Some observations on the effect of ozone treatment on suspended particulate matter in seawater     

Hasong Pak  James Kitchen  Percy Donaghay  J. Ronald  V. Zaneveld 《Estuarine, Coastal and Shelf Science》1981,13(3):327-336

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Knowledge based systems for risk assessment of the subsurface of contaminated sites     

S. Heynisch  A. Pekdeger  B. Richter  M. -Th. Schafmeister  W. Skala 《Mathematical Geology》1994,26(4):505-517

Computer-based risk evaluation methods are practical tools to compare automatically and evaluate contaminated sites. HYDRISK is an example of adequate knowledge-based systems: HYDRISK evaluates hydrogeological properties and chemical criteria relevant to contaminant transport with respect to the necessary remedial actions. It works at a high investigative level and enables geologists and engineers to draw differentiated conclusions for selecting remediation methods for the contaminated site. HYDRISK emphasizes space and time dependent aspects of the contaminant transport. It is supported by a geographic information system (GIS) to display the evaluation results. Some ideas on considering the spatiotemporal variability of relevant parameters by means of geostatistical methods and numerical models will be given.  相似文献   

DISTRIBUTIONS OF TOTAL, INORGANIC AND ORGANIC PHOSPHORUS IN THE SEDIMENTS NEAR THE HUANGHE RIVER ESTUARY   总被引：1，自引：0，他引：1  

林荣根  吴景阳 《中国海洋湖沼学报》1992,10(3):204-214

For some hundred surface sediment samples from five cores taken in two cruises near the Huanghe River Estuary, total phosphorus (TP (.inorganic phosphorus (IP (and organic phosphorus (OP)were determined.On the average, 527×10-6, 455×10~6 and 72×10-6 were found for TP,IP and OP for the surface sediments taken in the two cruises. The distribution of OP and IP was controlled by the sample particle size: OP content increased with the decreasing of the sample particle size, while the maximal value of IP was found in the silt fraction due to the existence of apatite in our samples. Vertical distributions reflected well the channel change of the Huanghe River. Results from the multiple regressions between the three forms of phosphorus and the percentages of different particle size agreed well with the analytical data.  相似文献   

RAPID ESTIMATION OF THE NUMBER OF COELUTING COMPONENTS IN LIQUID CHROMATOGRAPHY BY FACTOR ANALYSIS     

CHENGBOSHEN  THOMASJ.VICKERS  CHARLESK.MANN 《地理学报(英文版)》1991,(5)

Evaluation of the results of factor analysis of sets of spectroscopically detected chromatograms is carriedout by examining the shapes of the abstract factors.This is done either by visual inspection or by analysisof the power density spectra produced from them.Owing to constraints imposed by the column functionand the spectroscopic instrument function,the information content of the chromatograms necessarilyoccurs at low spatial frequencies.As a consequence,it appears as relatively broad features in the abstractchromatograms and as a peak in the low-frequency region of the corresponding power density plot.Onthe basis of examination of the power density distribution,a well-defined distinction is made betweenprimary and secondary abstract factors.The major uncertainty encountered in determining the numberof chemical components appears to arise from effects of contaminants in reagents.  相似文献   

Statistical control chart for regime identification in volcanic time series     

Chih-Hsiang Ho 《Mathematical Geology》1992,24(7):775-787

In an important paper, Mulargia et al. (1987) address the importance of quantitative and objective identification of different regimes of a volcano. They develop a procedure based on the two-sample Kolmogorov-Smirnov (K-S) statistic. The K-S test is a general-purpose test that discriminates between two data sets as belonging to two different regimes based on their empirical distribution functions. The empirical distribution function is designed to describe the aggregate behavior of the volcanic activity, and it is constructed from the orders of the length of the collected repose times in each data set. In this article, we use the idea of statistical process control to distinguish between the variation inherent in the observed repose times and the extraordinary variation that signals a real change in the regimes. We construct a table of control limits, and we demonstrate the procedure of regime identification based on a simple control chart. It shows a point outside the control limits almost as soon as the process enters a new regime. The basis of the statistical process control mechanism is a simple Poisson process, which is state of the art. The proposed control charting procedure is an eruption by eruption procedure, which follows the original chronological order of the eruptions. This procedure is applied to the eruptive history of the Mount Etna volcano. The application shows schematically that the procedure presents a visual interpretation of the identified regimes and can be practically translated for tabular or manual use.  相似文献   

湖北省棉花产量的变化与棉田布局的战略调整^*     

唐文雅 《地理研究》1988,7(3):34-43

本文揭示了湖北省棉花亩产的增长具有北高南低的特点,分析了鄂北地区种植棉花的自然优势和经济效盆大于江汉平原,从而提出湖北省棉花北移的战略调整的设想。  相似文献   

Intertidal macroalgae and macroinvertebrates: Seasonal and spatial abundance patterns along an estuarine gradient     

