North American Croplands Richard Massey & Dr. Teki Sankey.
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Transcript of North American Croplands Richard Massey & Dr. Teki Sankey.
North American CroplandsRichard Massey & Dr. Teki Sankey
Overview for North America
• Preprocessing • Classification method• Accuracy assessment
Preprocessing MODIS Data (MOQ09Q1, 250 m)
Reprojected MODIS images for North America:
Geographic Lat/LonSinusoidal
• 2000 (1502 tiles, 1.9 TB)• 2001 (2162 tiles, 2.4 TB)• 2002 (2162 tiles, 2.4 TB)• 2003 (2162 tiles, 2.4 TB)• 2004 (2162 tiles, 2.4 TB)• 2005 (2162 tiles, 2.4 TB)• 2006 (2162 tiles, 2.4 TB)
• 2007 (2162 tiles, 2.4 TB)• 2008 (2162 tiles, 2.4 TB)• 2009 (2162 tiles, 2.4 TB)• 2010 (2162 tiles, 2.4 TB)• 2011 (2162 tiles, 2.4 TB)• 2012 (2162 tiles, 2.4 TB)• 2013 (2162 tiles, 2.4 TB)
Preprocessing MODIS Data (MOQ09Q1, 250 m)
Mosaicked MODIS images for North America:• 2000 (1502 tiles, 1.9 TB)• 2001 (2162 tiles, 2.4 TB)• 2002 (2162 tiles, 2.4 TB)• 2003 (2162 tiles, 2.4 TB)• 2004 (2162 tiles, 2.4 TB)• 2005 (2162 tiles, 2.4 TB)• 2006 (2162 tiles, 2.4 TB)
• 2007 (2162 tiles, 2.4 TB)• 2008 (2162 tiles, 2.4 TB)• 2009 (2162 tiles, 2.4 TB)• 2010 (2162 tiles, 2.4 TB)• 2011 (2162 tiles, 2.4 TB)• 2012 (2162 tiles, 2.4 TB)• 2013 (2162 tiles, 2.4 TB)
Band 2 Mosaic
Preprocessing MODIS Data (MOQ09Q1, 250 m)
• NDVI calculated for North America:• 2000 (32 image dates, 1.9 TB)• 2007 (46 image dates, 2.4 TB)• 2008 (46 image dates, 2.4 TB)
NDVI Image
Preprocessing MODIS Data (MOQ09Q1, 250 m)
• NDVI layers stacked for North America:• 2000 (32 image dates, 1.9 TB)• 2007 (46 image dates, 2.4 TB)• 2008 (46 image dates, 2.4 TB)
Preprocessing MODIS Data (MOQ09Q1, 250 m)
• NDVI stacks masked for cloud:• 2000 (32 image dates, 1.9 TB)• 2007 (46 image dates, 2.4 TB)• 2008 (46 image dates, 2.4 TB)
MODIS Classification
• Classification method developed • Classification:• 2008 (46 image dates, 2.4 TB)
Classification Assessment
• Classification outputs• Testing for:• Model development • Model refinement• 20,000 randomly selected pixels
• Accuracy assessment• No extensive assessment• Needs discussion
Crop classification• Subset data with Global Cropland Extent (GCE) version 1.0
Class description Croplands 4 of 4 Croplands 3 of 4 Croplands 2 of 4 Croplands1 of 4
Crop classification• Subset GCE v1.0 with Food and Agricultural Organization’s
Agro Ecological Zones (AEZ)• Classify each AEZ separately
Crop classification• Derive training spectra from USDA Cropland Data Layer (CDL)
CDL availability for conterminous US
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
0 8 16 24 32 40 48
4
5
16
8
9
8
15
21
48
48
48
48
Number of states
Class Rain-fed % all crop US1 Corn 29.62 Soybeans 22.43 Wheat (w) 12.54 Wheat (s) 6.05 Wheat (d) 0.86 Barley 0.77 Potatoes 0.28 Alfalfa 2.59 Cotton 2.5
10 Rice 0.4
Rainfed Croplands of USA (Source: USDA CDL)
Rainfed Croplands of USA (Source: USDA CDL)
Corn Winter WheatSoybean
Spring Wheat BarleyDurum Wheat
Potatoes CottonAlfalfa
Rice
Rainfed Croplands of USA (Source: USDA CDL)
