中国农业科学 ›› 2017, Vol. 50 ›› Issue (15): 2983-2992.doi: 10.3864/j.issn.0578-1752.2017.15.012

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

基于无人机载LiDAR数据的玉米涝灾灾情评估

甘平1,2,3,4,董燕生2,3,4,孙林1,杨贵军2,3,4,李振海2,3,4,杨凡2,3,4,王立志2,3,4,王建雯1,2,3,4

 
  

  1. 1山东科技大学测绘科学与工程学院,山东青岛 266590;2国家农业信息化工程技术研究中心,北京100097;3农业部农业信息技术重点实验室,北京100097;4北京市农业物联网工程技术研究中心,北京100097
  • 收稿日期:2016-12-20 出版日期:2017-08-01 发布日期:2017-08-01
  • 联系方式: 甘平,E-mail:ganpingzd@163.com
  • 基金资助:
    国家自然科学青年科学基金(41401476)

Evaluation of Maize Waterlogging Disaster Using UAV LiDAR Data

GAN PING1,2,3,4, DONG YanSheng2,3,4, SUN Lin1, YANG GuiJun2,3,4, LI ZhenHai2,3,4, YANG Fan2,3,4, WANG LiZhi2,3,4, WANG JianWen1,2,3,4   

  1. 1Geomatics College, Shandong University of Science and Technology, Qingdao 266590, Shandong; 2National Engineering Research Center for Information Technology in Agriculture, Beijing 100097; 3Key Laboratory of Agricultural Information Technology, Ministry of Agriculture, Beijing 100097; 4Beijing Engineering Research Center of Agricultural Internet of Things, Beijing 100097
  • Received:2016-12-20 Published:2017-08-01 Online:2017-08-01

摘要: 【目的】基于无人机平台的遥感技术是目前研究的热点,也是推动现代化农业快速发展的主要力量之一。笔者欲通过分析涝灾研究区激光雷达点云数据反演的玉米冠层高度,快速准确实现玉米涝灾受灾范围监测和灾情评估,为防灾减灾、高产稳产、农业保险理赔等提供依据。拓展无人机载LiDAR数据在农业领域的应用价值,为农业等相关部门快速有效掌握农情信息提供保障。【方法】2016年7月19—20日,以因大暴雨导致涝灾的北京市昌平区一块玉米大田作为研究区,基于无人机平台获取研究区激光雷达数据。通过冠层高度模型(canopy height model,CHM)反演出玉米冠层高度,采用正态统计理论的双阈值划分策略确定阈值,构建基于玉米冠层高度差异的涝灾灾情遥感监测模型,评价玉米涝灾灾情严重程度,并基于地面实测数据进行精度评价。【结果】涝灾发生后,玉米长势存在一定差异,最明显的差异体现在玉米植株高度。基于正态统计理论和野外测量,最终确定严重涝灾玉米冠层高度为0.30—0.84 m,中度涝灾玉米冠层高度为0.84—1.70 m冠层高度1.70 m以上为轻度受灾区域。通过野外实测样本对无人机载LiDAR数据估算结果进行混淆矩阵分析,总体分类精度达到72.15%,Kappa系数为0.44。结合数码影像做进一步验证,结果表明研究区玉米涝灾遥感空间制图结果与数码影像结果基本一致。【结论】通过无人机载LiDAR数据能实现玉米冠层高度反演,结合涝灾后玉米植株高度差异特征能有效反映不同涝灾程度,实现区域尺度下玉米涝灾受灾范围监测和灾情等级评估,有利于便捷高效获取灾情灾害信息

关键词: 玉米, 涝灾, 灾情评估, 无人机载LiDAR, 冠层高度

Abstract: ObjectiveUnmanned aerial vehicle (UAV) remote sensing technology is a hot research topic in the remote sensing sector, which is also one of the forces driving the development of modern agriculture. The objective of this study is to quickly and precisely measure the area of maize waterlogging disaster and evaluate disaster levels by analyzing maize canopy height derived from UAV LiDAR point cloud data. Thus it can provide a guideline for disaster prevention and mitigation, high and stable yield, agricultural insurance claims, etc. The aim of this study is to expand the application of UAV LiDAR data in agriculture, and provide a guarantee for agriculture field to quickly and effectively master agricultural information.MethodThe experiment was carried out and the UAV LiDAR data were obtained in Changping District, Beijing, where suffered a heavy rainstorm which led to a large-scale maize waterlogging on July 19-20, 2016. LiDAR point cloud data were classified and extracted, and canopy height of maize was obtained by LiDAR point cloud data from canopy height model (CHM). A double threshold partition strategy based on the normal statistics theory was adopted to determine the thresholds and a remote sensing monitoring model for maize waterlogging was built by analyzing the differences of canopy heights to evaluate the disaster levels of the maize waterlogging. Finally, the accurate assessment of the model was conducted by comparing the in-field measured data with predicted results from the built model.Result(1) After the occurrence of waterlogging of maize, there was a significant difference of maize growth between pre and post the disaster, and maize height showed the most obvious difference after the disaster. The maize canopy heights of final severe waterlogging, medium waterlogging, and the slight waterlogging were 0.30-0.84 m, 0.84-1.70 m, and above 1.70 m, respectively. (2) The confusion matrix analysis on the results estimated using the airborne LiDAR data was performed via ground survey samples; the overall classification accuracy of waterlogging degree reached 72.15%, and the Kappa coefficient was 0.44. (3) In general, remote sensing mapping was consistent with the monitoring data from the digital images.ConclusionThe maize canopy height inversion can be achieved by UAV LiDAR data, and the waterlogging levels can be effectively reflected by the differences in maize plant heights. UAV LiDAR data can measure the area of maize waterlogging and evaluate disaster levels at regional scale, providing a convenient and efficient way to acquire the disaster information.

Key words: maize, waterlogging, evaluation of disaster level, unmanned aerial vehicle (UAV) LiDAR, canopy height