User's guide of Proceessing Modflow 5.0

Processing Modflow 179
the cell indexing system is located at the upper, top, left cell of the model. MODFLOW numbers
the layers from the top down, an increment in the K index corresponds to a decrease in
elevation z.
PMPATH always displays the model grid parallel to the Worksheet, while PMWIN allows
a user to shift and rotate a model grid by giving the rotation angle A and the coordinates (x , y )
0 0
of the upper-left corner of the grid. The relation between the model grid and the real-world (x,
y, z) coordinate system is illustrated in Fig. 4.5. The Worksheet displays the plan view of the
current model layer and the projection of pathlines on the horizontal IJ-plane. The cross-section
windows display the projection of pathlines on the IK- and JK-planes. The Environment
Options dialog box of PMPATH (see sec. 4.3) allows the user to change the appearance of these
windows.
The projection of pathlines on the cross-sections is useful when running PMPATH with a
three-dimensional (multi-layer) flow field. One should always keep in mind that only the
projections of pathlines are displayed. The projection of a pathline may be intersected by another
or even itself, particularly if a three-dimensional flow field or a transient flow field is used.
Status bar
The Statusbar displays the following messages:
1. the current position of the mouse cursor (in both [x, y, z] coordinates and [J, I, K] indices);
2. the hydraulic head at the cell [J, I, K];
3. the average horizontal pore velocity at the center of the cell [J, I, K];
4. the average vertical pore velocity at the center of the cell [J, I, K];
5. the current stress period of the flow simulation;
6. the current time step of the flow simulation; and
7. the number of particles.
See Particle Tracking (Time) Properties dialog box (sec. 4.3) for how to change the current
stress period and time step. The hydraulic heads at the current stress period and time step are
calculated by MODFLOW. The average horizontal pore velocity at the center of a cell is obtained
by averaging the velocities v , v and v , v respectively (see equation 4.3a-4.3d). The average
x1 x2 y1 y2
vertical pore velocity at the center of a cell is the average of the velocities v , v (see equation
z1 z2
4.3e and 4.3f). The vertical velocity is defined as positive when it points in the k-direction.
4.2 PMPATH Modeling Environment