%0 Dataset
%T OasisMap30: a 30 m annual land cover dataset of China's oases from 1987 to 2024
%J National Cryosphere Desert Data Center
%I National Cryosphere Desert Data Center(www.ncdc.ac.cn)
%U http://www.ncdc.ac.cn/portal/metadata/3808cedc-34aa-4244-8651-8faa911c6e71
%W NCDC
%R 10.12072/ncdc.landcover.db7473.2026
%A Chen Peng
%A Tang Qiang
%A Liu Yanxu
%A Wang Shuai
%K Oasis;land use and land cover changes (LUCC);LandTrendr;Drylands
%X High-temporal and spatial resolution oasis land cover maps are of great value in clarifying the ecological evolution and social development process of arid areas. However, research on oases started late, coupled with the high fragmentation of oasis landscapes and frequent conversion of land cover types, constructing high-temporal and spatial resolution oasis land cover datasets faces many challenges. Therefore, such data products specifically for oases are still scarce.Based on this, this paper builds a 30-meter land cover mapping framework every year, integrating Landsat satellite images, machine learning algorithms, time series segmentation model (LandTrendr) and principal component analysis methods. Based on this framework, the 30-meter annual land cover data set (OasisMap30) of China oases from 1987 to 2024 is generated based on the Google Earth Engine (GEE) platform. Accuracy verification based on more than 6300 visual interpretation samples shows that the overall accuracy of OasisMap30 is higher than 90%. Combining visual interpretation samples with third-party verification data to conduct cross-comparison among multiple products, OasisMap30 has significant advantages in classification accuracy and error control. In addition, comparing this dataset with a variety of 30-meter special products on impervious surface, cultivated land, and surface water bodies, it was found that OasisMap30 is in good agreement with existing data.Based on the OasisMap30 dataset, this paper analyzes the evolution characteristics of land cover pattern in oases in China. The results show that from 1987 to 2024, the total area of oases in my country expanded by 45.87%, with an increase of 7.75 million hectares. The core driving force for expansion was cultivated land reclamation and grassland restoration. Among them, 4.04 million hectares of desert were transformed into grassland, and 3.19 million hectares of desert were reclaimed into cultivated land; impervious surface expanded by 580