MODELING THE EFFECTS OF VARIABLE ANNUAL FLOW ON RIVER CHANNEL MEANDER MIGRATION PATTERNS,SACRAMENTO RIVER,CALIFORNIA, USA1

ABSTRACT: Flow regulation impacts the ecology of major rivers in various ways, including altering river channel migration patterns. Many current meander migration models employ a constant annual flow or dominant discharge value. To assess how flow regulation alters river function, variable annual flows ‐ based on an empirical relationship between bank erosion rates and cumulative effective stream power ‐ were added into an existing migration model. This enhanced model was used to evaluate the potential geomorphic and ecological consequences of four regulated flow scenarios (i.e., different hydrographs) currently being proposed on the Sacramento River in California. The observed rate of land reworked correlated significantly with observed cumulative effective stream power during seven time increments from 1956 to 1975 (r²= 0.74, p = 0.02). The river was observed to rework 3.0 ha/yr of land (a mean channel migration rate of 7.7 m/yr) with rates ranging from 0.8 ha/yr to 5.1 ha/yr (2.0 to 13.3 m/yr), during the analyzed time periods. Modeled rates of land reworked correlated significantly with observed rates of land reworked for the variable flow model (r²= 0.78, p = 0.009). The meander migration scenario modeling predicted a difference of 1 to 8 percent between the four flow management scenarios and the base scenario.     

绿洲城市化的生态环境影响与对策

随着西部大开发的不断深入，新疆的城市化进程不断加快，城市化水平不断提高，新疆城市所处的绿洲区域的资源、环境、生态也将面临前所未有的巨大压力，城市化正在或即将对绿洲生态环境造成现实的破坏和潜在的威胁。因此，正确认识城市化给绿洲生态环境所带来的影响并提出消除不利影响的对策，合理规划和发展绿洲城市是关系到新疆绿洲可持续发展的重要问题。     

论生态工业园区的法制建设

生态工业园区是循环经济理论应用的重要层面，但部分工业区仍处在无序的“量”的扩张上，呈现重、轻工业交叉污染的现象。生态工业园区的发展和建设需健全的政策法制保障，依赖正确的法律法规贯彻执行，以促进和保障生态工业园区的发展。     

东方艺韵——中国传统室内设计风格

中国传统的室内设计具有中国传统文化的一切特征，不管是空间的布局，还是装饰风格，都体现其内在的含蓄风格，在整体意境及设计理念上追求天人合一的自然和谐，同时也是传统建筑有机的组成部分。中国传统的设计元素越来越多地被当今世界设计师所借鉴。     

燕岩溶洞旅游资源及其旅游深度开发研究

广东怀集的燕岩溶洞因金丝燕的定期群居而成为独特的溶洞旅游景观。基于对它的深入考察，阐述了地貌环境与结构、小气候生境、溶蚀过程等与金丝燕群居于此溶洞的关系。结果表明，新生代造山运动形成的高险地貌，继之溶蚀形成的节理裂隙发育的巨洞为金丝燕提供了着附的安全环境；宽阔的地下河及其造就的高湿度提供了金丝燕习惯栖息的海洋性小气候；硬质水温条件以及盆地孤峰模拟的海岛生境则成为金丝燕久居的重要原因。燕岩旅游资源划分为观赏性旅游资源、参与性旅游资源、娱乐性旅游资源等不同类型，形成洞内与洞外不同组合。燕岩旅游的深入开发有赖于对生态文化的发掘。为此，要通过客流分流、建筑控制、活动限定等措施保护金丝燕的生存环境；提炼金燕文化的精髓，积极利用“燕子节”等节庆活动以及其它文化场馆展示其深厚的文化底蕴，优化旅游资源结构，塑造燕岩生态文化旅游的独特品牌形象。     

长江三峡重庆库区城镇化与生态协调性评析

长江三峡成库后，库区生态环境更加脆弱，产业空心化日益突显。随着库区移民投资的逐渐减少，库区城镇化动力已显不足。分析了库区城镇化发展与生态建设间存在的主要问题，以ARCGIS9软件为工作平台，应用多级加权求和综合评价模型进行了城镇化和生态环境的协同度评价，并以评价值为基础将研究区划分为低级——较协调、初级——较失调、中级——失调、准发展——微协调、发展——较协调5个阶段，针对各阶段提出了城镇化和生态的发展调控方向。     

三峡水利工程与长江流域生态环境建设和农业持续发展

本文简述了三峡水利工程对长江流域,特别是库区及中、下游地区资源、生态与环境的影响,并提出了持续农业与生态环境建设的措施与对策,以便更好地发挥三峡工程的综合效益。     

Remotely Sensed Data for Ecosystem Analyses: Combining Hierarchy Theory and Scene Models

Remotely sensed data have been used extensively for environmental monitoring and modeling at a number of spatial scales; however, a limited range of satellite imaging systems often constrained the scales of these analyses. A wider variety of data sets is now available, allowing image data to be selected to match the scale of environmental structure(s) or process(es) being examined. A framework is presented for use by environmental scientists and managers, enabling their spatial data collection needs to be linked to a suitable form of remotely sensed data. A six-step approach is used, combining image spatial analysis and scaling tools, within the context of hierarchy theory. The main steps involved are: (1) identification of information requirements for the monitoring or management problem; (2) development of ideal image dimensions (scene model), (3) exploratory analysis of existing remotely sensed data using scaling techniques, (4) selection and evaluation of suitable remotely sensed data based on the scene model, (5) selection of suitable spatial analytic techniques to meet information requirements, and (6) cost–benefit analysis. Results from a case study show that the framework provided an objective mechanism to identify relevant aspects of the monitoring problem and environmental characteristics for selecting remotely sensed data and analysis techniques.     

Impacts of Camping on Vegetation: Response and Recovery Following Acute and Chronic Disturbance

Experiments with controlled levels of recreational camping were conducted on previously undisturbed sites in two different plant communities in the subalpine zone of the Wind River Mountains, Wyoming, USA. The plant communities were coniferous forest with understory dominated by the low shrub Vaccinium scoparium and a riparian meadow of intermixed grasses and forbs, of which Deschampsia cespitosa was most abundant. Sites were camped on at intensities of either one or four nights per year, for either one (acute disturbance) or three consecutive years (chronic disturbance). Recovery was followed for three years on sites camped on for one year and for one year on sites camped on for three years. Reductions in vegetation cover and vegetation height were much more pronounced on sites in the forest than on sites in the meadow. In both plant communities, increases in vegetation impact were not proportional to increases in either years of camping or nights per year of camping. Close to the center of campsites, near-maximum levels of impact occurred after the first year of camping on forested sites and after the second year on meadow sites. Meadow sites recovered completely within a year, at the camping intensities employed in the experiments. Forest sites, even those camped on for just one night, did not recover completely within three years. Differences between acute and chronic disturbance were not pronounced.