神府矿区生态系统健康水平评价

煤矿区生态系统健康对矿区可持续发展有着重要影响。在对神府矿区调查分析的基础上,利用模糊综合评价模型研究了2000-2006年神府矿区生态系统健康水平的变化轨迹。结果表明:神府矿区的生态系统健康整体状况基本呈现逐年改善趋势,健康状况从疾病上升到一般疾病。对5个要素变化过程分析得出,矿区生态系统对人类健康的影响、活力和恢复力3个因素均具有较大的提升空间,并呈现出较快的发展速度。      

哀牢山区梯田景观多功能的综合评价

景观多功能的概念、研究内容和评价是景观生态学的研究热点之一。以哀牢山区梯田景观为例,从景观的生产价值、生态价值、文化价值与美学价值等4个方面提出其多功能价值综合评价的体系和标准,并分析和评价了梯田景观的多功能价值。结果表明：（1）梯田景观美学价值的6个指标均处于比较高的水平,美学价值高;（2）梯田景观生产价值的7个指标说明其生产功能低下;（3）梯田景观生态功能的7个指标说明其生态功能良好;（4）梯田景观文化价值的6个指标说明其文化社会功能很高;（5）梯田景观四种价值的顺序是文化价值〉美学价值〉生态价值〉生产价值,而从景观价值的总体水平看,其价值仅为良好状态,可见高层的综合评价结果是其下一级水平的平均状态。     

Operational performance of current synthetic aperture radar sensors in mapping soil surface characteristics in agricultural environments: application to hydrological and erosion modelling

Synthetic aperture radar (SAR) sensors are often used to characterize the surface of bare soils in agricultural environments. They enable the soil moisture and roughness to be estimated with constraints linked to the configurations of the sensors (polarization, incidence angle and radar wavelength). These key soil characteristics are necessary for different applications, such as hydrology and risk prediction. This article reviews the potential of currently operational SAR sensors and those planned for the near future to characterize soil surface as a function of users' needs. It details what it is possible to achieve in terms of mapping soil moisture and roughness by specifying optimal radar configurations and the precision associated with the estimation of soil surface characteristics. The summary carried out for the present article shows that mapping soil moisture is optimal with SAR sensors at low incidence angles (<35 ). This configuration, which enables an estimated moisture accuracy greater than 6% is possible several times a month taking into account all the current and future sensors. Concerning soil roughness, it is best mapped using three classes (smooth, moderately rough, and rough). Such mapping requires high‐incidence data, which is possible with certain current sensors (RADARSAT‐1 and ASAR both in band C). When L‐band sensors (ALOS) become available, this mapping accuracy should improve because the sensitivity of the radar signal to Soil Surface Characteristics (SSC) increases with wavelength. Finally, the polarimetric mode of certain imminent sensors (ALOS, RADARSAT‐2, TerraSAR‐X, etc.), and the possibility of acquiring data at very high spatial resolution (metre scale), offer great potential in terms of improving the quality of SSC mapping. Copyright © 2007 John Wiley & Sons, Ltd.     

分析及其在生态环境领域研究中的应用

Meta分析（Meta-Analysis）是当今比较流行的综合具有同一主题的多个独立研究的统计学方法,是较高一级逻辑形式上的定量文献综述。20世纪90年代后,Meta分析被引入生态学领域的研究,并得到高度的重视和长足的发展。文章介绍了Meta分析的基本概念;回顾了Mata分析的发展历程,及其在生态环境领域研究中的应用;归纳了如何进行Meta分析;最后讨论了Meta分析的局限性。以期能合理应用Meta分析,为生态环境领域综合研究提供合理有效的分析方法。     

卫星雷达干涉测量原理与应用

本文综述卫星雷达干涉测量和差分干涉测量的基本原理及其应用。文章从比较雷达干涉测量与一般航测遥感的基本差别出发 ,介绍各种干涉模式下的雷达干涉测量原理、差分干涉测量原理和数据处理流程。在简要叙述雷达干涉测量应用领域后 ,重点列出 INSAR在地形测量、火山地形测量和 D- INSAR在地形沉降监测中的应用。最后 ,本文还探讨了存在的问题和应用前景。     

