Landsat-based Irrigation Dataset (LANID): 30 m resolution maps of irrigation distribution, frequency, and change for the US, 1997–2017

[摘要] Data on irrigation patterns and trends at field-leveldetail across broad extents are vital for assessing and managing limitedwater resources. Until recently, there has been a scarcity of comprehensive,consistent, and frequent irrigation maps for the US. Here we present thenew Landsat-based Irrigation Dataset (LANID), which is comprised of 30 mresolution annual irrigation maps covering the conterminous US (CONUS) forthe period of 1997–2017. The main dataset identifies the annual extent ofirrigated croplands, pastureland, and hay for each year in the study period.Derivative maps include layers on maximum irrigated extent, irrigationfrequency and trends, and identification of formerly irrigated areas andintermittently irrigated lands. Temporal analysis reveals that 38.5×10 6  ha of croplands and pasture–hay has been irrigated, among which theyearly active area ranged from ∼22.6 to 24.7×10 6  ha. The LANID products provide several improvements over otherirrigation data including field-level details on irrigation change andfrequency, an annual time step, and a collection of ∼10 000 visually interpreted ground reference locations for the eastern US wheresuch data have been lacking. Our maps demonstrated overall accuracy above 90 % across all years and regions, including in the more humid andchallenging-to-map eastern US, marking a significant advancement overother products, whose accuracies ranged from 50 % to 80 %. In terms ofchange detection, our maps yield per-pixel transition accuracy of 81 %and show good agreement with US Department of Agriculture reports at bothcounty and state levels. The described annual maps, derivative layers, andground reference data provide users with unique opportunities to study localto nationwide trends, driving forces, and consequences of irrigation andencourage the further development and assessment of new approaches forimproved mapping of irrigation, especially in challenging areas like theeastern US. The annual LANID maps, derivative products, and groundreference data are available through https://doi.org/10.5281/zenodo.5548555 (Xie and Lark, 2021a).

[学科分类] 眼科学