Determinants of Spatial and Temporal Patterns in Compensatory Wetland Mitigation

Development projects that impact wetlands commonly require compensatory mitigation, usually through creation or restoration of wetlands on or off the project site. Over the last decade, federal support has increased for third-party off-site mitigation methods. At the same time, regulators have lowered the minimum impact size that triggers the requirement for compensatory mitigation. Few studies have examined the aggregate impact of individual wetland mitigation projects. No previous study has compared the choice of mitigation method by regulatory agency or development size. We analyze 1058 locally and federally permitted wetland mitigation transactions in the Chicago region between 1993 and 2004. We show that decreasing mitigation thresholds have had striking effects on the methods and spatial distribution of wetland mitigation. In particular, the observed increase in mitigation bank use is driven largely by the needs of the smallest impacts. Conversely, throughout the time period studied, large developments have rarely used mitigation banking, and have been relatively unaffected by changing regulatory focus and banking industry growth. We surmise that small developments lack the scale economies necessary for feasible permittee responsible mitigation. Finally, we compare the rates at which compensation required by both county and federal regulators is performed across major watershed boundaries. We show that local regulations prohibiting cross-county mitigation lead to higher levels of cross- watershed mitigation than federal regulations without cross-county prohibitions. Our data suggest that local control over wetland mitigation may prioritize administrative boundaries over hydrologic function in the matter of selecting compensation sites.     

基于数字地下空间与工程的人防信息系统的设计探讨

以提高人防工程管理质量、效益、信息化为根本目的,采用计算机技术、图形学技术、数据管理技术、数据分析技术、智能技术、人机交互技术、数据交换技术、网络通信技术等,基于数字地下空间与工程,旨在建立高度综合的、统一的、开放的和真三维的人防信息系统。文章着重讨论了系统总体结构、技术结构、信息数据的获取和处理、系统的功能,并通过一工程实例说明数字地下空间与工程在人防信息系统中的应用。人防信息系统对城市人防工程设备的承载力、辐射范围缓冲区、人口疏散隐蔽最佳路径、实时监测等空间分析提供支持;对提高人防工程的管理水平、工作效率、功能发挥以及地下空间的可持续发展也将起到积极的作用,产生巨大的社会和经济效益。     

天津水质自动监测通讯系统─—电源易损及信息传输

本文对引进的天津水质自动监测系统在运行期间，通讯系统出现的故障作了全面的剖析研究，并提出了解决这些问题的方法。     

环境影响评价需要新的突破

中国环境影响评价已取得巨大成绩，在项目建设、区域发展中起着重要的作用，成为环境保护的重要保证手段。但中国环境影响评价依然存在十分突出的问题，还不能充分发挥其应有的功能。为此，环境影响评价应坚持正确的价值观，要打破环评单位隶属于项目建设单位的主从关系，环境单位要有独立行使调整、考察、分析、评价和下环评结论的权利；环境影响评价的时间要适时、充分，杜绝项目先上马后补环评，或项目要上马临时补环评的做法；战略环评应在宏观发展战略发挥更大的作用，成为国家宏观调控的有力工具之一；要构建环评的公共服务信息平台，反对信息部门垄断和数据虚假；环评方法贵在创新、重在实用，要积极应用新方法、新技术，反对数学方法与模型的滥用。     

Water information: what is it good for? The use of information in transboundary water management

Consistent and relevant information on the status of water systems is indispensable for rational and cost-effective water management. This statement has general validity for all types of river basins, but is particularly relevant for transboundary water regions. Information is used to support decision-making and to evaluate the effects of water resources management decisions. Information production however lags behind developments in water management, which becomes clear from the fact that information still focuses on ecological components of water bodies and largely ignores the importance of socio-economic data stemming from human activities taking place in the river basin. Production of improved information is hindered by strong boundaries between different disciplines that are not easily overcome. Moreover, consideration of information needs and the goals of information dissemination prior to producing information is insufficient and the relevant actors are often reluctant to participate in these processes as they are time consuming. Differences in institutional behaviour also hinder cooperation between institutions, while organisational structures are insufficiently tuned to the needs of the external environment. All these issues hinder the use of information as the basis for decision-making. This paper provides an overview of relevant aspects of information from a broad range of perspectives and establishes the need for changes in the production and use of environmental information in support of water management. The paper is largely based on the outcomes of a closed multi-disciplinary specialist meeting on the role and use of environmental data and information in transboundary water contexts held in Arendal, Norway, September 2002.     

