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1.
A number of local, regional, state, and federal programs are in place that strive to protect and restore coastal waters and habitats, and which specifically address eutrophication and nutrient over-enrichment. There are, however, no easily implemented and reliable methods or sources of data and information for citizens, coastal managers, elected officials, and agency staff who are responsible for managing a coastal area to determine sources of nutrients and potential impacts to coastal waters. Coordination among federal and local agencies remains inadequate. In the few examples of successful coastal nutrient management programs, effective nutrient management strategies are often partnerships of national, regional, and local efforts. The recent National Research Council (2000) examination of issues and management options calls for development of a National Coastal Nutrient Management Strategy, coordinated between national, state and local programs, academia, and the private sector. The proposed National Coastal Nutrient Management Strategy includes recommendations for local programs to consider in developing an effective nutrient management strategy, such as setting goals for restoration, determining nutrient reductions needed to meet goals, and monitoring results. The proposed strategy also identifies priority actions which federal programs should consider, including identifying gaps and overlaps in existing and proposed national programs for all aspects of nutrient over-enrichment; increasing accessibility to data, information and expertise on nutrient over-enrichment causes, effects, and management options; and setting clear guidelines for nutrient loads. A nationally consistent monitoring program and targeted research, specifically for atmospheric deposition, seasonal variability of nitrogen and phosphorus enrichment effects, the role of specific nutrients in the occurrence of harmful algal blooms, and economic impacts of nutrient over-enrichment were also identified as priority needs.  相似文献   

2.
The development of a standardized system for conveniently coding lithologic-log data for use in the digital computer has long been needed. The technique suggested involves a reduction of the original written alphanumeric log to a numeric log by use of computer programs. This numeric log can then be retrieved as a written log, interrogated for pertinent information, or analyzed statistically.publication authorized by Director, U.S. Geological Survey.  相似文献   

3.
BGHMS:AGeohistoryModelingSystemforCratonicBasinsYeJiaren;LuMingd;WangFeiqiao(DepartmentofPetroleumGeology,ChinaUniversityofGe...  相似文献   

4.
Increased nutrient loadings have resulted in low dissolved oxygen (DO) concentrations in bottom waters of the Patuxent River, a tributary of Chesapeake Bay. We synthesize existing and newly collected data to examine spatial and temporal variation in bottom DO, the prevalence of hypoxia-induced mortality of fishes, the tolerance of Patuxent River biota to low DO, and the influence of bottom DO on the vertical distributions and spatial overlap of larval fish and fish eggs with their gelatinous predators and zooplankton prey. We use this information, as well as output from watershed-quality and water-quality models, to configure a spatially-explicit individual-based model to predict how changing land use within the Patuxent watershed may affect survival of early life stages of summer breeding fishes through its effect on DO. Bottom waters in much of the mesohaline Patuxent River are below 50% DO saturation during summer. The system is characterized by high spatial and temporal variation in DO concentrations, and the current severity and extent of hypoxia are sufficient to alter distributions of organisms and trophic interactions in the river. Gelatinous zooplankton are among the most tolerant species of hypoxia, while several of the ecologically and economically important finfish are among the most sensitive. This variation in DO tolerances may make the Patuxent River, and similar estuaries, particularly susceptible to hypoxia-induced alterations in food web dynamics. Model simulations consistently predict high mortality of planktonic bay anchovy eggs (Anchoa mitchilli) under current DO, and increasing survival of fish eggs with increasing DO. Changes in land use that reduce nutrient loadings may either increase or decrease predation mortality of larval fish depending on the baseline DO conditions at any point in space and time. A precautionary approach towards fisheries and ecosystem management would recommend reducing nutrients to levels at which low oxygen effects on estuarine habitat are reduced and, where possible, eliminated.  相似文献   

