Cropland mapping in South America Global Food Security-Support Analysis Data @30 m Chandra Giri Ying Zhong 5/21/2015

Workflow Continent segmentation Cropland masking Training data selection Random Forest classification

Continent segmentation Landsat Tile 56 Landsat tiles segmentation Ecoregion segmentation Eco-regions of South America

Cropland mask Landsat Tile 56 Giri, C., & Long, J. (2014)

“Cropland” definition “All cultivated plants harvested for food, feed, and fiber, including plantation.” (Teluguntla et al. 2009) Is pasture included as a type of cropland?

“Cropland” definition Is rangeland included as a type of cropland? Google Earth photos

Training sample database Training points selection Random sample strategy Reference data Google Earth – high resolution images and photos 2009 GlobCover Time-series NDVI composite Landsat image Ground truth data – geo-wiki validation and geo-wiki competition

Training sample database Training dataset : Dataset A: Non-cropland: 129, Cropland: 54 Dataset B: Non-cropland: 44, Cropland: 41

Random Forest Classification Tool: Google Earth Engine Input bands: Landsat 5 and 7, band 2, 3, 4

Pasture Barren Result from training dataset A: Non-cropland: 129, Cropland: 54 Result from training dataset B: Non-cropland: 44, Cropland: 41 Barren Pasture

Classification results Result from training dataset A Result from training dataset B

Take-home message The same training sample dataset can have different classification performance in different eco-regions. Harvested cropland is difficult to be distinguished from barren land.

Thoughts Add temporal various images Classify at eco-region segmentation level Mosaic best

Thank you!