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					 Integrated Water
Resource Planning
Systems User Forum


  WRYM - New features


        1 July 2004




                        1
      Layout – new features

• Automated search for stochastic firm yield


• Alternative method of modeling IFR - LHWP


• Reconciliation scenario analysis using the


  historical sequence – F16.DAT

                                               2
    Automatic search for
 stochastic firm yield (1 of 2)
– User defines the assurance level at
  which the yield needs to be
  determined (1:50, 1:20 return period)
– Iterative analyses are undertaken to
  search for the firm yield using an
  upper and lower target drafts as
  starting point
– User provides the initial upper and
  lower limits                            3
    Automatic search for
 stochastic firm yield (2 of 2)
– Activation variable: OPTFY=2, FO1.DAT

– Upper and lower target drafts defined
 through variable YIELD

– New variable TARGRI defines the
 recurrence interval for which the yield is
 determined
 (“50” for 1:50 or “20” for 1:20), F01.DAT
                                              4
   Alternative method of
 simulating the IFR (1 of 4)
– Application: Lesotho Highlands Water Project

– Method approved by the Lesotho Highlands

 Development Authority

– Use annual total flows as driver for IFRs – as

 apposed to normal method using monthly flow

– Additional data provided in the F14.DAT file

                                                   5
   Alternative method of
 simulating the IFR (2 of 4)
– Two options are available:

   • 1 – Annual IFR is a constant percentage of the annual natural

    inflows as defined by a set of reference inflow nodes –

    smooth annual IFR duration curve

   • 2 - User defines finite set of IFR definitions and one

    definition is imposed exactly for a range of annual inflows as

    defined by a set of reference inflow nodes – IFR for a year

    is one out of the set of IFR values
                                                                  6
   Alternative method of
 simulating the IFR (3 of 4)
– Monthly disagregation:


– Apply one of a set of user defined monthly values (12) for a

  simulation year which are selected based on a range of annual

  natural inflows that are referenced by a set of inflow nodes


– Option 1 > Normalization of 12 monthly values are used


– Option 2 > Exact specified 12 monthly values are used

                                                                  7
       Alternative method of
     simulating the IFR (4 of 4)
    – Example of additional data in F14.DAT file:
.
.
2 / Number of annual IFR structures
276 1 5 0.121 /IFR channel, # of inflow nodes, # of classes, IFR
factor
21            / Reference node number
756.6 3.21 22.74 12.21 11.48 12.14 11.48 7.74 4.71 7.35
4.45 7.18 4.09
563.8 2.95 13.61    3.21 11.48 12.14     6.98 7.74 3.21 2.85
2.41 6.91 3.83
501.7 2.95 12.11    3.21   7.98 12.14    3.48 7.74 3.21 2.85
2.41 6.67 2.15
348.4 2.68   2.85   3.08   7.71 12.14    2.95 4.09 2.41 1.45
1.61 6.64 2.33
   0.0 2.28  2.33   2.68   2.68   2.30   2.41 6.70 2.14 1.81
1.61 5.97 2.07

                                        Monthly IFR flows
Annual reference flows
                                             (m3/s)                8
  Reconciliation Scenario
         Analysis
– A method to reconcile the water requirements with the
  available water by taking the interdependencies among users in
  a water resource system into account
– Apply a water user type risk criteria that portions the demand
  into assurance categories – annual sequence only
– Scenario defined by single multiplication factor for each
  abstraction channel in a system – input variables allow multiple
  scenario runs, maximum 10
– Factors applied to min-max and specified demand abstraction
  channel types
– Simulation results assessed for compliance with risk criteria
  and summary of all channels presented as output
                                                                     9
  Reconciliation Scenario
         Analysis
 Model input (F16.DAT):
 2 5 1            / # user types, # risk criteria levels, #
 scenarios
 50 20 10 5 2     / Recurrence interval for each criteria level
 (1:X years)
 0.0 0.5 0.2 0.1 0.2 / Portion of demand for each criteria
 level – Type 1
 1.0 0.0 0.0 0.0 0.0 / Portion of demand for each criteria
 level – Type 2
 5                    / Number of water use channels
   27 1 1.00   /Channel number, user type, portion of demand to
 be imposed
   29 1 0.01   /Channel number, user type, portion of demand to
 be imposed
   32 1 0.03   /Channel number, user type, portion of demand to
 be imposed
Add further columns of factors for more scenarios, maximum = 10
   33 2 0.81   /Channel number, user type, portion of demand to   10
 be imposed
       Reconciliation Scenario
              Analysis
     Model results (DBG.OUT):
 Reconciliation summary
| Chn. nr | Type |User T| Demand(1) | Demand(2) |   Supply   |    Fct    | Recon(F/T)
|Failure Years per

Criteria Level
    27       2      1        3.513      3.513       3.513        1.000      T           0
0   0   0   0
    29       2      1        9.499      0.095       0.089        0.010      T           0
0   0 14 18
    32       2      1       29.260      0.878       0.859        0.030      T           0
0   0   0 17
    33       1      2        1.578      1.278       1.278        0.810      T           1
1   1   1   1
   901       1      2        1.578      0.237       0.237        0.150      T           1
1   1   1   1

                                                                                   11

				
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