available soil water- a practical communication tool in southern nsw michael cashen agricultural...
TRANSCRIPT
Available soil water-a practical communication tool in
southern NSW
Michael CashenAgricultural Climatologist
Acknowledge contribution from John Smith, Ian Hume & Sam North
My Talk
Case study site - Deniliquin Explore rainfall Links with research outcomes ~ SEACI
phase 1 Comparing periods 61-90 & 91-09 using PAW The future 2030 ~ unseen risks?
Case study: Deniliquin
Deniliquin yearly rainfall
Deniliquin yearly rainfall - Post Office (1863-2010)
0
100
200
300
400
500
600
700
800
900
1863
1868
1873
1878
1883
1888
1893
1898
1903
1908
1913
1918
1923
1928
1933
1938
1943
1948
1953
1958
1963
1968
1973
1978
1983
1988
1993
1998
2003
2008
Year
mm
/ye
ar
Federation drought (1900-2006)
World War II
(1936-1945)
‘Big Dry’ (1997-2009)
Data:http://www.longpaddock.qld.gov.au/silo/
Autumn outside the box
Deniliquin autumn rainfall trend (1863-2010)
0102030405060708090
100110120130140150160
1863
1868
1873
1878
1883
1888
1893
1898
1903
1908
1913
1918
1923
1928
1933
1938
1943
1948
1953
1958
1963
1968
1973
1978
1983
1988
1993
1998
2003
2008
Year
mm
/sea
son
Autumn 11 yr mov average
Data:http://www.longpaddock.qld.gov.au/silo/
Estimated PAW 61-90
ETc Wheat: Median monthly pan * Pan factor (0.72) * Crop Coefficient KcPan factor variant ~Sam North Pers Comm, 20th June 2011
Estimated PAW Deniliqin 61-90
0
10
20
30
40
50
60
70
80
90
100
110
120
Jan Feb Mar Apr May June July August Sept Oct Nov Dec
Month
mm
/mth
Median 61-90 ETc wheat (pan) 61-90
A tale of two periods -rainfall
Median rainfall Deniliquin
0
5
10
15
20
25
30
35
40
45
Jan Feb Mar Apr May June July August Sept Oct Nov Dec
Month
mm
/mth
Median 61-90 Median 91-09
Data:http://www.longpaddock.qld.gov.au/silo/
A tale of two periods- ETc (Wheat)
Comparison of Wheat ETc (pan)- Deniliquin
0.0
20.0
40.0
60.0
80.0
100.0
120.0
Jan Feb Mar Apr May June July August Sept Oct Nov Dec
month
mm
/mth
ETc wheat (pan) 61-90 Etc wheat (pan) 91-09
Data:http://www.longpaddock.qld.gov.au/silo/
A visual comparison of PAW
A tale of two periods Denilquin PAW
05
101520253035404550556065707580859095
100
Jan Feb Mar Apr May June July August Sept Oct Nov Dec
Month
mm
/mth
Median 61-90 Median 91-09 ETc wheat (pan) 61-90 Etc wheat (pan) 91-09
Data:http://www.longpaddock.qld.gov.au/silo/
Quantifying the difference
Rainfall ~ ETc comparison Deniliquin
-70.0
-60.0
-50.0
-40.0
-30.0
-20.0
-10.0
0.0
10.0
20.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
mm
/mth
Rainfall - ETc (pan) 61-90 Rainfall - ETc (pan) 91-09
Data:http://www.longpaddock.qld.gov.au/silo/
The future?
Deniliquin rainfall projections 2030
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
mm
/mth
CSIRO projection 2030 A1B 10th percentile CSIRO projections 2030 A1B 50th percentile
CSIRO projections 2030 A1B 90th percentile Median rainfall 61-90
Data:http://www.longpaddock.qld.gov.au/silo/
What about autumn?
Comparison of CSIRO projections and rainfall Deniliquin 91- 09
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
mm
/mth
CSIRO projection 2030 A1B 10th percentile CSIRO projections 2030 A1B 50th percentile
CSIRO projections 2030 A1B 90th percentile median rainfall 91-09
Given the findings of SEACI phase 1 (i.e. link between STR and temperature), are we at risk of under estimating the impact of CC ?
Conclusion
- Autumn rainfall in decline since mid 80’s.
- Strong linkage to intensification of the Subtropical
Ridge (SEACI Phase 1)
- Autumn decline reducing growing season length
and Plant Available Water for growth in spring
- Current CSIRO/BoM 2007 projections not indicating significant autumn declines
References
CSIRO and Australian Bureau of Meteorology, 2007,Climate Change in Australian, Technical report 2007.
CSIRO (2010) Climate variability and change in south-eastern Australia: A synthesis of findings from Phase 1 of the South Eastern Australian Climate Initiative (SEACI)
The Centre for Australian Weather and Climate Research, 2007, Understanding the anthropogenic nature of the observed rainfall decline across south-eastern Australia, CAWCR Technical Report No. 026
Deniliquin seasonal rainfall trends
Deniliquin seasonal rainfall trends (1863-2010)
0
20
40
60
80
100
120
140
160
Year
mm
/yea
r
Summer 11 yr mov average
Autumn 11 yr mov average
Winter 11 yr mov average
Spring 11 yr mov average
Data:http://www.longpaddock.qld.gov.au/silo/
Monthly median rainfall 61-90
Median rainfall Deniliquin
0
5
10
15
20
25
30
35
40
45
Jan Feb Mar Apr May June July August Sept Oct Nov Dec
Month
mm
/mth
Median 61-90
Data:http://www.longpaddock.qld.gov.au/silo/