5.
A diverse set of computer programs has been developed at the Lawrence Livermore National Laboratory (LLNL)to process geophysical data obtained from boreholes. These programs support such services as digitizing analog records, reading and processing raw data, cataloging and storing processed data, retrieving selected data for analysis, and generating data plots on several different devices. A variety of geophysical data types are accommodated, including both wireline logs and laboratory analyses of downhole samples. Many processing tasks are handled by means of a single, flexible, general-purpose, data-manipulation program. Separate programs are available for processing data from density, gravity, velocity, and epithermal neutron logs. The computer-based storage and retrieval system, which has been in operation since 1973, currently contains over 4400 data files. Most of this data was obtained from the Nevada Test Site (NTS)in conjunction with the nuclear test program. Each data file contains a single geophysical parameter as a function of depth. Automatic storage and retrieval are facilitated by the assignment of unique file names that define the storage location of each data file. Files of interest to the user may be located and retrieved by means of a search program that examines the catalog. A convention recognized by all programs in the system is that of a zero ordinate denoting a gap in an otherwise continuous data trace. This convention provides a simple mechanism for editing and displaying data files in an automated and consistent manner.  相似文献   

6.
随着城市建设的迅速发展,勘测单位计算机应用已从孤立地处理单项工程走向管理和决策,以大型关系数据库为核心的信息管理和决策支持已经成为大型勘测单位设计地质信息系统的新命题。本文介绍了地质信息系统的特点及大型关系数据库在城市地质信息系统中的地位和作用。  相似文献   

7.
A sampling technique has been developed for increasing the information gathered during routine monitoring of impingement at water intake structures. Samples from impingement catches on traveling screens were taken from the sluiceway of the Brunswick Steam Electric Plant near Southport, North Carolina during the screen wash process so as to divide the catch into vertical catch components. Each component represented 1.2 m of the water column. Results showed differences in day and night vertical distributions of impinged organisms according to the spatial preferences of each species. Impingement during daytime was lower than during night. Impingement of surface-oriented species during daytime occurred at mid-depth, midwater species near the bottom, and bottom species were seldom impinged. During the night surface-oriented species were impinged at the surface, midwater species at mid-depth, and bottom species near the bottom. Residue (animals and debris) which remained within the screen wash system from collection of the previous sample, and those organisms which became impinged on the screens during retrieval of the sample, were used to calculate the rate of “continuous impingement” on the traveling screens. These rates were compared to the impingement catch in order to determine biases in the vertical catch components. Comparison of these rates indicated that impingement estimates determined by routine monitoring methods may under-estimate true impingement rates for certain species. We have concluded that this sampling technique for monitoring impingement at intake structures will increase knowledge of the local biologic system while minimizing the cost of obtaining the information. The technique will also aid in pinpointing specific impingement problems which may be corrected through modifications to the design of the intake structure.  相似文献   

8.
The Yucatan Peninsula is a coastal plain underlain by permeable limestone and receives abundant rainfall. Such hydrogeologic conditions should provide major supplies of water; however, factors of climate and hydrogeology have combined to form a hydrologic system with chemical boundaries that limits the amount of fresh water available. Management of water resources has long had a major influence on the cultural and economic development of the Yucatan. The Mayan culture of the northern Yucatan developed on extensive use of groundwater. The religion was water oriented and the Mayan priests prayed to Chac, the water god, for assistance in water management, primarily to decrease the severity of droughts. The Spaniards arrived in 1517 and augmented the supply by digging wells, which remained the common practice for more than 300 years. Many wells now have been abandoned because of serious problems of pollution. A historical perspective of a paper such as this provides insight into the attitudes concerning water of early people and perhaps provides insight into current attitudes concerning water. Hydrogeologists possess the expertise to generate relevant information required by water managers to arrive at management programs to achieve sustainable development.  相似文献   

9.
曹睿  宋震 《江苏地质》2011,35(3):280-285
馆藏地质资料的网络化、多元化、社会化是未来地质资料信息化发展的重要方向。在地质资料信息化服务过程中,既要保证提供服务,又要确保安全是资料管理工作中需要解决的问题。基于NAS的地质资料信息化解决方案针对地质资料的图文数字化、管理与复用、提取与存储等常用地质服务,使用Java语言及平台构建的C/S与B/S两套应用系统相辅相成,支持在线检索、预览与实地借阅、打印等功能,集成了用户统一管理、全局统一控制、日志统一查询,同时确保了地质资料的易用性与安全性,为地质资料信息网络化、社会化、集群化管理提供了新的技术支撑。  相似文献   

