A 30-m resolution distribution map of maize for China based on Landsat and Sentinel images

As the second largest producer of maize, China contributes 23% of global maize production and plays an important role in guaranteeing maize markets stability. In spite of its importance, there is no 30 m spatial resolution distribution map of maize for all of China. This study used a time-weighted dynamic time warping method to identify planting areas of maize by comparing the similarity of time series of a satellite-based vegetation index at each pixel with a standard time series derived from known maize fields and mapped maize distribution from 2016 to 2020 over 22 provinces accounting for more than 99% of the maize planting area in China. Based on 18800 field-surveyed pixels at 30-meter spatial resolution, the distribution map yields 76.15% and 81.59% of producer’s and user’s accuracies averaged over the entire investigated provinces, respectively. Municipality- and county-level census data also show a good performance in reproducing the spatial distribution of maize. This study provides an approach to mapping maize over large areas based on a small volume of field survey data.<br>classification system:1: maize0: non-maize<br>Ruoque Shen, Jie Dong, Wenping Yuan, Wei Han, Tao Ye, Wenzhi Zhao, "A 30 m Resolution Distribution Map of Maize for China Based on Landsat and Sentinel Images", <i>Journal of Remote Sensing</i>, vol. 2022, Article ID 9846712, 12 pages, 2022. https://doi.org/10.34133/2022/9846712

作为全球第二大玉米生产国，中国玉米产量占全球总产量的23%，对保障全球玉米市场的稳定具有重要意义。尽管玉米产业地位举足轻重，但目前尚无覆盖全国范围的30米空间分辨率玉米种植分布地图。本研究采用时间加权动态时间规整（time-weighted dynamic time warping）方法，通过将每个像素对应的卫星植被指数时间序列与已知玉米田块构建的标准时间序列进行相似度比对，完成了2016—2020年中国22个省份的玉米种植区域识别，该区域覆盖了全国99%以上的玉米种植总面积。基于18800个30米空间分辨率的野外调查像素点，在全部调研省份中，该分布图的生产者精度与使用者精度分别可达76.15%和81.59%。市县级普查数据也验证了该方法在复现玉米种植空间分布上的良好表现。本研究提出了一种基于少量野外调查数据即可实现大区域玉米种植分布制图的方法。<br>分类体系：1：玉米；0：非玉米<br>沈若鹊，董杰，袁文平，韩伟，叶涛，赵文智. 基于Landsat与Sentinel影像的中国30米分辨率玉米分布地图[J]. 遥感学报, 2022, 第2022卷, 文章编号9846712, 共12页. https://doi.org/10.34133/2022/9846712