Class Irrigated % crop US11 Corn 6.012 Soybeans 3.6
13 Wheat (w) 2.614 Wheat (s) 0.415 Wheat (d) 0.116 Barley 0.217 Potatoes 0.218 Alfalfa 1.019 Cotton 1.420 Rice 1.0
Irrigated Croplands of USA (Source: USDA CDL)
Richard MasseyUpdate: 10/22/2014Richard MasseyUpdate: 10/22/2014
Corn Winter WheatSoybean
Spring Wheat BarleyDurum Wheat
Irrigated Croplands of USA (Source: USDA CDL)
Richard MasseyUpdate: 10/22/2014Richard MasseyUpdate: 10/22/2014
Potatoes CottonAlfalfa
Rice
Irrigated Croplands of USA (Source: USDA CDL)
Crop type curves• 5x5 pixel buffer to extract pure pixels only• Resample 56m to 250m• Maximum of 10,000 random points/crop type/AEZ• Crop classes with <50 available points were discarded
Subset of major crop type fields derived from CDL 2008 Subset of major crop type fields derived from CDL 2008
Randomly selected pixels Rainfed crop type for 2008
Class Crop AEZ3 AEZ4 AEZ5 AEZ6 AEZ7 AEZ8 AEZ9 AEZ10 AEZ11 Total1 Corn 2,969 10,000 10,000 10,000 10,000 10,000 10,000 - 10,000 72,9692 Soybean - 1,026 10,000 10,000 10,000 10,000 10,000 10,000 10,000 71,0263 Winter Wheat 10,000 10,000 10,000 10,000 10,000 10,000 3,912 10,000 84 73,9964 Spring Wheat 10,000 10,000 10,000 10,000 10,000 10,000 - 10,000 - 70,0085 Durum Wheat - 1,005 7,443 10,000 - 66 - - - 18,5816 Barley 7,018 8,566 6,127 9,376 3,383 2,278 - - 36,7507 Potato 5,914 9,922 1,288 249 279 1,065 468 138 - 19,3458 Alfalfa 10,000 10,000 10,000 10,000 9,295 7,565 2,917 1,613 - 61,406 Total 42,968 49,493 44,858 49,625 32,988 30,974 7,305 21,753 122
Note:1. The numbers are 56m pixels 2. Each crop type with more than 10,000 pure sample pixels were capped at 10,000
Random sample pointsIrrigated crop type for 2008
Class Crop AEZ3 AEZ4 AEZ5 AEZ6 AEZ7 AEZ8 AEZ9 AEZ10 AEZ11 Total9 Corn 1,035 6,541 10,000 10,000 10,000 3,602 10,000 10,000 5,151 66,32910 Soybean - 142 10,000 10,000 7,333 1,962 10,000 10,000 3,217 52,65411 Winter Wheat 2,082 10,000 10,000 4,132 3,309 1,544 618 377 - 32,06212 Spring Wheat 956 3,101 3,387 1,582 305 157 - - - 9,48813 Durum Wheat - 210 360 318 - - - - - 88814 Barley 1,239 1,866 534 350 - - - - 3,98915 Potato 2,154 3,546 248 - - 102 - - - 6,05016 Alfalfa 3,728 7,904 5,967 4,423 2,390 220 - - - 24,63217 Cotton - - 4,253 821 332 - 10,000 3,758 122 19,28618 Rice - - - 73 8,163 7,082 10,000 1,500 1,816 28,634 Total 11,194 33,310 44,749 31,699 31,832 14,669 40,618 25,635 10,306
Note:1. The numbers are 56m pixels 2. Each crop type with more than 10,000 pure sample pixels were capped at 10,000
Classification:Decision treeCorn + Soybean (AEZ6)
No AEZ=6
No Region subset (.shp)
No Temporal/Spectral Window
No Max NDVI location=12±2
No Max NDVI(0.6<NDVI<0.9)
Corn/Soybean
Cropland extent
Accuracy Assessment
Change Parameters
10
10
10
10
10
No
Parameters for classification:
NDVI curve identification
NDV
I
0 5 10 15 20 25 30
-0.2
0
0.2
0.4
0.6
0.8
1
NDVI
Upper Bound
Lower Bound
Input NDVI
Upper limit of Max NDVI
Lower limit of Max NDVI
Max NDVI location
Maximum NDVI window
Classification window
Unique NDVI
