Modeling ecohydrological impacts of land management and water use in the Silver Creek basin, Idaho

Abstract

A number of anthropogenic stressors, including land use change and intensive water use, have caused stream habitat deterioration in arid and semiarid climates throughout the western U.S. These often contribute to high stream temperatures, a widespread water quality problem. Stream temperature is an important indicator of stream ecosystem health and is affected by catchment-scale climate and hydrological processes, morphology, and riparian vegetation. To properly manage affected systems and achieve ecosystem sustainability, it is important to understand the relative impact of these factors. In this study, we predict relative impacts of different stressors using an integrated catchment-scale ecohydrological model that simulates hydrological processes, stream temperature, and fish growth. This type of model offers a suitable measure of ecosystem services because it provides information about the reproductive capability of fish under different conditions. We applied the model to Silver Creek, Idaho, a stream highly valued for its world-renowned trout fishery. The simulations indicated that intensive water use by agriculture and climate change are both major contributors to habitat degradation in the study area. Agricultural practices that increase water use efficiency and mitigate drainage runoff are feasible and can have positive impacts on the ecosystem. All of the mitigation strategies simulated reduced stream temperatures to varying degrees; however, not all resulted in increases in fish growth. The results indicate that temperature dynamics, rather than point statistics, determine optimal growth conditions for fish. Temperature dynamics are influenced by surface water-groundwater interactions. Combined restoration strategies that can achieve ecosystem stability under climate change should be further explored.

Local control on precipitation in a fully coupled climate-hydrology model

“…The model has been widely applied for both research and applied management studies focusing on e.g. climate change effects on hydrology 35 , water management 36 , water quality 37 and eco-hydrology 38 . The coupled hydrological catchment covers the 2500 km 2 area of the Skjern River catchment located in the western part of the Jutland peninsula dominated by sandy soils and low topography (0–130 m.a.s.l.).…”

Integrating process‐based flow and temperature models to assess riparian forests and temperature amelioration in salmon streams

“…MIKE SHE was chosen because it has been widely used to integrate surface water-groundwater processes (e.g., Larsen et al, 2014;McMichael, Hope, & Loaiciga, 2006) and to model water temperature at the catchment scale (Loinaz et al, 2013). Furthermore, as a physically based deterministic model, it has been successfully applied to assess the potential effect of land management on stream water temperatures and its ecological implications (Loinaz, Gross, Unnasch, Butts, & Bauer-Gottwein, 2014).…”

Observations and modeling of hillslope throughflow temperatures in a coastal forested catchment

“…MIKE SHE models groundwater flow dynamics, but not heat transport, and thus requires an input temperature that represents the temperature of the upper portion of the aquifer and is assumed to be spatially uniform [ Loinaz et al ., ]. MIKE SHE does calculate a surface drainage flux that is aimed at representing heat contributions from overland flow.…”