Morgan N. Hardwick-Witman  Arthur C. Mathieson 《Estuarine, Coastal and Shelf Science》1983,16(2):113-129

Quantitative sampling of the dominant intertidal epibiota was conducted seasonally along an estuarine gradient within the Great Bay Estuary System, New Hampshire, U.S.A. The abundance and zonation of the dominant macroorganisms varied with distance into the estuary. Replacement of marine by estuarine species occurred, and overall abundance and species richness decreased along the estuarine gradient. Zonation patterns within the inner estuary were primarily allied with substrata. Maximum abundance of invertebrates occurred in the mid-intertidal zone where a dense fucoid canopy provided habitat heterogeneity. Densities of epibiotic organisms decreased toward low water, especially in the inner estuary where hard substratum was limiting. Settlement blocks, introduced into the low intertidal zone, were dominated by barnacles and fucoid algae; after 16 months, the species composition on the settlement blocks resembled the adjacent community. Semibalanus balanoides settled in the spring, while Fucus vesiculosus var. spiralis exhibited low but constant settlement. Despite the physical rigors of the estuarine environment, only Semibalanus balanoides, Ilyanassa obsoleta and Spartina alterniflora showed significant seasonal changes in density. Thus, there are predictable and persistent epibiotic species assemblages within the intertidal zone of the Great Bay Estuary System.  相似文献   

Estuarine retention of larvae of the crab Rhithropanopeus harrisii     

Thomas W. Cronin 《Estuarine, Coastal and Shelf Science》1982,15(2):207-220

Larvae of estuarine organisms continually face possible export from the parent estuary. Retention of larvae of the estuarine crab Rhithropanopeus harrisii was investigated in the upper Newport River estuary, North Carolina. All of the developmental stages occurred in the same area of the estuary with similar horizontal distributions, and the concentrations of intermediate and late stages were not greatly reduced from those of the first larval stage. This was strong evidence for the continuous retention of larvae in the upper estuary.To determine mechanisms by which retention might be effected, field studies of the vertical distributions and migrations of these larvae were made. The four zoeal stages had similar but complex vertical migration patterns, which varied from study to study. These migrations centered on the depth of no net flow, reducing longitudinal transport during development. Cross-spectral analysis of the larval migrations and the environmental cycles of light, salinity and current speed revealed that each of these external cycles affected larval depth. Megalopae of R. harrisii also migrated vertically, but they were present in much lower concentrations than the zoeal stages, an indication of a change to benthic existence in this final larval form.  相似文献   

Hydrogeological and Gasgeochemical Earthquake Precursors – A Review for Application     

Jens?HartmannEmail author  Jason?K.?Levy 《Natural Hazards》2005,34(3):279-304

Even if earthquake precursory signals can be identified, how can they be useful? This paper investigates relationships among the attributes of 229 proposed earthquake related gasgeochemical and hydrogeological precursory signals, and applies these results to improve future earthquake prediction strategies. Sub-groups of these reported signals and relationships between sub-groups are established using parameters, including earthquake magnitude, signal duration, precursory time, and epicentral distance to the monitoring site (original studies are used wherever possible to improve data quality). A strong correlation (r=0.86) between signal duration and precursory time was identified. This suggests a relationship between the investigated precursory signals and tectonic processes related to the referenced earthquakes. Moreover, these signals are categorized into four groups, reflecting differences in monitoring station densities, measurement methods and physical processes related to signal occurrence: (a) radon exhalation from the earth’s crust, (b) exhalation of other gases (helium, argon and others), (c) temporal variation in water level or discharge of springs and (d) temporal variation in temperature and dissolved ions in the water of the monitoring sites. In addition, boundary functions are used to separate signal group subsets. Finally, it is shown how these boundary functions can be used in the context of an earthquake prediction strategy by identifying potential minimum magnitudes and maximum epicentral distances from the monitoring site.  相似文献   

我国地下水质量分布特征浅析   总被引：2，自引：0，他引：2  

郭秀红  孙继朝  李政红  汪珊 《水文地质工程地质》2005,32(3):51-54

以新一轮《全国地下水资源评价》项目为依托,以几十年地下水化学资料和水文地质资料为基础,对我国地下水质量进行了综合评价,阐述了我国地下水质量分布特征,简要分析了其成因,并提出了预防地下水水质恶化的建议。我国地下水质量总体状况较好,但局部质量低下,区域分布差异很大,是自然地理、地质、水文地质条件、人类活动等因素共同作用的结果。作者认为要想改善地下水质量就要合理开发利用地下水资源,合理布局工农业,并建立和完善地下水质量监测和预警系统。  相似文献