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251.
Lack of accurate data has led some hydrologists and city planners to assume that urban infiltration is zero and runoff is 100% of the rainfall. These assumptions lead to an over estimation of road runoff volume and an underestimation of direct recharge to groundwater, which is already rising under some UK cities. This study investigates infiltration and runoff processes and quantifies the percentage of rainfall that contributes to storm drainage, and that which infiltrates through different types of road surface. Access tubes were installed for measuring soil water content using a neutron probe in three car parks, a road and a grass site at the Centre for Ecology and Hydrology, Crowmarsh Gifford, Wallingford. Storm drainage was recorded at the exit of the Thamesmead Estate in Crowmarsh Gifford, just before the drain joins the River Thames at Wallingford. Rainfall and water table depth were also recorded. Weekly measurements of soil moisture content indicated that the top 40 cm layer is not influenced by water‐table fluctuations and, therefore, positive changes in soil moisture could be attributed to infiltration of rainfall through the surface. Depending on the nature of the surface, subsurface layers, level of traffic, etc., between 6 and 9% of rainfall was found to infiltrate through the road surfaces studied. The storm drainage generated by road runoff revealed a flow pattern similar to that of the receiving watercourse (River Thames) and increased with the increase of infiltration and soil water content below the road surface. The ratio of runoff to rainfall was 0·7, 0·9 and 0·5 for annual, winter (October–March) and summer (April–September) respectively. As the results of the infiltration indicated that 6 to 9% of annual rainfall infiltrates through the road surface, this means that evaporation represents, 21–24% of annual rainfall, with more evaporation taking place during summer than winter. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
252.
The DEEP2 Galaxy Redshift Survey: the relationship between galaxy properties and environment at z∼ 1
Michael C. Cooper Jeffrey A. Newman † Darren J. Croton Benjamin J. Weiner Christopher N. A. Willmer Brian F. Gerke Darren S. Madgwick † S. M. Faber Marc Davis Alison L. Coil † Douglas P. Finkbeiner Puragra Guhathakurta David C. Koo 《Monthly notices of the Royal Astronomical Society》2006,370(1):198-212
253.
Christian Koeberl Wolf Uwe Reimold Gordon Cooper Duncan Cowan Pierre M. Vincent 《Meteoritics & planetary science》2005,40(9-10):1455-1471
Abstract— Shuttle Radar Topography Mission data was used to investigate the Aorounga and Gweni Fada impact structures in Chad as part of a new remote sensing study. We believe the results of various data treatments provide extensive new perspective on the macro‐structural and topographic divisions for these two impact structures. Our remote sensing studies indicate revised diameters of Aorounga and Gweni Fada of 16 and 22 km, respectively. We selected samples from these two structures for their petrographic, geochemical, and Rb‐Sr and Sm‐Nd isotopic characteristics. In samples from both structures, evidence for shock metamorphism was found in the form of single or multiple sets of planar deformation features in quartz, which confirms the impact origin for both the Aorounga and Gweni Fada structures. The crystallographic orientations of PDFs indicate maximum shock levels of 20–30 GPa for samples from the central parts of both structures. The PDF orientations are characteristic for the orientations observed elsewhere in shocked sandstones, with the higher angles in the orientation histograms being fairly abundant. Geochemically, the rocks are typical upper‐crustal sandstones. 相似文献
254.
Oxygen is seen in the reflectance spectra of the icy surfaces of Ganymede and Europa via absorption bands at 627 and 573 nm. Here we show that the trapped O2 associated with these spectral features can be produced via radiation-induced decomposition of hydrogen peroxide dimers contained in hydrogen peroxide inclusions in these icy satellite surfaces. 相似文献
255.
256.
Wolf U. Reimold Gordon R. J. Cooper Rafael Romano Duncan R. Cowan Christian Koeberl 《Meteoritics & planetary science》2006,41(2):237-246
Abstract— The Serra da Cangalha crater structure in northeast Brazil, ?13 km in diameter, has long been widely considered to be a confirmed impact structure, based on reports of shatter cone findings. Only very limited field work has been carried out at this crater structure. Landsat Thematic Mapper (TM) and Shuttle Radar Topography Mission (SRTM) data sets for the region around this crater structure are compared here with regard to their suitability to determine first‐order structural detail of impact crater structures. The SRTM data provide very detailed information regarding drainage patterns and topography. A pronounced central ring of up to 300 m elevation above the surrounding area, two comparatively subdued intermediate rings of 6 and 10.5 km diameter, respectively, and the broad, complex crater rim of up to >100 m elevation can be distinguished in the Serra da Cangalha data. The maximum cratering‐related regional deformation (radial and concentric features) seems to be limited to a radial distance of 16–18 km from the center of the structure. A first comparison of macrostructural information from several impact structures with that from Serra da Cangalha does not yield firm trends, but the database is still very small at this stage. The varied nature of the target geology strongly influences the development of structural features in any impact event. 相似文献
257.
