The California Department of Water Resources (DWR) has publicly released the 2020 land use data set, as well as a provisional release of the 2021 land use data set. Both are available for viewing on DWR’s website and download here. The release of these important data sets means there are four water years of continuous statewide land use mapping.
The statewide land use data for 2021 has been released as provisional, based on requests by data users and DWR partner agencies. Unlike all previous land use data releases, the current provisional release is intended to get land use information out to users quickly, and the data has not been carefully reviewed or edited by DWR. The final and official version of the 2021 water year land use dataset is planned for release by the first quarter of 2024.
The Land IQ land use mapping began with the 2014 main season crop. 2016 mapping was conducted in the same way, and then moved to a continuous, water year basis (October 1 – September 30) in 2018. The mapping currently categorizes nearly 15.4 million acres of land use into more than 50 crop and land use types, with accuracies exceeding 97%. Field by field classification results in over 440,000 individually classified polygons with a minimum field size of 0.5-2.0 acres depending on crop type. Accuracy assessments for each mapping event are available for review.
The 2020 and 2021 datasets, along with 2018 and 2019, include up to four crop rotation patterns within each field in the areas of the state where multiple crops are grown on the same field in the same water year. The data set also includes the peak date of vegetative production for the field and percentage of the field cropped, if not fully planted. These attributes allow end users to estimate planting and harvest dates as well as refine crop water use estimates.
Amongst its many uses, this statewide data resource has been developed to support the needs of the Sustainable Groundwater Management Act (SGMA). The intent of this work is for all Groundwater Sustainability Agencies (GSAs) to use this data as a consistent foundational land use layer in developing and implementing their groundwater sustainability plans (GSPs), groundwater modeling efforts, compliance monitoring, annual reporting, etc.
Land IQ is currently in the process of mapping the 2022 water year and collecting ground truth data for the 2023 water year. We take pride in being able to develop this important data in a timely manner so that end users have the ability to use it in their decision-making processes.
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