This attribute represents thermal energy to stream channels(watt-hours/m²) based on current shade conditions (throughout the hottest day of the year, July 20^th) but summed (averaged) downstream, providing an index of thermal refugia at the scale of entire tributaries. The calculation depends on latitude, solar angle, channel width, channel orientation, topographic shading and vegetative shading. Vegetation information (tree height and basal area) is from LEMMA.  If these attributes are not available for your own watershed, please contact us.   See more.

 

 

Thermal Refugia within streams is important for certain aquatic life, including endangered fish species such as salmon and trout. Thermal refugia is particularly important in watersheds that have less than optimum shade conditions because of historical and current land use including forestry, agriculture and urbanization. In addition, climate change that decreases summer stream flow or increases stream temperatures can exacerbate warm water conditions, making thermal refugia even more important.