in Asia Andy Nelson Thursday11 th Sep 2014 Do we need better data yes Regional and global modelling efforts need a ccurate information on the where and when of staple crops for yield and yield gap estimation area estimations riskexposure assessments etc ID: 799286
Download The PPT/PDF document "Incorporating regional knowledge into gl..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Incorporating regional knowledge into global data sets: Some ideas for rice
in
Asia
Andy Nelson
Thursday11
th
Sep, 2014
Slide2Do we need better data? – yes!
Regional and global
modelling efforts need a
ccurate information on the
where
and
when
of staple crops for yield and yield gap estimation, area estimations, risk/exposure assessments, etc.
Commodity research centers, like IRRI, can contribute and improve multi-commodity spatial datasets (SPAM, MIRCA2000 etc.).
Here are some ideas on how regional nodes can go beyond data-sharing to improve data on the
where
and
when
of crops.
Slide3The where
of rice
Substantial literature on the use of remote sensing data to map irrigated and lowland rice. Opportunity to apply published methods to derive better information on rice extent in Asia.
Rice is a huge component of cropping systems in Asia, 144m ha. This one crop accounts for
48%
of the cereal crop area in Asia.
Improving information on rice will significantly improve other crop area estimates from SPAM, MIRCA etc.
We applied one algorithm (Xiao et al. 2006) to 13 years (2000-2012) of MODIS data for Asia. 44 tiles x 13 years x 46 tiles/yr and used this to estimate rice extent on a10km x 10km grid.
Slide4MODIS tiles – about 44 cover our area
Slide5Automated paddy mapping algorithm
Irrigated and lowland
rainfed
rice has a distinctive temporal signature that can indentified using various indices (vegetation and water indices) derived from RS data like MODIS.
Rice paddies are generally flooded at the start of the season and rice biomass increases rapidly after seeding or transplanting.
A simple rule is applied. IF the value of the water index (LSWI) is greater than either of the two vegetation indices (NDVI or EVI) and IF that is quickly followed by a rapid increase in NDVI then the pixel is labeled as rice.
Xiao, X.; Boles, S.;
Frolking
, S.; Li, C.;
Babu
, J. Y.; Salas, W.; Moore, B. Mapping paddy rice agriculture in South and Southeast Asia using multi-temporal MODIS images.
Remote Sens. Environ.
2006
,
100
, 95–113.
Slide6Automated paddy mapping algorithm
Xiao, X.; Boles, S.;
Frolking
, S.; Li, C.;
Babu
, J. Y.; Salas, W.; Moore, B. Mapping paddy rice agriculture in South and Southeast Asia using multi-temporal MODIS images.
Remote Sens. Environ.
2006
,
100
, 95–113.
Slide73.1 The where
of rice
Rice area in Asia from SPAM
green: rice dominates the cropped area / gray: some rice in the cropped area
In general the SPAM map has the right spatial pattern but the distribution is too diffuse. There is rice in areas where there is no rice and not enough rice in the ‘rice bowls’
Slide83.1 The where
of rice
Rice area in Asia from IRRI
green: rice dominates the cropped area / gray: some rice in the cropped area
IRRI map shows that the spatial distribution of rice is more focused, dramatically reducing
low density
rice areas and highlighting the main rice producing areas.
Slide93.1 The where
of rice
Rice area in Asia from IRRI
green: rice dominates the cropped area / gray: some rice in the cropped area
Still some issues to address.
Is there that much rice in NW China?
Papua, probably wetland, and not rice?
Missing rice areas in Sumatra?
What is the effect of using this in SPAM?
?
?
?
Slide10The when
of rice
I believe that not enough importance is placed on temporal information in cropping systems. It is essential for initializing crop models for yield estimates and climate stress impacts. It is essential for risk management and mitigation. It leads to better rice market information. It also contributes to the improvement of global datasets on cropped area.
Again, regional nodes are best placed to improve existing crop calendars.
In this case, IRRI coordinated an effort across
GRiSP
partners to collect sub-national crop calendars for
all
rice growing countries and seasons in the world.
Around 2,100 spatial units, a 10 fold increase over previous calendars.
Slide11162m ha of rice, 113m in the main season, 44m in the second season, 5m in the third season
Jan
Feb
Mar
Apr
May
Jun
jul
Aug
Sep
Oct
Nov
Dec
Slide12The
when
of rice
– production by month
90% of production is in Asia (667mt)
Over 50% occurs in just three months
Africa and LAC increasing rapidly
Slide13The when
of rice – area by month
IRRI calendar has more rice concentrated in the wet season and much less in the dry season
Again, this new dataset shows less diffuse patterns in rice
Slide14The when
of rice – climate impacts.
Preliminary rice crop calendar developed by
GRiSP
. Storm frequency from Joint Typhoon Warning Center (2011). 2011 Annual Tropical Cyclone Report: Western Pacific (Report). United States Navy, United States Air Force.
0
20
40
60
80
100
120
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Rice area under cultivation (M ha) per month
Asia
Others
0
1
2
3
4
5
6
Tropical storm frequency (1959
-
2011)
Slide15Key Messages
When
is as least as important as where, but
where
gets most of the attention.
Regional nodes are more than just data providers, they give GEOSHARE access to a bigger network and they can lead on new ways to integrate data.
How to get these data into
Workflows
?
Fusing these data in an elegant and repeatable way will need some further work
GEOSHARE Scientific Committee (GSC)
Can GEOSHARE do more to demonstrate best practice in data sharing in regions where data is still
closed
?
GSC
Slide16Thank you
Andy Nelson
a.nelson@irri.org