10.
The fish community of Swartvlei, a southern African coastal lake, was sampled using gill and lift nets. A primary aim of the research was to determine the fish biomass of the lake shelf region as well as the distribution patterns of marine species which utilize this estuarine system as a nursery and/or foraging area. The catch per unit effort of fishes was more than three times higher in the littoral zone when compared to the pelagic, slope, or profundal zones. Both habitat diversity and available food resources were maximal in the shelf region. The biomass of the littoral fish community during 1980 was estimated at 12.4 g m2 wet weight, with detritivorous species contributing 3.2 g m?2, zoobenthos consumers 2.8 gm2, piscivorous species 2.3 g m2, herbivorous/epifaunal consumers 2.7 g m?2, and zooplanktivorous species 1.4 g m2. Published information on fish atanding stock estimates from various estuaries and coastal habitats around the world is collated and compared. It is concluded that estuarine fish biomasses do not excced those of productive freshwater or marine environments and that further research is necessary to determine the size and variability of estuarine fish stocks in relation to other ecosystems.  相似文献   

11.
基于MapGIS的地质遗迹管理信息系统的设计与实现   总被引:4,自引:0,他引:4  
左仁广  方世明 《地质通报》2007,26(2):223-230
地质遗迹管理信息系统利用地理信息系统技术、数据库技术,整合地质遗迹(地质公园)数据库和基础地理、地质、生态环境、旅游资源、管理规划等空间数据库,全面掌握地质遗迹保护、地质公园建设等方面的现状和规划情况,便于管理地质遗迹(地质公园)保护和建设的信息,为制定国家、区域或省市自然保护区规划和其他专项规划提供数据支持。地质遗迹管理信息系统应遵循点源信息系统的设计原则,以主题式关系数据库系统和空间数据库系统为基础,以空间信息和属性信息管理为核心,实现数据库与GIS的有效集成;并用C/S与B/S相结合的方式,使系统在局域网和广域网都能安全运行,满足用户的需求。  相似文献   

12.
8098系列单片机近几年在工业控制、数据采集等方面得到了广泛的应用。因缺少大容量存储器限制了它的应用。介绍了8098单片机与IBM系列软盘驱动的接口,硬件连接,实现数据的读、写操作和数据传送方法,扩大了8098单片机的使用范围。  相似文献   

13.
Implementing efficient water resources management plans at trans-boundary river catchments is a difficult task that requires strong international cooperation, intensive monitoring programs, and common understanding of the impacts imposed on water resources by human pressures. Evros River, which flows through Bulgaria, Greece, and Turkey, is an ecologically important water body, protected by international legislation but nevertheless it is susceptible to numerous significant pollution sources that may lead to the deterioration of its environmental status. In this study, a water monitoring program was applied, incorporating chemical and biological parameters to assess the environmental status in the Greek part of the river and identify the associated pollution pressures. For this purpose, seasonal water sampling occurred in 13 sites along the longitudinal course of the river and a series of parameters were recorded including nutrients, heavy metals, microbiological loads, macroinvertebrate, and fish assemblages and abundance. The results indicated that the water quality of Evros River illustrate substantial spatiotemporal fluctuations, which can be well related to specific human activities and associated pressures. Therefore, a trans-boundary monitoring program should be initiated that will provide continuous information for the development and revision of the catchment’s adaptive management plan in order to restrict pollution impacts and achieve a good ecological status as required by the Water Framework Directive 2000/60EC.  相似文献   

