A Remote Sensing Approach to Characterize Cold Region Watershed Storage and its Influence on Streamflow Generation

The Prairie Pothole Region (PPR) has an extremely variable climate and has pronounced impacts on wetlands as they are highly responsive to the variability in air temperature and precipitation. In recent years, the PPR has been in a novel wet climate continuum since 1993, facilitating severe flooding in the Devils Lake Basin (DLB), North Dakota– costing the US ~$1B USD. Many studies using remotely sensed imagery reported a substantial increase in the number of surface water bodies and expansion of the existing water bodies during 1988–2013 period. In addition to surface water area, the water storage of the potholes also substantially increased. However, very few studies quantify the surface water storage and its dynamics to the recent increase in precipitation using remotely sensed data in the PPR. In this study, we utilize high resolution LiDAR DEM and monthly global surface water data (GSWD) to estimate filled storage of each pothole in the Starkweather Coulee Basin (SCB, 700 km²)– a headwater basin draining to a terminal lake (Devils Lake). Our findings suggest that the SCB storage gradually filling up during two wet periods: 1990–1998 and 2009–2013, resulting in massive streamflow and subsequent flooding. The SBC fractional storage also exhibits a strong positive and exponential relationship with peak streamflow and annual streamflow volume indicating strong influence of wetland storage and fill-spill hydrology on the streamflow generation. The exponential relationships also point toward a threshold SCB fractional storage for generating extreme streamflow generation.