XSPRO: A Channel Cross-Section Analyzer
VERSION/DATE: August 1992
OPERATING SYSTEM: DOS
DOCUMENTATION (58 Pages):
XSPRO: A CHANNEL CROSS-SECTION ANALYZER August 1992 By Gordon E. Grant, Joseph E. Duval, Greg J. Koerper & James L. Fogo, U.S. Bureau of Land Management
DOS 2.1 or Higher 256K of RAM
XSPRO is an interactive, menu-driven software package designed to assist watershed specialists in analyzing stream channel cross-section data. It has been specifically developed to handle channel geometry and hydraulic conditions for single transacts in steep (gradient > 0.01) streams. Several resistance equations are supported, including those specifically designed for large roughness channels. Analysis options include developing stage-to-discharge relationships and evaluating changes in channel cross-sectional area. Both graphical and tabular output can be generated. XSPRO can assist resource specialists in analyzing instream flow needs, performing hydraulic reconstructions, designing effective channel and riparian structures, and monitoring channel changes.
Surveys of stream-channel cross sections provide important information for hydrologists, river engineers, geomorphologists, fishery biologists, and other professionals associated with river management issues. Data from cross-section surveys are useful for analyzing channel form and function, and the processes that influence a channel's hydrologic performance. Use of survey data to construct relationships between streamflow, channel geometry, and various hydraulic characteristics provides information that serves a variety of applications.
APPLICATIONS OF CROSS-SECTION DATA ANALYSIS
Information on stream-channel geometry and hydraulic characteristics is useful for channel design, restoration of riparian areas, and placement of instream structures. The analysis of cross section hydraulics, along with an evaluation of flood frequency, is a primary consideration in channel design. Once a recurrence interval is defined for bank-full flow, the channel is designed to contain that flow, and higher flows are allowed to spread over the floodplain. Such periodic flooding is extremely important for the formation of channel macrofeatures (e.g., point bars and meander bends) and for establishment of certain kinds of riparian vegetation. A cross-section analysis may also help optimize placement of such items as culverts and fish habitat structures.
Additionally, knowledge of the relationships between discharge and channel geometry and hydraulics is useful for reconstructing the conditions associated with a particular flow situation. For example, in many channel- stability analyses, it is customary to relate movement of substrate materials to some measure of stream power or average bed shear stress. If the relations between streamflow and certain hydraulic variables (e.g., mean depth and water-surface slope) are known, it is possible to estimate stream power and average bed shear at any given level of flow. Thus, a channel cross-section analysis makes it possible to estimate conditions of substrate movement at various levels of streamflow.
Finally, cross-section analyses provide important information for instream flow assessments. Various resource values may be altered by changes in hydraulic parameters associated with changes in streamflow. For example, the relation between low-water discharge and channel wetted perimeter may be an important consideration for macroinvertebrate production or the scenic enjoyment of a stream. Similarly, cross-section data may be used to define the depth-discharge relationship for analysis of fish habitat.
FEATURES OF XSPRO
Computer programs can be useful tools in channel cross-section analysis. One such program is XSPRO. The XSPRO program is designed for analyzing channel cross-section data in an interactive, user-friendly environment. The program is menu-driven with easy-to-read input and output screens, and an integrated graphics package to facilitate data entry. XSPRO uses a resistance equation approach to single cross-section hydraulic analysis (e.g., Manning's equation), and is capable of analyzing both the geometry and hydraulics of a given channel cross section. XSPRO was specifically developed for use in high-gradient streams and supports three alternative resistance equations for handling boundary roughness and resistance to flow. The program allows the user to subdivide the channel cross section so that overbank areas, mid-channel islands, and highwater overflow channels may be analyzed separately. The program also allows input of variable water-surface slopes so that slope may be varied with discharge to reflect natural conditions.