storage {reservoir}

Storage-Reliability-Yield (SRY) relationships: Storage computation

Description

Returns the required storage for given inflow time series, yield, and target time-based reliability. Assumes standard operating policy. Storage is computed iteratively using the bi-section method.

Usage

storage(Q, yield, reliability, demand_profile, plot = TRUE, S_initial = 1,
  max_iterations = 50, double_cycle = FALSE)

Arguments

Q

vector or time series object. Net inflow totals to the reservoir. Recommended units: Mm^3 (Million cubic meters).

yield

the required yield. Must be same volumetric units as Q.

reliability

numerical. The required time-based reliability.

demand_profile

a vector of factors with length = frequency(Q). Represents within-year demand profile. Defaults to constant release if left blank.

plot

logical. If TRUE (the default) the storage behavior diagram and release time series are plotted.

S_initial

numeric. The initial storage as a ratio of capacity (0 <= S_initial <= 1). The default value is 1.

max_iterations

Maximum number of iterations for yield computation.

double_cycle

logical. If TRUE the input series will be replicated and placed end-to-end to double the simulation. (Recommended if the critical period occurs at the end of the recorded inflow time series)

Value

Returns the required storage capacity necessary to supply specified yield with specified reliability.

Examples

# Determine the required storage for 95 % reliability and yield equal to 80 % of the mean inflow.
layout(1:3)
storage(resX$Q_Mm3 * 20, yield = 0.9 * mean(resX$Q_Mm3), reliability = 0.95)