0
É"enne	
  Boucher	
  
Taha	
  B.M.	
  J.	
  Ouarda	
  
Yves	
  Bégin	
  	
  
Antoine	
  Nicault	
  
Ins<tut	
  Na<onal	
  ...
Why	
  reconstruct	
  spring	
  floods?	
  
Hudson	
  bay	
  
LA	
  GRANDE	
  (LG)	
  
hydroelectric	
  complex	
  
Why	
  reconstruct	
  spring	
  floods?	
  
Infilling	
  of	
  
hydroelectric	
  
reservoirs	
  
Spring	
  
Why	
  reconstruct	
  spring	
  floods?	
  
boucher@cerege.f...
Pros	
  
Cons	
  
A	
  mul<-­‐proxy	
  dendrohydrological	
  approach	
  to	
  
reconstruct	
  spring	
  floods	
  
Discon<...
Discrete	
  event	
  series	
  
e.g.	
  ice	
  scarred	
  trees	
  
Uncertain	
  discrete	
  series	
  
[0.05,	
  0.5,	
  0.95]	
  
Propor<on	
  of	
  ice-­‐scarred	
  trees	
  around	
  a	
...
Model	
  uncertain"es	
  of	
  discrete	
  event	
  series	
  
Uncertain<es	
  around	
  observed	
  propor<ons	
  are	
  ...
Reconstruc<on	
  of	
  May	
  water	
  supplies	
  to	
  the	
  
Caniapiscau	
  reservoir	
  (northern	
  Québec,	
  Canad...
Hudson	
  bay	
  
La	
  Grande	
  HE	
  complex	
  
Dendrochronological	
  data	
  
=	
  Earlywood	
  density	
   =	
  Ice	
  scar	
  chronology	
  at	
  lake	
  Montausier	
...
Water	
  supplies	
  to	
  the	
  Caniapiscau	
  reservoir,	
  	
  
&	
  hydrological	
  variables	
  to	
  reconstruct	
 ...
Discrete	
  and	
  con<nuous	
  dendroseries	
  
Propor<on	
  of	
  ice	
  scoured	
  trees	
  around	
  lake	
  Montausie...
The	
  Montausier	
  lake	
  ice	
  scar	
  chronology	
  
(an	
  other	
  look	
  at	
  it…)	
  
Propor<ons	
  
N=300	
  ...
Rela<onships	
  between	
  TR	
  series	
  &	
  
	
  water	
  supplies	
  (QMay)	
  to	
  the	
  Caniapiscau	
  Reservoir	...
Calibra<on	
  /	
  verifica<on	
  sta<s<cs	
  	
  
&	
  comparison	
  with	
  a	
  tradi<onal	
  MLR	
  approach	
  
€
g(E(...
Historical	
  May	
  water	
  supplies	
  to	
  the	
  	
  
Caniapiscau	
  Reservoir	
  
boucher@cerege.fr	
  
Discussion	
  and	
  Conclusion	
  
-­‐  A	
  new	
  approach	
  to	
  reconstruct	
  paleofloods	
  from	
  tree	
  rings	...
BIENVILLE	
  
MONTAUSIER	
  
CORVETTE	
  
LEC	
  
NECOPASTIC	
  
HERVÉ	
  
POLARIS	
  
Many	
  thanks	
  to	
  
+	
  field	
  assistants	
  throughout	
  the	
  years	
  boucher@cerege.fr	
  
Spring flood reconstruction from tree rings (continuous and discontinuous series)
Upcoming SlideShare
Loading in...5
×

Spring flood reconstruction from tree rings (continuous and discontinuous series)

759

Published on

In this presentation, we use tree rings (continuous and discontinuous series) to reconstruct past spring floods in cold environments. Spring floods are short duration events that may not be visible in classical tree ring indicators such as ring widths. Ice scars are conspicuous evidences of past spring floods and can greatly augment the reconstruction’s reliability, but pose a certain number of statistical problems when they are used as proxies. Some of these problems are described and solved here, using a novel reconstruction procedure.

