COMPUTATION MENU¶
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# COMPUTATION MENU¶
In this menu you can find the commands that help establish the basin's balance, its high flood flows for every section, homogeneous and permanent flow conditions verification and the riverbed section view (longitudinal profile).
Hydro graphical and Morphometrical Analysis
For every basin defined by a break point an analysis is performed regarding its morphometrical proprieties and its time of concentration. During this phase the program carries out also the computations for every sub-basin automatically generated according to the position of each breakpoint.
After the analysis is completed alterations can be undertaken for every sub-basin from the control panel in the right of the work area. Activating the
Triangularization
This operation is carried out automatically by the program for the morphometrical and hydro graphical analysis. This command enables the basin's 3D view and its printing from the preview window - to activate it press the right button of the mouse.
Carries out the computations using Kennessey's flow coefficient. For this parameter, compulsory for the next step in the hydrological balance, the following data must be provided:
rainfall: expressed in mm of rain, for expressing P rushes;
medium temperature: monthly medium temperature;
maximum temperature: monthly maximum temperature;
minimum temperature: monthly minimum temperature.
The program calculates the aridity index for provided data, from which, depending on the calculation for the surface slices that define the vegetal distribution, the steepness and the permeability, the partial and total efflux coefficient are obtained.
In this window are asked the main basin's inflow and outflow data.
In this window are computed long rain data (1 – 3 – 6 – 12 – 24 hours for several years); consequently the basin's Rain model is defined. The program performs the calculation of the rain's maximum and critical height corresponding to every day and period (1, 3, 6, 12, 24 hours), in function of every recurrence interval assigned by the user in General Data from the Data Input menu.
Rain data acquired from a rainfall station can be directly filled in the period's table or copied from another file.
The program computes data with Gumbel's probability distribution, and finds the parameters, the medium standard deviation, k and m.
The Rainfall Probability Curve graphic is available in semi-algorithmic and algorithmic scale (x and y). By pressing the right button of the mouse you can copy the graph to clipboard, paste it in bitmap image format or copy the containing values for another project.
The print report allows sending input data and results to the printer.
High flood flow - Empirical Methods
For every transversal section the high flood flow is calculated with empirical methods. This requires the author's selection. The program reads the flow value in m³/sec, the specific flow in m³/sec Km².
High flood flow - Empirical and Rational Method
For the assigned Recurrence interval the program calculates the high flood flow corresponding with the specified transversal section. The program develops a flow analysis for every sub-basin on the activation of the
For every recurrence interval assigned by the user the program generates the high flood hygrograph with Nash's method. In the respective window, for every elected transversal section can be viewed: k and n function parameters, basin's characteristics (calculated with Nash or Mc Sparran) and n and a Rain model parameters (for every Tr). Calculation step, in hours, and the maximum period (hours) are user defined; in order to change them press the
Uniform flow hydraulic verification
For every selected section the program carries out the uniform flow conditions verification. The verification sections definition (transversal sections) takes place before this stage, so, after having developed the Hygrograph and Morphological Analysis, the program proceeds with the determination of the maximum high flood flow (empirical and classical methods). Every sections' roughness and form must be defined. Sections' generation can be obtained by activating the
Steady flow boundary conditions
The command opens the steady flow boundary conditions window. It is in Hydraulic checks > Boundary conditions, next to Steady flow hydraulic check, and in Computation options > Computation options. For each return period you choose the condition at the downstream end section (catchment closure section) and at the upstream end section: imposed depth, uniform flow depth or critical depth. The downstream condition is used for subcritical flow, the upstream one for supercritical flow; the calculation chooses between subcritical and supercritical flow, section by section. How to choose the conditions is explained in Steady flow hydraulic check.
For each return period the program computes the water surface profile along the channel, from the downstream section to the upstream one, with the method described in Steady flow hydraulic check. If the boundary conditions have never been set (imposed depth with all depths equal to zero), the boundary conditions window opens before the calculation. When the calculation is done, each section has its water depth, flow type (subcritical, supercritical or critical) and channel type (mild or steep slope); the status bar shows the boundary conditions used. The Profile and results command shows the longitudinal profile and the table of results section by section.
Overfill mapping
The command shows the high flood area for every recurrence interval. The overfill mapping is available only after the sections' verification in permanent flow conditions. For printing it choose the
Riverbed section preview
Views the longitudinal section of the riverbed with the water profile height determined in slice by slice flow conditions. For returning to the basin's view deselect the command.
Data block/free
command that allows to block or free the input/ output data.