. The specific objectives of the research study are:

• To measure infiltration amount/rate into frozen soil at field and laboratory conditions.
• To develop a snowmelt water infiltration model based on historic, laboratory and field data.
• To evaluate model outputs with other available infiltration models.

Progress:

Hydra Probe II sensors for soil moisture and temperature measurement, SR50A Sonic ranging sensor for monitoring snow depth, and modified TE525 rain gage for rainfall and snow fall measurement are installed in the field. Three wireless weather stations were also set up in the research site to collect weather parameters like air temperature, relative humidity, solar radiation, wind speed and direction. A Cornell sprinkler infiltrometer is now being calibrated and tested in field for infiltration measurement.

Significance:

Understanding the infiltration process into frozen soils could have a broad impact to the hydrological field for the entire and especially in permafrost regions. It would help to better understand the runoff processes and flooding events in winter and spring. Properly adjusted numerical infiltration model could be used to predict actual runoff peaks to prevent damage from floods or to prevent overestimation of runoff. The benefit from this proposed study will be several million dollars each year in flood preparation.