Climatological Perspec ve on Extreme Hydrological Events in the Catskill Mountains and Hudson River Valley
Allan Frei Department of Geography, Hunter College, City University of New York CUNY Ins tute for Sustainable Ci es
Collaborators: Adao Matonse (NYCDEP), NYCDEP BWS Water Quality Modeling Group, NYSERDA, colleagues at CUNY Ins tute for Sustainable Ci es, Rutgers University
Presented at 5th Annual Ashokan Watershed Conference Ashokan Center, Olivebridge, NY, April 2014 Presenta on Outline
• Background • How Unique were Irene and Lee? • Changing Frequency of Extreme Events in our Region • Conclusions
Tannersville, photo by Sean Mahoney Main Street, Margaretville h p://www.wnyc.org/blogs/wnyc-newsblog/2011/aug/31/focus- h p://www.buzzfeed.com/mjs538/frightening-hurricane- shi s-people-stranded-catskills-flood-waters-recede/ irene-destruc on-photos
Irene in
Windham New Windsor the Catskills h p://www.buzzfeed.com/mjs538/frightening-hurricane-irene- h p://en.wikipedia.org/wiki/ destruc on-photos File:Forge_Hill_Road_bridge_washout_a er_Hurricane_Irene,_ New_Windsor,_NY.jpg Irene in the Catskills: EB Delaware, Margaretville
Main Street
Above: Immediately a er Irene, Sep 1, 2011, photo by Dannyelle Davis, NYCDEP Right: during Irene h p://www.buzzfeed.com/mjs538/frightening-hurricane-irene-destruc on-photos Irene in the Catskills: Schoharie Creek, Pra sville
Above: Immediately a er Irene, Sep 1, 2011, photo by Dannyelle Davis, NYCDEP Extreme Events and Turbidity in the Catskills
Ou low from Shandakan Tunnel into Esopus Creek, May 2012, photos by A. Frei Warner Creek (tributary of Stony Clove Creek), sediment entering creek under calm condi ons, October 2013
photos by A. Frei IPCC AR5 WG1 Fall, 2013 (welcome to my world of acronyms) Kunkel et al, BAMS, 2013
Change in 20-yr precipita on return value units are Z-score (standard dev.); Larger dots have greater sta s cal significance 1910 1930 1950 1970 1990 2010 1910 1930 1950 1970 1990 2010
NOAA Climate Extremes Index (CEI) for the Northeast US h p://www.ncdc.noaa.gov/extremes/cei/ NYSERDA funded study : Hydrology, Vulnerability and Adapta on Implica ons of Hurricane Irene and Tropical Storm Lee: Case Study of the Mid-Hudson Valley and Greater Catskills
Emergent Vulnerabili es as Perceived by Stakeholders [based on interviews, public mee ng transcripts, press ar cles and le ers to the editor from local newspapers, community e-message boards, blogs, ...]
1) Transporta on, agricultural and tourism sectors were the most heavily impacted
2) Flooding in previously un-flooded (according to local knowledge) areas (e.g. in higher eleva on areas that are not floodplains)
3) predicted return interval for floods not a good indicator of actual frequency.
4) infrastructural weaknesses (e.g. road washouts)
5) Dispropor onate socioeconomic effects (on availability of affordable housing) Study of Irene, Lee, and changes over me: Study Area and Sta on Loca ons
Map by David Lounsbery, NYCDEP Monthly Climatologies of Extreme (95th % le) Events
a) 10 inches 25 warm season
) 20 y a d / m
c 15 Unimodal ( Daily n o i
t (peak in Fall) a
t 10 Precipita on i p i c e r
P 5
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
b) 32,000 CFS 900 warm 800 season
) 700 s /
m 600 . Bimodal u c
( 500
Daily w (peaks in
o 400 l f
m 300 Streamflow a Spring & Fall) e r t 200 S 100
0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Precipita on Recurrence Intervals for Irene and Lee
Record Period Irene Annual Irene Warm Lee Annual Lee Warm Station ID for Frequency Return Period Return Period Number Station Name (County) Analysis Period (yrs) Return (yrs) Period (yrs) Return (yrs) 300254 Arkville (Delaware) 1952 - 2011 n/a n/a 2 4 302036 Delhi (Delaware) 1952 - 2011 7 7 4 5 302060 Deposit (Delaware) 1962 - 2011 2 2 7 7 302582 Ellenville (Ulster) 1952 - 2011 n/a n/a 2 3 304731 Liberty (Sullivan) 1952 - 2011 16 20 2 2 305310 Middletown (Orange) 1952 - 2011 n/a n/a 7 8 305426 Mohonk Lake (Ulster) 1952 - 2011 407 387 <2 2 306774 Port Jervis (Orange) 1952 - 2011 9 11 2 2 307274 Rosendale (Ulster) 1958 - 2011 472 449 <2 2 307799 Slide Mtn (Ulster) 1952 - 2011 88 169 <2 2 308932 Walton 2 (Delaware) 1956 - 2011 2 2 6 6 309292 West Point (Orange) 1952 - 2011 7 9 <2 2 Precipita on Contours and Recurrence Hurricane Irene (26-29 Aug., 2011) Tropical Storm Lee (5-8 Sep., 2011) Intervals >34 cm (13 in) Precipita on-Difference Contours and Sta on Loca ons Irene minus Lee
Lee > Irene Irene > Lee Irene & Lee Precipita on Percen les and Ranks (Warm Season)
4-day Precipita on 30-day Antecedent 4-d Precip 30-d Historical antecedent Rank of 2011 warm Historical season 60-d Rank of 2011 Irene Lee Irene Lee Irene % le Lee % le Irene % le Lee % le Precip60-d Precip Arkville na >99 na na na Delhi >98 >99 >95 >97 1 Deposit >98 >99 >91 >93 1 Ellenville na >99 na na na Liberty >99 >99 >85 >95 2 Middletown na >99 na na na Mohonk >99 >99 >91 >98 1 Port Jervis >99 >98 >91 >98 1 Rosendale >99 >97 >87 >97 1 Slide Mt. >99 >99 >61 >96 1 Walton >99 >99 >75 >93 2 West Pt. >99 >99 >98 >99 1 Percen le values in bold >= 98 percen le Percentage of Seasons During Which Extreme 4-day Precipita on Events Occur Within 12 days of each other (prior to Irene and Lee)
Values are ranges across all sta ons. Changes over Time in the Frequencies of Extreme Events
Warner Creek, Near Stony Clove, Catskills, May 2012
Headcut incised during storms of 2011 exposing glacial ll that has probably not been exposed in 15-20K yrs. Course sediment is being recruited from upstream, but channel bed now at a lower base level than prior to Irene.