14.
We evaluated two types of wire-mesh minnow traps for sampling mummichogs (Fundulus heteroclitus) from intertidal rivulets on the surface of a salt marsh. In field trials, mean catch (no. of fish trap−1) did not differ significantly between trap types nor across soak times ranging from 30 to 240 min. Catch rate (no. of fish trap−1 min−1) was significantly (K-W ANOVA on ranked data, H4df=24.79; p<0.001) greater at shorter soak times, and larger size classes (>45 mm TL) of fish were relatively more abundant (Kolmogorov-Smirnov test, p<0.0001) in collections from double-funnel cylindrical traps (volume=10,330 cm3) compared to rectangular traps having about twice the volume and a single funnel cylindrical traps (volume=10,330 cm3) compared to rectangular traps having about twice the volume and a single funnel opening. We estimated entry and escape rates by adding marked fish to traps at initial densities of 30, 60, and 120 trap−1 and measuring changes in the numbers of marked and unmarked fish in each trap type at soak times ranging from 15 to 120 min during the flood stage of the tidal cycle. Escape rate was almost, twice as great from the two-funnel cylindrical traps (0.77 fish min−1) than from the single-funnel rectangular type (0.42 fish min−1) but entry rates did not differ significantly (K-W ANOVA, H4df=0.06; p=0.813) between trap types. Escape rate increased and entry rate decreased as fish density within traps was increased. Escape rates were highest immediately following immersion of the traps, but approached a constant value after 30 min. Trap-specific rates of entry and escape can be affected by a variety of factors including physical characteristics of different trap types, method and timing of trap deployment, and fish behavior. Catch data from minnow traps are unlikely to be useful in measuring relative abundance of mummichogs among habitats unless very short soak times (≤60 min) are used and calibration tests are performed. Use of longer soak times virtually ignores the dynamics involved in determining catch, and is unlikely to provide accurate information on either abundance or size distribution of mummichogs from tidal marsh habitats.  相似文献   

15.
Beam trawls are a practical method for sampling vagile fauna from deep seagrass beds. The catches of fish and macroinvertebrates associated with Posidonia australis from two beam trawl designs were compared with the catch from a new design of beam trawl. Greater numbers of species and individuals of fish and macroinvertebrates were caught by the new trawl. Its catch also included almost the full range of species taken by the other two trawls. The new trawl was then trialed in the day and at night to compare differences in the catch of species between these times. Trawling at night yielded significantly more species and individuals of macroinvertebrates. In general, more fish were caught at night than during the day, but this was not the case at all sites, nor for all species. We emphasize the need for testing of sampling methods, and consideration of diel behavior patterns, when estimating abundance and species richness of macrofaunal seagrass communities.  相似文献   

16.
We analysed a 25-year time series of fishery catch and effort data, and age/size information for four large-bodied, native fish species to investigate the hypotheses that under conditions of reduced freshwater inflows and high fishing pressure: (1) the structure of fish assemblages in the lower Murray River system have changed, (2) species diversity of fishes has declined and (3) population age structures of large-bodied, late-maturing, native fish (Macquaria ambigua, Argyrosomus japonicus, Rhombosolea tapirina and Acanthopagrus butcheri) have been reduced. Annual catches and effort in the lower Murray River system were stable for 25 years, but proportional contribution to the total catch from each of freshwater, estuarine and adjacent marine habitats, and the species within them varied. Fish assemblages generally differed between subsequent 5-year periods, with the exception of 1989–1993 when floods occurred in 4 out of 5 years, and the following 5-year period (1994–1998). Species richness declined steeply over 25 years in freshwater and estuarine habitat and species diversity (Hill’s H 2) also declined after 2001 in estuarine habitat. Species with rapid growth and early maturation (opportunistic strategists), increasingly dominated catches, whilst species with slow growth and late maturation (periodic strategists) declined. Truncated population age structures suggested longevity overfishing of three periodic strategist species: golden perch (M. ambigua), black bream (A. butcheri), mulloway (A. japonicus) and a fourth species with an intermediate strategy, greenback flounder (R. tapirina). This has implications for management because loss of older/larger individuals suggests reduced capacity to withstand or recover from deteriorated environmental conditions associated with a historically extreme drought in the lower Murray River system. Management of these species should seek to preserve the remnant population age structures and then to rebuild age structures by allowing recruits to become established in the adult population. We recommend that assessment of multi-species fisheries in changeable environments, such as occur in estuaries and other end-river environments, requires a suite of indicators that address changes in fish assemblages and populations.  相似文献   

