基于无人机影像VDVI指数的不同草地类型地上生物量估算

Estimation of aboveground biomass of different grassland types based on VDVI index of UAV visible image

【目的】对天然草地地上生物量进行快速、高效及无损伤估算。【方法】本研究利用无人机对青藏高原高寒草原及高寒草甸2种不同类型的天然草地进行航拍调查,通过构建无人机可见光波段差异性植被指数(VDVI,Visible Band Difference Vegetation Index),分析VDVI与不同草地类型地上生物量之间的关系并对研究区地上生物量进行无人机遥感估算。【结果】VDVI指数与两种草地类型地上生物量均具有较高的相关性,高寒草原地上生物量估算精度达到70.68%,最优估产模型为y=-17070x2+2120.4x+4.9506;高寒草甸地上生物量估算精度达到80.76%,最优估产模型为y=332.15x2+39.712x+14.638。【结论】小型可见光无人机结合VDVI指数被证明可用于高寒草原和高寒草甸生物量快速无损估算,可为高寒草地高效估产提供实用帮助。

【Objective】The study was implemented in order to estimate the aboveground biomass of natural grassland efficiently and non-destructively.【Method】In this study,an unmanned aerial vehicle(UAV)was used to take photos of alpine steppe and alpine meadow.Then,by constructing the visible-band differential vegetation index(VDVI),the relationship between VDVI and aboveground biomass was analyzed,and the aboveground biomass in the study area was estimated.【Result】The results showed that the VDVI index had a high correlation with the aboveground biomass of the two grassland types.The estimation accuracy of aboveground biomass in alpine grassland reached 70.68%,and the optimal estimation model was y=-17070x2+2120.4x+4.9506.The estimation accuracy of aboveground biomass in an alpine meadow reached 80.76%,and the optimal estimation model was y=332.15x2+39.712x+14.638.【Conclusion】In summary,UAVs combined with the VDVI index have been proven to be used for rapid and non-destructive estimation of aboveground biomass,which can provide a method for rapid and efficient estimation of aboveground biomass in alpine grassland.