云南热海热田中的碱金属元素

1982至1983年在云南腾冲一已知水热区及其毗邻约 60km² 范围内采集了131个土壤样品。样品分析结果表明锂和铷的异常能圈定两个已知水热区,且与若干已知热田地球化学指示元素的异常相当一致,从而进一步肯定了这一地区的开发前景。与此同时,对区内水样中的钠钾含量也进行了测定并做出解译。锂铷和已知地球化学指标之间的相关分析表明它们之间确存有某种内在联系,同时可看出盐湖与古地热系统之间的一些联系。最后得出结论:土壤中的锂铷可作为圈定热田的地球化学指标;地热系统不仅能作为能源资源而且也应视作矿产资源。     

河流型饮用水水源保护区划分比较

比较分析了国内外河流型水源保护区划分的原则、方法和标准,例证了我国不同省份的划分实践。指出,我国各省多采用经验值划分水源保护区范围,部分省份划分方案久未更新,没有充分发挥保护区的作用。提出,应进一步细化水源保护区划分规范指导要求,及时修订省级水源保护区划分方案,并借鉴国外水源保护区划分经验,通过调整水质标准、重视公众参与、利用地理信息系统等方式划分水源保护区,从源头上预防水源污染,降低饮用水公共风险,保障饮用水安全。     

长江流域生态环境的意义及生态功能区段的划分

中国加入WTO之后,中国经济进一步与国际市场接轨,融入世界经济体系,机遇和挑战同在。欧美各国近年大力推行的环境标志产品认证,对第三世界商品质量设置入关的环境门槛。长江产业带作为世界最大的内河产业带和制造业基地,现在世界通行的环境管理认证体系和环境标志产品的认证,对长江流域产业尤其是外贸出口产业有长远而深刻的影响。这种认证制度,一方面对我出口商品设置了新的障碍,另一方面又将环境保护压力直接施加到企业。重视流域生态环境将从政府行为、公民压力扩展到企业行动,由于流域生态环境的负荷愈来愈重,流域生态环境的自我调节和恢复功能大幅下降,引起了日益严重的流域性生态安全问题。根据长江流域生态环境特征、不同的生态功能及存在的主要生态安全问题,将长江流域划性生态安全问题。根据长江流域生态环境特征、不同的生态功能及存在的主要生态安全问题,将长江流域划分成以下五个不同的生态功能区段,即长江源地区、金少江段（直门达至宜宾）、长江上游段（宜宾至宜昌）、长江中游段（宜昌至湖口段）、长江下游段（湖口至入海口）。针对不同区段主要的生态安全问题,应因地制宜采取相应的防范和整治措施。为保护与恢复生态功能服务。     

Demonstrating Floodplain Uncertainty Using Flood Probability Maps1

Abstract: The U.S. Federal Emergency Management Agency (FEMA) flood maps depict the 100‐year recurrence interval floodplain boundary as a single line. However, because of natural variability and model uncertainty, no floodplain extents can be accurately defined by a single line. This article presents a new approach to floodplain mapping that takes advantage of accepted methodologies in hydrologic and hydraulic analysis while including the effects of uncertainty. In this approach, the extents of computed floodplain boundaries are defined as a continuous map of flood probabilities, rather than as a single line. Engineers and planners can use these flood probability maps for viewing the uncertainty of a floodplain boundary at any recurrence interval. Such a flood probability map is a useful tool for visualizing the uncertainty of a floodplain boundary and represents greater honesty in engineering technologies that are used for flood mapping. While institutional barriers may prevent adoption of such definitions for use in graduated flood insurance rates (as most other insurance industries use to account for relative risks), the methods open the door technically to such a reality.     

FORESTED WETLANDS IN EASTERN CONNECTICUT: THEIR TRANSITION ZONES AND DELINEATION1

ABSTRACT: The delineation of inland wetlands requires close field examination of the biological and physical gradients (transition zones) between wetlands and bordering uplands. As part of a study on the detection and delineation of inland wetlands in eastern Connecticut by remote sensing techniques, this effort was designed to investigate vegetation distribution and composition and selected physical and chemical properties of the soils of wetland to upland transition zones in deciduous wetland forests. Field research was conducted during the growing season of 1975 within a test area consisting of the 45 mi² Town of Mansfield, Connecticut. Changes in vegetation composition and structure, soil pH, and soil water content were determined along line transects extended over wetland to upland transition zones. Differences in soil pH occurred along the transects but were of such magnitude that they probably have little impact on plant distribution. There were significant changes in soil water content along the wetland to upland gradients. Discriminant analysis applied to statistical “index of abundance” data describing vegetation distribution among the various zones (wetland, transition, upland) showed which plant species best distinguish wetlands from uplands. Of the criteria studied, vegetation composition and distribution, soil water content, and relief are the most useful criteria for delineating deciduous wetland forests.     

