briefing on the 2010 – 2011 drought in south florida · 2016. 10. 16. · technical oversight...
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Technical Oversight CommitteeSeptember 14, 2011
Briefing on the g2010 – 2011 Drought in South Florida
Wossenu Abtew Ph D P E D WREWossenu Abtew Ph D P E D WREWossenu Abtew, Ph.D., P.E., D.WREPrincipal Engineer, Water Quality BureauWossenu Abtew, Ph.D., P.E., D.WRE
Principal Engineer, Water Quality Bureau
Factors Determining the Severity of a Droughtof a Drought
Rainfall Amount
Rainfall Temporal Distribution
Rainfall Spatial Distribution
Antecedent Hydrologic Condition Antecedent Hydrologic Condition
Spatial Variation of Annual Rainfall with Temporal Extremes (100-year return periods)Temporal Extremes (100-year return periods)
Monthly Variation of WY2011 and Historical Average RainfallHistorical Average Rainfall
)
Most months had far below average rainfall
ly ra
infa
ll (in
)
8
10
WY2011historical average
October rainfall was a 1-in-100 yr drought
Upper KissimmeeL Ki i
erag
e m
onth
l
6
Lower KissimmeeLake OkeechobeeMartin/St. LuciePalm Beach
hist
oric
al a
ve
4
WY2
011
and
h
0
2
2010 - 2011
May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr
W 0
Driest 3-month Rainfall since 1895(October through December 2010)(October through December, 2010)
WY2011 Rainfall Deficits and Return Periods by Rain AreaPeriods by Rain Area
Return Period is expectedfrequency or recurrence intervalfrequency or recurrence intervalReturn Period in
yearsProbability of being
exceeded in any year (%)5 2010 1020 520 550 2100 1
Palmer Drought Severity Index (July 2011)Palmer Drought Severity Index (July 2011)
South Florida EvaporationDrought severity increases by increasing EvaporationDrought severity increases by increasing Evaporation
Water Conservation Area 1 Inflows
Water Conservation Area 3 and S333 Headwater StagesHeadwater Stages
10.0G
VD
29)
9.0
9.5
10.0ai
ly s
tage
(ft N
G
7 5
8.0
8.5
Ave
rage
da
6.5
7.0
7.5
WCA 3 average stageS333 headwater stage WCA3 floor
1/1/
2011
2/1/
2011
3/1/
2011
4/1/
2011
5/1/
2011
6/1/
2011
7/1/
2011
8/1/
2011
9/1/
2011
6.0
Date
S333 Headwater Stage (record low in the last 20 years)(record low in the last 20 years)
13N
GVD
29)
11
12
13ily
sta
ge (f
t N
8
9
10
Ave
rage
da
6
7
8
June 8th, 2011
01/0
1/90
01
/01/
91
01/0
1/92
01
/01/
93
01/0
1/94
01
/01/
95
01/0
1/96
01
/01/
97
01/0
1/98
01
/01/
99
01/0
1/00
01
/01/
01
01/0
1/02
01
/01/
03
01/0
1/04
01
/01/
05
01/0
1/06
01
/01/
07
01/0
1/08
01
/01/
09
01/0
1/10
01
/01/
11
01/0
1/12
5
Date
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
El Niño Southern Oscillation Prediction with Cumulative Sea Surface Temperature IndexCumulative Sea Surface Temperature Index
Cumulative SST Index (Abtew and Trimble 2010; Abtew et al 2009)
Abtew, W. and P. Trimble. 2010. El Niño Southern Oscillation Link to South Florida Hydrology and
(Abtew and Trimble, 2010; Abtew et al., 2009)o C
) 10
15
strong El Niño
Hydrology and Water Management Applications. Water Resources Management, 24(5):4255‐4271, DOI:10 1007/s1126 SS
T In
dex
(o
0
5El Niño 2009
DOI:10.1007/s11269‐010‐9656‐2.
Abtew, W., A. Melesse and T. Dessalegne. 2009. El Niño Southern
Cum
mul
ativ
e
10
-5
t L Niñ
La Niña
2008
20112010
Oscillation link to the Blue Nile River Basin Hydrology. Hydrological Processes. Vol. 23:3653‐3660;
M th
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
C
-15
-10 strong La Niña
DOI:10.1002/hyp.7367.
Month
What does La Niña Mean for the Everglades Protection Area?Everglades Protection Area?
Reduced inflowsL t l l Lower water levels
More wildfires Less water quality sampling events in
the EPA
Hydrology Impact on Number of Sites Sampled (Refuge Monitoring, 1994-2011)(Refuge Monitoring, 1994 2011)
• The 2011 number of sites in the Refuge that were not sampled due to low stagesthat were not sampled due to low stages is the highest since 1994
• In calendar year 2011 (through July), there were 59 events with no sampling
Droughts and Wildfire (Water Conservation Area 1 5/7/11)(Water Conservation Area 1, 5/7/11)
Dry Conditions in Water Conservation Area 2 (5/4/11)Area 2 (5/4/11)
Summaryy
WY2011 d ht d WY2011 was a severe drought year and WY2012 is likely to be another dry yearH d l i diti i t t lit Hydrologic conditions impact water quality sampling and parameter concentrationsI t ti R f d P k TP Interpreting Refuge and Park TP compliance must take antecedent and prevailing hydrology into accountprevailing hydrology into account