模拟实验研究利用植被冠层光谱探测CO_2轻微泄漏点

Simulated Experimental Research on Using Canopy Spectra of Surface Vegetation to Detect CO_2 Microseepage Spots

温室气体（CO2）过量排放可以导致全球气候变暖,而碳捕捉与储存（carbon capture and storage,CCS）技术是一种减少CO2气体排放的有效措施。但存储在地下的CO2有泄漏的风险,如何快速监测CO2轻微泄漏点是一个值得研究的问题。该文通过野外模拟实验,研究草地和大豆在CO2轻微泄漏胁迫下的冠层光谱特征,构建CO2轻微泄漏点高光谱遥感探测模型。在2008年5月—9月于英国诺丁汉大学Sutton Bonington校区（52.8N,1.2W）进行了野外模拟实验。实验共设置16个小区,8个草地及8个大豆地,其中各有4个小区进行CO2泄漏胁迫。冠层光谱采用美国ASD光谱仪进行测量,草地测量了6次数据,大豆地测量了3次数据。实验结果表明,草地与大豆地的冠层光谱反射率在580~680nm波段范围内随CO2泄漏胁迫程度的增大而增大,且在整个试验期内都保持同样的规律,因此构建面积指数AREA（580~680nm）（光谱曲线在580~680nm波段范围内包围的面积）识别遭受CO2泄漏胁迫下的植被。通过J-M距离检验,发现该指数能够较好地识别出CO2轻微泄漏胁迫下center区与core区的草地,但对edge区草地的识别能力不足（J-M距离小于1.8）;该指数可以可靠且稳健地识别出遭受CO2轻微泄漏胁迫的大豆。该研究结果可为未来应用高光谱遥感探测CO2轻微泄漏点提供理论依据与方法支持。

With the global warming ,people now pay more attention to the problem of the emission of greenhouse gas （CO2 ） . Carbon capture and storage （CCS） technology is an effective measures to reduce CO2 emission .But there is a possible risk that the CO2 might leak from underground .However ,there need to research and develop a technique to quickly monitor CO2 leaking spots above sequestration fields .The field experiment was performed in the Sutton Bonington campus of University of Notting‐ham（52.8N ,1.2W） from May to September in 2008 .The experiment totally laid out 16 plots ,grass（cv Long Ley） and beans （Vicia faba cv Clipper） were planted in eight plots ,respectively .However ,only four grass and bean plots were stressed by the CO2 leakage ,and CO2 was always injected into the soil at a rate of 1 L？min^-1 .The canopy spectra were measured using ASD instrument ,and the grass was totally collected 6 times data and bean was totally collected 3 times data .This paper study the canopy spectral characteristics of grass and beans under the stress of CO2 microseepages through the field simulated experiment , and build the model to detect CO2 microseepage spots by using hyperspectral remote sensing .The results showed that the canopy spectral reflectance of grass and beans under the CO2 leakage stress increased in 580~680 nm with the stressed severity eleva‐ting ,moreover ,the spectral features of grass and beans had same rule during the whole experimental period .According to the canopy spectral features of two plants ,a new index AREA（580~680 nm） was designed to detect the stressed vegetations .The index was tested through J‐M distance ,and the result suggested that the index was able to identify the center area and the core area grass under CO2 leakage stress ,however ,the index had a poor capability to discriminate the edge area grass from control .Then , the index had reliable and steady ability to identify beans under CO2 leakage stress .This result could provide theoretical basis and methods for detecting CO2 leakage spots using hyperspectral remote sensing in the future .