Published in: Education, Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
759
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
8
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Transcript of "Spring flood reconstruction from tree rings (continuous and discontinuous series)"

  1. 1. É"enne  Boucher   Taha  B.M.  J.  Ouarda   Yves  Bégin     Antoine  Nicault   Ins<tut  Na<onal  de  la  Recherche  Scien<fique   Centre  Eau-­‐Terre-­‐Environnement   boucher@cerege.fr   Photo  credit:  S.  Popov   World  Dendro  2010,  Rovaniemi,  Finland  
  2. 2. Why  reconstruct  spring  floods?   Hudson  bay   LA  GRANDE  (LG)   hydroelectric  complex  
  3. 3. Why  reconstruct  spring  floods?  
  4. 4. Infilling  of   hydroelectric   reservoirs   Spring   Why  reconstruct  spring  floods?   boucher@cerege.fr  
  5. 5. Pros   Cons   A  mul<-­‐proxy  dendrohydrological  approach  to   reconstruct  spring  floods   Discon<nuous  series  /  uncertain<es  /  non-­‐lineari<es   Direct  rela<onship  with  streamflow  Con<nuous  series   Indirect   rela<onships  with   streamflow  
  6. 6. Discrete  event  series   e.g.  ice  scarred  trees  
  7. 7. Uncertain  discrete  series   [0.05,  0.5,  0.95]   Propor<on  of  ice-­‐scarred  trees  around  a  northern  lake   Propor<ons    N  trees  sampled   boucher@cerege.fr  
  8. 8. Model  uncertain"es  of  discrete  event  series   Uncertain<es  around  observed  propor<ons  are  binomialy   distributed  1)     Model  verifica"on   Jackknife  resampling  3)     Calibra"on  /  Reconstruc"ons     Performed  using  Generalized  Addi<ve  Models  (GAMs)   2)     € g(E(Q)) = B0 + f1TR1 + f2TR2 + ... boucher@cerege.fr  
  9. 9. Reconstruc<on  of  May  water  supplies  to  the   Caniapiscau  reservoir  (northern  Québec,  Canada)   boucher@cerege.fr  
  10. 10. Hudson  bay   La  Grande  HE  complex  
  11. 11. Dendrochronological  data   =  Earlywood  density   =  Ice  scar  chronology  at  lake  Montausier   boucher@cerege.fr  
  12. 12. Water  supplies  to  the  Caniapiscau  reservoir,     &  hydrological  variables  to  reconstruct   boucher@cerege.fr  
  13. 13. Discrete  and  con<nuous  dendroseries   Propor<on  of  ice  scoured  trees  around  lake  Montausier   Earlywood  density,  PC1   Earlywood  density,  PC2   boucher@cerege.fr  
  14. 14. The  Montausier  lake  ice  scar  chronology   (an  other  look  at  it…)   Propor<ons   N=300   boucher@cerege.fr   For  each  year,  N=300  possible  propor<ons  were  randomly  generated     from  a  binomial  distribu<on.       Colors  indicate  «  the  number  of  "mes  a  simulated  propor<on  value  falls  in  each  class  »  
  15. 15. Rela<onships  between  TR  series  &    water  supplies  (QMay)  to  the  Caniapiscau  Reservoir   Propor<ons   of  ice  scarred  trees,   Montausier  lake   PC1     Index   (wet  sites)   PC2    index   (mesic  xeric  sites)  
  16. 16. Calibra<on  /  verifica<on  sta<s<cs     &  comparison  with  a  tradi<onal  MLR  approach   € g(E(QMay )) = B0 + f1X1 + f2X2 + ... € E(QMay ) = B0 + B1X1 + B2X2 + ... +   boucher@cerege.fr  
  17. 17. Historical  May  water  supplies  to  the     Caniapiscau  Reservoir   boucher@cerege.fr  
  18. 18. Discussion  and  Conclusion   -­‐  A  new  approach  to  reconstruct  paleofloods  from  tree  rings  in   northern  environment.  It  allows:     1)  to  take  advantage  of  both  discrete  and  con"nuous  tree  ring  proxys   2)  to  model  and  include  the  uncertainty  of  discrete  TR  series  within  the   calibra<on  /  reconstruc<on  process   3)  to  account  for  non-­‐linear  rela"onships  that  occur  in  natural   environments   -­‐      Our  approach  can  be  used  in  other  environments  /  situa<ons   where  discrete  and  con<nuous  tree  ring  series  are  available  
  19. 19. BIENVILLE   MONTAUSIER   CORVETTE   LEC   NECOPASTIC   HERVÉ   POLARIS  
  20. 20. Many  thanks  to   +  field  assistants  throughout  the  years  boucher@cerege.fr  
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×