河流型饮用水水源保护区划分技术方法研究--以淮河淮南段某水厂为例

划定饮用水水源地保护区是保护环境、确保供水质量的有效手段。通过对国内外饮用水水源保护区划分方法的研究进程分析,以HJ/T 338—2007《饮用水水源保护区划分技术规范》为依据,通过实例研究河流型水源保护区划分技术方法。     

Spatial Relationships of Levees and Wetland Systems within Floodplains of the Wabash Basin,USA

Given the unique biogeochemical, physical, and hydrologic services provided by floodplain wetlands, proper management of river systems should include an understanding of how floodplain modifications influence wetland ecosystems. The construction of levees can reduce river–floodplain connectivity, yet it is unclear how levees affect wetlands within floodplains, let alone the cumulative impacts within an entire watershed. This paper explores spatial relationships between levee and floodplain wetland systems in the Wabash Basin, United States. We used a hydrogeomorphic floodplain delineation technique to map floodplain extents and identify wetlands that may be hydrologically connected to river networks. We then spatially examined the relationship between levee presence, wetland area, and other river network attributes within discrete subbasins. Our results show that cumulative wetland area is relatively constant in subbasins that contain levees, regardless of maximum stream order within the subbasin. In subbasins that do not contain levees, cumulative wetland area increases with maximum stream order. However, we found that wetland distributions around levees can be complex, and further studies on the influence of levees on wetland habitat may need to consider finer resolution spatial scales.     

土地利用变化及流域尺度大小对水文类型分区的影响

以海河流域为研究对象,根据1956-2005 年的年降雨量和水面蒸发资料以及DEM、土地利用和土壤的遥感资料,采用地理信息系统和多元统计分析的方法,划分一定单元流域,对海河流域进行水文类型分区划分,并讨论了土地利用转移变化及单元流域尺度大小对水文类型分区的影响。结果表明,不同土地利用情况下水文类型分区的结果是不同的,土地利用的变化会直接或间接影响流域水文类型分区的空间分布,土地利用变化越大,水文类型分区的转移变化也越大。单元流域尺度较小时,水文类型分区分布较为离散,反之,单元流域尺度较大时,水文类型分区的分布则较为连续。当单元流域平均面积变化小于150 km²时,分区分布虽然有一定的变化,但总体来看分区结果相对比较稳定,当单元流域平均面积变化较大,并达到250km²以上时,分区结果会发生较大变化。     

USING REFERENCE SITES AND SIMPLE LINEAR REGRESSION TO ESTIMATE LONG‐TERM WATER LEVELS IN COASTAL PLAIN FORESTS1

ABSTRACT: The ability of regulators, resource managers, and consultants to assess accurately wetland hydrology is crucial when identifying and delineating wetlands. In this study, simple linear regression and long‐term (ten year) New Jersey Pinelands stream gaging and pitch pine lowland water‐level data sets were used to estimate long‐term hydroperiods at lowland test sites with short‐term (two year) records. Separate regression equations were developed for each test site using reference site data and stream gaging data, and two sets of equations for selected test sites were produced using two different short‐term periods of record. Test sites had long‐term records ranging from four to ten years, allowing validation of the regression models. Measured and predicted test site growing season water levels were similar regardless of which short‐term period of record was used. The results based on the stream gaging site data were similar, although the difference between measured and estimated growing season water levels was greater when this approach was used. Excellent agreement was found between measured and estimated frequencies of near‐surface saturation at test sites for each growing season month, and these relationships improved when cumulative, seasonal frequencies were considered. The reference wetland approach used in this study may have its greatest value in regions with both high development pressures and problem wetlands and may provide an effective way of resolving costly wetland delineation disputes.     

RUNOFF VOLUME ESTIMATION USING GIS TECHNIQUES1

ABSTRACT: Rainfall runoff of six watersheds was modeled via the Soil Conservation Service runoff curve number model in two ways: conventionally (manually) and via a geographic information system (GIS). Input data (elevation, soils, and landcover) were digital for the latter method. In contrast to previous studies, the GIS was ised for all phases of the modeling process, including watershed delineation and routing of runoff. A comparison between the two methods was consistent with results reported by others and indicates that the use of a GIS is an acceptable alternative to the conventional method for watersheds lacking relatively flat terrain. Given this limitation, the GIS method may prove advantageous over manual methods when study areas are large or numerous, runoff is modeled repetitively, alternative landcover scenarios are explored, or a digital database already exists for the study area.