对岩石风化程度敏感的化学风化指数研究

风化是引起岩石力学性能劣化的重要因素,风化敏感性指数是对岩石风化程度进行定量评价和较准确地确定岩石风化深度的基础。本文在大量不同风化等级、时间及不同深度下岩样化学测试资料的基础上对风化敏感性化学风化指数进行了研究,研究表明：在前人提出的化学风化指数中,WI、WPI和LOI这三个指数对风化程度、时间和深度的变化都显示出明...     

景观评价方法研究的新进展

景观环境质量评价是新兴的一种环境评价.本文简要介绍了景观环境质量评价的新方法,地理信息系统(GIS)法、心理物理学方法、景观综合评价指数法、等距离专家组目视评测法(EDVAET)的基本思想和特点.评述了近年来国内外将这些新理论,新技术运用于景观环境评价中取得的最新成果,展望了景观环境评价方法的发展前景.     

不同季节中水回用于景观水体的藻类增长模拟

文章基于wASP的富营养化模型,模拟了在各季节中水回用于城市景观水体时,不同水质和换水周期条件下叶绿素a峰值和平衡浓度的变化情况.模拟结果表明:(1)在中水水质和换水周期一定时,水华风险在夏季最大,春秋季次之,冬季最小;(2)在夏季和春秋季节,叶绿素a平衡浓度随着换水周期的减小先升高后降低;并且当换水周期小于3天时,减...     

生物接触氧化对景观水体中氨氮的去除研究

采用自行设计的试验装置,研究了生物接触氧化技术在景观水体抽出处理回用中的应用,探讨了氨氮的去除规律。试验内容包括生物膜的挂膜及驯化;在不同水力停留时间、曝气强度下,氨氮的去除效果及三氮的变化情况;最后研究了水温对氨氮去除率的影响。试验结果表明,在最佳试验条件下,即曝气强度为0.030 m3/h,水力停留时间为3 h时,氨氮的去除率可以达到90%以上,COD的去除率达到43.5%,并且没有出现亚硝态氮累积的问题。该技术对温度的适宜性较好,即使温度在5~8℃,对氨氮也可以保持较高的去除率,满足景观水体水质要求。当温度小于5℃时,系统氨氮的去除率迅速减小。     

基于多期遥感数据对岱海湿地的景观格局分析

文章提取了3期遥感数据的湿地类型,通过对景观格局的动态变化分析,说明了人为干扰和气候因素对岱海湿地的影响,为湿地管理提供了依据。     

2000—2010中国景观生态研究进展的文献综述

自80年代初期我国学者开始开展景观生态学研究以来,景观生态学的研究在我国获得了蓬勃发展。文章针对所搜集的2000—2010年我国研究景观生态学的学者发表在国内的18种核心期刊上的中文文献471篇,分不同专题进行分类统计,并在其基础上对我国景观生态学研究进行分析和论述,为我国的景观生态学者了解和把握中国景观生态学研究热点和发展趋势提供依据。     

Effects of irrigation and landscape heterogeneity on butterfly diversity in Mediterranean farmlands

Irrigation effects on biodiversity are poorly known, particularly in Mediterranean agro-ecosystems. In this study we analyzed irrigation effects on butterfly species richness, abundance and diversity as well as on species composition in a farmed landscape under Mediterranean climate. The study area consisted of four contiguous agricultural sub-areas with a decreasing degree of intensification: irrigated, mixed (dry and irrigated), dry and environmentally protected (i.e. Special Protection Area, SPA) dry farmland. Forty one km-transects (ten per sub-area) were searched for butterflies in 2008 and 2009. Contrary to expectations, species richness (alfa, beta and gamma diversity) was highest in both years in the most intensified sub-area (i.e. irrigated) followed by SPA, dry and mixed sub-areas. Landscape characteristics accounted for most of the between-subareas differences in species richness. Species richness was negatively related to mean field size at the landscape level and positively related to the number of trees and large shrubs along transects. Therefore, the higher number of butterfly species recorded in the irrigated farmland could be due to a more complex landscape. In contrast, butterfly abundance was highest in cereal steppes (i.e. dry and SPA sub-areas), with abundance being negatively affected by mean field size. Inter-annual change in butterfly abundance was much sharper in rainfed (i.e. dry and SPA) than in irrigated (i.e. irrigated and mixed) sub-areas. Irrigated farmland may provide more favorable conditions for butterflies by buffering the (year-to-year and summer) drought periods characterising Mediterranean climate. Species composition differed among sub-areas, with differences being partly explained by field size and number of trees and shrubs along transects. Our study suggest an important role of landscape characteristics in boosting butterfly biodiversity in intensively managed irrigated croplands and emphasizes the importance of encouraging studies on farmland butterfly diversity in different (bioclimatic) regions allowing the design of region-specific agri-environmental schemes.     

