干旱区研究 ›› 2021, Vol. 38 ›› Issue (6): 1659-1667.doi: 10.13866/j.azr.2021.06.17

• 植物与植物生理 • 上一篇    下一篇

基于WorldView-2高分影像的胡杨林结构参数获取研究

杨雪峰1,2(),叶茂1,2,木尼热·买买提1,2   

  1. 1.新疆师范大学地理科学与旅游学院,新疆 乌鲁木齐 830054
    2.新疆干旱区湖泊环境与资源实验室,新疆 乌鲁木齐 830054
  • 收稿日期:2021-03-07 修回日期:2021-05-20 出版日期:2021-11-15 发布日期:2021-11-29
  • 作者简介:杨雪峰(1972-),男,副教授,主要从事干旱区资源环境遥感技术应用研究. E-mail: 744157426@qq.com
  • 基金资助:
    国家自然科学基金项目(41761075);国家自然科学基金联合基金项目(U1803245)

Structural parameter acquisition of Populus euphratica by WorldView-2 remote sensing image

YANG Xuefeng1,2(),YE Mao1,2,Munire Maimaiti1,2   

  1. 1. College of Geographic Science and Tourism, Xinjiang Normal University, Urumqi 830054, Xinjiang, China
    2. Xinjiang Laboratory of Lake Environment and Resources in Arid Zone, Urumqi 830054, Xinjiang, China
  • Received:2021-03-07 Revised:2021-05-20 Online:2021-11-15 Published:2021-11-29

摘要:

森林结构特征是评价森林生态系统的重要指标,如何使用遥感技术获取大尺度森林结构具有重要的科学研究意义。塔里木河下游作为我国干旱区生态保护的重点区域,该区域的胡杨林作为生态恢复的主要对象,研究其森林结构参数具有重要的现实意义。通过采用高分辨率WorldView-2遥感影像,结合无人机遥感技术,利用光谱混合理论与基于对象影像处理技术,获取位于塔里木河下游研究区的胡杨株数、冠幅、植被覆盖度和胡杨高度信息。通过与无人机观测数据在1 hm2尺度上进行比较,使用高分影像获取的胡杨冠幅、树高、植被覆盖度和密度的R2分别为0.69、0.63、0.89和0.86,证明高分影像与无人机技术结合可以在区域尺度上获取较为准确的森林结构信息。最终对塔里木河下游研究区胡杨林结构信息估测得出:总株数约1.05×105株,每公顷平均树高7.38 m,平均冠幅为5.86 m,平均密度26株,平均覆盖度为7.8%。

关键词: 森林结构参数, 胡杨, 高分辨率遥感, 光谱混合分析, 面向对象影像分析

Abstract:

Forest structure information is an important index to evaluate forest ecosystems and applying remote sensing technology to explore forest structure offers practical scientific applications. The lower reaches of the Tarim River are a key area of ecological protection in arid areas of China, in this paper, we applied WorldView-2 very high-resolution remote sensing imagery using spectral unmix analysis theory and object-based image analysis processing technology to examine tree density, crown diameter, and Fractional Vegetation Cover (FVC) of Populus euphratica in the study area. Using UAV photogrammetry, we also obtained height data of Populus euphratica by establishing a regression model between canopy reflectance, texture, and tree height. By comparing structural data with UAV, we found the following results based on a 1 hm2 scale: R2 of Populus euphratica’s crown diameter=0.69 and RMSE=0.69 m; R2 of Populus euphratica’s height = 0.63 and RMSE=0.57 m; R2 of Populus euphratica’s FVC=0.89 and RMSE=2.8%; and R2 of Populus euphratica’s density=0.86 and RMSE=9.64 trees·hm-2. We found forest structural information can be obtained using WorldView-2 very high-resolution imagery with UAV technology support. We calculated 105000 trees Populus euphratica individuals and 2000 trees distributed per kilometer of the Tarim River, tree height of 55% of the study area at 6-8 m·hm-2, crown width of 49.52% at 6-8 m·hm-2, density of 51.8% lower than 20 trees·hm-2, and a FVC of 49.24% lower than 5% per hectare. The average height of the Populus euphratica forest was 7.38 m, the average density was 26 trees·hm-2, the average crown width was 5.86 m, and the average FVC was 7.8%. Tree height and crown width were slightly overestimated, while density and coverage were underestimated. As a representative river section in the lower reaches of the Tarim River, these data are useful for understanding the overall ecological status of Populus euphratica in the lower reaches of the Tarim River.

Key words: forest structural parameters, Populus euphratica, high spatial resolution remote sensing, spectral mixture analysis, object-oriented image analysis