15.The next step is to set the initial heads. The heads will vary uniformly from 1 on the left to 0 on the right. Select Data|Edit Data Sets… Select the Initial_Head data set (under Required|Hydrology). Note that the Use PHAST-style interpolation for all cells checkbox becomes enabled on the PHAST Interpolation tab. Check this checkbox. Leave the Interpolation direction set to X. Set Distance 1 and Distance 2 to 0 and 12 respectively. Set Value 1 to 1 and Value 2 to 0 (fig. 46).
Figure 46. Data Sets dialog box showing how to set up a gradient in initial head.
16.The next step is to set the initial conditions for chemistry. The solution, surface and kinetics will all have an initial index of 1. With the Data Sets dialog box still visible, set the formula for Chemistry_Initial_Solution, Chemistry_Initial_Surface, and Chemistry_Initial_Kinetics each to 1. They are found under Required|Chemistry. Click the Apply and then the Close buttons.
