基于PROSAIL模型和Sentinel-2数据的陕北煤炭矿区植被叶绿素含量监测

Monitoring of Chlorophyll Content of Vegetation in Coal Mining Area in Northern ShaanxiBased on PROSAIL Model and Sentinel-2 Data

为满足煤炭矿区植被叶绿素含量高精度动态监测需求,该文以陕北大柳塔矿区为研究区,首先分析PROSAIL模型对矿区典型植被欧李、野樱桃的适用性,然后根据PROSAIL辐射传输模型建立查找表,结合基于正则化的代价函数对欧李、野樱桃叶绿素含量进行反演,并利用SNAP软件反演结果与地面实测数据对PROSAIL模型反演结果进行验证,最后利用所构建模型反演得到2016—2019年大柳塔矿区植被叶绿素含量空间分布。结果表明:PROSAIL模型模拟光谱与地面实测光谱的绝对偏差平均值最大为0.016,该精度满足植被参数反演;PROSAIL模型反演得到的欧李、野樱桃叶绿素含量与地面实测数据的决定系数、均方根误差和相对均方根误差分别为0.679、1.926和4.625%,优于SNAP软件反演结果,反演得到的大柳塔矿区叶绿素含量时空变化与实际植被生态修复情况和土地利用覆盖类型一致。研究结果可为矿区植被叶绿素反演和生态修复效果评估提供技术参考。

Taking the Daliuta mining area in northern Shaanxi as the study area,this paper explores the dynamic monitoring method of vegetation chlorophyll content in coal mining area.Firstly,the applicability of the PROSAIL model to typical vegetation such as plum and wild cherry in the mining area was analyzed.Then,a lookup table was established based on the PROSAIL radiative transfer model,and the chlorophyll content of typical vegetation in the mining area was retrieved based on a regularized cost function.The inversion results of the PROSAIL model were verified by the inversion results of SNAP software and ground-measured data.Finally,the spatial distribution of vegetation chlorophyll content in the Daliuta mining area from 2016 to 2019 was obtained by inversion of the constructed model.The results show that the average absolute deviation between the simulated results of the PROSAIL model and the measured spectrum was not more than 0.016,and the accuracy can meet the inversion of vegetation parameters;the R 2,RMSE and RRMSE of chlorophyll content of typical vegetation retrieved by PROSAIL model and measured data were 0.679,1.926 and 4.625%,respectively,which were significantly better than those retrieved by the SNAP module.The spatiotemporal variation of chlorophyll content in the Daliuta mining area was consistent with the actual vegetation ecological restoration and land use cover type.The study results can provide technical support for chlorophyll inversion and ecological restoration evaluation.