Abstract. Aquatic ecosystems can be significantly altered by the
construction of dams and modification of riparian buffers, and the effects
are often reflected in spatial and temporal changes to water temperature. To
investigate the implications for water temperature of spatially and
temporally varying riparian buffers and dam-induced hydrologic alterations,
we have implemented a modeling system (DHSVM-RBM) within the framework of
the state-space paradigm that couples a spatially distributed land surface
hydrologic model, DHSVM, with the distributed stream temperature model, RBM.
The basic modeling system has been applied previously to several
similar-sized watersheds. However, we have made enhancements to DHSVM-RBM
that simulate spatial heterogeneity and temporal variation (i.e., seasonal
changes in canopy cover) in riparian vegetation, and we included additional
features in DHSVM-RBM that provide the capability for simulating the impacts
of reservoirs that may develop thermal stratification. We have tested the
modeling system in the Farmington River basin in the Connecticut River
system, which includes varying types of watershed development (e.g., deforestation and reservoirs) that can alter the streams' hydrologic regime
and thermal energy budget. We evaluated streamflow and stream temperature
simulations against all available observations distributed along the
Farmington River basin. Results based on metrics recommended for model
evaluation compare well to those obtained in similar studies. We demonstrate
the way in which the model system can provide decision support for watershed
planning by simulating a limited number of scenarios associated with
hydrologic and land use alterations.