The California Department of Water Resources (DWR) has released the provisional 2022 land use data set. The data are available for viewing and download on DWR’s website. The release of this important data set means there are five water years of continuous statewide land use mapping.
Similar to the initial release of the 2021 statewide land use data, the 2022 has been released provisionally, 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 gone under final review by DWR or been edited by DWR.
Changes in the Water Year (WY) 2022 mapping include:
An irrigation type of “Not Irrigated” was included in the Mixed Pasture class to describe the variability in condition of Mixed Pasture.
Prior to WY 2022 final mapping release, pasture areas that where mechanically harvested during a water year were classified as P6-Miscellaneous Grasses (DWR Legend). In WY 2022 mapping, the harvested pasture areas are classified as P3-Mixed Pasture (DWR Legend).
Ground truth data collection routes were expanded in WY 2022 to collect data in all ten hydrologic regions. This enabled Land IQ to perform accuracy assessments in each of the hydrologic regions for the first time.
Prior to WY 2022, multi cropping and percent cover was only identified or calculated in Detailed Analysis Units that had a history of multi-cropping according to DWR. The methodology changed in WY 2022 so that all fields were reviewed for multi-cropping statewide and percent cover was calculated on resulting fields.
Land Use Mapping History
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 15.6 million acres of land use into more than 50 crop and land use types, with accuracies exceeding 97%. Field by field classification results in nearly 480,000 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.
Land Use Mapping Uses
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 implementing their groundwater sustainability plans (GSPs), groundwater modeling efforts, compliance monitoring, annual reporting, etc.
Land IQ is currently in the process of mapping the 2023 water year and collecting ground truth data for the 2024 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.