Ocean wave imaging mechanism by imaging radar

Analytical representations of the high frequency spectra of ocean wave and its variation due to the variation of ocean surface current are derived from the wave-number spectrum balance equation. The ocean surface imaging formulation of real aperture radar (RAR) is given using electromagnetic wave backscattering theory of ocean surface and the modulations of ocean surface winds, currents and their variations to RAR are described. A general representation of the phase modulation induced by the ocean surface motion is derived according to standard synthetic aperture radar (SAR) imaging theory. The detectability of ocean current and sea bottom topography by imaging radar is discussed. The results constitute the theoretical basis for detecting ocean wave fields, ocean surface winds, ocean surface current fields, sea bottom topography, internal wave and so on.     

InSAR可检测的最大最小变形梯度的函数模型研究

InSAR干涉图中的相位噪声是相干性和视数的函数.InSAR能检测的地表最大最小形变梯度,除了受到InSAR硬件的限制外,还直接受到InSAR干涉图中噪声强弱的影响.此外,由于多视处理会改变像元的大小,也会引起可检测的最大最小形变梯度显著变化.本文研究了InSAR可检测的地表最大最小形变梯度与相干性和视数的关系,并建立了视数为1、5和20时（ERS和ENVISAT常采用的多视数）InSAR可检测的最大最小形变梯度的经验函数模型.最后,本文用伊朗Bam地区的Enivsat ASAR数据进行了试验,结果表明该模型能够准确地判别不同视数和相干性情况下地表变形能否被InSAR技术所检测.与Baran只考虑了相干性的模型相比,本文的模型适用范围更广.     

模糊数学在水资源价值研究中的应用

利用模糊综合评价法对江西省临川市水资源价值进行了初步评价 ,并估算了水资源价格 ,其结果较为客观实际 ,具有推广价值     

Leaf margins and temperature in the North American flora: Recalibrating the paleoclimatic thermometer

For almost a century, leaf margin analysis has been an important method of estimating Cenozoic paleotemperatures. However, the relation between the proportion of toothed versus entire leaves and temperature has so far been calibrated and characterized using relatively small numbers of opportunistically and irregularly collected floras.Here we present the results of the first systematic spatially-distributed analysis of the relation between leaf margins and temperature for North America.We used species range maps of native North American dicot trees to derive synthetic local floras for each 50 km grid cell in the USA and Canada, and compared the percentage of entire-margined species with the mean annual temperature in each cell. Leaf margin type for each species was assigned using illustrations from appropriate regional North America floras.This analysis confirms that high-rainfall areas of the eastern USA and Canada show a strong inverse relationship between toothed margin percentage and mean annual temperature in the range 0–25 °C. The values we estimate are roughly similar to those obtained from floras in east Asia and previous analyses in North America, but the detailed curve is more complex, showing a distinct change in slope above a mean annual temperature of 20 °C. Wetter climate areas of the coastal western USA do not show any significant correlation between leaf margin percentage and temperature. This may relate to the confounding effect of the diverse topography of the West Coast, or it may be caused by the depleted dicotyledonous tree flora of this area.Like previous studies, this paper demonstrates that there indeed is a strong relationship between leaf margin percentage and temperature on a regional scale in eastern North America. However the relationship does not have the same linear behavior as results obtained from previous analyses. We discuss the implications of the results obtained here for paleoclimatic reconstruction in the content of other leaf margin analyses based on North American sites.     

A novel synthetic aperture radar scattering model for sea surface with breaking waves

In this study a novel synthetic aperture radar(SAR) scattering model for sea surface with breaking waves is proposed. Compared with existing models, the proposed model considers an empirical relationship between wind speed and wave breaking scattering to present the contribution of wave breaking. Moreover, the scattering weight factor p, and wave breaking rate q, are performed to present the contribution of the quasi-specular scattering term, Bragg scattering term, and wave breaking scattering t...