User Manual for Graphical User Interface (GUI) LFArk1.exe for Estimating
Low-Flow Characteristics at Ungaged Basins in Arkansas

1.  *List of required files:*

-   MCRInstaller.exe

-   LFArk1.exe

-   LFArk1.ctf

2.  *Installation instructions for MCRInstaller.exe:*

Before beginning the installation on your computer, verify that you have
full administration privileges on the computer. Set the permissions on
this folder to read and write access. The purpose of MCRInstaller.exe is
to allow a computer to use stand-alone Matlab executables, such as
LFArk1.exe, without having a license from Mathworks, Inc.

To begin installation, go to Windows Explorer and find the folder
containing the program MCRInstaller.exe. Double click on this folder to
launch the application. The following screen will appear on your desktop
environment:

![](media/image1.png){width="4.104166666666667in"
height="1.6145833333333333in"}

Select language and press the "OK" button. A window opens next showing
the status of the program preparing to install.

![](media/image2.png){width="5.354166666666667in" height="4.0625in"}

The following window opens:

![](media/image3.png){width="5.354166666666667in" height="4.0625in"}

Click the "Next \>" button to continue and the following window opens:

![](media/image4.png){width="5.354166666666667in" height="4.0625in"}

After entering the "User Name" and "Organization" information, click on
the "Next \>" button. You will be prompted for a directory to install
the program in the following window:

![](media/image5.png){width="5.354166666666667in" height="4.0625in"}

It is strongly suggested to install the files in the default location
indicated in the window. It should begin with "c:\\Program
Files\\MATLAB\\MATLAB Component Runtime\\..." . Click the "Next \>"
button to begin the installation, and you should see the following
window:

![](media/image6.png){width="5.354166666666667in" height="4.0625in"}

Click on the "Install" button to begin installation. During
installation, the status will be displayed in the following window:

![](media/image7.png){width="5.354166666666667in" height="4.0625in"}

When the installation is complete, you will see the following window:

![](media/image8.png){width="5.354166666666667in" height="4.0625in"}

3.  *Running the Low-Flow Characteristics Program LFArk1.exe:*

To run the stand-alone executable program LFArk1.exe, please go to
Windows Explorer and locate LFArk1.exe program on your computer (not on
the CD) and double-click the program. The following window will appear:

![](media/image9.png){width="5.993055555555555in"
height="3.0277777777777777in"}

Note: If a "Warning:..." message appears in this window, please ignore
because the program is looking for a toolbox that the program does not
use. After this step, in the same directory of the stand-alone
executable program, a folder called LFArk1_mcr will be created. Do not
open, change, or move any files in the .ctf folder that accompanies the
stand-alone executable program. This file and a resulting folder
"LFArk1_mcr" must remain in the same directory as LFArk1.exe.

After several moments (30 seconds -- 2 minutes), the main graphical user
interface (GUI) program window will open for the Low-Flow
Characteristics Estimation program for Arkansas (hereafter referred to
as the main GUI interface) and should look like the following:

![](media/image10.png){width="5.995833333333334in"
height="3.6930555555555555in"}

Note that all GUI interfaces are resizable, so just place the cursor
over any corner of a GUI interface and click and drag to desired size.

4.  *Computation of Low-Flow Characteristics using LFArk1.exe:*

    a.  Region Selection

Go to the upper left of the main GUI interface (shown below) and click
on the miniature map to enlarge it (the default region is 1).

![](media/image10.png){width="5.995833333333334in"
height="3.6930555555555555in"}

![](media/image11.png){width="4.503472222222222in"
height="3.879166666666667in"}

Enlarged version of miniature map

> To select a region, toggle the corresponding radio button on the right
> side of the "Arkansas Map" window and an enlarged map will open. For
> example, if region 1 is selected the following window opens:

![](media/image12.png){width="5.996527777777778in" height="2.725in"}

b.  Low-flow characteristic selection

Click the box adjacent to the "Low-Flow Characteristics of Interest" in
the lower left box of the main GUI interface (shown on following example
of the main GUI interface). The "Select All" can be used if the user
desires all the characteristics, and the same button can be used to
clear all the selected entries. Please note that an "x" in the "L" and
"C" columns indicates that a logistic regression is available, and a
conventional weighted least squares (hereafter referred to as
conventional) regression is available, respectively.

![](media/image13.png){width="5.995833333333334in"
height="3.6930555555555555in"}

c.  Entering basin characteristic values

The upper right box of the main GUI interface lists all the variables
used (and associated units) in the logistic and conventional regression
models. Enter the numerical data into the active boxes in the lower
right corner of the following interface called "Enter Logistic
Regression Data (Table 6)" and "Enter Conventional Regression Data
(Table 7)." Black text in the preceding GUI interface example indicates
active boxes which require values for the selected regression models.
The following example of the main GUI interface shows values entered in
the active boxes.

