Using satellite altimetry data to augment flow estimation techniques on the Mekong River   总被引：2，自引：0，他引：2  

S. J. Birkinshaw  G. M. O'Donnell  P. Moore  C. G. Kilsby  H. J. Fowler  P. A. M. Berry 《水文研究》2010,24(26):3811-3825

Satellite altimetry is routinely used to provide levels for oceans or large inland water bodies from space. By utilizing retracking schemes specially designed for inland waters, meaningful river stages can also be recovered when standard techniques fail. Utilizing retracked waveforms from ERS‐2 and ENVISAT along the Mekong, comparisons against observed stage measurements show that the altimetric measurements have a root mean square error (RMSE) of 0·44–0·65 m for ENVISAT and 0·46–0·76 m for ERS‐2. For many applications, however, stage is insufficient because discharge is the primary requirement. Investigations were therefore undertaken to estimate discharges at a downstream site (Nakhon Phanom (NP)) assuming that in situ data are available at a site 400 km upstream (Vientiane). Two hypothetical, but realistic scenarios were considered. Firstly, that NP was the site of a de‐commissioned gauge and secondly, that the site has never been gauged. Using both scenarios, predictions were made for the daily discharge using methods with and without altimetric stage data. In the first scenario using a linear regression approach the altimetry data improved the Nash‐Sutcliffe r² value from 0·884 to 0·935. The second scenario used known river cross‐sections while lateral inflows were inferred from a hydrological model: this scenario gave an increase in the r² value from 0·823 to 0·893. The use of altimetric stage data is shown to improve estimated discharges and further applications are discussed. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Toxicity testing,risk assessment,and options for dredged material management   总被引：3，自引：0，他引：3  

Munns WR  Berry WJ  Dewitt TH 《Marine pollution bulletin》2002,44(4):294-302

Programs for evaluating proposed discharges of dredged material into waters of the United States specify a tiered testing and evaluation protocol that includes performance of acute and chronic bioassays to assess toxicity of the dredged sediments. Although these evaluations reflect the toxicological risks associated with disposal activities to some degree, analysis activities are limited to the sediments of each dredging project separately. Cumulative risks to water column and benthic organisms at and near the designated disposal site are therefore difficult to assess. An alternate approach is to focus attention on the disposal site, with the goal of understanding more directly the risks of multiple disposal events to receiving ecosystems. Here we review current US toxicity testing and evaluation protocols, and describe an application of ecological risk assessment that allows consideration of the temporal and spatial components of risk to receiving aquatic ecosystems. When expanded to include other disposal options, this approach can provide the basis for holistic management of dredged material disposal.  相似文献   

The Geochemistry of Supraglacial Streams of Canada Glacier,Taylor Valley (Antarctica), and their Evolution into Proglacial Waters     

Sarah?K.?FortnerEmail author  Martyn?Tranter  Andrew?Fountain  W.?Berry?Lyons  Kathleen?A.?Welch 《Aquatic Geochemistry》2005,11(4):391-412

We have investigated the geochemistry of supraglacial streams on the Canada Glacier, Taylor Valley, Antarctica during the 2001–2002 austral summer. Canada Glacier supraglacial streams represent the link between primary precipitation (i.e. glacier snow) and proglacial Lake Hoare. Canada Glacier supraglacial stream geochemistry is intermediate between glacier snow and proglacial stream geochemistry with average concentrations of 49.1 μeq L⁻¹ Ca2+, 19.9 μeq L⁻¹ SO₄²⁻, and 34.3 μeq L⁻¹ HCO₃⁻. Predominant west to east winds lead to a redistribution of readily soluble salts onto the glacier surface, which is reflected in the geochemistry of the supraglacial streams. Western Canada Glacier supraglacial streams have average SO₄²⁻:HCO₃⁻ equivalent ratios of 1.0, while eastern supraglacial streams average 0.5, suggesting more sulfate salts reach and dissolve in the western supraglacial streams. A graph of HCO₃⁻ versus Ca2+ for western and eastern supraglacial streams had slopes of 0.87 and 0.72, respectively with R2 values of 0.84 and 0.83. Low concentrations of reactive silicate (> 10 μmol L⁻¹) in the supraglacial streams suggested that little to no silicate weathering occurred on the glacier surface with the exception of cryoconite holes (1000 μmol L⁻¹). Therefore, the major geochemical weathering process occurring in the supraglacial streams is believed to be calcite dissolution. Proglacial stream, Anderson Creek, contains higher concentrations of major ions than supraglacial streams containing 5 times the Ca²⁺ and 10 times the SO₄²⁻. Canada Glacier proglacial streams also contain higher concentrations (16.6–30.6 μeq L⁻¹) of reactive silicate than supraglacial streams. This suggests that the controls on glacier meltwater geochemistry switch from calcite and gypsum dissolution to both salt dissolution and silicate mineral weathering as the glacier meltwater evolves. Our chemical mass balance calculations indicate that of the total discharge into Lake Hoare, the final recipient of Canada Glacier meltwater, 81.9% is from direct glacier runoff and 19.1% is from proglacial Andersen Creek. Although during a typical, low melt ablation season Andersen Creek contributes over 40% of the water added to Lake Hoare, its overall chemical importance is diluted by the direct inputs from Canada Glacier during high flow years. Decadal warming events, such as the 2001–2002 austral summer produce supraglacial streams that are a major source of water to Lake Hoare.  相似文献   

