modeling issues with in-delta agricultural uses
DESCRIPTION
Figure IV.2-6. DSM2 results on the source water and salinity (“volumetric and constituent fingerprints) for the period November 2004 to February 2005. Reproduced from DWR (2005). Modeling Issues with In-Delta Agricultural Uses. Drainage salinity Drainage volume Net depletion. - PowerPoint PPT PresentationTRANSCRIPT
Figure IV.2-6. DSM2 results on the source water and salinity (“volumetric and constituent fingerprints) for the period November 2004 to February 2005. Reproduced from DWR (2005).
Modeling Issues with In-Delta
Agricultural Uses
• Drainage salinity
• Drainage volume
• Net depletion
Data available at http://wdl.water.ca.gov/wq-gst/
Figure IV.2-1. Approximate sampling locations of agricultural drainage salinity by DWR's Municipal Water Quality Investigation Program, data collected between 1986 and 1997.
B Bacon Island
Bo Bouldin Island
Br Brannan Island
B Bacon Island
E Empire Tract
G Grand Island
H Holland Tract
J Jersey Island
K King Island
M Mandeville Island
O Orwood Tract
P Palm Tract
Pe Pescadero
R Rindge Tract
S Staten Island
T Tyler Island
U Upper Jones Tract
V Venice Island
W Woodward Island
Wb Webber Tract
0
250
500
750
1,000
1,250
1,500
1,750
2,000
2,250
10/2/87 10/1/88 10/1/89 10/1/90 10/2/91 10/1/92 10/1/93 10/1/94
Tot
al D
isso
lved
Sol
ids
in m
g/L
Kings Island Bacon Island Mandeville Island
Pescadero Empire Tract PP Upper Jones Tract PP#2
Rindge Tract Woodward Island Bulletin 123-67
Data collected by the Municipal Water Quality Investigation Program of the California Department of Water Resources.
Figure IV.2-2. Agricultural drainage salinity in south and southeast Delta. Drainage salinity at different pump stations on the same island (e.g. Kings Island) could be significantly different.
0
250
500
750
1,000
1,250
1,500
1,750
2,000
1 2 3 4 5 6 7 8 9 10 11 12
Calendar Month
Tot
al D
isso
lved
Sol
ids
in m
g/L
South and southeast West and Central North
South and Southeast West and Central North
Recent data collected by the Municipal Water Quality Investigation Program of the California Department of Water Resources.
Monthly average of recent measurements:Bulletin 123-67:
Figure IV.2-5. Model input and recent measurements of agricultural drainage salinity in the Delta.
Observations
Wide scatter of drainage salinity:
• between islands• between years• between months
Model input could be significantly different from field measurements
Source tracking could be a solution
Issues• Drainage salinity
• Drainage volume
• Net depletion
Jung, M. And Q. Tran. 1998. Delta island drainage volume estimates, 1954-1955 versus 1995-1996. Report to DWR, MWQI Program.
Jung, M. And Q. Tran. 1998. Delta island drainage volume estimates, 1954-1955 versus 1995-1996. Report to DWR, MWQI Program.
Jung, M. And Q. Tran. 1998. Delta island drainage volume estimates, 1954-1955 versus 1995-1996. Report to DWR, MWQI Program.
Issues• Drainage salinity
• Drainage volume
• Net depletion
Delta Salinity at different Delta outflowsG-Model estimates for constant outflows
100
150
200
250
300
350
400
450
500
2,500 3,000 3,500 4,000 4,500 5,000
Delta Outflow (cfs)
Ch
lori
de (
mg/
L)
0
4
8
12
16
20
24
28
32
Rock Slough (Cl) Martinez (EC) Chipps (EC) Jersey (EC)
EC
(mS
/cm)
Salinity changes through adjacent minor grid points show the potential impacts of a 200 cfs decrease in Delta outflow.
ObservationsDrainage salinity• Highly variable (season, island, year)• Higher salinity assumed in model
Drainage volume• Large difference in 2 field estimates
Net depletion• Uncertainty of even a few hundred cfs could
lead to large difference in simulated salinity