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101.
102.
湘中断裂体系分维与锑矿分布 总被引:15,自引:3,他引:15
笔者将分形几何学的原理和方法,应用于湘中地区断裂体系的二维平面分布特征研究,发现在研究的标度范围内(r约2~80km)不仅具有统计自相似性,并且同一地区,不同分区具有不同的分维值D,分维值分布特征为东南区分维值高于西北区分维值,将本区断裂体系的这种分维值分布特征与锑矿床分布特征对比,可发现锑矿床(点)产出较多,矿床规模较大的地区,其分维值较大。 相似文献
103.
黄骅坳陷在勘探石油过程中发现了丰富的地下热水。根据实际资料对黄烨坳陷大港探区的地热资源进行了初步评价,提出了黄骅场陷储热系统和热异常区的分布规律,通过水化学分析,指出坳陷补给条件差,可实行人工回灌,增加地下热水资源。 相似文献
104.
105.
Chih-Chiang Lu Chu-Hui Chen Tian-Chyi J. Yeh Cheng-Mau Wu I-Fang Yau 《Stochastic Environmental Research and Risk Assessment (SERRA)》2006,20(1-2):6-22
Typhoons and storms have often brought heavy rainfalls and induced floods that have frequently caused severe damage and loss
of life in Taiwan. Our ability to predict sewer discharge and forecast floods in advance during storm seasons plays an important
role in flood warning and flood hazard mitigation. In this paper, we develop an integrated model (TFMBPN) for forecasting
sewer discharge that combines two traditional models: a transfer function model and a back propagation neural network. We
evaluated the integrated model and the two traditional models by applying them to a sewer system of Taipei metropolis during
three past typhoon events (NARI, SINLAKU, and NAKR). The performances of the models were evaluated by using predictions of
a total of 6 h of sewer flow stages, and six different evaluation indices of the predictions. Finally, an overall performance
index was determined to assess the overall performance of each model. Based on these evaluation indices, our analysis shows
that TFMBNP yields accurate results that surpass the two traditional models. Thus, TFMBNP appears to be a promising tool for
flood forecasting for the Taipei metropolis sewer system.
For publication in Stochastic Environmental Research and Risk Analysis. 相似文献
106.
Yong Xu Leping Yue Jianxing Li Lu Sun Bo Sun Jiayin Zhang Ji Ma Jianqi Wang 《Environmental Earth Sciences》2012,66(7):2021-2030
Loess and red clay on the Chinese Loess Plateau have produced a detailed history of the East Asia monsoon for the past eight
million years. Recently, a well-conserved red clay sequence was discovered at Shilou on the eastern edge of Chinese Loess
Plateau, extending the monsoon history back to approximately 11 Ma. By comparing lithologic features, particle size distribution,
magnetic susceptibility and deposition rate of Shilou red clay sequence, the paleomonsoon evolution from 11 to 2.6 Ma can
be divided into four stages: largely fluctuated stage (11.0–8.0 Ma), relatively strengthened period (8.0–6.5 Ma), extremely
changed stage (6.5–4.9 Ma) and further intensified period (4.9–2.6 Ma). The new evidence indicates that variation of paleomonsoon
has close relationship with uplifting of the Tibetan Plateau and ongoing global cooling and the consequent expansion of ice
sheets during 11.0–2.6 Ma. 相似文献
107.
地理认知理论内涵分析 总被引:18,自引:2,他引:18
在分析现有地理信息系统以及地理专家系统的研究特点之后,提出对于以研究和模拟地理学家的逻辑思维方式为目的的“地理认知理论”进行了研究。 相似文献
108.
GIS-based flood hazard mapping at different administrative scales: A case study in Gangetic West Bengal, India 总被引:4,自引:0,他引:4
This paper addresses the need for an efficient and cost-effective methodology for preparing flood hazard maps in data poor countries, particularly those under a monsoon regime where floods pose a recurrent danger. Taking Gangetic West Bengal, India, as an example and using available historical data from government agencies, the study compiled a regional map indicating hazard prone subregional areas for further detailed investigation, thereby isolating actual high risk localities. Using a GIS (Geographical Information System), a composite hazard index was devised incorporating variables of flood frequency, population density, transportation networks, access to potable water, and availability of high ground and maximum risk zones were mapped accordingly. A digital elevation model derived from high resolution imagery available in the public domain was used to calculate elevated areas suitable for temporary shelter during a flood. Selecting administrative units of analysis at the lowest possible scales – rural development blocks (regional) and revenue villages (subregional) – also ensures that hazard mapping is prepared in line with the existing rural planning and administrative authorities responsible for remedial intervention. 相似文献
109.
A harmful algae bloom (HAB) is a dense aggregation of algae in a marine or aquatic environment that can result in significant
environmental problems. To forecast the occurrence of HAB, development of a rapid and precise detection method is urgently
required. In this study, two Skeletonema costatum-like diatoms (SK-1 and SK-2), were identified morphologically under a light microscope, and detected using fluorescent in situ hybridization (FISH). Strain SK-1 was isolated from a frequently HAB affected area of the East China Sea, and strain SK-2
from an aquatic farm in Qingdao, China. Fluorescent DNA probes were designed that were complementary to the ITS sequence (including
5.8S rDNA) of strain SK-1. After hybridization, strong green fluorescence was observed in cells of strain SK-1 under an epifluorescence
microscope; however, no such fluorescence was observed with strain SK-2, which indicates that probes hybridized only the DNA
of the target strain, SK-1, in species-specific manner, and that the two strains do not belong to a same species. This finding
was confirmed by ITS sequence analysis. The FISH technique used in this study was sensitive, simple, and rapid, and is a promising
tool for detecting target HAB species in natural environments. 相似文献
110.