Effects of spatial resolution of remotely sensed data on estimating urban impervious surfaces

Impervious surfaces are the result of urbanization that can be explicitly quantified, managed and controlled at each stage of land development. It is a very useful environmental indicator that can be used to measure the impacts of urbanization on surface runoff, water quality, air quality, biodiversity and microclimate. Therefore, accurate estimation of impervious surfaces is critical for urban environmental monitoring, land management, decision-making and urban planning. Many approaches have been developed to estimate surface imperviousness, using remotely sensed data with various spatial resolutions. However, few studies, have investigated the effects of spatial resolution on estimating surface imperviousness. We compare medium-resolution Landsat data with high-resolution SPOT images to quantify the imperviousness in Beijing, China. The results indicated that the overall 91% accuracy of estimates of imperviousness based on TM data was considerably higher than the 81% accuracy of the SPOT data. The higher resolution SPOT data did not always predict the imperviousness of the land better than the TM data. At the whole city level, the TM data better predicts the percentage cover of impervious surfaces. At the sub-city level, however, the ring belts from the central core to the urban-rural peripheral, the SPOT data may better predict the imperviousness. These results highlighted the need to combine multiple resolution data to quantify the percentage of imperviousness, as higher resolution data do not necessarily lead to more accurate estimates. The methodology and results in this study can be utilized to identify the most suitable remote sensing data to quickly and efficiently extract the pattern of the impervious land, which could provide the base for further study on many related urban environmental problems.     

公路路段安全保障度评价的改进物元可拓模型

为克服现有公路安全性评价方法难以客观量化评价因子权重这一不足,从道路安全保障度的概念出发,基于已有相关标准规范和安全理论研究成果构建了公路路段安全保障度评价指标体系,利用改进物元可拓模型建立了公路路段安全保障度评价模型.实例分析结果表明,该路段安全保障度等级为"低",且偏向于"很低"等级的程度较大,符合其实际情况.实例中将所建模型与3种常用评价模型进行比较,结果表明其用于公路路段安全保障度评价具有更好的实用性.敏感性分析显示,最大纵坡、平曲线超高和加宽设计指数、路面摩擦系数、交通饱和度、建筑物或植被等侵入率更易影响该路段的安全保障度.     

基于污染物平衡分析的污水厂尾水补水城市内湖的优化运行研究——以昆明翠湖为例

针对污水厂尾水补水的城市内湖污染调控问题,提出了基于水量和污染物收支平衡分析的污染物净积累(NPA)模型,建立了污染物输入和输出量化计算方法.最后,以昆明翠湖为案例,在调查水体污染物输入和输出途径及水体自净量计算的基础上,选择COD、TN和TP为代表性污染物,开展了模型和计算方法的应用.结果表明,尾水补水是污染物输入的最主要途径,排水和渗漏是污染物输出的两个主要途径,COD在水体中的净积累程度较低,TN和TP的净积累比例分别达到42.9%和39.0%.以此为基础,本文提出了以调整补水和用水途径为主要手段的水体优化运行方案,并对方案实施后的预期效果进行了分析验证.本研究可为城市景观水体的污染物积累分析提供新方法和典型案例.