EVAPORATION FROM SHALLOW PONDS AT UTAH VALLEY UNIVERSITY: AN ANALOGY FOR UTAH LAKE

Evaporation in the arid western United Stated can cause large amounts of water to be lost before it can be used by regional communities. To better understand how much water is being lost in this process a study was conducted on two concrete-lined ponds at the campus of Utah Valley University (UVU) in Orem, Utah. The conditions at these ponds are analogous to water that is evaporating from Utah Lake, a local body of water that is an important local resource. Evaporation rates were used from evaporation pan measurements taken by the Western Regional Climate Center (WRCC) for two localities in the region and then averaged (1.3 m/yr). Pond volume and surface area with depth was initially measured from an airbone LiDAR – derived digital elevation model (DEM) of the area (Utah AGRC). Due to uncertainty whether water was present in the ponds when the LiDAR was collected, we generated a DEM from aerial photographs taken with an sUAS using structure-from-motion processing (SfM) and on-board dGNSS geotagging. Preliminary results suggest that 89% of the volume (11,962 m³) of the ponds are evaporated annually while the ponds are at full capacity. These same evaporation rates and calculations are also being applied to study the amount of water lost at Utah Lake. Using the same evaporation rates preliminary estimates suggest that 43% of the lakes volume (0.48 km³) is evaporated annually. However, as we continue to better estimate changes in its surface area and evaporation rates we can get a better manage this valuable water resource.