Climate change poses a significant challenge for the future of Northern Ireland’s coast due to impacts that include, inter alia, mean sea level rise of between 13 cm and 74 cm by 2050. Whilst flooding is regarded as a major hazard in the United Kingdom (UK), to date Northern Ireland’s experiences of coastal flooding have been infrequent and less severe compared to those in England and Wales. Similarly, coastal erosion has historically been, and remains, only a minor concern in Northern Ireland. Partly as a result of this, Government administrative arrangements for Flood and Coastal Erosion Risk Management (FCERM) in Northern Ireland operate in the absence of any statutory provision for coastal erosion, as well as without formal or strategic shoreline management planning and any integrated flood and coastal erosion risk management policy. This paper provides a commentary on Northern Ireland’s approach to FCERM, comparing this with its UK counterparts, highlighting both congruence and divergence in policy evolution and development. It is noted that the recent EU Floods Directive has been a significant catalyst and that the current institutional landscape for FCERM is in flux. 相似文献
258.
Piotr Kowalczuk William J. Cooper Michael J. Durako Amanda E. Kahn Michael Gonsior Heather Young 《Marine Chemistry》2010,118(1-2):22-36
In this study, the CDOM absorption coefficient at 350 nm [aCDOM(350)] and CDOM excitation emission matrix (EEM) fluorescence were used to estimate annual fluxes of dissolved organic carbon (DOC) from the Cape Fear River to Long Bay in the South Atlantic Bight. Water samples were collected during a 3.5 year period, from October 2001 through March 2005, in the vicinity of the Cape Fear River (CFR) outlet and adjacent Onslow Bay (OB). Parallel factor analysis (PARAFAC) of CDOM EEM spectra identified six components: three terrestrial humic-like, one marine humic-like and two protein-like. Empirical relationships were derived from the PARAFAC model between DOC concentration and aCDOM(350), total fluorescence intensity and the intensities of respective EEM components. DOC concentration and CDOM optical parameters were very well correlated and R2 values ranged from 0.77 to 0.90. Regression analyses revealed that the non-absorbing DOC fraction, in DOC concentration estimated from CDOM optical parameters, varied with the qualitative composition of the CDOM. DOC concentration and intensity of the humic-like CDOM components characterized by excitation maxima at longer wavelengths have significantly higher estimated non-absorbing DOC compared to the analogous relationships between DOC and intensity of the humic-like CDOM components characterized by excitation maxima at shorter wavelengths. The relationships between DOC concentration and intensity of one of the protein-like components resulted in significantly reduced non-absorbing DOC fraction in DOC concentration estimation. Results of regression analyses between fluorescence intensities of specific EEM components and CDOM-specific absorption coefficients suggest that the relative proportion of humic-like CDOM components (characterized by excitation maximum at longer wavelengths) and the main protein-like component have the most impact on the values of a?CDOM(350). Based on the relationships between aCDOM(350), Cape Fear River flow, and DOC concentrations, DOC fluxes were estimated for 2002, 2003 and 2004. DOC fluxes varied from 1.5 to 6.2 × 1010 g C yr? 1, depending on river flow. 相似文献
259.
The participative, 'bottom-up' approaches of contemporary European ICZM (integrated coastal zone management) are ineffectual and unsustainable. The approach lacks the authority and resources to deliver ICZM and should be abandoned. A new model of ICZM in a predominantly sectoral administrative framework is presented. It requires that capacity be built in existing statutory authorities and in-house ICZM groups be established. Time-limited participatory projects would be used to gain information on conflicts and issues that transcend existing sectoral boundaries, but this information would be passed to the established statutory authorities for action. A sound statutory and legislative basis is the essential prerequisite for effective coastal management – not voluntary partnerships. 相似文献