改进相似性测度的高光谱影像FCM聚类分析

高光谱遥感将反映目标辐射属性的光谱信息与反映目标空间几何关系的图像信息有机地结合在一起,能够实现地面目标的精细分类识别。FCM是一种有效的聚类算法,但存在相似性测度模型单一、分类精度的提高受到限制等问题。文中结合高光谱影像的技术特点,综合考虑光谱曲线的形状、地物辐射亮度及其权重,提出可以更好描述光谱向量之间的相似性的距离测度,并将其引入到FCM聚类模型中。聚类分析试验结果表明：通过改进和优化相似性测度的FCM,可以显著提高高光谱影像聚类精度。     

Sediment-Based Study of the Effects of Decreasing Mine Water Pollutionon a Heavily Modified, Nutrient Enriched Lake

Ni and Cu mining and ore processing in Hitura, Western Finland, have resulted in emissions of metal-rich wastewaters into the nearby Kalajoki River since 1970. The wastewaters are discharged into the river 3 km upstream from the eutrophic Lake Pidisjärvi, which is a widening of the river by the town of Nivala. The water level of the lake was elevated by 1.5 m and the extensive macrophyte stands were cut in 1979, profoundly changing the environmental conditions. The effects of the decreasing metal emissions and nutrient concentrations since 1979 on the now open 3.9 km² lake were studied with paleolimnological techniques. A 2-m sediment core was taken from the lake in February 2004 and analysed for sediment chemistry and diatom assemblages. At the coring site, 13 cm of sediment had been deposited since 1979, on top of a bed of undecomposed macrophyte remains. When the sediment chemistry was compared with records of decreasing metal loading since 1979, no correlation was found because post-depositional mobility and changes in sediment characteristics affect the sediment metal profiles. Thus, the reduced emissions from the mine and the lower lake water phosphorus levels have not caused a corresponding decrease in sediment metal and P concentrations. However, both of these environmental variables accounted for a statistically significant percentage of variation in the sedimentary diatom assemblages in a redundancy analysis constrained to a single variable. This relationship persisted for Ni loading even in a partial analysis, while the importance of nutrients was confirmed by the good correlation between diatom-inferred and measured P concentrations. The results suggest that reductions in metal and nutrient loading have had an effect on the algal assemblages even though the sediment concentrations of Ni, Cu or P have not decreased.     

The Earthquake Readiness Scale: The Development of a Valid and Reliable Unifactorial Measure

Preparedness is a key dependent variable in many studies examining people’s response to disasters such as earthquakes. A feature of many studies on this issue, however, is the lack of attention given to psychometric issues when constructing measures of preparedness. With regard to earthquake preparation, for example, many studies could be greatly improved by the use of a valid and reliable measure of preparedness. This research developed such a measure that assessed both low-level preparedness, such as having an emergency kit, and high-level preparedness, such as altering home structures to mitigate damage. Studies of Wellington (New Zealand) residents using two samples totalling n=652 showed that 23 items measuring these different aspects of earthquake preparation could be combined into a reliable, valid, unifactorial scale. This brief scale should have utility in multivariate studies of earthquake preparation, either as a dependent variable, where preparation is the outcome variable of primary interest, or as one of several independent variables, where preparation and other measures predict another outcome variable.     

奎屯河流域冰雹天气发生规律及防御措施

根据1989～2003年奎屯河流域中小尺度强对流冰雹天气资料,统计分析了其发生规律,给出了雹暴发生源地、移动路径和基本类型,探讨了地形和下垫面的作用,并提出了综合防御措施.     

施放氢气球时存在的安全隐患及防范措施

针对采用球服务中的安全隐患，提出有效的防范措施，对开展此项工作的同志有很好的借鉴意义。     

双台河口自然保护区濒海湿地景观变化及其管理对策研究

从国内外湿地研究进展看，濒海湿地景观变化及其管理对策研究得到人们越来越广泛的重视。以辽宁双台河自然保护区为研究区域，利用1994和1997年两期TM数据进行GIS数据处理，通过各种类型的湿地景观在该时段的面积变化得到保护区濒海湿地景观的动态变化特征，并在变化原因分析的基础上提出了一些相应的保护区管理对策，以便更好地为湿地保护和管理提供决策依据。     

Tracking recent recovery from eutrophication in a high arctic lake (Meretta Lake, Cornwallis Island, Nunavut, Canada) using fossil diatom assemblages

Meretta Lake (Resolute Bay, Cornwallis Island, Nunavut, Canada) is a high arctic lake that received raw sewage for almost 50 years from the Canadian Department of Transport Base. The lake was sampled from 1968–72 during the International Biological Programme, as part of the Char Lake Project. As the number of users at the Transport Base declined throughout the 1990s, so too did the lake's nutrient levels, and Meretta Lake is now classified as oligotrophic. A previous diatom-based paleolimnological study revealed marked species assemblage shifts coincident with sewage inputs beginning in the late 1940s; however, because the core was taken at a time when nutrient levels were still relatively high (i.e., 1993), the diatom record did not yet track any signs of recovery. In this present study, we examined fossil diatom assemblages from a sediment core taken in 2001. Our results indicate a shift to the pre-impact diatom assemblages in the most recent sediments, indicating that the paleolimnological record is tracking the decreased nutrient inputs to this high arctic lake, and confirms that no significant lags exist in these largely ice-covered lakes.     

西藏扎达生态旅游开发方式探讨

提出了扎达生态旅游开发的观点，指出了扎达的旅游价值及开展生态旅游的意义，同时对开发原则和模式提出了具体的建议。预见了扎达旅游开发会遇到的环境问题，并根据其特点提出了具体的有针对性的措施。     

广州白云堡豪苑观光塔滑坡的形成与防治研究

以往常有两种误区：(1)认为单斜岩层边坡只要坡脚处岩层不被切断，就不会破坏；(2)植树绿化和排水设施的设置总是对边坡的稳定性有利的。文章通过野外调查和力学模型分析了坡脚处岩层未被切断的白云堡豪苑观光塔处单斜岩层滑坡的形成机制，认为该滑坡属于顺层边坡溃屈型的板裂破坏——溃屈破坏，分析了滑坡的稳定性及剩余滑动力。分析表明，人工开挖后边坡的防治方法和措施不当对该滑坡的产生起了非常关键性的作用，其中盲目的植树绿化和排水沟设置成了边坡不稳定的主要诱导因素。由此可见，边坡(滑坡)防治措施的选择对其稳定性具有非常重要的意义。最后，提出切中要害的滑坡防治方案。     

活动断裂引发的环境地质问题及措施

随着经济的飞速发展和现代化建设的加快，全社会防灾减灾意识的增强，在国土规划、抗震规划及高、深、大型工程项目的建设中，对活动断裂的研究，已成为勘测、设计中的重要课题。本文就影响张家口市城市安全的活动断裂的类型、空间展布、活动特征、引发的环境地质灾害及工程对策等予以阐述，为城市规划提供依据。