Classified ImageCorn + Soybean (AEZ6)
Classified Image Corn + Soybean Layer from CDL 2008
Preliminary AccuracyCorn + Soybean (AEZ6)
Parameters AEZRegion subset
NDVI Comparison
Tolerance
Left Limit
Right Limit
Shift Up
Shift Down Shift
Maximum Location
widthUnique NDVI 1
Unique NDVI Location 1
Unique NDVI 2
Unique NDVI Location 2
Unique NDVI 3
Unique NDVI Location 3
Unique NDVI 4
Unique NDVI Location 4
Cumulative NDVI
Left Limit (Cumulative NDVI)
User’s accuracy
Producer’s accuracy
AEZ6Corn+ Soybean 6 1 1 3 8 22 0.05 -0.05 0 14 3 10 <0.5 15 >0.52 16 >0.55 >9 1 96 89Winter Wheat 6 1 1 2 6 21 0 0 0 12 2 16 <0.5 73 76Spring Wheat + Durum wheat + Barley 6 0 1 5 1 23 0 0 0 15 >0.2 15 <0.5 10 >0.24 82 79
Alfalfa 6 0 1 3 3 25 0.1 -0.1 0 >3.5 5 73 75
Cotton 6 0 1 5 2 26 0 0 9 <0.3 14 >0.55 1.8 1 81 79
Algorithm parameters for AEZ 6
Model refinement
• Total of 20,000 points for each crop type per AEZ (irrigated + rainfed)• Accuracy calculated for each crop class in each AEZ• Reiterating the algorithm with modified parameters
for higher accuracy
List of accuracies for all AEZsAEZ Parameter User’s accuracy (%) Producer’s accuracy (%)
AEZ3Barley + Spring Wheat + Winter Wheat 93 72Alfalfa 81 72
AEZ4
Corn + Soybean 83 86Durum Wheat + Barley + Spring Wheat 73 76Winter Wheat 71 68Alfalfa 73 75
AEZ5
Corn + Soybean 88 86Winter Wheat 81 79Alfalfa 75 71
AEZ6
Corn + Soybean 96 89Winter Wheat 73 76Durum Wheat + Barley + Spring Wheat 82 79Alfalfa 73 75Cotton 81 79
AEZ7
Corn + Soybean 94 90Winter Wheat 81 79Spring Wheat + Durum Wheat + Barley 96 90Alfalfa 84 85
AEZ8
Corn + Soybean 94 90Winter Wheat 96 90Spring Wheat + Durum Wheat + Barley 80 85Alfalfa 69 80
AEZ9
Corn + Soybean 80 85Winter Wheat 63 71Cotton 78 71
AEZ10Corn + Soybean 79 81Alfalfa 63 71
AEZ11 Corn + Soybean 79 84
Cropland Extent• Cropland Extent derived from mosaicking binary crop maps
of AEZs• Compared with cropland extent from CDL 2008• CDL extent is reference class
Fractions of CDL areaClassified map
subset by GCEv2.0 CDL GCEv1.0
4 of 4 0.49 1.00 0.59
3 of 4 added 0.51 1.00 0.98
2 of 4 added 1.12 1.00 1.92
1 of 4 added 2.60 1.00 5.59
Irrigation Vs Rainfed
• Irrigated and Rainfed crops separated by MODIS irrigated map for 2001 (Ozdogan et al., 2010)• Irrigated and rainfed spectra shows different
cumulative NDVI in classification Window
Crop type map for all USA
Class All % US1 Corn
80.12 Soybeans3 Wheat (w) 6.694 Wheat (s)
11.135 Wheat (d)6 Barley7 Potatoes8 Alfalfa 0.6059 Cotton 0.81
10 Rice
Crop Intensity
• Identify number of NDVI maximums• Identify location of maximums• Separation > 4 image dates, classify as double crop
Cropland Extent NDVI
No Number of Maximum>1
NoLocation of
Maxima separation > 4
Double Crop
Accuracy Assessment
Change Parameters
10
10
No
Looking Forward• Automated optimization of the preselected parameters• Produce cropland map for another year and compare with
CDL• Extrapolate to the entire continent of North America at 250m• Implementation of algorithm via Google Earth Engine on
multiple years of MODIS data
Thank you