G3技术集成及其在青藏铁路信息化中的应用研究

青藏铁路是世界上海拔最高、线路最长的高原铁路。铁路沿线环境恶劣(严寒缺氧,气候恶劣、多年冻土地段长、生态环境脆弱等)。因此,不仅要求在工程建设过程中采用先进的设备和技术手段,而且,要求在线路建成后实现其运营、维修管理信息化。笔者提出采用G3(包括全球定位系统GPS、地理信息系统GIS、全球移动通讯系统GSM)技术集成来确保建成后线路的安全运营。在集成系统中:GPS主要用于实施、快速地获取空间目标的三维坐标;GIS为系统集成提供基础平台,对空间信息进行综合分析和综合处理;GSM实现信息的无线、实时的传输。采用G3技术可以实现列车行车信息的实时发布、传输与接收,实现数据共享,从而保证行车安全。     

上海城市森林综合评价研究

近年来,许多国家把发展城市森林作为实施城市可持续发展战略的一项重要内容。城市森林的综合评价在城市森林的理论研究、规划、设计和管理中具有重要的实践意义。根据城市森林评价的特点和实际，依据信息系统建设的原则和方法，以VB为开发平台，采用ESRI公司的Areobjects组件技术，设计开发了上海城市森林综合评价信息支持系统，探讨了在系统开发过程中的主要技术问题。包括系统分析与设计的原则、方法。以及系统的结构、功能设计和系统的实现等。并利用该系统对上海城市森林进行了尝试性评价。认为：上海城市森林的协调性相对较好，而城市森林生态结构有待进一步提高。     

Identifying Habitat Variables Important to the Rare Columbia Spotted Frog in Utah (U.S.A.): an Information-Theoretic Approach

Abstract:  We identified habitat associations of the rare Columbia spotted frog (  Rana luteiventris ). We used an information-theoretic approach that encouraged careful consideration of previous studies, demanded a priori formulation of hypotheses and models, and provided interpretable results while avoiding some criticisms of traditional statistical analyses. We formulated hypotheses about habitat associations based on conductivity, emergent vegetation, littoral zone depth, pond hydrology, and water temperature. We modeled hypothesized associations with logistic regression and used Akaike's information criterion to quantify evidence for models, weigh the relative importance of each habitat variable, and select predictive models. Although variable, results suggested that spotted frogs are more likely to occur in ponds that do not shrink in size seasonally, maintain relatively constant seasonal water temperature, and have high emergent vegetation cover. Associations we identified will assist actions in Utah that may be critical to local persistence of spotted frogs. Moreover, this approach for identifying associations has great potential for other rare species.     

Urbanization and Its Effect On Runoff in the Whiteoak Bayou Watershed,Texas1

Abstract: The capacity of a watershed to urbanize without changing its hydrologic response and the relationship between that response and the spatial configuration of the developed areas was studied. The study was conducted in the Whiteoak Bayou watershed (223 km²), located northwest of Houston, Texas, over an analysis period from 1949 to 2000. Annual development data were derived from parcel data collected by the Harris County Appraisal District. Using these data, measures of the spatial configuration of the watershed urban areas were calculated for each year. Based on regression models, it was determined that the annual runoff depths and annual peak flows depended on the annual precipitation depth, the developed area and the maximum 12‐h precipitation depth on the day and day before the peak flow took place. It was found that, since the early 1970s, when the watershed reached a 10% impervious area, annual runoff depths and peak flows have increased by 146% and 159%, respectively. However, urbanization is responsible for only 77% and 32% of the increase, respectively, while precipitation changes are responsible for the remaining 39% and 96%, respectively. Likewise, an analysis of the development data showed that, starting in the early 1970s, urbanization in the watershed consisted more of connecting already developed areas than of creating new ones, which increases the watershed’s conveyance capacity and explains the change in its response. Before generalizing conclusions, though, further research on other urban watersheds with different urbanization models appears to be necessary.     

太湖流域城镇形态的遥感信息提取模型研究

城市形态学在城市地理学的发展过程中占有重要地位，为战后城市地理学成为一门独立学科起了重要的推动作用。20世纪50年代后，因城市形态的研究没有取得突破性的进展，城市形态的研究似乎变成传统景观研究内容的一部分。20世纪80年代后，城市化、城市郊区化进程加快，城镇研究越来越受到重视，但城市地理学者在研究城镇之前必须对城乡进行划分，而城乡划分的基础是城市形态的信息提取，因而对城市形态的研究又得到重视，但城镇形态信息提取没有找到一个切实有效的方法。利用遥感技术，以太湖流域苏锡常地区为例，建立城镇形态信息的提取模型－仿归一化植被指数法，且通过对比监督分类法，说明仿归一化植被指数法提取城镇信息的特点，为城乡划分，城镇聚落结构，城市群等研究提供客观，简便的获取城镇信息的方法。