Agricultural crop change in the Willamette Valley, Oregon, from 2004 to 2017

Authors: STRIMBU, BOGDAN - Oregon State University; Mueller Warrant, George; Trippe, Kristin

Submitted to: Data
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/4/2021
Publication Date: 2/7/2021
Citation: Strimbu, B., Mueller Warrant, G.W., Trippe, K.M. 2021. Agricultural crop change in the Willamette Valley, Oregon, from 2004 to 2017. Data. 6(2). Article 17. https://doi.org/10.3390/data6020017.
DOI: https://doi.org/10.3390/data6020017

Interpretive Summary: The Willamette Valley, bounded on the west by the Coast Range and on the east by the Cascade Mountains, is the largest river valley in Oregon. The fertile valley soils combined with a temperate, marine climate create ideal agronomic conditions for seed production. Historically, seed cropping systems in the Willamette Valley have focused on the production of grass and forage seeds. In addition to growing over two-thirds of the nation’s cool-season grass seed, cropping systems in the Willamette Valley include a diverse rotation of seed crops; however, very little information is available on which crops are planted in any given year, or the sequence of the crop rotation. Tracking the sequence of crop rotations could help answer agronomic, environmental, and economical questions. We used satellite imagery to determine which crops were grown on which fields in any given year between 2004-2017. Each crop was classified into a broad classification (annual crop, perennial crop, forest, urban development) and a specific (57 subclasses) classification. Here, we describe the data that support these classifications and provide links to the publicly available datasets.

Technical Abstract: The Willamette Valley, bounded on the west by the Coast Range and on the east by the Cascade Mountains, is the largest river valley completely confined to Oregon. The fertile valley soils combined with a temperate, marine climate create ideal agronomic conditions for seed production. Historically, seed cropping systems in the Willamette Valley have focused on the production of grass and forage seeds. In addition to growing over two-thirds of the nation’s cool-season grass seed, cropping systems in the Willamette Valley include a diverse rotation of over 250 commodities for forage, seed, food, and cover cropping applications. Tracking the sequence of crop rotations that are grown in the Willamette Valley is paramount to answering a broad spectrum of agronomic, environmental, and economical questions. Landsat images covering approximately 25,303 km2 were used to identify agricultural crops in production from 2004 to 2017. The agricultural crops were distinguished by classifying images acquired by three platforms: Landsat 5 for the 2003-2013 period, Landsat 7 for the 2003-2017 period, and Landsat 8 for the 2013-2017 period. Before classification, the images acquired by the Landsat 7 were pre-processed to reduce the impact of the scan line corrector failure. The corrected images were subsequently used in classification of 61 different land use classes, namely 4 super-classes and 57 regular classes. The land was classified into annual crops (19 classes), perennial crops (20 classes), forests (13 classes), and urban developments (5 classes). Annual drive-by ground truth efforts validated the classifications and were used to develop object-based procedures to improve accuracy.