add SWAT/SWAT+ dependency to README and DESCRIPTION

DESCRIPTION

@@ -7,7 +7,7 @@ Maintainer: Tam V. Nguyen <tamnva@gmail.com>
 Description: Parameter calibration and uncertainty analysis with SWAT/SWAT+ and their modified versions.
 Encoding: UTF-8
 LazyData: true
-RoxygenNote: 7.3.1
+RoxygenNote: 7.3.2
 URL: https://github.com/tamnva/R-SWAT
 BugReports: https://github.com/tamnva/R-SWAT/issues
 Depends: R (>= 4.0)
@@ -40,3 +40,4 @@ Suggests:
     testthat (>= 3.0.0)
 Config/testthat/edition: 3
 VignetteBuilder: knitr
+SystemRequirements: SWAT/SWAT+ executable files (https://swat.tamu.edu/software/)

README.md

@@ -10,7 +10,9 @@
 
 ## Quick Start!
 
-RSWAT is an R package hosted on GitHub (to be submitted to CRAN soon). First, you need to install [R](https://cloud.r-project.org/), and [RStudio](https://posit.co/download/rstudio-desktop/) (installing RStudio is recommended, not a MUST) then **run** the following commands **in RStudio**. If you run in R, package vignettes cannot be built, however, this DOES NOT affect the functionalities of RSWAT.
+RSWAT is an R package hosted on GitHub (to be submitted to CRAN soon). First, you need to install [R](https://cloud.r-project.org/), and [RStudio](https://posit.co/download/rstudio-desktop/) (installing RStudio is recommended, not a MUST) then run the following commands **in RStudio**. If you run in R, package vignettes cannot be built, however, this DOES NOT affect the functionalities of RSWAT.
+
+To run RSWAT, the SWAT/SWAT+ model is required.  The SWAT/SWAT+ model (executable file) could be obtained from the official [SWAT website](https://swat.tamu.edu/software/).
 
 ```R
 # First install remotes package if you have not installed
@@ -24,6 +26,7 @@ remotes::install_github("tamnva/R-SWAT", force = TRUE, dependencies = TRUE, buil
 library(RSWAT)
 
 # Extract example data (3.6 MB of storage). TODO: replace tempdir() with your path, e.g., "C:/example"
+# The example data DO NOT include the SWAT executable files (please download them at https://swat.tamu.edu/software/)
 extracExampleData(exampleData, "all", tempdir())
 
 # Call RSWAT graphical user interface: DO NOT use RSWAT::showRSWAT()

inst/R-SWAT/HTML/introduction.html

@@ -30,7 +30,6 @@
 <div>
 <ul style="margin-bottom: 0in;" type="square">
 <li style="font-size: 16px; font-family: 'Times New Roman'; margin: 0in 0in 8.0pt 0in;">Nguyen, T. V., Dietrich, J., Dang, D. T., Tran, D. A., Doan, B. V., Sarrazin, F. J., Abbaspour, K., Srinivasan, R. (2022). An interactive graphical interface tool for parameter calibration, sensitivity analysis, uncertainty analysis, and visualization for the Soil and Water Assessment Tool. Environmental Modelling &amp; Software, 156, 105497. <a href="https://doi.org/10.1016/j.envsoft.2022.105497" target="_blank" rel="noopener">https://doi.org/10.1016/j.envsoft.2022.105497.</a></li>
-<li style="font-size: 16px; font-family: 'Times New Roman'; margin: 0in 0in 8.0pt 0in;">Nguyen, T. V. (2024). RSWAT: An R package for the Soil and Water Assessment Tool models. Submitted to The Journal of Open Source Software.</li>
 </ul>
 </div>
 </div>
@@ -43,7 +42,7 @@
 <div>
 <ul>
 <li style="font-size: 16px; font-family: 'Times New Roman'; margin: 0in 0in 8.0pt 0in;">This package was developed by <a href="https://www.ufz.de/index.php?en=46415" target="_blank">Dr. Tam V. Nguyen</a>, Department of Hydrogeology, Helmholtz Centre for Environmental Research - UFZ, Germany.</li>
-<li style="font-size: 16px; font-family: 'Times New Roman'; margin: 0in 0in 8.0pt 0in;">We thank <a href="https://chrisschuerz.github.io/" target="_blank">Dr. Christoph Sch&uuml;rz</a> and two anonymous reviewers, whose comments have helped to improve the quality of the app. We thank R-SWAT users for reporting bugs, suggestion on the app functionalities.</li>
+<li style="font-size: 16px; font-family: 'Times New Roman'; margin: 0in 0in 8.0pt 0in;">We thank reviewers of RSWAT papers, whose comments have helped to improve the quality of RSWAT. We thank RSWAT users for reporting bugs, suggestion on the app functionalities.</li>
 </ul>
 </div>
 </div>