Use of BasinTemp to model summer stream temperatures in the south fork of Ten Mile River, CA
This article is part of a larger document. View the larger document here.Abstract
We used BasinTemp to predict summer stream temperatures in South Fork Ten Mile River (SFTMR), Mendocino County. BasinTemp is a temperature model that attempts to quantify the basin-wide effects of high summer stream temperatures in basins where the data inputs are scarce. It assumes that direct solar radiation is the chief mechanism behind stream summer heating in mid latitudes. We applied it in the SFTMR basin to understand the dynamics of summer stream temperatures, the influence of timber management and the effects of climate change on water temperatures, and its implications for coho salmon habitat. Three vegetation scenarios (current vegetation conditions, reference vegetation conditions and topography only conditions) and their effects on the Maximum Weekly Average Temperatures (MWATs) throughout the basin were analyzed for 3 different years. We predicted a significant increase in water temperature related to the decrease in shade as vegetation conditions shift from reference to current and to topographic conditions under timber management. We also found that current vegetation conditions account for significant amounts of shade that reduce solar radiation and stream temperatures and that discharge has a growing effect in water temperatures as the basin approaches topographic conditions.