This method uses different slots and sets different slots if the Forecast Period is selected for the Incremental Hydrologic Inflows on Subbasin category. But, there is always a Source slot and a Target slot where the Source slot is input and used to forecasted and set the Target slot. If the Forecast Period is selected, the computational subbasin calls this method and uses the Cumulative Hydrologic Inflow (Source) to forecast and set the Forecasted Cumulative Hydrologic Inflow (Target). If it is not selected, the reservoir calls this method at the beginning of the timestep and uses the Deterministic Incremental Hydrologic Inflow (Source) slot to forecast and set the Hydrologic Inflow Forecast slot (Target). The following uses the Source/Target terminology to describe the methods.

The Source slot values are required inputs for each timestep. At the beginning of each controller timestep, the Geometric Recession method is executed. For each forecast timestep within the period of perfect knowledge, the Target is set to the Source value. For each forecast timestep after the period of perfect knowledge, the Target is set by multiplying the value of the Target from the previous timestep by the constant recession factor.

A value for the Source slot must be known at every timestep during the run. If Target values are desired past the end of the run, there must also be values in the Source slot at timesteps past the end of the run. If values for Source slot are not entered past the end of the run, the Target values for these timesteps are assumed to be zero.

This method uses and sets different slots if the Forecast Period is selected for the Incremental Hydrologic Inflows on Subbasin category. However, there is always a Source slot and a Target slot, where the Source slot is input and used to forecasted and set the Target slot. If the Forecast Period method is selected, the computational subbasin calls this method and uses the Cumulative Hydrologic Inflow (Source) to forecast and set the Forecasted Cumulative Hydrologic Inflow (Target). If it is not selected, the reservoir calls this method at the beginning of the timestep and uses the Deterministic Incremental Hydrologic Inflow (Source) slot to forecast and set the Hydrologic Inflow Forecast slot (Target). The following uses the Source/Target terminology to describe the methods.

The Source slot values are input for each timestep. At the beginning of each controller timestep, the Exponential Recession method is executed. For each forecast timestep within the period of perfect knowledge, the Target is set to the Source value. For each forecast timestep after the period of perfect knowledge, the Target slot is set as follows:

If the Source at the end of the period of perfect knowledge is negative, the Target at that timestep is exactly equal to the Source. However, the Source used in the recession equation, is the last positive value for Source. In the event that there is not a positive value for the Source, RiverWare issues a warning, and all values for Hydrologic Inflow Forecast within the forecast period will be set to the Minimum Forecasted Flow.

A value for the Source slot must be known at every timestep during the run. If the Target values are desired past the end of the run, there must also be values in the Source slot at timesteps past the end of the run. If values for Source are not entered past the end of the run, the Target values for these timesteps are assumed to be zero.

This method uses and sets different slots if the Forecast Period method is selected for the Incremental Hydrologic Inflows on Subbasin category. However, there is always a Source slot and a Target slot, where the Source slot is input and used to forecasted and set the Target slot. If Forecast Period method is NOT selected, the reservoir calls this method at the beginning of the timestep and uses the Deterministic Incremental Hydrologic Inflow (Source) slot to forecast and set the Hydrologic Inflow slot (Target). If it is selected, the computational subbasin calls this method and uses the Cumulative Hydrologic Inflow (Source) to forecast and set the Forecasted Cumulative Hydrologic Inflow (Target). The subbasin then computes the incremental flow and sets the value on the Hydrologic Inflow slot. The following description uses the Source/Target terminology to describe the method.

The method uses the following process:

On the current timestep, the Target is set equal to the Source. The method then loops through the remaining timesteps in the forecast period and sets the Target using the following formula starting at i = 1:

In the above formula, there is a mathematical problem if KIi-1 is zero. In this situation, the Target at that index is set to the known inflow at that index. This allows the simulation to continue with reasonable values for the Target. The logic uses the Lower Bound on the Target slot as the minimum value. This is specified on the Slot Configuration (select View, then Configure). If this value is specified it is checked, otherwise only 0.0 is used in the check. The logic is as follows:

At the end of the method, the Hydrologic Inflow Net is set equal to the Hydrologic Inflow plus the Hydrologic Inflow Adjust for each timestep in the loop. This allows the rules to be able to use the Hydrologic Inflow Net before the object dispatches (such as in the GetMaxOutflowGivenInflow() function).

A value for the Source slot must be known at every timestep during the run. If forecasted Hydrologic Inflow values are desired past the end of the run, there must also be values in the Source slot at timesteps past the end of the run. If values for Source are not entered past the end of the run, the Hydrologic Inflows for these timesteps are assumed to be zero.