h2>Arguments</h2>
    <dl><dt>Dir</dt>
<dd><p>A directory name to store gridded rainfall and rain stations files.</p></dd>
<dt>watershed</dt>
<dd><p>A study watershed shapefile spatially describing polygon(s) in a geographic projection sp::CRS('+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs').</p></dd>
<dt>DEM</dt>
<dd><p>A study watershed digital elevation model raster in a geographic projection sp::CRS('+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs').</p></dd>
<dt>start</dt>
<dd><p>Beginning date for