3种遥感产品检测黄土高原森林变化及差异比较

基于Landsat Vegetation Continuous Fields（LVCF）、MODIS Vegetation Continuous Fields（MVCF）和MODIS Land Cover（MODLC）等遥感产品和森林清查数据（NFI）检测2000-2015年黄土高原森林分布及变化。结果表明:1）2000-2015年黄土高原森林覆盖度升高，基于LVCF和MVCF的全区森林覆盖度均值分别由2000年的7.8%和9.6%增加到2015年的9.7%和13.2%。2）遥感产品估算的森林分布空间格局和面积差异较大，基于LVCF、MVCF和MODLC估算的黄土高原森林面积在2000年分别为726.6×10⁴、604.7×10⁴ hm²和325.1×10⁴ hm²，2015年分别为926.2×10⁴、998.3×10⁴ hm²和400.1×10⁴ hm²。3）遥感产品估算的省级尺度上森林面积与NFI的不一致性因省份和年份而异，LVCF与NFI一致性整体略优于MVCF，MODLC与NFI差异最大且估算的森林面积远低于LVCF、MVCF和NFI。4）遥感产品检测的陕西和山西2省的森林面积增加值与NFI一致性高于宁夏；基于遥感产品估算的宁夏森林面积及增加幅度均远低于NFI。

Detection of the Spatial Distribution and Changes of Forests in the Loess Plateau Using 3 Remote Sensing Products

This study detected the forest distribution and the changes over the Loess Plateau from 2000 to 2015 by using 3 remote sensing products,such as Landsat Vegetation Continuous Fields (LVCF),MODIS Vegetation Continuous Fields (MVCF) and MODIS Land Cover (MODLC),and the National Forest Inventory (NFI) data.The results showed that 1) the forest coverage in the Loess Plateau increased during the study period.The mean forest coverage increased from 7.8% and 9.6% in 2000 to 9.7% and 13.2% in 2015 based on LVCF and MVCF,respectively.2) Large discrepancies exhibited in these datasets in detecting the spatial distribution and area of forest.The estimated forest areas of the Loess Plateau were 726.6×10⁴,604.7×10⁴ hm² and 325.1×10⁴ hm² in 2000,and 926.2×10⁴,998.3×10⁴ hm² and 400.1×10⁴ hm² in 2015 based on LVCF,MVCF and MODLC,respectively.3) The inconsistence of provincial forest area between remote sensing datasets and NFI varied with region and time.LVCF and NFI showed higher consistency than those of MVCF and MODLC.The forest area estimated based on MODLC was much lower than those of other three.4) The remote sensing products exhibited a higher reliability in increased area detection in Shaanxi and Shanxi than that in Ningxia.Much lower forest area and forest area increase were estimated by three remote sensing products compared with NFI in Ningxia.