用微信扫码二维码

分享至好友和朋友圈

WE ARE COMMITTED TO REPORTING THE LATEST FORESTRY ACADEMIC ACHIEVEMENTS

基于无人机影像的城市绿地提取分析

Analysis of Urban Green Space Extraction Based on UAV Images

  • 摘要: 本文通过无人机获取四川省北川县高分辨率影像数据,经过空三加密,正射校正等一系列预处理,利用ENVI软件分别计算研究区可见光波段差异植被指数VDVI (visible-band difference vegetation index),归一化绿红差值指数NGRDI (normalized green-red difference index)、归一化绿蓝差值指数NGBDI (normalized green-blue difference index)。采用面向对象的影像分类方式,分别提取城市绿地并进行精度评价。结果表明:3种植被指数均能较好地提取城市绿地,总体提取精度均在83%以上,其中VDVI提取效果最优,总体精度达到89.5%。因此,利用无人机遥感技术进行城市绿地的提取统计是可行的。基于VDVI统计结果,通过去除小斑块以及目视解译校正城市绿地分类结果,统计得到北川县建成区绿地面积为2.3948 km2,城市绿化覆盖率为40.04%。

     

    Abstract: High-resolution image data of Beichuan County were obtained by unmanned aerial vehicles (UAV). After a series of pretreatments such as three-space encryption and orthophoto correction,ENVI software was used to calculate the visible-band difference vegetation index, normalized green-red difference index (NGRDI),and normalized green-blue difference index (NGBDI).The urban vegetation was extracted and analyzed by object-oriented image classification,and the accuracy was evaluated. The results showed that all the three planting cover indexes could extract the urban green space well, and the overall extraction precision was above 83%, among which the VDVI extraction effect was the best, and the overall precision was up to 89.5%.Therefore,it was feasible to extract statistics of the urban green space by UAV remote sensing technology. Based on the VDVI statistics, the classification results of the urban green space were corrected by removing small patches and visual interpretation. The area of urban green space was 2.3948 km2 in Beichuan County, and the coverage rate of the urban green space was 40.04%.

     

/

返回文章
返回