滑坡负样本在基于统计模型的滑坡危险度制图中具有重要作用,能够抑制模型的高估,以合理区划滑坡危险区与非危险区。目标空间外向化采样法(Target Space Exteriorization Sampling,TSES)是一种代表性的基于环境特征空间的负样本采样方法...滑坡负样本在基于统计模型的滑坡危险度制图中具有重要作用,能够抑制模型的高估,以合理区划滑坡危险区与非危险区。目标空间外向化采样法(Target Space Exteriorization Sampling,TSES)是一种代表性的基于环境特征空间的负样本采样方法,以往研究表明,TSES在基于广义加性模型的滑坡危险度制图中的应用效果较好,但是其采集的负样本是"虚拟"的样本,只存在于环境特征空间中,无法映射到地理空间,因而无法通过野外检核验证所采集负样本的可靠性。针对这一问题,该文提出一种改进TSES方法,不仅可以在环境特征空间中进行负样本采样,而且使得采集的负样本可以映射到地理空间中。以甘肃省油房沟流域为研究区,在TSES与改进TSES两种负样本采样方法下分别对油房沟流域构建基于支持向量机(Support Vector Machine,SVM)的滑坡危险度推测模型,对比并分析两种负样本采样方法下的滑坡危险度制图精度。结果发现,改进TSES方法采集的负样本在基于SVM的滑坡危险度制图中应用效果比TSES好,表明改进的TSES是一种有效的负样本采样方法。展开更多
The concentrations of lead and cadmium in the tree bark from Sanming and Xiamen, Fujian province, China were determined by atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry. The results...The concentrations of lead and cadmium in the tree bark from Sanming and Xiamen, Fujian province, China were determined by atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry. The results obtained in the outer tree bark and tree bark pocket could reflect the degree of present and historical air pollution at different sampling locations. Tree bark and tree bark pocket should be expected to be as a useful biomonitor of present and historical condition of air pollution.展开更多
文摘The concentrations of lead and cadmium in the tree bark from Sanming and Xiamen, Fujian province, China were determined by atomic fluorescence spectrometry and inductively coupled plasma mass spectrometry. The results obtained in the outer tree bark and tree bark pocket could reflect the degree of present and historical air pollution at different sampling locations. Tree bark and tree bark pocket should be expected to be as a useful biomonitor of present and historical condition of air pollution.