![](media/image14.png){width="5.995833333333334in"
height="3.6930555555555555in"}

Enter only numerical data into the boxes or the following error message
will occur:

![](media/image15.png){width="2.4993055555555554in"
height="1.1819444444444445in"}

Click "OK" and the Error box will be deleted.

d.  Computation of low-flow characteristics

Click the "Compute" button on the bottom of the main GUI interface to
compute the low-flow characteristics. Estimates of the low-flow
characteristics are reported on the main GUI interface for "Results:
Estimates of Low-flow Characteristics at Ungaged Basins" (Results GUI
interface) that will open automatically.

![](media/image16.png){width="5.990277777777778in" height="4.7in"}

The selected low-flow characteristics are displayed on the left side of
the Results GUI interface and the estimated flow values in cubic feet
per second (cfs) are displayed in the box. Purple fonts are used for
regression models (logistic or conventional regression model) that are
statewide models (tables 6 and 7), while black fonts are used for the
models associated with the three regions in Arkansas (tables 6 and 7).
For each low-flow characteristic of interest there are fourteen boxes
displayed indicating when extrapolation problems exist for the entered
basin characteristic values. A grayed box indicates that the basin
characteristic was not used in either logistic or conventional
regression models. An empty white box indicates that a basin
characteristic was used in either logistic or conventional regression
models, and that there is no problem of extrapolation based on the
entered value. An 'x' mark in a white box indicates that the entered
basin characteristic is outside the range that was used to develop
either the logistic or conventional regression models. Clicking on these
'x' boxes opens a window such as the following:

![](media/image17.png){width="2.0819444444444444in"
height="1.2861111111111112in"}

This interface displays the entered value and the acceptable ranges of
the logistic and conventional regression models.

e.  Saving images of GUI interfaces

To create image files of any GUI interface, the user can click onto the
desired GUI interface and press "Alt+Print Screen" buttons on their
keyboard. Then, open a program (such as Microsoft Word, Excel, Paint)
and paste the image.

f.  Output text files of LFArk1.exe

In addition to the producing images of the GUI interfaces, two text
tab-delimited output files are created. Programs such as WordPad or any
other program that can display text tab-delimited files can open them.
One output file (LogisticRegrSummary.txt) reports the results of the
logistic regression models, and the other file (WLSRegrSummary.txt)
reports the results of the conventional regression model. A screen
capture of the LogisticRegrSummary.txt file is shown here:

![](media/image18.png){width="6.5in" height="3.2819444444444446in"}

The "Low Flow' column lists the low-flow characteristic chosen by the
user, and the "Pzero" column reports the probability of a low-flow
characteristic being equal to zero. The values of "9999" indicate that
no logistic regression model is available for the selected low-flow
characteristics. A value of 1 in the "Regr. Needed" column indicates
when the Pzero value is less than 1/*T* (where *T* is the return period
of interest), so a conventional regression model is needed in this
example. The columns under the "Basin Characteristic Ranges" heading
report when a basin characteristic value that the user entered is
outside the range of values used to develop the equation. A "0"
indicates that the entered value is within the range of values used to
develop the equation, a "1" indicates that the entered value is outside
the range, and a "--9999" indicates a non-significant basin
characteristic. The "Performance Metrics" report the percent of basins
misclassified by the equation in the preceding image, which measures the
accuracy of the logistic regression models. The "State or Region" column
reports whether a statewide logistic regression model or a regional
regression model was used. Please note that the printed version of the
.txt file must use landscape mode (as noted at the bottom of the
LogisticRegrSummary.txt file).

A screen capture of a WLSRegrSummary.txt file is shown here:

![](media/image19.png){width="6.489583333333333in"
height="2.9854166666666666in"}

![](media/image20.png){width="6.489583333333333in"
height="2.9854166666666666in"}

The "Low Flow (cfs)" column lists the estimated low-flow characteristic
values in cubic feet per second. The 14 columns under the "Basin
Characteristic Ranges" report when a basin characteristic value that the
user entered is outside the range of values used to develop the
equation. A "0" indicates that the entered value is within the range of
values used to develop the equation, a "1" indicates that the entered
value is outside the range, and a "--9999" indicates a non-significant
basin characteristic. The "Performance Metrics" report the amount of
variability explained (pseudo *R^2^*) by the conventional regression
model in percent and the average standard error of prediction (*S~p~*)
in percent of the model. The "State or Region" column reports whether a
statewide conventional regression model or a regional one was used.
Please note that to view the entire 14 columns, the user must print the
file in landscape mode using 11 17 paper (as noted at the bottom of the
WLSRegrSummary.txt file).