2014 Dissolved Oxygen Assessment CHRP Meeting July 7, 2015 Heather Stoffel.
Transcript of 2014 Dissolved Oxygen Assessment CHRP Meeting July 7, 2015 Heather Stoffel.
2014 Dissolved Oxygen Assessment
CHRP MeetingJuly 7, 2015
Heather Stoffel
Data from 5 rivers that discharge into the Providence River Normalized to the 10 year seasonal total average
-1.5E+08
-1.0E+08
-5.0E+07
0.0E+00
5.0E+07
1.0E+08
1.5E+08
2.0E+08
2.5E+08
3.0E+08
Providence River Seasonal Total Flow Fl
ow (m
ᵌ/da
y)
PD BR CP NP GB SR MV QP PP MH0
10
20
30
40
50
60
70
80
Exceedences During Dry Years
2002
2004
2005
2007
2010
2012
2014
RID
OCS
Day
s
PD BR CP NP GB SR MV QP GD PP MH TW0
20
40
60
80
100
120
Exceedences During Wet Years
2001200320062008200920112013
RID
OCS
Day
s
Seasonal Cumulative River Flow from the Blackstone River
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
0.0E+00
5.0E+07
1.0E+08
1.5E+08
2.0E+08
2.5E+08
3.0E+08
Blackstone River Flows SeptAugJulyJune
FL
OW
(s
ea
so
na
l c
um
. m
ᵌ./d
ay
)
Influences on River Flow during Wet Years
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 20140
1
2
3
4
5
6
7
8Number of Extreme Flow Days from Blackstone River
Sept Aug
July June
Year
Num
ber o
f Day
s >3
St D
ev.
over
Dai
ly M
ean
Conclusions
• 2014 was a “good year” (drier and cooler than average).
• NP appears to be showing a downward trend in oxygen exceedences and chlorophyll levels.
• MV may also be showing a downward trend in low oxygen, but further analysis is needed.
• MH needs further examination. It is possible hypoxia is increasing in this area.