| This research effort developed and demonstrates a modeling tool to simulate different water resource system operational scenarios in the Virgin River Basin and the effect that those operations may have on endangered fish in terms of a temperature-based habitat suitability metric. The objective of developing an integrated operations, temperature, and habitat modeling tool for the Virgin River study area is to demonstrate its use in the comparative assessment of temperature and habitat changes resulting from water resource system operational changes.;Existing models utilized are a daily system mass balance model, and a water temperature model. The daily operations model simulates storage, releases, hydropower, etc. based on existing and projected demands for agriculture, municipal, and industrial uses. A new temperature-based habitat suitability metric for endangered woundfin was developed and integrated into the temperature model. Maximum daily water temperatures are used to calculate the new habitat suitability metric. The research is presented in the form of two papers. The majority of the first paper focuses on describing the heat budget used in the VR_Temp model as well as the data preparation and finally the selection of a preferred parameter set used for calibration of the model.;The second paper discusses the integration of the models into an optimization framework, as well as the addition of economics. The integrated modeling framework was applied, as a demonstration project in the Virgin River Basin, for use in the comparative analysis of water resource system operational scenarios. Results were compared on the basis of quantified fish habitat and net cost. This new model framework, the Virgin River Operation Optimization Model (VROOM), is considered a basin level planning model. The two optimization objectives were minimize net cost and maximize endangered fish habitat which resulted in a tradeoff surface or Pareto front. This was done for various hydrologic year types and water demand conditions. Different year types were modeled separately in combination with existing water demands and a future water demand estimate. New infrastructure options were also considered. |