These sorts of fluvial geomorphological changes are related to the frequency and magnitude of extreme events, as well as human impact on channel condi ons. Human impacts up- or down- stream can also play a role.
Photos and geomorphological informa on from Dannyelle Davis, NYCDEP Changes over Time in the Frequencies of Extreme Events
Warner Creek (tributary of Stony Clove Creek, Esopus Creek)
May 2012 November 2013 exposed pleistocene proglacial lake sediment Post treatment probably has been only intermi ently exposed throughout the Holocene (D. Davis, NYCDEP)
Photos by A. Frei Changes over Time in the Magnitudes of Events of Different Recurrence Intervals
Example from one stream gauge sta on, daily streamflow
Tremper Kill
Data Used 56,500 CFS 1600 All Hist. 1940-1970 1400 1950-1980 1960-1990 1970-2000
) 1200
s 1980-2011 /
m Each color is a .
u 1000
c different (
w
o 800 overlapping l f
m 30-year period a
e 600 r
t star ng 10 S 400 years apart Y-axis shows magnitude
200
0 Return Period 2 5 10 25 50 100
X-axis shows Recurrence Interval (years) Changes over Time in the Frequencies of Extreme Events
All Events 5 highest values Example from one sta on (Ellenville 4-day Precipita on) 95 % le value
Cold Season Warm Season Changes over Time in the Frequencies of Extreme Events
Number of 95% le values per year max smooth value Example from one sta on (Ellenville 4-day Precipita on) Smooth (11-yr mean)
Cold Season Warm Season Changes over Time in the Frequencies of Extreme Events
Number of 95% le 4-d precipita on values per year: all sta ons
Cold Season Warm Season max smooth value Smooth (11-yr mean)
1985, 2006 Changes over Time in the Frequencies of Extreme Events
Number of 95% le daily streamflow values per year: all sta ons
Cold Season Warm Season max smooth value Smooth (11-yr mean)
1985, 2006 Number of 95% le values per year: all sta ons Cold season Warm season
4-day Precipita on
1-day Streamflow Intergovernmental Panel on Climate Change Special Report on Extreme Events: SREX (2012)
Projected recurrence intervals for daily Tmax equal to 20-year recurrence during the late 20th Century. Different colors = different scenarios Intergovernmental Panel on Climate Change Special Report on Extreme Events: SREX (2012)
Projected recurrence intervals for daily Precip equal to 20-year recurrence during the late 20th Century. Different colors = different scenarios IPCC AR5: WG1,Fall 2013
WG2, Spring 2014
WG1
WG2
WG2 Intergovernmental Panel on Climate Change Special Reports: SREX (2012)
dryer wetter
Projected changes in soil moisture compared to the late 20th Century. Conclusions
• The events of Fall 2011 were unprecedented in this region due to a combina on of: - the magnitude of precipita on in each event - the proximity in space and me of the two events - antecedent and subsequent precipita on
• As a result, Fall 2011 had the highest 60-day precipita on total on record in this region Conclusions (cont’d)
• Geomorphological evidence suggests the recent period has had more frequent extreme events compared to condi ons during the last 10,000 yrs
• Since 1900, the frequency of extreme warm season hydrologic events peaked during the last 1-2 decades
• Since 1900, the frequency of extreme cold season hydrologic events peaked in the 1970s – 1980s
• Climate models predict that the trend toward more extreme events will con nue through the 21st century
Minor Conclusion
• Standard parametric analysis (recurrence interval) is the appropriate tool for infrastructure planning, but may be insufficient for climatological understanding (it is based on annual maxima, and it requires >=30 years of data). Perhaps it needs to be adapted for non- sta onary climate. Deep gorge created in Frost Valley (Ulster County Route 47) when floods a er Hurricane Irene blew out a culvert below the road in Oliverea, NY. h p://en.wikipedia.org/wiki/Effects_of_Hurricane_Irene_in_New_York#Orange_County Number of 95% le values per year: all sta ons 30 day results Cold season Warm season
30-day Precipita on
30-day Streamflow Number of 95% le values per year: all sta ons 60 day results Cold season Warm season
60-day Precipita on
60-day Streamflow