17.
火山岩岩石化学,地球化学数据库管理系统及应用程序   总被引:1,自引:0,他引:1  
在微机上用dBASEⅢ建立了火山岩岩石化学、地球化学数据库管理系统;开发了应用程序。火山岩数据库包括岩石描述、主要氧化物含量、稀土元素含量、其他微量元素含量、同位素分析、矿物分析等六个子库,可以存贮二百余项有关火山岩的数据和信息。数据库管理系统具有建立数据库结构、数据维护、数据输出、应用程序接口及退出系统等项功能。操作简便,易于掌握。应用程序主要包括岩石化学、地球化学和数理统计等计算程序,各种地球化学图件的绘图程序。火山岩数据库及其管理系统和应用程序为火山岩岩石化学、地球化学的综合研究提供了一种方便、实用和有效的手段。  相似文献   

18.
从网格概念出发,详细介绍了实现地质图协同编辑的SIG(SPATIAL INFORMATIONGR ID)空间信息网格技术,以及国家地质空间信息网格体系的结构和服务机制。国家地质空间信息网格采用万维网体系架构,以资源和信息共享、协同为主线,构成一个三层次体系架构。主要组成为:网格应用层、网格平台层、网格基础设施。并针对地质图空间数据共享与服务,设计了地质图服务流程,提供了信息查询、信息服务页面,展示了地质图的在线协同编辑。  相似文献   

19.
Spatial relations between land use and groundwater quality in the watershed adjacent to Assateague Island National Seashore, Maryland and Virginia, USA were analyzed by the use of two spatial models. One model used a logit analysis and the other was based on geostatistics. The models were developed and compared on the basis of existing concentrations of nitrate as nitrogen in samples from 529 domestic wells. The models were applied to produce spatial probability maps that show areas in the watershed where concentrations of nitrate in groundwater are likely to exceed a predetermined management threshold value. Maps of the watershed generated by logistic regression and probability kriging analysis showing where the probability of nitrate concentrations would exceed 3 mg/L (>0.50) compared favorably. Logistic regression was less dependent on the spatial distribution of sampled wells, and identified an additional high probability area within the watershed that was missed by probability kriging. The spatial probability maps could be used to determine the natural or anthropogenic factors that best explain the occurrence and distribution of elevated concentrations of nitrate (or other constituents) in shallow groundwater. This information can be used by local land-use planners, ecologists, and managers to protect water supplies and identify land-use planning solutions and monitoring programs in vulnerable areas.  相似文献   

20.
A ground characterisation exercise was conducted in order to identify sites suitable for a blast furnace at the Redcar steelworks in northeast England. The purpose of this exercise, conducted some 20 years after the investigations were carried out and a decade after the steelworks had been constructed, was to develop techniques for managing spatial data using Geographical Information Systems (GIS) and geostatistics.

Borehole details, from the factual site investigation reports, were entered into a database using a relational structure with linked files. The borehole location and lithology files were keyed in using codes for geological material, weathering grade, strength, borehole type and verification status. Laboratory and field test data were input by scanning tables in the ground investigation reports and processing the scanned images using optical character recognition software.

The XBase programming language was used to execute graphing, GIS and geostatistics programs; thereby enabling repetitive tasks to be carried out by the computer. This both saved time and reduced errors and inconsistencies that could result from repeated manual execution of the same program. Some simple spatial operations could also be carried out entirely from within dBase, an example being the use of moving-window statistics employing rectangular windows aligned parallel to the axes of the coordinate system to study local stationarity.

GIS have been found to offer an effective tool for analysing, querying and presenting spatial site investigation information. Geostatistical kriging and simulation techniques offer powerful spatial modelling tools for creating visualisations of the spatial variability of parameters measured at points during a ground investigation.

The Redcar case history demonstrates how a database management system (DBMS) can be used to manipulate site investigation data as part of a modelling and interpretation exercise. DBase source code allows others to follow the same path or build upon the foundations herein.  相似文献   


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