Book reviews     

F. Berry  M. George  G. M. Steed  R. Gayer 《Mineralium Deposita》1995,30(6):476-478

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Simultaneous flow of water and solutes through geological membranes—I. Experimental investigation     

Yousif K. Kharaka  Frederick A.P. Berry 《Geochimica et cosmochimica acta》1973,37(12):2577-2603

The relative retardation by geological membranes of cations and anions generally present in subsurface waters was investigated using a high pressure and high temperature ‘filtration cell’. The solutions were forced through different clays and a disaggregated shale subjected to compaction pressures up to 9500 psi and to temperatures from 20 to 70°C.The overall efficiences measured increased with increase of exchange capacity of the material used and with decrease in concentration of the input solution. The efficiency of a given membrane increased with increasing compaction pressure but decreased slightly at higher temperatures for solutions of the same ionic concentration.The results further show that geological membranes are specific for different dissolved species. The retardation sequences varied depending on the material used and on experimental conditions. The sequences for monovalent and divalent cations at laboratory temperatures were generally as follows: Li < Na < NH₃ < K < Rb < Cs Mg < Ca < Sr < Ba.The sequences for anions at room temperature were variable, but at 70°C, the sequence was: HCO₃ < I < B < SO₄ < Cl < Br.Monovalent cations contrary to some field data were generally retarded with respect to divalent cations. The differences in the filtration ratios among the divalent cations were smaller than those between the monovalent cations. The passage rate of B, HCO₃, I and NH₃ was greatly increased at 70°C.  相似文献   

Dissolved organic carbon in pore waters from a hypersaline environment     

W. M. Berry Lyons  Henri E. Gaudette  Heidi C. Gustafson 《Organic Geochemistry》1981,3(4):133-135

Pore waters were collected from a sea-marginal, hypersaline pond in the Sinai and analyzed for dissolved organic carbon (DOC). The pore water DOC values ranged from 121 to 818 mg 1⁻¹ with maxima between 15 and 54 cm deep. These values are some of the highest observed from recent sediments and probably reflect production via abiotic as well as biotic sources.  相似文献   

Deformation and metamorphism of the Aileu Formation,north coast,East Timor and its tectonic significance     

R.F. Berry  A.E. Grady 《Journal of Structural Geology》1981,3(2):143-167

The large block of metamorphic rocks along the north coast of East Timor is of special interest as it occurs at the boundary between continental and oceanic crust in an island arc-continent collision zone. A detailed study of the structure and metamorphic history of 400 km² of this formation showed it has a complex history of penetrative deformation but the structure is coherent.Pelites, psammites and limestones interlayered with dolerites and amphibolites have been metamorphosed in a medium pressure environment. They now form a metamorphic province zoned from low greenschist facies in the southwest to upper amphibolite facies in the east. The earliest recognised deformation phase predated the metamorphism and produced a widespread layer—parallel schistosity but no recognisable folds. The second deformation phase post-dated the metamorphic maximum and micropetrological evidence indicates a gradual cooling during this event. This deformation produced tight folds with an axial plane schistosity and transposed the earlier structures. The progressively weaker third and fourth phases developed crenulation cleavages and related folds, under greenschist facies conditions. Open, fifth phase, macroscopic folds were probably synchronous with strike slip faulting parallel to the north coast. Later dip slip faulting juxtaposed the Aileu Formation with Permian and Mesozoic sediments of very low metamorphic grade.Reconnaissance K/Ar radiometric dating using hornblende and biotite showed the prograde metamorphic maximum occurred before 11 Ma ago and implies that the second, and strongest, deformation phase occurred in the late Miocene. This young age establishes the relationship of the deformation events to the collision between Australia and the Inner Banda Arc.The proposed models for the structure of Timor must be modified to fit the deformation history of the Aileu Formation. If Timor is essentially autochthonous, the Aileu Formation was probably deposited in a Palaeozoic graben and the metamorphic maximum may have occurred in the Jurassic. The overthrusting models must be modified in the light of the close correlation in time between penetrative deformation and emplacement of the proposed thrust sheets. The analogy proposed between Timor and ‘normal’ convergent margins is not supported but it may be possible to draw analogies with the Molucca Sea.  相似文献   

Sovereign Sugar: Industry and Environment in Hawai'i          下载免费PDF全文

Kate A. Berry 《Geographical review》2018,108(2):328-330

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Climate change uncertainty: building flexibility into water and flood risk infrastructure   总被引：1，自引：0，他引：1  

Berry Gersonius  Richard Ashley  Assela Pathirana  Chris Zevenbergen 《Climatic change》2013,116(2):411-423

Infrastructure for water, urban drainage and flood protection has a typical lifetime of 30–200 years and its continuing performance is very sensitive to climate change. Investment decisions for such systems are frequently based on state-of-the-art impact assessments using a specified climate change scenario in order to identify a singular optimal adaptive strategy. In a non-stationary world, however, it is risky and/or uneconomic to plan for just one climate change scenario as an average or best estimate, as is done with the use of the Predict-Then-Adapt method. We argue that responsible adaptation requires an alternative method that effectively allows for the lack of knowledge about future climate change by adopting a managed/adaptive strategy. The managed/adaptive strategy confers the ability, derived from built-in flexibility, to adjust to future uncertainties as they unfold. This will restrict the effect of erroneous decisions and help avoid maladaptation. Real In Options (RIO) analysis can facilitate the development of an optimal managed/adaptive strategy to climate change. Here, we show the economic benefits of adopting a managed/adaptive strategy and building in flexibility, using RIO analysis applied for the first time to urban drainage infrastructure.  相似文献