基于无人机图像的草地植被盖度估算方法比较  

Comparison of grassland vegetation coverage extraction algorithms from UAV technology

作　　者：伏帅 冯琦胜[1] 党菁阳 雷可欣 乔万鑫 梁天刚[1] 潘冬荣 孙斌 姜佳昌 FU Shuai;FENG Qisheng;DANG Jingyang;LEI Kexin;QIAO Wanxin;LIANG Tiangang;PAN Dongrong;SUN Bin;JIANG Jiachang(State Key Laboratory of Grassland Agro-ecosystems/Key Laboratory of Grassland Livestock Industry Innovation,Ministry of Agriculture and Rural Affairs/Engineering Research Center of Grassland Industry,Ministry of Education/College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,Gansu,China;Gansu Grassland Technical Extension Station,Lanzhou 730000,Gansu,China)

机构地区：[1]草地农业生态系统国家重点实验室/农业农村部草牧业创新重点实验室/草地农业教育部工程研究中心/兰州大学草地农业科技学院,甘肃兰州730020 [2]甘肃省草原技术推广总站,甘肃兰州730000

出　　处：《草业科学》2022年第3期455-464,共10页Pratacultural Science

基　　金：国家自然科学基金项目(41801191、41805086);甘肃省农业财政项目(2016276);现代农业产业技术体系建设专项资金(CARS-34);中国工程院重点咨询项目(2021-HZ-5、2020-XZ-29);长江学者和创新团队发展计划(IRT17R50);兰州大学中央高校基本科研业务费专项资金(lzujbky2021-kb13)。

摘　　要：植被盖度是反映植被基本情况的客观指标和重要参数。本研究在对比8种常用的可见光植被指数计算草地盖度精度的基础上,发现这些植被指数对荒漠草地的植被盖度估测效果较差,因此提出一种适用于荒漠草地植被盖度估测的荒漠植被指数(DVI),并评价了不同植被指数对不同草地类型的植被盖度估测效果,分析了不同草地类型阈值取值的变化情况。结果表明:1)所选植被指数对草甸草地和典型草地的盖度估测效果均较好,精度较高(准确率>90%,F_(1)得分> 0.9)。草甸草地中超绿指数(Ex G)的盖度估测效果最好(准确率> 93%,F_(1)得分> 0.95),典型草地中各植被指数无明显差异,但对荒漠草地植被盖度估测效果较差,精度较低(F_(1)得分≤0.6)。2) DVI对荒漠草地植被盖度估测精度较高(准确度> 93%,F_(1)得分达到0.71),能够有效弥补上述植被指数的缺陷。3)绿叶指数(GLI)和植被颜色指数(CIVE)的阈值对草地类型敏感性最弱;Ex G、超绿超红差分指数(Ex GR)、植被因子指数(VEG)、Woebbecke指数(WI)等植被指数的阈值对草甸草地和典型草地的敏感性较弱,但对荒漠草地的敏感性较强;组合指数(COM)和Lab指数(Lab)对草地类型的敏感性最强。Vegetation coverage is an objective index and an important parameter that reflects the basic extent of vegetation.In this study, we evaluated and analyzed the effectiveness of eight different visible-light-based vegetation indices for estimating the vegetation cover of different grassland types. Upon comparison of accuracy of these vegetation indices, we found that these vegetation indices were less effective in estimating the vegetation cover of desert grasslands. Therefore, we have proposed a desert vegetation index(DVI) to estimate the vegetation cover of desert grasslands. The effects of different vegetation indices on the vegetation cover estimation of different grassland types were evaluated, and the changes in the threshold values of different grassland types were analyzed. The results showed that: 1) The common vegetation indices could estimate the vegetation coverage in meadow grasslands and typical grasslands with a high accuracy(accuracy > 90%,F_(1) > 0.9). The Ex G(excess green index) was the best in estimating the vegetation coverage in meadow grasslands(accuracy >93%, F_(1) > 0.95), and there was no significant difference among the estimation power of vegetation indices when estimating the coverage in typical grasslands. However, the common vegetation indices exhibited low accuracy of vegetation coverage estimation(F_(1) ≤ 0.6) in desert grasslands. 2) The DVI proposed in this study has a high estimation accuracy of vegetation coverage in desert grasslands(accuracy > 93%, F_(1) score reached 0.71), which can effectively compensate for the defects of the above-mentioned vegetation indices. 3) The thresholds of GLI(green leaf index) and CIVE(color index of vegetation extraction) were the least sensitive to grassland types;the thresholds of Ex G, Ex GR(excess green minus excess red index),VEG(vegetative index), and WI(woebbecke index) were less sensitive to the effects of meadow grasslands and typical grasslands, but more sensitive to the effect of desert grasslands;and COM(combination index) and Lab

关 键 词：无人机 可见光波段 植被盖度 植被指数 荒漠 草地 阈值法 

分 类 号：S812[农业科学—草业科学] TP391.41[农业科学—畜牧学]