"This tutorial demonstrates the application of piecewise regression to bedload data to define a shift in phase of transport so that the reader may perform similar analyses on available data. The use of piecewise regression analysis implicitly recognizes different functions fit to bedload data over varying ranges of flow. The transition from primarily low rates of sand transport (Phase I) to higher rates of sand and coarse gravel transport (Phase II) is termed "breakpoint" and is defined as the flow where the fitted functions intersect. The form of the model used here fits linear segments to different ranges of data, though other types of functions may be used. Identifying the transition in phases is one approach used for defining flow regimes that are essential for self-maintenance of alluvial gravel bed channels. First, the statistical theory behind piecewise regression analysis and its procedural approaches are presented. The reader is then guided through an example procedure and the code for generating an analysis in SAS is outlined. The results from piecewise regression analysis from a number of additional bedload datasets are presented to help the reader understand the range of estimated values and confidence limits on the breakpoint that the analysis provides. The identification and resolution of problems encountered in bedload datasets are also discussed. Finally, recommendations on a minimal number of samples required for the analysis are proposed."

Instream Flow Protection is a comprehensive overview of Western water use and the issues that surround it. The authors explain instream flow and its historical, political, and legal context; describe current instream flow laws and policies; and present methods of protecting instream flow. They provide numerous examples to illustrate their discussions, with case studies of major river systems including the Bitterroot, Clark's Fork, Colorado, Columbia, Mimbres, Mono Lake, Platte, Snake, and Wind. Policymakers, land and water managers at local, state, and federal levels, attorneys, students and researchers of water issues, and anyone concerned with instream flow protection will find the book enormously valuable.