首套全球30 m分辨率土地覆被产品区域尺度精度评价——以河南省为例

以河南省为研究区,对全球首套30 m分辨率土地覆盖产品GlobleLand30进行区域尺度精度评价。首先,以中国1\begin{array}{c}:\end{array}10万土地利用数据（CHINA-2010）为参考,分析两种产品的空间一致性;而后,通过Google Earth样本分析GlobleLand30在空间不一致区域的制图精度;最后,利用野外实地考察样本对GlobleLand30进行总体精度评价,并从土地覆被复杂度、高程等方面分析影响精度的原因,结果表明：① GlobleLand30与CHINA-2010空间一致性达80.20%。两种产品对耕地、林地、人工地面一致性高,对草地、水体、灌木、湿地、未利用土地的一致性低。② 在空间不一致区域,GlobleLand30的总体分类正确率略低于CHINA-2010,但两者对不同地类的优势不同。③ 经野外实地考察验证可知,GlobleLand30的总体精度达83.33%。④GlobleLand30与CHINA-2010的空间一致性随土地覆被复杂度的增加而降低,并在高程过渡带较低。

Regional accuracy assessments of the first global land cover dataset at 30-meter resolution: A case study of Henan province

Accurate global land cover datasets are key environmental information for research on global changes and regional sustainable development, such as global climate change, ecosystem assessment, biodiversity conservation. However, there are still some shortcomings in showing spatial and thematic details for the existing global land cover products at medium and low resolutions (300-1000 m). Recently, GlobeLand30, a global land cover product based on Landsat images at a 30-m resolution, was produced and released by China. The product made a breakthrough in enhancing spatial resolution of global land cover products, and has a wide range of application prospects. As with any land cover products, it is necessary to carry out accuracy evaluation of GlobeLand30 in global, regional or local scales before it is widely applied. This study aims at assessing the accuracy of GlobleLand30 in Henan province with cross-comparison analyses and sampling methods respectively. Firstly, the national land use database of China at a 1\begin{array}{c}:\end{array}100000 scale (CHINA-2010) was used as a reference data to analyze the spatial consistency between these two products. Secondly, validation samples collected from Google Earth were used to assess the producer's accuracy in spatially inconsistent areas. Finally, the overall accuracy of GlobleLand30 was assessed by field survey. Moreover, several factors influencing the accuracy of GlobleLand30 were also taken into consideration, such as land cover complexity and elevation. The following conclusions were drawn: (a) Spatial consistency between GlobleLand30 and CHINA-2010 reached up to 80.20%. There was high spatial consistency for croplands, forests and artificial surfaces, and low spatial consistency for grasslands, water bodies, shrubs, wetlands and unused lands. (b) The overall accuracy of GlobleLand30 was slightly lower than that of CHINA-2010 in spatially inconsistent areas. As for forests, producer's accuracy of GlobleLand30 was relatively higher than that of CHINA-2010. (c) It was found by field survey that the overall accuracy of GlobleLand30 was 83.33%. (d) On the one hand, with the increase of the complexity of land cover types, spatial consistency between GlobleLand30 and CHINA-2010 decreased; on the other hand, with the increase of elevation, spatial consistency between the two products decreased first and then rose, and became lower in the elevation transition zones.