Response to pumping of a weathered-fractured granite aquifer

A pumping test in a granite aquifer provides information about the interaction between the upper weathered zone and lower fractured zone. A radial flow numerical model is used to interpret the test and estimate aquifer parameters. This model successfully reproduces both the fractured zone response and the shallow weathered zone response which is characterised by increasing drawdown even after abstraction ceases. When the deep fractured aquifer was exploited, a serious decline in groundwater heads and yields occurred; this behaviour can be reproduced by the model. The model is then used to investigate the effective long-term exploitation of the aquifer and the results indicate that dug-cum-bore wells can be used for the safe and efficient exploitation of the aquifer resources.     

Control of the variability of nutrients and suspended sediments in a gulf coast estuary by climatic forcing and spring discharge of the Atchafalaya River

Water column nutrients (nitrate, ammonium, soluble reactive phosphate, total Kjeldahl nitrogen, and total phosphorus) and suspended sediments (SS) were measured during one 44-h and two 28-h periods in March 1982 at two stations in Fourleague Bay, Louisiana, which is located at the mouth of the Atchafalaya River, a distributary of the Mississippi River. River water (a source of nitrate, total Kjeldahl nitrogen, total phosphorus, and suspended sediments to Fourleague Bay) flows into the upper reaches of the bay during high tide and frontal overrunning conditions with northerly and westerly winds. During one sampling period, decreasing wind speed and the rising tide resulted in Atchafalaya River water inundating the bay and nitrate concentrations in the upper bay increasing from 30–70 μM to 90–118 μM. Significant variations in nutrients associated with the movement of water masses from the river, marshes, and Gulf of Mexico occurred over several different time scales. Tidal transport occurred over 25-h periods, while frontal passages occurred at 3-d to 5-d intervals. Variability in nutrient and suspended sediment concentrations over these relatively short time scales can be as great as seasonal variability in the bay.     

小波变换在三维地震数据处理中的应用

近年来，小波变换作为一项理论在三维地震数据的处理中日益受到重视。本文利用小波变换的变焦特性及思想设计了一缩短地震波长、提高地震子滠主瓣与旁瓣幅度比的算法，并将此算法运用于胜利油田弧岛东斜坡Ｂ７０１井三维地震数据处理中。结果表明此算法对提高地层厚度分辨率是卓有成效的。     

Gender and physical geography in the United Kingdom

Summary This paper presents the results of a questionnaire survey of all higher education geography departments in the United Kingdom, in order to provide an overview of the current status of women employed in the discipline, particularly female physical geographers. The survey examined the position of female physical geographers of doctoral level and above, in terms of employment status, type of contract, career structure, research and teaching disciplines and successful grant applications. The publication records of female academic staff were also examined. The results of the survey demonstrate that women are under-represented in physical geography at all levels of the academic hierarchy and that the majority of female physical geography academic staff are below 40 years of age, and employed at the lecturer level on permanent contracts.     

Sedimentary diatom and pigment-inferred recent anthropogenic accelerated eutrophication of a Mediterranean lake (Lake Dojran,Republic of North Macedonia / Greece)

Journal of Oceanology and Limnology - Lake eutrophication is recognised as a serious global challenge, and many regional legislative programmes are being made to attempt to relieve nutrient...     

Variation in the Sizes of Chthamalid ­Barnacle Post-Settlement Cyprids on European Shores

Abstract. As part of a wider study on the settlement and recruitment of Chthamalus spp. in Europe, this study investigated whether chthamalid cyprids can be separated by length on a European scale. Variation in cyprid length with latitude and temporal variation at selected localities were also examined. The lengths of cyprids collected between 1996 – 1999 on nine rocky shores in Europe are reported. Elminius modestus cyprids were found only at Roscoff, NW France and could be distinguished due to their carapace shape and length. They showed a unimodal length distribution, measuring between 450 and 625 µm, with no variation in length between the two sampling dates (1997 and 1998). Based on carapace shape and length, the remaining cyprids in the collections were identified as one of three chthamalid species, Chthamalus montagui, Chthamalus stellatus or Euraphia depressa. Bimodal length distributions of chthamalid cyprids were seen on some shores, while others had a single small‐sized modal group (representing C. montagui on Atlantic shores and/or E. depressa in the Mediterranean) separated from a few distinctly larger cyprids (C. stellatus). Metamorphs collected simultaneously with cyprid collections were identified as C. stellatus or C. montagui, except at Roscoff, where E. modestus were also found. In southern Portugal, where all metamorphs collected were C. montagui and adult C. montagui were the dominant barnacles, most cyprids measured between 350 and 550 µm long and this size distribution coincides with the distribution expected for C. montagui. Cyprids collected on these four more southerly Portuguese shores had the same modal length class (475 µm) and this remained constant between successive years at Luz and Albufeira, Algarve. The smallest (350 µm long) wild chthamalid cyprids found were from southern Portugal and Italy. In Spain, France and Ireland the smallest chthamalid cyprid was 425 µm long. The results from the present study support the hypothesis that on Atlantic shores cyprids of C. montagui can be separated from those of C. stellatus based on size, although there is some variation in cyprid length with latitude as well as temporal variation at selected localities.     

The coastal ocean off Oregon from 1961 to 2000: is there evidence of climate change or only of Los Niños?

A zonal hydrographic section along 44.65°N, from the coast of Oregon to 300 km offshore, was occupied regularly (at least seasonally) from 1961 to 1971 and then sporadically until recently. Regular monitoring of this section to 160 km offshore resumed in July 1997 as part of the GLOBEC Long Term Observational Program; the recent data provide observations in Oregon coastal waters of El Niño 1997–98 and La Niña conditions that followed. The complete seasonal data from the decade 1961–1971 provide a basis for comparison with the recent temperature and salinity sections, steric height profiles, geostrophic velocity, and water mass characteristics. These data, and sporadic observations in intervening years, allow us to compare conditions during several ENSO events with the recent event and to search for evidence of climate change. The PFEL Coastal Upwelling Index, sea level from the University of Hawaii Sea Level Center, the Multivariate ENSO Index (MEI), the Pacific Decadal Oscillation (PDO), and outflow from the Columbia River are used to distinguish local and remote causes of variability in physical oceanographic conditions off Oregon. The sequence of El Niño/La Niña/El Niño in 1963–66, during a cool phase of PDO, provides a comparison to El Niño/La Niña of 1997–2000. El Niño in 1982–83 and 1997–98, during a warm phase of PDO, caused the largest oceanographic anomalies in the 40 years. The comparison indicates warming of the coastal ocean off Oregon and suggests a modulation of ENSO effects by PDO. Such modulation would mask evidence for secular climate change in our 40-year oceanographic data series.