CRDSS_Task1_15-16_DataManagementInterfaceToEstimateNaturalStreamflowAtNetworkNodes

• Title: CRDSS Task 1.15-16 - Water Rights Planning Model - Data Management Interface Utility to Estimate Natural Streamflow and Inflow at Network Model Nodes
• Description: This task memorandum outlines and describes the procedures of the data management interface ‎(DMI)‎ utility that will be used to estimate natural streamflow and inflow at network model nodes.
• Decision Support - Doc Type: Task Memorandum
• Date: 1/9/1995
• DSS Category: Surface Water
• DSS: Colorado River
• Basin: Colorado Mainstem
• Contract/PO #: C153658, C153727, C153752
• Grant Type: Non-Reimbursable
• Bill Number: SB92-87, HB93-1273, SB94-029, HB95-1155, SB96-153, HB97-008
• Prepared By: Riverside Technology inc.

It is important that the input cont rol file (<basin>.NCT) be structured such that the most upstream inflow
nodes are listed first. This struct ured sequence is necessary because the calculations for downstream inflow
nodes require that the natural streamflow for the immediate upstream inflow nodes has previously been
determined.
The locations of the model inflow nodes and estimates of the natural streamflow and inflows for the model
inflow nodes will be established during the initial se tup of the MODSIM network. The initial estimates of
nodeflow
natural streamflow and inflows will be perman ently saved and maintained. The DMI utility will
estimate monthly natural streamflow and inflows at specified locations using the following information: (1)
natural streamflow estimated at CRDSS core stations, (2) unit basin natural streamflow for the selected
CRDSS core stations, (3) mean drainage basin elevation of the se lected CRDSS core stations and the model
node of interest, and (4) regression analysis relating un it basin natural streamflow to mean drainage basin
elevation.
nodeflow
Appendix A of this task memorandum provides a general flow chart of the DMI utility .
Appendix B provides a general flow chart for using the database and MODSIM interface in relation to the
coreflow nodeflow
DMIs and . The following steps outline the pro cedure to estimate natural streamflow
and inflow at a specified location:
If the user has specified to estimate natural flow at an existing inflow node (for recalculation), the
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initial estimates of natural streamflow a nd inflow will be saved and maintained.

If the user has specified to estimate natural inflo w at a CRDSS core station, skip steps 2 through 7
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and start with step 8.

Implement a low-level DMI to return time series data for monthly natural streamflow at the
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selected CRDSS core stations. For each year of the study period, determine the annual natural
streamflow for each of the se lected CRDSS core stations:
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ANLFLW = NATFLW (1)
s,y s,m
m=1
where ANLFLW is the annual natural streamflow ( acre-feet) for the CRDSS core station s
s,y
during the year y, NATFLW is the natural streamflow (acre-f eet per month) at the core station
s,m
for the month m. January is represented by m=1 and December corresponds to m=12. For each
selected core station, there will be a value of ANLFLW for each year, y, of the study period.
Determine the average annual natural streamflow for each of the selected CRDSS core stations:
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Y
DIS =(1/Y)* ANLFLW (2)
s,y
s
y=1
where DIS is the average annual natural streamflow ( acre-feet per year) for CRDSS core station s,
s
and Y is the total number of years in the study period.
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A275 01.09.95 1.15-16 Hyre, Fosha