中国建设用地省际分布的统计分析   总被引：8，自引：0，他引：8  

梁进社 《地球科学进展》2002,17(2):195-200

建设用地的扩张是中国耕地减少的最重要因素，通过建立建设用地分布的定量关系，揭示建设用地增长的动力学基础。通过居民点和工矿用地、交通用地、建设用地总量（前二者之和）的省际分布与人口、人均耕地的省际分布的单因素和双因素统计分析发现：这三者的分布与这两个因素存在很强的二元线性相关；人口分布对居民点和工矿用地总量分布的影响要比对交通用地总量分布的影响大，人均耕地分布对这二者的人均值分布的影响，则恰恰相反。  相似文献   

Application of Uranium Isotope Chronology for Partical Comminution in the Eolian Dust System     

Yuanhe Fu  Le Li  Jun Chen 《地球科学进展》2018,33(10):1034-1047

The wind dust system is an important part of the terrestrial surface system and plays an important role in many key belts. The mechanism of wind dust and the handling process are important to understand the environmental function of wind dust and to interpret the paleoclimate record. In the past, traditional geochemical methods can only reflect the rock composition or age in the final denudation zone, and it is not possible to distinguish the different silt mechanism and the intermediate process under the same eventual source background, which is one of the biggest challenges of the present research. The ²³⁴U/²³⁸U ratio of fine matter caused by alpha decay recoil reflects the time experienced by the particle since it was broken and may be able to effectively trace the mechanism of wind dust generation and the transport of the intermediate process, but the age of uranium isotope fragmentation is rarely used in the wind dust system. The complicated factors restricting the wide application of uranium isotope were summarized, and according to the latest research progress, the verification and development of the uranium isotope comminution age in the wind dust system, and the problem solution of the mechanism of wind dust production and the way of transporting were discussed.  相似文献   

唐山开滦煤矿区Se、Hg元素地球化学特征及其迁移循环规律研究          下载免费PDF全文

张秀芝  马忠社  王志军  谢伟民 《地质科学》2012,(3):908-920

唐山开滦煤矿已有百余年的开采史。河北平原多目标区域地球化学调查在矿区内发现了以Se、Hg元素为主的多种微量元素土壤地球化学异常。本文利用地球化学方法,研究Se、Hg元素地球化学空间分布特征、赋存状态及其在表生环境中的迁移循环规律。结果表明,Se、Hg元素含量在大气降尘中高度富集,土壤异常区与煤田分布范围几乎一致。Se、Hg元素主要通过大气降尘及地表水系途径在煤-大气-土壤-水系体系内迁移,迁移过程中其赋存状态发生了改变,活化趋势明显。迁移范围遍及矿区外围1 200 km²区域及流经矿区的整个水系覆盖区域。  相似文献   

Multi-hazard susceptibility mapping based on Convolutional Neural Networks     

《地学前缘(英文版)》2022,13(5):101425

Multi-hazard susceptibility prediction is an important component of disasters risk management plan. An effective multi-hazard risk mitigation strategy includes assessing individual hazards as well as their interactions. However, with the rapid development of artificial intelligence technology, multi-hazard susceptibility prediction techniques based on machine learning has encountered a huge bottleneck. In order to effectively solve this problem, this study proposes a multi-hazard susceptibility mapping framework using the classical deep learning algorithm of Convolutional Neural Networks (CNN). First, we use historical flash flood, debris flow and landslide locations based on Google Earth images, extensive field surveys, topography, hydrology, and environmental data sets to train and validate the proposed CNN method. Next, the proposed CNN method is assessed in comparison to conventional logistic regression and k-nearest neighbor methods using several objective criteria, i.e., coefficient of determination, overall accuracy, mean absolute error and the root mean square error. Experimental results show that the CNN method outperforms the conventional machine learning algorithms in predicting probability of flash floods, debris flows and landslides. Finally, the susceptibility maps of the three hazards based on CNN are combined to create a multi-hazard susceptibility map. It can be observed from the map that 62.43% of the study area are prone to hazards, while 37.57% of the study area are harmless. In hazard-prone areas, 16.14%, 4.94% and 30.66% of the study area are susceptible to flash floods, debris flows and landslides, respectively. In terms of concurrent hazards, 0.28%, 7.11% and 3.13% of the study area are susceptible to the joint occurrence of flash floods and debris flow, debris flow and landslides, and flash floods and landslides, respectively, whereas, 0.18% of the study area is subject to all the three hazards. The results of this study can benefit engineers, disaster managers and local government officials involved in sustainable land management and disaster risk mitigation.  相似文献