"Slope" vs. "Calculated Slope"

The difference between "Slope" and "Calculated Slope"

CALCULATED SLOPE –  is the slope that the program CALCULATES when you draw or assign PIPE INVERT. I advise you to always use this one, to show it in profiles, tables and labels.

SLOPE  is the one that you ASSIGN, or that the program calculates in HYDRAULIC DIMENSIONING by minimum slope. This is rarely used. Usually, those two types of slope will have the same data. But it can happen that those are not the same.

So, how can it happen that those two slopes have different values? 

It can happen in two cases.

1. You an assign SLOPE value manually

We added the possibility for the user to define SLOPE for certain part of the network, without actually DRAWING THE PIPE INVERT. Then you can run some preliminary hydraulic calculation and calculate hydraulic values for such gradient, that you assume it will be done. You can assign it here:

If you add SLOPE and CALCULATED SLOPE to the table, you will see that the CALCULATED SLOPE is empty UNTIL you draw / define pipe invert:

When you assign PIPE INVERT, both slopes will be the same !

BUT, IF YOU GO TO INPUT DATA - SLOPES, and input SLOPE data AFTER you've defined pipe invert in profiles, the data will be different:

To correct this error, just go to INPUT DATA - SLOPES and assign slope by checking option “from pipe invert” and SAVE THE DATA:

2. Program will calculate this value (SLOPE) in Hydraulic calculation, if you use option MINIMUM SLOPE CALCULATION:

When would you want to calculate it?

Well, if you define PIPE DIAMETERS for your network and calculate FLOW RATES, and then you want to calculate the minimal slope that must be achieved to make this flow rate pass through the selected pipe diameter, you can use this option. But then, SLOPE and CALCULATED SLOPE data will also be different! 

However, this is not really useful, because there is no option to define pipe invert from this SLOPE. The program used to have this option - to define pipe invert according to this minimum SLOPE. It was possible to do it only for one profile at the time, and you had to define the depth at the first node. It was too complicated to use it, so we removed it.  

So I do not reccomend you to use this "SLOPE" data (we will remove it from the next version, only CALCULATED SLOPE will be available, the one from real values of pipe invert elevation).

In the next version of the softvare (11), only one value of SLOPE will be available.