ISSN:1025-6016    

DOI:10.1080/10256019508036248

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

THE FIRST STEPES OF ISOTOPE HYDROLOGY

ISSN:1025-6016    

DOI:10.1080/10256019508036249

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Hydrologic investigations using isotopes and the runoff component analysis procedure DIFGA were carried out in two small catchment areas located in the Erzgebirge region. The amount of runoff in the observed watersheds and the runoff residence time based on tritium analyses are presented.

ISSN:1025-6016    

DOI:10.1080/10256019508036250

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Detailed investigations of the unsaturated zone in regard to water and tritium balance and tritium input into groundwater are necessary especially in the case of thick and inhomogeneous aeration zone (different soil layers, clay horizons etc.) and inhomogeneous land utilization. The paper shows a method to quantify water and tritium movement and storage in unsaturated zone by means of a two-dimensional conceptual box model called BOWAM(T). The model was tested on 4 sandstone aquifers in the Finne region (brink of the Thuringia basin). The results show that water balance depends strongly on surface morphology and infiltration capacity, non- or semiconducting layers within aeration zone, land usage (forest, agriculture, meadow…) and atmospheric conditions. Especially runoff, evapotranspiration and groundwater recharge at Finne region have a sensitive variation. Naturally, the tritium balance is connected with water balance. There is a difference in tritium input functions into groundwater between covered and uncovered aquifers. In the case of a covered aquifer with a deep groundwater table, tritium “bomb peak” is within the aeration zone and has not left the aeration zone into groundwater up to now. In the case of uncovered aquifers with a groundwater table near the surface it was found a time different tritium input function by means of the BOWAM(T) model, depends on groundwater distance from soil surface and land usage. A comparison to measured tritium activities in groundwater (wells and springs) shows a respectable correspondence. Further investigation and groundwater modelling is planned.

ISSN:1025-6016    

DOI:10.1080/10256019508036251

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A concept for a site evaluation with respect to groundwater protection is explained. In this concept isotope methods are used as a tool to verify and confirm the results. Two examples are described where tritium, stable isotopes, tritium-3He and radiocarbon are used to determine the infiltration rate, turnover time/mean residence time of aquifer systems. These results were compared with those obtained from classical hydrogeologic data. Assuming different scenarios for possible contaminant output from landfills, waste-management facilities, or waste disposal sites possible consequences for the groundwater quality are derived. It can be shown that the reliability and accuracy of the predictions can be increased considerably by the application of isotope methods.

ISSN:1025-6016    

DOI:10.1080/10256019508036252

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The migration of152Eu in a fine sand/water-system containing humic substances was tested under natural conditions in flowthrough-column arrangements. In this system the trivalent Eu forms colloids (Eu-Humate); these are transported without retardation at the natural filter velocity, however, at recoveries clearly below 100%.

ISSN:1025-6016    

DOI:10.1080/10256019508036253

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

LABORATORY TECHNIQUES FOR DETERMINATION OF SORPTION AND DESORPTION OF RADIONUCLIDES IN SEDIMENT/WATER SYSTEMS

ISSN:1025-6016    

DOI:10.1080/10256019508036254

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The paper considers regularities of distribution and concentration of total helium and its isotopes in the solute gas in the groundwaters of the Baikal rift zone.

ISSN:1025-6016    

DOI:10.1080/10256019508036255

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Unexpectedly elevated δ15N values (8 to 16‰) were found in adult raspberry beetles (Byturus tomentosus), collected shortly after emergence from over-wintering sites. Elevated δ15N values (11 to 14‰) were also found in over-wintered larvae, but young adults, collected shortly after metamorphosis in autumn, and larvae collected from raspberry drupelets and receptacles in summer, did not show such elevated δ15N. δ15N values of feeding larvae (∼ 2‰) were close to those of their food plant, red raspberry (Rubus idaeus). The elevated δ15N values in overwintered larvae and adults of raspberry beetle are consistent with an hypothesis of extensive amino acid nitrogen recycling during prolonged fasting. Predatory seven-spot and two-spot ladybirds (Coccinella septempunctata and Adalia bipunctata), (δ15N-∼7‰) showed an expected trophic level increase of ∼1‰ relative to their prey, the large raspberry aphid (Amphorophora idaei). The potential is assessed for using continuous flow isotope-ratio-mass-spectrometry (CF-IRMS) at natural abundance levels for studying invertebrate development and food webs.

ISSN:1025-6016    

DOI:10.1080/10256019508036256

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Representative water samples were collected from different oases in the western desert of Egypt to examine characteristics of Egyptian groundwater. Chemical data recognized two basic groundwater types; alkali bicarbonate and alkali chloride, where sodium has the highest concentration. For each region the median SD, δ180 and ionic strength of water calculated from their chemical analyses are recorded and plotted.

ISSN:1025-6016    

DOI:10.1080/10256019508036257

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor