INTEGRATED METHODOLOGY FOR INSTREAM FLOW STRATEGIES.
Instream flow assessments have traditionally resulted in the recommendation of a threshold value for the fishery resource: a minimum flow. More recently, an incremental methodology has been used to quantify the amount of potential habitat available for each life history state of a species as a function of streamflow. In a previous study, a framework was developed to address the impact of water quality fluctuations in determining instream flow strategies. Continuous hydrologic and water quality (transient) simulation models were applied to derive the frequency and duration of violations of established stream standards according to State stream use classifications. In this study an integrated methodology is presented, based on a hierarchical package of computer models ranging from simple microcomputer programs to more complex mainframe simulation. The microcomputer programs are statistically-based, and assume that both flows and pollutant concentrations are lognormally-distributed for upstream sources, non-point sources and point sources. Refs.
